//Javascript document

var alg = {
	toObj: function(txt) {
		txt = simplifyText(clone(txt));
		txt = removeTags(txt);
		var exp = [];
		
		//console.log('---');
		//console.log('txt',txt);
		var terms = splitTerms(txt);
		
		//console.log('terms',clone(terms));
		
		for (var t = 0; t < terms.length; t++) processTerm(terms[t]);
		
		//console.log('toObj:',JSON.stringify(exp));
		
		return exp;
		
		function splitTerms(txt) {
			var terms = [[]];
			var bracketCount = 0;
			for (var i = 0; i < txt.length; i++) {
				var txt1 = txt[i];
				if (typeof txt1 === 'string') {
					for (var c = 0; c < txt1.length; c++) {
						if (txt1.charAt(c) === '(') {
							bracketCount++;
						} else if (txt1.charAt(c) === ')') {
							bracketCount--;
						} else if (bracketCount === 0 && (txt1.charAt(c) === '+' || txt1.charAt(c) === '-')) {
							if (c > 0) {
								terms.last().push(txt1.slice(0,c));
								txt1 = txt1.slice(c);
								c = 0;
							}
							if (terms.last().length > 0) {
								terms.push([]);
							}
						}
					}
					terms.last().push(txt1);
				} else {
					terms.last().push(txt1);
				}
			}
			return terms;
		}
		function getAlgFrac(term) {
			//console.log('term:',clone(term));

			var sign = 1;
			if (term[0] === '-') {
				sign = -1;
				term.shift();
			} else if (term[0] === '+') {
				term.shift();
			}
			var num = alg.toObj(term[0][1]);
			var denom = alg.toObj(term[0][2]);
			
			var coeff = [1,1];
			if (num.length === 1) {
				coeff[0] *= num[0].coeff[0];
				coeff[1] *= num[0].coeff[1];
				num[0].coeff = [1,1];
			} else {
				num = [{sign:1,coeff:[1,1],subterms:[[num,1]]}];
			}
			if (denom.length === 1) {
				coeff[0] *= denom[0].coeff[1];
				coeff[1] *= denom[0].coeff[0];
				denom[0].coeff = [1,1];
				for (var s = 0; s < denom[0].subterms.length; s++) {
					denom[0].subterms[s][1]  *= -1;
				}
			} else {
				denom = [{sign:1,coeff:[1,1],subterms:[[denom,-1]]}];
			}
			
			var numSubterms = num[0].subterms;
			var denomSubterms = denom[0].subterms;
			var subterms = numSubterms.concat(denomSubterms);
			//subterms = alg.simplifySubterms(subterms);
			subterms = alg.orderSubterms(subterms);
			
			var obj = {
				sign:sign,
				coeff:coeff,
				subterms:subterms
			};

			term.shift();
			return obj;
		}
		function processTerm(term) {
			if (term.length === 0) return;
			//console.log('term',clone(term));
			
			var obj = {};
			exp.push(obj);
			while (term[0] === '') term.shift();
			
			var coeff = 1;
			if ((term[0] === '-' || term[0] === '+') && typeof term[1] === 'object' && term[1][0] === 'frac') {
				if (term[1][1].length === 1 && !isNaN(Number(term[1][1][0])) && term[1][2].length === 1 && !isNaN(Number(term[1][2][0]))) {
					obj.sign = term[0] === '-' ? -1: 1;
					obj.coeff = [Number(term[1][1][0]),Number(term[1][2][0])];
					term.shift();
					term.shift();
				} else {
					exp[exp.length-1] = getAlgFrac(term);
				}
			} else if (typeof term[0] === 'string') {
				var sign = 1;
				if (term[0][0] === '-') {
					sign = -1;
					term[0] = term[0].slice(1);
				} else if (term[0][0] === '+') {
					term[0] = term[0].slice(1);
				}
				var charCount = 0;
				for (var c = 1; c < term[0].length+1; c++) {
					if (isNaN(Number(term[0].slice(0,c)))) {
						term[0] = term[0].slice(charCount);
						break;
					} else {
						coeff = Number(term[0].slice(0,c));
						charCount++;
						if (c === term[0].length) {
							term[0] = term[0].slice(charCount);
							break;
						}
					}
				}
				obj.sign = sign;
				obj.coeff = [coeff,1];
			} else if (typeof term[0] === 'object' && term[0][0] === 'frac') {
				if (term[0][1].length === 1 && !isNaN(Number(term[0][1][0])) && term[0][2].length === 1 && !isNaN(Number(term[0][2][0]))) {
					obj.sign = 1;
					obj.coeff = [Number(term[0][1][0]),Number(term[0][2][0])];
					term.shift();
				} else {
					exp[exp.length-1] = getAlgFrac(term);
				}
			}
			while (term[0] === '') term.shift();
			
			if (term.length === 0) {
				obj.subterms = [];
				return;
			}
			var subterms = [];
			var count = 0;
			while (!un(term[0]) && typeof term[0] === 'string' && count < 100) {
				count++;
				var subterms2 = [];
				if (typeof term[0] === 'string') {
					if (term[0][0] === '(') {
						term[0] = term[0].slice(1);
						if (term[0] === '') term.shift();
						var term2 = [];
						var bracketCount = 1;
						var count = 0;
						while (bracketCount > 0 && count < 100) {
							count++;
							if (typeof term[0] === 'string') {
								var str = term[0];
								for (var c = 0; c < str.length; c++) {
									var char = str[c];
									if (char === '(') {
										bracketCount++;
									} else if (char === ')') {
										bracketCount--;
										if (bracketCount === 0) {
											if (c > 0) term2.push(str.slice(0,c));
											term[0] = str.slice(c+1);
											break;
										}
									}
								}
								if (bracketCount !== 0) {
									term2.push(term[0]);
									term.shift();
								}
							} else if (typeof term[0] === 'object') {
								term2.push(term[0]);
								term.shift();
							}
						}
						subterms2 = [alg.toObj(term2),1];
						if (term[0] === '') term.shift();
						if (typeof term[0] === 'object' && term[0][0] === 'pow') {
							if (!isNaN(Number(term[0][2]))) subterms2[1] = Number(term[0][2]);
							term.shift();
						}
					} else {
						subterms2 = [term[0][0],1];
						term[0] = term[0].slice(1);
						if (term[0] === '') term.shift();
						if (typeof term[0] === 'object' && term[0][0] === 'pow') {
							if (!isNaN(Number(term[0][2]))) subterms2[1] = Number(term[0][2]);
							term.shift();
						}
					}
				}
				if (term[0] === '') term.shift();
				subterms.push(subterms2);
			}
			obj.subterms = subterms;
		}

	},
	toText: function(exp,type) {
		if (un(type)) type = 'default'; // default is fracTerms
		var txt = [''];
		if (exp instanceof Array === false && typeof exp === 'object') exp = [exp];
		if (exp.length === 0) return ["0"];
		for (var e = 0; e < exp.length; e++) {
			var term = exp[e];
			//console.log('term',term);
			var isFirstTerm = e === 0 ? true : false;
			var isOnlyTerm = exp.length === 1 ? true : false;
			if (type === 'inline') {
				txt = txt.concat(termToTextInline(term,isFirstTerm,isOnlyTerm));
			} else {
				txt = txt.concat(termToTextFracTerms(term,isFirstTerm,isOnlyTerm))
			}
		}
		txt = simplifyText(txt);
		return txt;
		
		function termToTextInline(term,isFirstTerm,isOnlyTerm) {
			var txt = [];
			var sign = term.sign === -1 ? '-' : '+';
			var coeff = term.coeff;
			if (coeff[1] === 1) coeff = coeff[0];
			var subterms = term.subterms;
			if (coeff === 1 && subterms.length > 0) coeff = '';
			if (isFirstTerm === false || sign === '-') txt.push(sign);
			if (coeff instanceof Array) {
				txt.push(['frac',[String(Math.abs(coeff[0]))],[String(Math.abs(coeff[1]))]]);
			} else {
				txt.push(String(coeff));
			}
			var subtermsText = [];
			for (var s = 0; s < subterms.length; s++) {
				var sub = subterms[s];
				if (typeof sub[0] === 'string') {
					subtermsText.push(sub[0]);
				} else if (typeof sub[0] === 'object') {
					var brackets = sub.length > 1 ? true : false;
					if (brackets = true) subtermsText.push('(');
				 	subtermsText = subtermsText.concat(alg.toText(sub[0]));
					if (brackets = true) subtermsText.push(')');
				}
				if (!un(sub[1]) && sub[1] !== 1) subtermsText.push(['pow',false,String(sub[1])]);
			}
			txt = txt.concat(subtermsText);
			
			return txt;
		}
		function termToTextFracTerms(term,isFirstTerm,isOnlyTerm) {
			var num = [];
			var denom = [];
			
			var subterms = term.subterms;			
			for (var s = 0; s < subterms.length; s++) {
				var sub = subterms[s];
				var type = alg.getSubtermType(sub);
				if (type === 'single') {
					if (sub[1] > 0) {
						num.push(sub[0]);
						if (sub[1] > 1) num.push(['pow',false,String(sub[1])]);
					} else {
						denom.push(sub[0]);
						if (sub[1] < -1) denom.push(['pow',false,String(Math.abs(sub[1]))]);
					}
				} else if (type === 'compound') {
					if (sub[1] > 0) {
						var brackets = subtermRequiresBrackets(sub);
						if (brackets === true) num.push('(');
						num = num.concat(alg.toText(sub[0]));
						if (brackets === true) num.push(')');
						if (sub[1] > 1) num.push(['pow',false,String(sub[1])]);
					} else {
						var brackets = subtermRequiresBrackets(sub);
						if (brackets === true) denom.push('(');
						denom = denom.concat(alg.toText(sub[0]));
						if (brackets === true) denom.push(')');
						if (sub[1] < -1) denom.push(['pow',false,String(Math.abs(sub[1]))]);
					}	
				}
			}
			
			function subtermRequiresBrackets(subterm) {
				if (subterm[1] > 1 || subterm[1] < -1) return true;
				if (subterm[0].length > 1) return true;
				var exp = subterm[0][0].subterms;
				if (exp.length > 1 || un(exp[0])) return true;
				if (Math.abs(exp[0][1]) > 1) return false;
				if (arraysEqual(exp[0][0].coeff,[1,1]) === true) return false;
				return false;
			}
			
			var coeff = term.coeff;
			if (coeff[0] !== 1 || num.length === 0) num.unshift(String(coeff[0])); 
			if (coeff[1] !== 1 || denom.length === 0) denom.unshift(String(coeff[1])); 

			var sign = term.sign === -1 ? '-' : '+';
			if (isFirstTerm === true && sign === '+') sign = '';
			
			num = simplifyText(num);
			denom = simplifyText(denom);
			
			var isFraction = (arraysEqual(denom,['1']) || denom.length === 0) ? false : true;
			
			if (isFraction) {
				if (typeof num[0] === 'string' && num[0][0] === '(' && typeof num[num.length-1] === 'string' && num[num.length-1].slice(-1) === ')') {
					var bracketCount = 1;
					var bracketClosed = false;
					for (var i = 0; i < num.length; i++) {
						if (typeof num[i] !== 'string') continue;
						for (var j = 0; j < num[i].length; j++) {
							if (i == 0 && j == 0) continue;
							if (i == num.length-1 && j == num[i].length-1) continue;
							if (num[i][j] === '(') bracketCount++;
							if (num[i][j] === ')') bracketCount--;
							if (bracketCount === 0) {
								bracketClosed = true;
								j = num[i].length;
								i = num.length;
							}
						}
					}
					if (bracketClosed === false) {
						num[0] = num[0].slice(1);
						num[num.length-1] = num[num.length-1].slice(0,-1);
						num = simplifyText(num);
					}
				}
				
				if (typeof denom[0] === 'string' && denom[0][0] === '(' && typeof denom[denom.length-1] === 'string' && denom[denom.length-1].slice(-1) === ')') {
					var bracketCount = 1;
					var bracketClosed = false;
					for (var i = 0; i < denom.length; i++) {
						if (typeof denom[i] !== 'string') continue;
						for (var j = 0; j < denom[i].length; j++) {
							if (i == 0 && j == 0) continue;
							if (i == denom.length-1 && j == denom[i].length-1) continue;
							if (denom[i][j] === '(') bracketCount++;
							if (denom[i][j] === ')') bracketCount--;
							if (bracketCount === 0) {
								bracketClosed = true;
								j = denom[i].length;
								i = denom.length;
							}
						}
					}
					if (bracketClosed === false) {
						denom[0] = denom[0].slice(1);
						denom[denom.length-1] = denom[denom.length-1].slice(0,-1);
						denom = simplifyText(denom);
					}
				}
				var txt = [sign,['frac',num,denom,1]];
			} else {
				var txt = [sign].concat(num);
			}
			
			return txt;
		}
	},

	add: function(exp1,exp2) {
		var exp3 = clone(exp1);
		exp3 = exp3.concat(clone(exp2));
		//exp3 = alg.collect(exp3);
		return exp3;
	},
	subtract: function(exp1,exp2) {
		var exp2 = clone(exp2);
		var exp2 = alg.multiply(exp2,[{sign:-1,coeff:[1,1],subterms:[]}]);
		var exp3 = alg.add(exp1,exp2);
		return exp3;
	},
	multiply: function(exp1,exp2,simplify) {
		exp1 = clone(exp1);
		exp2 = clone(exp2);
		if (exp1.length > 1) exp1 = [{sign:1,coeff:[1,1],subterms:[[exp1,1]]}];
		if (exp2.length > 1) exp2 = [{sign:1,coeff:[1,1],subterms:[[exp2,1]]}];
		var term1 = clone(exp1[0]);
		var subterms1 = term1.subterms;
		var coeff1 = term1.coeff;
		var term2 = clone(exp2[0]);
		var subterms2 = term2.subterms;
		var coeff2 = term2.coeff;
		var sign3 = term1.sign*term2.sign;
		var coeff3 = [coeff1[0]*coeff2[0],coeff1[1]*coeff2[1]];				
		var subterms3 = subterms1.concat(subterms2);
		if (boolean(simplify,true) === true) {
			coeff3 = simplifyFrac2(coeff3);
			subterms3 = alg.orderSubterms(subterms3);
			subterms3 = alg.simplifySubterms(subterms3);
		}
		return [{sign:sign3,coeff:coeff3,subterms:subterms3}];		
	},
	divide: function(exp1,exp2,simplify) {
		var exp2 = alg.getExpressionReciprocal(exp2);
		var exp3 = alg.multiply(exp1,exp2,simplify);
		return exp3;
	},

	collect: function(exp) {
		exp = clone(exp);
		for (var e2 = exp.length-1; e2 >= 0; e2--) {
			var term2 = exp[e2];
			var subterms2 = term2.subterms;
			for (var e1 = e2-1; e1 >= 0; e1--) {
				var term1 = exp[e1];
				var subterms1 = term1.subterms;
				if (alg.likeTerms(term1,term2)) {
					term1.coeff[0] *= term1.sign;
					term2.coeff[0] *= term2.sign;
					var coeff = addFracs2(term1.coeff,term2.coeff);
					term1.sign = coeff[0]/coeff[1] < 0 ? -1 : 1;
					term1.coeff = simplifyFrac2([Math.abs(coeff[0]),Math.abs(coeff[1])]);
					exp.splice(e2,1);
					break;
				}
			}
		}
		for (var e = 0; e < exp.length; e++) {
			if (exp[e].coeff[0] === 0) {
				exp.splice(e,1);
				e--;
			}
		}
		return exp;
	},
	collectable: function(exp) {
		var exp2 = clone(exp);
		var exp3 = alg.collect(exp2);
		return !isEqual(exp2,exp3);
	},
	expand: function(exp) {
		//console.log('exp',JSON.stringify(exp));
		var exp3 = clone(exp);
		var exp2 = clone(exp);
		
		var count = 0;
		do {
			count++;
			var exp2 = clone(exp3);
			var exp3 = expandExp(exp3);
		} while (!isEqual(exp2,exp3) && count < 10);
		//console.log('exp3',JSON.stringify(exp3));
		return exp3;
		
		function expandExp(exp) {
			var exp2 = clone(exp);
			var exp3 = [];	
			for (var e = 0; e < exp2.length; e++) {
				var term = exp2[e];
				
				//console.log('term',JSON.stringify(term));
				
				var num = alg.getTermNumerator(term);
				var denom = alg.getTermDenominator(term);
				
				//console.log('num:',clone(num));
				//console.log('denom:',clone(denom));
				
				var num2 = expandTerm(num);
				var denom2 = expandTerm(denom);
				
				//console.log('num2:',clone(num2));
				//console.log('denom2:',clone(denom2));
				
				var term2 = alg.divide(num2,denom2);
				//console.log('term2',JSON.stringify(term2));
				
				exp3 = exp3.concat(term2);
			}
			var exp4 = [];
			for (var e = 0; e < exp3.length; e++) {
				var term = exp3[e];
				if (term.sign === 1 && arraysEqual(term.coeff,[1,1]) && !un(term.subterms) && term.subterms.length === 1 && !un(term.subterms[0]) && alg.getSubtermType(term.subterms[0]) === 'compound' && term.subterms[0][1] === 1) {
					exp4 = exp4.concat(term.subterms[0][0]);
				} else {
					exp4.push(term);
				}
			}
			//console.log('exp4',JSON.stringify(exp4));
			return exp4;
		}
		function expandTerm(term) {
			var term = clone(term);
			
			// apply powers to compound subterms
			for (var s = 0; s < term.subterms.length; s++) {
				var subterm = term.subterms[s];
				if (alg.getSubtermType(subterm) !== 'compound') continue;
				if (subterm[1] > 1) {
					var index = subterm[1];
					var subterm2 = clone(subterm[0]);
					for (var i = 1; i < index; i++) {
						subterm2 = alg.multiplyExpressions(subterm2,subterm[0]);
					}
					term.subterms[s] = [subterm2,1];
				} else if (subterm[1] < 1) {
					var index = -1*subterm[1];
					var subterm2 = clone(subterm[0]);
					for (var i = 1; i < index; i++) {
						subterm2 = alg.multiplyExpressions(subterm2,subterm[0]);
					}
					term.subterms[s] = [subterm2,-1];
				}
			}
			
			// mutiply subterms together
			var count = 0;
			while (term.subterms.length > 1 && count < 100) {
				count++;
				var subterm1 = term.subterms[0];
				var type1 = alg.getSubtermType(subterm1);
				if (type1 === 'single') {
					for (var i = 1; i < term.subterms.length; i++) {
						var subterm2 = term.subterms[i];
						var type2 = alg.getSubtermType(subterm2);
						if (type2 === 'compound') {
							for (var s = 0; s < subterm2[0].length; s++) {
								var subterm3 = subterm2[0][s].subterms;
								subterm3.push(clone(subterm1));
								subterm2[0][s].subterms = alg.simplifySubterms(subterm3);
							}
							term.subterms.shift();
							break;
						}
					}
				} else if (type1 === 'compound') {
					var subterm2 = term.subterms[1];
					var type2 = alg.getSubtermType(subterm2);
					if (type2 === 'single') {
						for (var s = 0; s < subterm1[0].length; s++) {
							var subterm3 = subterm1[0][s].subterms;
							subterm3.push(clone(subterm2));
							subterm1[0][s].subterms = alg.simplifySubterms(subterm3);
						}
						term.subterms.splice(1,1);
					} else if (type2 === 'compound') {
						term.subterms[1] = [alg.multiplyExpressions(subterm1[0],subterm2[0]),1];
						term.subterms.shift();
					}
				}				
			}
			
			var exp = [];
			//console.log(JSON.stringify(term));
			if (!un(term.subterms[0])) {
				if (alg.getSubtermType(term.subterms[0]) === 'compound') {
					var terms2 = term.subterms[0][0];
					for (var s = 0; s < terms2.length; s++) {
						var term2 = terms2[s];
						exp.push({
							sign:term.sign*term2.sign,
							coeff:simplifyFrac2([term.coeff[0]*term2.coeff[0],term.coeff[1]*term2.coeff[1]]),
							subterms:term2.subterms
						});
					}
				} else {
					exp.push({
						sign:term.sign,
						coeff:simplifyFrac2([term.coeff[0],term.coeff[1]]),
						subterms:term.subterms
					});
				}
			}
			if (exp.length === 0) exp.push({sign:term.sign,coeff:clone(term.coeff),subterms:[]});
			return exp;			
		}
	},
	expandable: function(exp) {
		var exp2 = clone(exp);
		var exp3 = alg.expand(exp2);
		return !isEqual(exp2,exp3);
	},
	factorise: function(exp) {
		var exp2 = clone(exp);
		if (alg.collectable(exp2) === true) return exp;
		//console.log('exp',JSON.stringify(exp));
		var exp3 = [];
		
		// look in each term for factorisable subterms
		for (var t = 0; t < exp2.length; t++) {
			var term = exp2[t];
			
			var num = alg.getTermNumerator(term);
			//console.log('num:',JSON.stringify(num));
			num = factoriseTerm(num);
			
			var denom = alg.getTermDenominator(term);
			//console.log('denom:',JSON.stringify(denom));
			denom = factoriseTerm(denom);
			
			var term2 = alg.divide([num],[denom],false);
			//console.log('term2:',JSON.stringify(term2));
			
			exp3 = exp3.concat(term2);
		}
		
		exp3 = factoriseExp(exp3);	
		return exp3;
		
		function factoriseTerm(term) {
			var term = clone(term);
			var factors = [];
			//console.log('factorise term',clone(term));
			for (var s = 0; s < term.subterms.length; s++) {
				var subterm = term.subterms[s];
				//console.log('-----',s);
				//console.log('term',clone(term));
				//console.log('subterm',JSON.stringify(subterm));
				if (un(subterm)) continue;
				if (alg.getSubtermType(subterm) === 'simple') continue;
				var index = subterm[1];
				var exp = subterm[0];
				//console.log('exp',clone(exp));
				//console.log('index',index);
				
				var factor = alg.getHCF(exp);
				//console.log('factor',JSON.stringify(factor));
				if (isEqual(factor,[{sign:1,coeff:[1,1],subterms:[]}])) continue;
				var dividend = [];
				for (var t = 0; t < exp.length; t++) {
					var termdiv = alg.divide([exp[t]],factor);
					termdiv = alg.simplify(termdiv);
					dividend.push(termdiv[0]);
				}
				if (isEqual(dividend,[{sign:1,coeff:[1,1],subterms:[]}])) continue;
				//console.log('dividend',JSON.stringify(dividend));
				
				if (index !== 1) {
					factor[0].coeff[0] = Math.pow(factor[0].coeff[0],index);
					factor[0].coeff[1] = Math.pow(factor[0].coeff[1],index);
					for (var s2 = 0; s2 < factor[0].subterms.length; s2++) {
						factor[0].subterms[s2][1] = index;
					}
				}
				
				term.sign *= factor[0].sign;
				term.coeff = [term.coeff[0]*factor[0].coeff[0],term.coeff[1]*factor[0].coeff[1]];
				factors = factors.concat(factor[0].subterms);
				term.subterms[s] = [dividend,index];
				
				//console.log('subterm',JSON.stringify(term.subterms[s]));
				//console.log('term',JSON.stringify(term));
			}
			term.subterms = factors.concat(term.subterms);
			//console.log('term = '+JSON.stringify(term,null,2));
			return term;
		}
		function factoriseExp(exp) {		
			//console.log('exp',clone(exp));
			var factor = alg.getHCF(exp);
			
			//console.log('-----');
			//console.log('exp',JSON.stringify(exp));
			//console.log('factor',JSON.stringify(factor));
			
			if (isEqual(factor,[{sign:1,coeff:[1,1],subterms:[]}])) {
				var exp2 = exp;
			} else {
				var dividend = [];
				for (var t = 0; t < exp.length; t++) {
					var termdiv = alg.divide([exp[t]],factor);
					termdiv = alg.simplify(termdiv);
					dividend.push(termdiv[0]);
				}
				//console.log('dividend',JSON.stringify(dividend));
				
				if (isEqual(dividend,[{sign:1,coeff:[1,1],subterms:[]}])) {
					var exp2 = exp;
				} else {
					var exp2 = factor;
					exp2[0].subterms.push([dividend,1]);
					//console.log('exp2',JSON.stringify(exp2));
				}
			}
			
			for (var t = 0; t < exp2.length; t++) {
				var term = exp2[t];
				for (var s = 0; s < term.subterms.length; s++) {
					var subterm = term.subterms[s];
					if (alg.getSubtermType(subterm) !== 'compound') continue;
					term.subterms[s][0] = alg.quadFactorise(term.subterms[s][0]);
				}
			}
			exp2 = alg.quadFactorise(exp2);
			
			//console.log('exp2',JSON.stringify(exp2));	
			
			return exp2;
		}
	},
	factorisable: function(exp) {
		var exp2 = clone(exp);
		var exp3 = alg.factorise(exp2);
		return !isEqual(exp2,exp3);
	},
	quadFactorise: function(exp) {
		if (exp.length > 3) return exp;
		var exp2 = clone(exp);
		exp2 = alg.collect(exp2);
		
		var terms = [];		
		for (var t = 0; t < exp2.length; t++) {
			var term = exp2[t];
			var subterms = term.subterms;
			if (subterms.length === 0) {
				terms[2] = term;
			} else if (subterms[0][1] === 2) {
				terms[0] = term;
			} else if (subterms[0][1] === 1) {
				terms[1] = term;
			}
		}
		if (un(terms[0])) return exp;
		if (un(terms[2])) return exp;
		var vari = terms[0].subterms[0][0];
		if (un(terms[1])) terms[1] = {sign:1,coeff:[0,1],subterms:[[vari,1]]};
		if (un(terms[2])) terms[2] = {sign:1,coeff:[0,1],subterms:[]};
		
		var a = terms[0].sign*terms[0].coeff[0];
		var b = terms[1].sign*terms[1].coeff[0];
		var c = terms[2].sign*terms[2].coeff[0];
		
		var det = b*b-4*a*c;
		if (det < 0) return exp;
		var detroot = Math.sqrt(det);
		if (detroot !== Math.round(detroot)) return exp;		
		
		var roots = [
			simplifyFrac2([-b+detroot,2*a]),
			simplifyFrac2([-b-detroot,2*a])
		];	
		
		var sign1 = roots[0][0]/roots[0][1] < 0 ? 1 : -1;
		var sign2 = roots[1][0]/roots[1][1] < 0 ? 1 : -1;
		roots[0][0] = Math.abs(roots[0][0]);
		roots[0][1] = Math.abs(roots[0][1]);
		roots[1][0] = Math.abs(roots[1][0]);
		roots[1][1] = Math.abs(roots[1][1]);
		
		var exp3 = [{sign:1,coeff:[1,1],subterms:[]}];
		
		if (sign1 === sign2 && arraysEqual(roots[0],roots[1])) {
			var exp3 = [{sign:1,coeff:[1,1],subterms:[[[{sign:1,coeff:[roots[0][1],1],subterms:[[vari,1]]},{sign:sign1,coeff:[roots[0][0],1],subterms:[]}],2]]}];
		} else {
			var exp3 = [
				{sign:1,coeff:[1,1],subterms:[
					[[{sign:1,coeff:[roots[0][1],1],subterms:[[vari,1]]},{sign:sign1,coeff:[roots[0][0],1],subterms:[]}],1],
					[[{sign:1,coeff:[roots[1][1],1],subterms:[[vari,1]]},{sign:sign2,coeff:[roots[1][0],1],subterms:[]}],1]
				]}
			];
		}
		
		
		return exp3;		
	},
	simplify: function(exp) { // simplifies fractions
		var exp2 = clone(exp);
		for (var e = 0; e < exp2.length; e++) {
			var term = exp2[e];
			term.coeff = simplifyFrac2(term.coeff);
			term.subterms = alg.simplifySubterms(term.subterms);
			for (var s = 0; s < term.subterms.length; s++) {
				var subterm = term.subterms[s];
				if (alg.getSubtermType(subterm) === 'compound') {
					term.subterms[s] = [alg.simplify(subterm[0]),subterm[1]];
				}
			}
		}
		var exp3 = [];
		for (var e = 0; e < exp2.length; e++) {
			var term = exp2[e];
			if (term.sign === 1 && arraysEqual(term.coeff,[1,1]) && !un(term.subterms) && term.subterms.length === 1 && !un(term.subterms[0]) && alg.getSubtermType(term.subterms[0]) === 'compound' && term.subterms[0][1] === 1) {
				exp3 = exp3.concat(term.subterms[0][0]);
			} else {
				exp3.push(term);
			}
		}
		return exp3;
		
		
		/*var exp2 = clone(exp);
		alg.collect(exp2);
		for (var t = 0; t < exp2.length; t++) {
			var term = exp2[t];
			term.coeff = simplifyFrac2(term.coeff);
			term.subterms = alg.simplifySubterms(term.subterms);
			for (var s = 0; s < term.subterms.length; s++) {
				var subterm = term.subterms[s];
				if (alg.getSubtermType(subterm) === 'compound') {
					term.subterms[s] = [alg.simplify(subterm[0]),subterm[1]];
				}
			}
			term.subterms = alg.orderSubterms(term.subterms);
		}
		return exp2;*/
	},
	simplifiable: function(exp) {
		var exp2 = clone(exp);
		var exp3 = alg.simplify(exp2);
		return !isEqual(exp2,exp3);
	},
	
	likeTerms: function(term1,term2) {
		var subterms1 = clone(term1.subterms);
		var subterms2 = clone(term2.subterms);
		if (subterms1.length !== subterms2.length) return false;
		for (var s1 = 0; s1 < subterms1.length; s1++) {
			var sub1 = subterms1[s1];
			for (var s2 = 0; s2 < subterms2.length; s2++) {
				var sub2 = subterms2[s2];
				if (alg.likeSubterm(sub1,sub2) === false || sub1[1] !== sub2[1]) return false;
			}
			return true;
		}
		return true;
	},	
	getTermNumerator: function(term) {
		if (typeof term === 'string') return {sign:1,coeff:[1,1],subterms:[[term,1]]};
		var num = {sign:term.sign,coeff:[term.coeff[0],1],subterms:[]};
		for (var s = 0; s < term.subterms.length; s++) {
			var subterm = term.subterms[s];
			if (subterm[1] >= 0) {
				num.subterms.push(subterm);
			}
		}
		return num;
	},
	getTermDenominator: function(term) {
		if (typeof term === 'string') return {sign:1,coeff:[1,1],subterms:[]};
		var denom = {sign:1,coeff:[term.coeff[1],1],subterms:[]};
		for (var s = 0; s < term.subterms.length; s++) {
			var subterm = term.subterms[s];
			if (subterm[1] < 0) {
				denom.subterms.push([subterm[0],-1*subterm[1]]);
			}
		}
		return denom;
	},
	multiplyExpressions: function(exp1,exp2) {
		var exp3 = [];
		for (var e1 = 0; e1 < exp1.length; e1++) {
			var term1 = clone(exp1[e1]);
			var subterms1 = term1.subterms;
			var coeff1 = term1.coeff;
			for (var e2 = 0; e2 < exp2.length; e2++) {
				var term2 = clone(exp2[e2]);
				var subterms2 = term2.subterms;
				var coeff2 = term2.coeff;
				var sign3 = term1.sign*term2.sign;
				var coeff3 = simplifyFrac2([coeff1[0]*coeff2[0],coeff1[1]*coeff2[1]]);				
				var subterms3 = subterms1.concat(subterms2);
				subterms3 = alg.simplifySubterms(subterms3);
				exp3.push({sign:sign3,coeff:coeff3,subterms:subterms3});
			}
		}
		return exp3;
	},
	getTermReciprocal: function(term) {
		var term2 = {
			sign:term.sign,
			coeff:[term.coeff[1],term.coeff[0]],
			subterms:[]
		};
		for (var s = 0; s < term.subterms.length; s++) {
			var sub = clone(term.subterms[s]);
			sub[1] *= -1;
			term2.subterms.push(sub);
		}
		return term2;
	},
	getExpressionReciprocal: function(exp) {
		var exp = clone(exp);
		if (exp.length === 1) {
			var term = alg.getTermReciprocal(exp[0]);
			return [term];
		} else {
			return [{sign:1,coeff:[1,1],subterms:[[exp,-1]]}];
		}
	},
	simplifySubterms: function(subterms) {
		var subterms = clone(subterms);
		for (var v2 = subterms.length-1; v2 >= 0; v2--) { // combine like subterms
			for (var v1 = v2-1; v1 >= 0; v1--) {
				if (alg.likeSubterm(subterms[v2],subterms[v1])) {
					subterms[v1][1] += subterms[v2][1];
					subterms.splice(v2,1);
					break;
				}
			}
		}
		for (var v2 = subterms.length-1; v2 >= 0; v2--) { // remove subterms with power 0
			if (subterms[v2][1] === 0) subterms.splice(v2,1);
		}
		return subterms;
	},
	orderSubterms: function(subterms) {
		//console.log(subterms);
		subterms.sort(function(a,b) {
			if (isEqual(a[0],b[0])) return b[1]-a[1];
			var typeA = alg.getSubtermType(a);
			var typeB = alg.getSubtermType(b);
			if (typeA === 'single' && typeB === 'single') {
				if (a[0] < b[0]) return -1;
				if (a[0] > b[0]) return 1;
			} else if (typeA === 'single') {
				return -1;
			} else if (typeB === 'single') {
				return 1;
			}
			return 0;
		});
		for (var s = 0; s < subterms.length; s++) {
			var subterm = subterms[s];
			var type = alg.getSubtermType(subterm);
			if (type === 'compound') {
				//console.log(subterm);
				for (var s2 = 0; s2 < subterm[0].length; s2++) {
					var sub2 = subterm[0][s2];
					alg.orderSubterms(sub2.subterms);
				}
			}
		}
		return subterms;
	},
	getSubtermType: function(subterm) {
		if (subterm.length === 2 && typeof subterm[0] === 'string' && typeof subterm[1] === 'number') {
			return 'single';
		} else {
			return 'compound';
		}
	},
	likeSubterm: function(subterm1,subterm2) {
		if (un(subterm1) && un(subterm2)) return true;
		var sub1 = subterm1[0];
		var sub2 = subterm2[0];
		if (un(sub1) && un(sub2)) return true;
		if (isEqual(sub1,sub2)) return true;
		if (sub1 instanceof Array && sub2 instanceof Array) {
			if (sub1.length !== sub2.length) return false;
			sub1 = clone(sub1);
			sub2 = clone(sub2);
			for (var s1 = 0; s1 < sub1.length; s1++) {
				var sub11 = sub1[s1];
				var found = false;
				for (var s2 = 0; s2 < sub2.length; s2++) {
					var sub22 = sub2[s2];
					if (sub11.sign === sub22.sign && arraysEqual(sub11.coeff,sub22.coeff) === true && arraysEqual(sub11.subterms,sub22.subterms) === true) {
						found = true;
						break;
					}
				}
				if (found === false) return false;
			}
			return true;
		}
		return false;
	},
	getHCF: function(exp) {
		var exp = clone(exp);
		if (exp.length === 1) return [{sign:1,coeff:[1,1],subterms:[]}];
		var term = exp[0];
		var sign = term.sign;
		var num = term.coeff[0];
		var denom = term.coeff[1];
		var subterms = clone(term.subterms);
		for (var t = 1; t < exp.length; t++) {
			var term = exp[t];
			if (term.sign === 1) sign = 1;
			num = hcf(num,term.coeff[0]);
			denom = hcf(denom,term.coeff[1]);
			for (var s1 = 0; s1 < subterms.length; s1++) {
				var subterm1 = subterms[s1];
				var found = false;
				for (var s2 = 0; s2 < term.subterms.length; s2++) {
					var subterm2 = term.subterms[s2];
					if (alg.likeSubterm(subterm1,subterm2) === true) {
						found = true;
						subterm1[1] = Math.min(subterm1[1],subterm2[1]);
						break;
					}
				}
				if (found === false) {
					subterms.splice(s1,1);
					s1--;
				}
			}
		}
		return [{sign:sign,coeff:[num,denom],subterms:subterms}];
	},
	
	hasNegativeIndices: function(exp) {
		for (var e = 0; e < exp.length; e++) {
			if (exp[e][1] < 0) return true;
		}
		return false;
	},
	getCommonDenominator: function(exp) {
		var exp = clone(exp);
		var denomCoeff = 1;
		var denomSubterms = [];
		for (var e = 0; e < exp.length; e++) {
			var term = exp[e];
			denomCoeff = (denomCoeff*term.coeff[1])/hcf(denomCoeff,term.coeff[1]);
			var subterms = term.subterms;
			for (var s = 0; s < subterms.length; s++) {
				if (subterms[s][1] < 0) {
					subterms[s][1] *= -1;
					denomSubterms.push(subterms[s]);
				}
			}
		}
		for (var s1 = denomSubterms.length-1; s1 >= 0; s1--) {
			var sub1 = denomSubterms[s1];
			for (var s2 = s1-1; s2 >= 0; s2--) {
				var sub2 = denomSubterms[s2];
				if (alg.likeSubterm(sub1,sub2) === true) {
					sub2[1] = Math.max(sub1[1],sub2[1]);
					denomSubterms.splice(s1,1);
					break;
				}
			}
		}
		
		var exp2 = {sign:1,coeff:denomCoeff,subterms:denomSubterms};
		return exp2;
	}
}

function bound(value, min, max, roundTo) {
	if (!un(roundTo))
		value = roundToNearest(value, roundTo);
	return Math.max(min, Math.min(max, value));
}

function pngVis(sf, dl) {
	if (un(sf)) sf = 0.4;

	var ctx = newctx({
			vis: false
		});

	var obj = container.childNodes;
	for (var o = 0; o < obj.length; o++) {
		if (obj[o].nodeType !== 1)
			continue;
		if (obj[o].nodeName.toLowerCase() !== 'canvas')
			continue;
		var dims = obj[o].getBoundingClientRect();
		var left = roundToNearest(xWindowToCanvas(dims.left), 1);
		var top = roundToNearest(yWindowToCanvas(dims.top), 1);
		flattenCanvases(ctx.canvas, obj[o], left, top);
	}

	if (sf !== 1) {
		var w = mainCanvasWidth * sf;
		var h = mainCanvasHeight * sf;
		var ctx2 = newctx({
				rect: [0, 0, w, h],
				vis: false
			});
		ctx2.drawImage(ctx.canvas, 0, 0, w, h);
		var imgURL = canvasToPNG(ctx2.canvas);
	} else {
		var imgURL = canvasToPNG(ctx.canvas);
	}

	//window.open(imgURL,'_blank');

	return imgURL;
	/*
	if (boolean(dl, true) == true) {
		var dlLink = document.createElement('a');
		dlLink.download = 'dl.png';
		dlLink.href = imgURL;
		dlLink.dataset.downloadurl = ["image/png", dlLink.download, dlLink.href].join(':');
		document.body.appendChild(dlLink);
		dlLink.click();
		document.body.removeChild(dlLink);
		return;
	}
	return imgURL;*/
}
function canvasToPNG(canvas, filename, l, t, w, h) {
	var width = mainCanvasWidth;
	var height = mainCanvasHeight;
	if (isElement(canvas)) {
		width = canvas.width;
		height = canvas.height;
	}
	var canvas2 = document.createElement('canvas');
	canvas2.width = width;
	canvas2.height = height;
	var ctx2 = canvas2.getContext('2d');
	if (isElement(canvas)) {
		ctx2.drawImage(canvas, 0, 0);
	} else if (typeof canvas == 'object') {
		for (var i = 0; i < canvas.length; i++) {
			ctx2.drawImage(canvas[i], canvas[i].data[100], canvas[i].data[101]);
		}
	}
	var left = l || 0;
	var top = t || 0;
	var w2 = w || width;
	var h2 = h || height;
	var canvas3 = document.createElement('canvas');
	canvas3.width = w2;
	canvas3.height = h2;
	var ctx3 = canvas3.getContext('2d');
	ctx3.drawImage(canvas2, -left, -top);
	var imgURL = canvas3.toDataURL("image/png");
	return imgURL;
}

function calcRects(obj) {
	if (un(obj))
		obj = {};
	var left = def([obj.left, 0]);
	var top = def([obj.top, 80]);
	if (typeof obj.margin == 'object') {
		obj.marginLeft = obj.margin[0];
		obj.marginTop = obj.margin[1];
		obj.marginRight = obj.margin[2];
		obj.marginBottom = obj.margin[3];
	}
	var marginLeft = def([obj.marginLeft, obj.margin, 20]);
	var marginBottom = def([obj.marginBottom, obj.margin, 20]);
	var marginTop = def([obj.marginTop, obj.margin, 20]);
	var marginRight = def([obj.marginRight, obj.margin, 20]);
	var paddingVert = def([obj.paddingVert, obj.padding, 40]);
	var paddingHoriz = def([obj.paddingHoriz, obj.padding, 40]);
	var rows = def([obj.rows, 2]);
	var cols = def([obj.cols, 2]);
	var order = def([obj.order, 'v']);

	var width = (1200 - left - marginLeft - marginRight - (cols - 1) * paddingHoriz) / cols;
	var height = (700 - top - marginTop - marginBottom - (rows - 1) * paddingVert) / rows;

	var arr = [];

	for (var r = 0; r < rows; r++) {
		for (var c = 0; c < cols; c++) {
			if (order == 'h') {
				var index = r * cols + c;
			} else {
				var index = c * rows + r;
			}
			arr[index] = [
				left + marginLeft + c * (width + paddingHoriz),
				top + marginTop + r * (height + paddingVert),
				width,
				height,
				left + marginLeft + c * (width + paddingHoriz) + width,
				top + marginTop + r * (height + paddingVert) + height,
				left + marginLeft + c * (width + paddingHoriz) + 0.5 * width,
				top + marginTop + r * (height + paddingVert) + 0.5 * height,
			];
		}
	}
	if (!un(obj.ctx)) { // if ctx is supplied, draw rects
		for (var i = 0; i < arr.length; i++) {
			obj.ctx.save();
			obj.ctx.strokeStyle = '#000';
			obj.ctx.lineWidth = 2;
			obj.ctx.strokeRect(arr[i][0], arr[i][1], arr[i][2], arr[i][3]);
			obj.ctx.lineWidth = 1;
			obj.ctx.strokeStyle = '#666';
			obj.ctx.setLineDash([15, 15]);
			obj.ctx.beginPath();
			obj.ctx.moveTo(arr[i][0], arr[i][7]);
			obj.ctx.lineTo(arr[i][4], arr[i][7]);
			obj.ctx.moveTo(arr[i][6], arr[i][1]);
			obj.ctx.lineTo(arr[i][6], arr[i][5]);
			obj.ctx.stroke();
			obj.ctx.restore();
		}
	}
	return arr;
}

var dropMenus = [];
function dropMenu(obj) {
	obj.open = false;
	obj.selected = -1;
	obj.buttonColor = def([obj.buttonColor, obj.selectedColor, '#3FF']);
	obj.buttonBorderColor = def([obj.buttonBorderColor, '#000']);
	obj.buttonBorder = boolean(obj.buttonBorder, true);
	obj.showDownArrow = boolean(obj.showDownArrow, true);
	obj.selectedColor = def([obj.selectedColor, '#3FF']);
	obj.unselectedColor = def([obj.unselectedColor, '#CFF']);
	obj.z = def([obj.z, 100000000]);
	obj.listShowMax = def([obj.listShowMax, -1]);
	obj.overflow = false;
	obj.fullWidth = clone(obj.listRect[2]);
	obj.font = def([obj.font, 'Arial']);
	obj.fontSize = def([obj.fontSize, 16]);
	obj.align = def([obj.align, 'left']);

	obj.canvas1 = createCanvas(obj.buttonRect[0], obj.buttonRect[1], obj.buttonRect[2], obj.buttonRect[3], true, false, true, obj.z);
	obj.canvas1.parent = obj;
	obj.canvas1.click = function () {
		var obj = this.parent;
		obj.open = !obj.open;
		if (obj.open == true) {
			showObj(obj.canvas2);
			showObj(obj.canvas3);
			if (obj.overflow)
				showScroller(obj.scroller);
			addListenerMove(window, obj.move);
			addListener(obj.canvas2, obj.click);
			addListenerStart(window, obj.windowClickClose);
			if (obj.overflow == true)
				window.addEventListener("mousewheel", obj.mouseWheelHandler, false);
		} else {
			obj.close();
		}
	}
	obj.canvas1.draw = function () {
		var obj = this.parent;
		var ctx = this.ctx;
		var w = obj.buttonRect[2];
		var h = obj.buttonRect[3];
		ctx.clearRect(0, 0, w, h);
		if (obj.buttonBorder == true) {
			text({
				ctx: obj.canvas1.ctx,
				text: [obj.title],
				left: 1.5,
				top: 1.5,
				width: w - 3,
				height: h - 3,
				align: 'center',
				vertAlign: 'middle',
				box: {
					type: 'loose',
					color: obj.buttonColor,
					borderWidth: 3,
					borderColor: obj.buttonBorderColor
				}
			});
		} else {
			text({
				ctx: obj.canvas1.ctx,
				text: [obj.title],
				left: 1.5,
				top: 1.5,
				width: w - 3,
				height: h - 3,
				align: 'center',
				vertAlign: 'middle'
			});
		}
		if (obj.showDownArrow == true) {
			ctx.fillStyle = '#000';
			ctx.lineJoin = 'round';
			ctx.lineCap = 'round';
			var l = w - 15;
			var t = h / 2;
			ctx.beginPath();
			ctx.moveTo(l - 8, t - 4);
			ctx.lineTo(l + 8, t - 4);
			ctx.lineTo(l, t + 8);
			ctx.lineTo(l - 8, t - 4);
			ctx.fill();
		}
	}
	obj.canvas1.draw();
	addListenerEnd(obj.canvas1, obj.canvas1.click);
	obj.windowClickClose = function (e) {
		for (var i = 0; i < dropMenus.length; i++) {
			if (dropMenus[i].open == true) {
				var obj = dropMenus[i];
				if (e.target !== obj.canvas1 && e.target !== obj.canvas2 && (un(obj.scroller) || (e.target !== obj.scroller.canvas && e.target !== obj.scroller.sliderCanvas))) {
					obj.close();
				}
			}
		}
	}
	obj.close = function () {
		var obj = this;
		hideObj(obj.canvas2);
		hideObj(obj.canvas3);
		hideScroller(obj.scroller);
		removeListenerMove(window, obj.move);
		removeListener(obj.canvas2, obj.click);
		removeListener(window, obj.windowClickClose);
		if (obj.overflow == true)
			window.removeEventListener("mousewheel", obj.mouseWheelHandler, false);
		obj.selected = -1;
		obj.open = false;
		obj.draw();
	}

	obj.canvas2 = createCanvas(obj.listRect[0], obj.listRect[1], obj.listRect[2], obj.listRect[3], false, false, true, obj.z); // text - drawn once
	obj.canvas2.parent = obj;
	obj.canvas3 = createCanvas(obj.listRect[0], obj.listRect[1], obj.listRect[2], obj.listRect[3], false, false, false, obj.z + 1); // colors
	obj.canvas3.parent = obj;
	obj.scroller = createScroller({
			rect: [obj.listRect[0] + obj.listRect[2] - 20, obj.listRect[1], 20, obj.listRect[3] * obj.listShowMax],
			z: obj.z + 2,
			min: 0,
			max: obj.data.length - obj.listShowMax,
			inc: 1,
			sliderHeight: (obj.listRect[3] * obj.listShowMax - 2 * 20) * (obj.listShowMax / obj.data.length),
			funcMove: function (value) {
				var obj = this.parent;
				value = roundToNearest(value, 1);
				obj.draw(value);
				removeListenerMove(window, obj.move);
				removeListener(obj.canvas2, obj.click);
				removeListener(window, obj.windowClickClose);
			},
			funcStop: function (value) {
				var obj = this.parent;
				value = roundToNearest(value, 1);
				obj.draw(value);
				addListenerMove(window, obj.move);
				addListener(obj.canvas2, obj.click);
				addListener(window, obj.windowClickClose);
			}
		});
	obj.scroller.parent = obj;
	obj.mouseWheelHandler = function (e) {
		// cross-browser wheel delta
		var e = window.event || e; // old IE support
		var delta = Math.max(-1, Math.min(1, (e.wheelDelta || -e.detail)));
		for (var i = 0; i < dropMenus.length; i++) {
			if (dropMenus[i].open == true) {
				var obj = dropMenus[i];
				setScrollerValue(obj.scroller, obj.scrollPos - delta, true);
				break;
			}
		}
	}
	hideScroller(obj.scroller);
	obj.updateData = function () {
		var obj = this;
		var height = this.listRect[3] * this.data.length;
		if (this.listShowMax !== -1 && this.listShowMax < this.data.length) {
			this.overflow = true;
			this.listRect[2] = this.fullWidth - 20;
			height = this.listRect[3] * this.listShowMax;
			var s = this.scroller;
			s.max = this.data.length - this.listShowMax;
			s.sliderHeight = (height - 2 * 20) * (this.listShowMax / this.data.length);
			s.incDist = (s.rect[3] - 2 * 20 - s.sliderHeight) / ((s.max - s.min) / s.inc);
			s.sliderRect[3] = s.sliderHeight;
			s.sliderCanvas.data[100] = s.sliderRect[0];
			s.sliderCanvas.data[101] = s.sliderRect[1];
			s.sliderCanvas.data[102] = s.sliderRect[2];
			s.sliderCanvas.data[103] = s.sliderRect[3];
			resizeCanvas(s.sliderCanvas, s.sliderCanvas.data[100], s.sliderCanvas.data[101], s.sliderCanvas.data[102], s.sliderCanvas.data[103]);
			setScrollerValue(s, 0, true);
		} else {
			this.overflow = false;
			this.listRect[2] = this.fullWidth;
		}
		this.scrollPos = 0;
		this.canvas2.data[102] = this.listRect[2];
		this.canvas2.width = this.listRect[2];
		this.canvas2.data[103] = height;
		this.canvas2.height = height;
		resizeCanvas(this.canvas2, this.listRect[0], this.listRect[1], this.listRect[2], height);
		this.canvas3.data[102] = this.listRect[2];
		this.canvas3.width = this.listRect[2];
		this.canvas3.data[103] = height;
		this.canvas3.height = height;
		resizeCanvas(this.canvas3, this.listRect[0], this.listRect[1], this.listRect[2], height);
		obj.drawListText();
		obj.draw();

	}
	obj.drawListText = function () {
		var obj = this;
		var top = 0;
		if (obj.overflow)
			top -= obj.scrollPos * obj.listRect[3];
		var ctx = obj.canvas3.ctx;
		for (var d = 0; d < obj.data.length; d++) {
			text({
				ctx: ctx,
				text: ['<<font:' + this.font + '>><<fontSize:' + this.fontSize + '>>' + obj.data[d]],
				left: 0,
				top: top,
				width: obj.listRect[2],
				height: obj.listRect[3],
				align: this.align,
				vertAlign: 'middle',
				box: {
					color: 'none',
					borderWidth: 0.01
				}
			});
			top += obj.listRect[3];
			ctx.strokeStyle = '#000';
			ctx.lineWidth = 1;
			ctx.beginPath();
			ctx.moveTo(0, top);
			ctx.lineTo(obj.listRect[2], top);
			ctx.stroke();
		}
		ctx.strokeStyle = '#000';
		ctx.lineWidth = 2;
		ctx.beginPath();
		ctx.moveTo(0, 0);
		ctx.lineTo(obj.listRect[2], 0);
		ctx.moveTo(0, 0);
		ctx.lineTo(0, top);
		ctx.moveTo(obj.listRect[2], 0);
		ctx.lineTo(obj.listRect[2], top);
		ctx.stroke();
	}
	obj.draw = function (newScrollPos) {
		var obj = this;
		var ctx = this.canvas2.ctx;
		if (this.overflow == true) {
			if (!un(newScrollPos) && newScrollPos !== obj.scrollPos) {
				obj.scrollPos = newScrollPos;
				var ctx2 = this.canvas3.ctx;
				ctx2.clearRect(0, 0, this.listRect[2], this.listRect[3] * this.listShowMax);
				obj.drawListText();
			}
			ctx.fillStyle = this.unselectedColor;
			ctx.fillRect(0, 0 - this.scrollPos * this.listRect[3], this.listRect[2], this.listRect[3] * this.data.length);
			ctx.fillStyle = this.selectedColor;
			ctx.fillRect(0, this.listRect[3] * this.selected - this.scrollPos * this.listRect[3], this.listRect[2], this.listRect[3]);
		} else {
			ctx.fillStyle = this.unselectedColor;
			ctx.fillRect(0, 0, this.listRect[2], this.listRect[3] * this.data.length);
			ctx.fillStyle = this.selectedColor;
			ctx.fillRect(0, this.listRect[3] * this.selected, this.listRect[2], this.listRect[3]);
		}
	}
	obj.updateData();
	obj.move = function (e) {
		updateMouse(e);
		var found = false;
		for (var i = 0; i < dropMenus.length; i++) {
			if (dropMenus[i].open == true) {
				obj = dropMenus[i];
				var found = true;
				break;
			}
		}
		if (found == false)
			return;
		if (mouse.x < obj.listRect[0] || mouse.x > obj.listRect[0] + obj.listRect[2] || mouse.y < obj.listRect[1] || mouse.y > obj.listRect[1] + obj.data.length * obj.listRect[3]) {
			if (obj.selected !== -1) {
				obj.selected = -1;
				obj.draw();
			}
		} else {
			var sel = Math.floor((mouse.y - obj.listRect[1]) / obj.listRect[3]);
			if (obj.overflow == true)
				sel += obj.scrollPos;
			if (obj.selected !== sel) {
				obj.selected = sel;
				obj.draw();
			}
		}
	}
	obj.click = function () {
		var obj = this.parent;
		if (!un(obj.func))
			obj.func.apply();
		obj.close();
	}
	resize();
	obj.index = dropMenus.length;
	dropMenus.push(obj); // place in global array
	return obj;
}

function drawTable(context, lineWidth, lineColor, l, t, hLines, vLines) {
	context.save();
	context.beginPath();
	context.lineWidth = lineWidth;
	context.strokeStyle = lineColor;
	context.lineCap = 'round';
	// draw horizontal lines
	for (h = 0; h < hLines.length; h++) {
		context.moveTo(l + vLines[0], t + hLines[h]);
		context.lineTo(l + vLines[vLines.length - 1], t + hLines[h]);
	}
	// draw vertical lines
	for (v = 0; v < vLines.length; v++) {
		context.moveTo(l + vLines[v], t + hLines[0]);
		context.lineTo(l + vLines[v], t + hLines[hLines.length - 1]);
	}
	context.stroke();
	context.restore();
}
function calcTable2(object) {
	var left = object.left;
	var top = object.top;
	var cells = object.cells;

	var minCellWidth = object.minCellWidth || 80;
	var maxCellWidth = object.maxCellWidth || 150;
	var minCellHeight = object.minCellHeight || 100;
	var minCellPadding = object.minCellPadding || 10;
	var horizAlign = object.horizAlign || object.align || 'center';
	if (typeof object.text == 'object') {
		var font = object.text.font || 'Arial';
		var fontSize = object.text.size || 32;
		var textColor = object.text.color || '#000';
	} else {
		var font = 'Arial';
		var fontSize = 32;
		var textColor = '#000';
	}

	var numRows = cells.length;
	var numCols = 0;
	for (var i = 0; i < cells.length; i++) {
		numCols = Math.max(cells[i].length, numCols);
	}
	var cellHeights = [];
	for (var i = 0; i < numRows; i++) {
		cellHeights[i] = minCellHeight;
	}
	var cellWidths = [];
	for (var j = 0; j < numCols; j++) {
		cellWidths[j] = minCellWidth;
	}
	var totalWidth = 0;
	var totalHeight = 0;

	for (var i = 0; i < cells.length; i++) {
		var maxHeight = minCellHeight;
		for (var j = 0; j < cells[i].length; j++) {
			if (typeof cells[i][j] == 'object') {
				if (typeof cells[i][j].text !== 'object')
					cells[i][j].text = [];
				if (typeof cells[i][j].minWidth !== 'number')
					cells[i][j].minWidth = 0;
				if (typeof cells[i][j].minHeight !== 'number')
					cells[i][j].minHeight = 0;
				cells[i][j].text.unshift('<<font:' + font + '>><<fontSize:' + fontSize + '>><<color:' + textColor + '>>');
				cells[i][j].text = reduceTags(cells[i][j].text);
				var dims = drawMathsText(ctx, cells[i][j].text, fontSize, 0, 0, false, [], horizAlign, 'middle', text.color, 'measure');
				maxHeight = Math.max(dims[1] + 2 * minCellPadding, cells[i][j].minHeight, maxHeight);
				cellWidths[j] = Math.max(dims[0] + 2 * minCellPadding, cells[i][j].minWidth, cellWidths[j]);
			}
		}
		cellHeights[i] = Math.max(maxHeight, cellHeights[i]);
		totalHeight += cellHeights[i];
	}
	for (var j = 0; j < cellWidths.length; j++) {
		totalWidth += cellWidths[j];
	}

	var horizPos = [left];
	for (var i = 0; i < cellWidths.length; i++) {
		horizPos.push(horizPos[horizPos.length - 1] + cellWidths[i])
	}

	var vertPos = [top];
	for (var i = 0; i < cellHeights.length; i++) {
		vertPos.push(vertPos[vertPos.length - 1] + cellHeights[i])
	}

	var cellDims = [];

	var topPos = top;
	for (var i = 0; i < cells.length; i++) {
		var leftPos = left;
		cellDims[i] = [];
		for (var j = 0; j < cells[i].length; j++) {
			cellDims[i][j] = {
				left: leftPos + 2,
				top: topPos + 1,
				width: cellWidths[j] - 9,
				height: cellHeights[i] - 8,
				border: false,
				offset: [-40, 0.5 * (cellHeights[i] - 8) - 20],
				fontSize: fontSize,
				leftPoint: minCellPadding,
				textColor: textColor,
				textAlign: horizAlign,
				fontSize: fontSize
			};
			leftPos += cellWidths[j];
		}
		topPos += cellHeights[i];
	}

	return {
		cell: cellDims,
		xPos: horizPos,
		yPos: vertPos
	};
}
function drawTable2(object) {
	/* EXAMPLE USAGE:
	var j0001table1 = drawTable2({
	ctx:j0001buttonctx[0],
	left:100,
	top:150,
	minCellWidth:80,
	minCellHeight:50,
	horizAlign:'center',
	text:{font:'Arial',size:32,color:'#000'},
	outerBorder:{show:true,width:4,color:'#000'},
	innerBorder:{show:true,width:2,color:'#666',dash:[5,5]},
	cells:[
	[    // row 0{text:['<<fontSize:36>><<font:algebra>>x'],color:'#CCF',minWidth:100,minHeight:70},{text:['<<fontSize:36>><<font:algebra>>y'],color:'#CCF',minWidth:100,minHeight:70},{text:['<<fontSize:36>><<font:algebra>><<color:#F00>>z'],color:'#CCF',minWidth:100,minHeight:70},
	], [ // row 1{},{text:['2']},{text:['<<color:#F00>>3']},
	], [ // row 2{text:['4']},{},{text:['<<color:#F00>>6']},
	],
	]
	});

	// CAN EASILY USE IN CONJUNCTION WITH INPUTS()...
	inputs({
	inputs:[
	// j0001table1.cell[row][col] - nb. start counting from zero
	j0001table1.cell[1][0],
	j0001table1.cell[2][1]
	],
	checkFuncs:[
	function(input) {
	if (input.stringJS == '1') {
	return true;
	} else {
	return false;
	}
	},
	function(input) {
	if (input.stringJS == '5') {
	return true;
	} else {
	return false;
	}
	},
	]
	});
	 */

	if (typeof object.sf !== 'undefined') {
		var sf = object.sf;
	} else {
		var sf = 1;
	}
	var ctx = object.ctx || object.context;
	var left = object.left * sf;
	var top = object.top * sf;
	var cells = object.cells;

	var minCellWidth = object.minCellWidth * sf || 80 * sf;
	var maxCellWidth = object.maxCellWidth * sf || Math.max(1200 * sf, object.minCellWidth * sf);
	var minCellHeight = object.minCellHeight * sf || 100 * sf;
	var minCellPadding = object.minCellPadding * sf || 7 * sf;
	var paddingH = minCellPadding;
	var paddingV = minCellPadding;
	if (typeof object.paddingH == 'number')
		paddingH = object.paddingH * sf;
	if (typeof object.paddingV == 'number')
		paddingV = object.paddingV * sf;
	var horizAlign = object.horizAlign || object.align || 'center';
	if (typeof object.text == 'object') {
		var font = object.text.font || 'Arial';
		var fontSize = object.text.size || 32;
		var textColor = object.text.color || '#000';
	} else {
		var font = 'Arial';
		var fontSize = 32;
		var textColor = '#000';
	}
	if (typeof object.alpha == 'number') {
		var alpha = object.alpha;
	} else {
		var alpha = 1;
	}
	var lineJoin = object.lineJoin || object.lineCap || 'round';
	var lineCap = object.lineCap || object.lineJoin || 'round';
	var outerBorder = {};
	if (typeof object.outerBorder == 'object') {
		outerBorder.show = boolean(object.outerBorder.show, true);
		outerBorder.width = object.outerBorder.width * sf || 4 * sf;
		if (typeof object.outerBorder.color == 'undefined') {
			outerBorder.color = colorA('#000', alpha);
		} else {
			outerBorder.color = colorA(object.outerBorder.color, alpha);
		}
		outerBorder.dash = object.outerBorder.dash || [];
	} else {
		outerBorder.show = true;
		outerBorder.width = 4 * sf;
		outerBorder.color = colorA('#000', alpha);
		outerBorder.dash = [];
	}
	outerBorder.dash = enlargeDash(outerBorder.dash, sf);
	var innerBorder = {};
	if (typeof object.innerBorder == 'object') {
		innerBorder.show = boolean(object.innerBorder.show, true);
		innerBorder.width = object.innerBorder.width * sf || 4 * sf;
		if (typeof object.innerBorder.color == 'undefined') {
			innerBorder.color = colorA('#000', alpha);
		} else {
			innerBorder.color = colorA(object.innerBorder.color, alpha);
		}
		innerBorder.dash = object.innerBorder.dash || [];
	} else {
		innerBorder.show = true;
		innerBorder.width = 4 * sf;
		innerBorder.color = colorA('#000', alpha);
		innerBorder.dash = [20, 15];
	}
	innerBorder.dash = enlargeDash(innerBorder.dash, sf);
	var tableAlignHoriz = object.tableAlignHoriz || 'left'; // is the whole table centred on [left,top]?
	var tableAlignVert = object.tableAlignVert || 'top';

	var numRows = cells.length;
	var numCols = 0;
	for (var i = 0; i < cells.length; i++) {
		numCols = Math.max(cells[i].length, numCols);
	}
	var cellHeights = [];
	for (var i = 0; i < numRows; i++) {
		cellHeights[i] = minCellHeight;
	}
	var cellWidths = [];
	for (var j = 0; j < numCols; j++) {
		cellWidths[j] = minCellWidth;
	}
	var totalWidth = 0;
	var totalHeight = 0;

	if (typeof hiddenCanvas == 'undefined') {
		var hiddenCanvas = document.createElement('canvas');
		hiddenCanvas.width = mainCanvasWidth * sf;
		hiddenCanvas.height = mainCanvasHeight * sf;
		hiddenCanvas.ctx = hiddenCanvas.getContext('2d');
	}

	for (var r = 0; r < cells.length; r++) {
		var maxHeight = minCellHeight;
		for (var c = 0; c < cells[r].length; c++) {
			if (typeof cells[r][c] == 'object') {
				if (typeof cells[r][c].text !== 'object') {
					cells[r][c].text = [];
				} else {
					cells[r][c].text = clone(cells[r][c].text);
				}
				if (typeof cells[r][c].color !== 'string')
					cells[r][c].color = 'none';
				if (typeof cells[r][c].minWidth !== 'number')
					cells[r][c].minWidth = 0;
				if (typeof cells[r][c].minHeight !== 'number')
					cells[r][c].minHeight = 0;
				var font2 = font;
				var fontSize2 = fontSize;
				var textColor2 = textColor;
				if (!un(cells[r][c].font))
					font2 = cells[r][c].font;
				if (!un(cells[r][c].fontSize))
					fontSize2 = cells[r][c].fontSize;
				if (!un(cells[r][c].textColor))
					textColor2 = cells[r][c].textColor;
				if (un(cells[r][c].styled)) {
					cells[r][c].text.unshift('<<font:' + font2 + '>><<fontSize:' + fontSize2 + '>><<color:' + textColor2 + '>>');
					cells[r][c].styled = true;
				}
				//var dims = drawMathsText(ctx,cells[r][c].text,fontSize,0,0,false,[],horizAlign,'middle',text.color,'measure');
				//maxHeight = Math.max(dims[1]+2*minCellPadding,cells[r][c].minHeight,maxHeight);
				//cellWidths[c] = Math.max(dims[0]+2*minCellPadding,cells[r][c].minWidth,cellWidths[c]);

				var cellText = text({
						ctx: hiddenCanvas.ctx,
						left: 0,
						top: 0,
						width: maxCellWidth,
						textArray: cells[r][c].text,
						minTightWidth: 5,
						minTightHeight: 5,
						box: cells[r][c].box,
						sf: sf
					});
				maxHeight = Math.max(cellText.tightRect[3] + 2 * paddingV, cells[r][c].minHeight * sf, maxHeight);
				cellWidths[c] = Math.max(cellText.tightRect[2] + 3 * paddingH, cells[r][c].minWidth * sf, cellWidths[c]);
			}
		}
		cellHeights[r] = Math.max(maxHeight, cellHeights[r]);
		totalHeight += cellHeights[r];
	}
	for (var j = 0; j < cellWidths.length; j++) {
		totalWidth += cellWidths[j];
	}

	if (tableAlignHoriz == 'center') {
		left = left - totalWidth / 2;
	} else if (tableAlignHoriz == 'right') {
		left = left - totalWidth;
	}

	if (tableAlignVert == 'middle') {
		top = top - totalHeight / 2;
	} else if (tableAlignVert == 'bottom') {
		top = top - totalHeight;
	}

	ctx.save();
	ctx.lineCap = lineCap;
	ctx.lineJoin = lineJoin;

	var cellDims = [];

	var horizPos = [left];
	for (var i = 0; i < cellWidths.length; i++) {
		horizPos.push(horizPos[horizPos.length - 1] + cellWidths[i])
	}

	var vertPos = [top];
	for (var i = 0; i < cellHeights.length; i++) {
		vertPos.push(vertPos[vertPos.length - 1] + cellHeights[i])
	}

	// write text to each cell
	var topPos = top;
	for (var i = 0; i < cells.length; i++) {
		var leftPos = left;
		cellDims[i] = [];
		for (var j = 0; j < cells[i].length; j++) {
			cellDims[i][j] = {
				left: leftPos + 2,
				top: topPos + 1,
				width: cellWidths[j] - 9,
				height: cellHeights[i] - 8,
				border: false,
				offset: [-40, 0.5 * (cellHeights[i] - 8) - 20],
				fontSize: fontSize,
				leftPoint: paddingH,
				textColor: textColor,
				textAlign: horizAlign,
				fontSize: fontSize
			};
			if (cells[i][j].highlight == true) {
				if (typeof cells[i][j].color == 'undefined' || cells[i][j].color !== 'none') {
					ctx.fillStyle = colorA(invertColor(cells[i][j].color), alpha);
				} else {
					ctx.fillStyle = colorA(invertColor('#FFC'), alpha);
				}
				ctx.fillRect(leftPos, topPos, cellWidths[j], cellHeights[i]);
			} else if (typeof cells[i][j].color == 'undefined' || cells[i][j].color !== 'none') {
				ctx.fillStyle = colorA(cells[i][j].color, alpha);
				ctx.fillRect(leftPos, topPos, cellWidths[j], cellHeights[i]);
			}
			/*if (horizAlign == 'left') {
			var dims = drawMathsText(ctx,cells[i][j].text,fontSize,leftPos+minCellPadding,topPos+0.5*cellHeights[i],false,[],horizAlign,'middle',textColor);
			} else if (horizAlign == 'center') {
			var dims = drawMathsText(ctx,cells[i][j].text,fontSize,leftPos+0.5*cellWidths[j],topPos+0.5*cellHeights[i],false,[],horizAlign,'middle',textColor);
			} else if (horizAlign == 'right') {
			var dims = drawMathsText(ctx,cells[i][j].text,fontSize,leftPos+cellWidths[j]-minCellPadding,topPos+0.5*cellHeights[i],false,[],horizAlign,'middle',textColor);
			}*/
			var align = horizAlign;
			if (!un(cells[i][j].align))
				align = cells[i][j].align;
			var cellText = text({
					ctx: ctx,
					left: leftPos + paddingH,
					top: topPos + paddingV,
					width: cellWidths[j] - 2 * paddingH,
					height: cellHeights[i] - 2 * paddingV,
					textArray: cells[i][j].text,
					textAlign: align,
					vertAlign: 'middle',
					padding: 0.001,
					box: cells[i][j].box,
					sf: sf
					//box:{type:'tight'}
				});
			//console.log(cellText.tightRect[2],cellText.tightRect[3]);
			leftPos += cellWidths[j];
		}
		topPos += cellHeights[i];
	}

	// draw inner border
	if (innerBorder.show == true) {
		ctx.strokeStyle = innerBorder.color;
		ctx.lineWidth = innerBorder.width;
		if (!ctx.setLineDash) {
			ctx.setLineDash = function () {}
		}
		ctx.setLineDash(innerBorder.dash);
		var leftPos = left;
		for (var i = 0; i < cellWidths.length - 1; i++) {
			leftPos += cellWidths[i];
			ctx.beginPath();
			ctx.moveTo(leftPos, top);
			ctx.lineTo(leftPos, top + totalHeight);
			ctx.stroke();
		}
		var topPos = top;
		for (var i = 0; i < cellHeights.length - 1; i++) {
			topPos += cellHeights[i];
			ctx.beginPath();
			ctx.moveTo(left, topPos);
			ctx.lineTo(left + totalWidth, topPos);
			ctx.stroke();
		}
	}

	// draw outer border
	if (outerBorder.show == true) {
		ctx.strokeStyle = outerBorder.color;
		ctx.lineWidth = outerBorder.width;
		if (!ctx.setLineDash) {
			ctx.setLineDash = function () {}
		}
		ctx.setLineDash(outerBorder.dash);
		ctx.beginPath();
		ctx.strokeRect(left, top, totalWidth, totalHeight);
	}

	ctx.restore();

	return {
		cell: cellDims,
		xPos: horizPos,
		yPos: vertPos
	};
}
function drawTable3(object) {
	var sf = typeof object.sf !== 'undefined' ? object.sf : 1;
	var ctx = object.ctx || object._ctx || object.context;
	var left = object.left * sf;
	var top = object.top * sf;
	var cells = object.cells;

	var widths = clone(object.widths);
	var heights = clone(object.heights);
	if (sf !== 1) {
		for (var w = 0; w < widths.length; w++) widths[w] = widths[w] * sf;
		for (var h = 0; h < heights.length; h++) heights[h] = heights[h] * sf;
	}
	var minCellPadding = object.minCellPadding * sf || 0;
	var paddingH = minCellPadding;
	var paddingV = minCellPadding;
	if (typeof object.paddingH == 'number') paddingH = object.paddingH * sf;
	if (typeof object.paddingV == 'number') paddingV = object.paddingV * sf;
	//var innerPaddingH = !un(obj.innerPaddingH) ? obj.innerPaddingH*sf : 0;
	//var innerPaddingV = !un(obj.innerPaddingV) ? obj.innerPaddingV*sf : 0;
	var horizAlign = object.horizAlign || object.align || 'center';
	var alpha = typeof object.alpha == 'number' ? object.alpha : 1;
	var lineJoin = object.lineJoin || object.lineCap || 'round';
	var lineCap = object.lineCap || object.lineJoin || 'round';
	var outerBorder = {};
	if (typeof object.outerBorder == 'object') {
		outerBorder.show = boolean(object.outerBorder.show, true);
		outerBorder.width = object.outerBorder.width * sf || 4 * sf;
		if (typeof object.outerBorder.color == 'undefined') {
			outerBorder.color = colorA('#000', alpha);
		} else {
			outerBorder.color = colorA(object.outerBorder.color, alpha);
		}
		outerBorder.dash = object.outerBorder.dash || [];
		outerBorder.radius = object.outerBorder.radius*sf || 0;
	} else {
		outerBorder.show = true;
		outerBorder.width = 4 * sf;
		outerBorder.color = colorA('#000', alpha);
		outerBorder.dash = [];
		outerBorder.radius = 0;
	}
	outerBorder.dash = enlargeDash(outerBorder.dash, sf);
	var innerBorder = {};
	if (typeof object.innerBorder == 'object') {
		innerBorder.show = boolean(object.innerBorder.show, true);
		innerBorder.width = object.innerBorder.width * sf || 4 * sf;
		if (typeof object.innerBorder.color == 'undefined') {
			innerBorder.color = colorA('#000', alpha);
		} else {
			innerBorder.color = colorA(object.innerBorder.color, alpha);
		}
		innerBorder.dash = object.innerBorder.dash || [];
		innerBorder.dash = enlargeDash(innerBorder.dash, sf);
	} else {
		innerBorder.show = false;
		/*innerBorder.show = true;
		innerBorder.width = 4 * sf;
		innerBorder.color = colorA('#000', alpha);
		innerBorder.dash = [20, 15];
		innerBorder.dash = enlargeDash(innerBorder.dash, sf);*/
	}
	
	var tableAlignHoriz = object.tableAlignHoriz || 'center'; // is the whole table centred on [left,top]?
	var tableAlignVert = object.tableAlignVert || 'middle';
	if (!un(object.align)) {
		tableAlignHoriz = object.align[0] == -1 ? 'left' : object.align[0] == 0 ? 'center' : 'right';
		tableAlignVert = object.align[1] == -1 ? 'top' : object.align[1] == 0 ? 'middle' : 'bottom';
	}
	if (typeof object.text == 'object') {
		var font = object.text.font || 'Arial';
		var fontSize = object.text.size || 28;
		var textColor = object.text.color || '#000';
	} else {
		var font = 'Arial';
		var fontSize = 28;
		var textColor = '#000';
	}
	var fracScale = object.fracScale;
	var algPadding = object.algPadding;

	var totalWidth = arraySum(widths);
	var totalHeight = arraySum(heights);

	ctx.save();
	ctx.lineCap = lineCap;
	ctx.lineJoin = lineJoin;

	var cellDims = [];

	var horizPos = [left];
	for (var i = 0; i < widths.length; i++) {
		horizPos.push(horizPos[horizPos.length - 1] + widths[i])
	}

	var vertPos = [top];
	for (var i = 0; i < heights.length; i++) {
		vertPos.push(vertPos[vertPos.length - 1] + heights[i])
	}

	// color, inner border & text for cells
	var topPos = top;
	var cellTextMeasure = [];
	for (var i = 0; i < cells.length; i++) {
		var leftPos = left;
		cellDims[i] = [];
		var skipCells = 0;
		cellTextMeasure[i] = [];
		for (var j = 0; j < cells[i].length; j++) {
			var cell = cells[i][j];
			if (skipCells > 0) {
				skipCells--;
				continue;
			}
			if (un(cell.colSpan)) {
				var cellWidth = widths[j];
			} else {
				var cellWidth = 0;
				for (var k = j; k < Math.min(j + cell.colSpan, cells[i].length); k++) {
					cellWidth += widths[k];
				}
				skipCells = cell.colSpan - 1;
			}
			var cellPaddingH = def([cell.paddingH, cell.padding, paddingH]);
			var cellPaddingV = def([cell.paddingV, cell.padding, paddingV]);
			cellDims[i][j] = {
				left: leftPos,
				top: topPos,
				width: cellWidth,
				height: heights[i],
				border: false,
				offset: [-40, 0.5 * (heights[i]) - 20],
				leftPoint: cellPaddingH,
			};

			var c1 = (typeof cell.color !== 'undefined' && cell.color !== 'none') ? true : false;
			var c2 = (!un(cell.box) && cell.box.show == true) ? true : false;
			var hl = cell.highlight;
			/*if (!un(object.isInput)) {
				if (draw.mode == 'interact') {
					var selected = boolean(cell.toggle, false);
				} else {
					var selected = boolean(cell.ans, false);
				}
				if (!un(cell.selColors)) {
					var isInputColor = selected ? cell.selColors[1] : cell.selColors[0];
				} else if (!un(object.isInput.selColors)) {
					var isInputColor = selected ? object.isInput.selColors[1] : object.isInput.selColors[0];
				} else {
					var isInputColor = selected ? '#66F' : '#CCF';
				}
			*/

			if (c2 == true) {
				var box = cell.box;
				//var fillColor = isInputColor || box.fillColor || box.color || undefined;
				var fillColor = box.fillColor || box.color || undefined;
				var lineColor = box.borderColor || box.lineColor || undefined;
				if (hl == true) {
					if (!un(fillColor) && fillColor !== 'none')
						fillColor = colorA(invertColor(fillColor), alpha);
					if (!un(lineColor) && lineColor !== 'none')
						lineColor = colorA(invertColor(lineColor), alpha);
				}
				var lineWidth = box.borderWidth || box.lineWidth || box.width || 3;
				lineWidth = lineWidth * sf;
				var dash = def([box.dash, []]);
				var radius = box.borderRadius || box.radius || 0;
				radius = radius * sf;
				roundedRect(ctx, leftPos + cellPaddingH, topPos + cellPaddingV, cellWidth - 2 * cellPaddingH, heights[i] - 2 * cellPaddingV, radius, lineWidth, lineColor, fillColor, dash);
			} else if (c1 == true) {
				//var fillColor = isInputColor || cell.color;
				var fillColor = cell.color;
				if (hl == true) {
					fillColor = colorA(invertColor(fillColor), alpha);
				} else {
					fillColor = colorA(fillColor, alpha);
				}
				/*ctx.fillStyle = fillColor;
				ctx.globalCompositeOperation = 'destination-over'; // draw behind existing content
				ctx.fillRect(leftPos,topPos,cellWidth,heights[i]);
				ctx.globalCompositeOperation = 'source-over'; // default*/
				roundedRect(ctx, leftPos + cellPaddingH, topPos + cellPaddingV, cellWidth - 2 * cellPaddingH, heights[i] - 2 * cellPaddingV, 0, 0, 'none', fillColor);
			} else {
				if (hl == true) {
					ctx.fillStyle = colorA(invertColor(mainCanvasFillStyle), alpha);
					ctx.globalCompositeOperation = 'destination-over'; // draw behind existing content
					ctx.fillRect(leftPos, topPos, cellWidth, heights[i]);
					ctx.globalCompositeOperation = 'source-over'; // default
				}
			}

			if (innerBorder.show == true) {
				ctx.strokeStyle = innerBorder.color;
				ctx.lineWidth = innerBorder.width;
				if (un(ctx.setLineDash)) {
					ctx.setLineDash = function () {}
				}
				ctx.setLineDash(innerBorder.dash);
				ctx.beginPath();
				if (i > 0) {
					ctx.moveTo(leftPos, topPos);
					ctx.lineTo(leftPos + cellWidth, topPos);
				}
				if (i < cells.length - 1) {
					ctx.moveTo(leftPos, topPos + heights[i]);
					ctx.lineTo(leftPos + cellWidth, topPos + heights[i]);
				}
				if (j > 0) {
					ctx.moveTo(leftPos, topPos);
					ctx.lineTo(leftPos, topPos + heights[i]);
				}
				if (j < cells[i].length - 1 && (un(cell.colSpan) || j + cell.colSpan < cells[i].length - 1)) {
					ctx.moveTo(leftPos + cellWidth, topPos);
					ctx.lineTo(leftPos + cellWidth, topPos + heights[i]);
				}
				ctx.stroke();
			}

			if (!un(cell.text)) {
				var txt = clone(cell.text);
				var align = [0, 0];
				if (tableAlignHoriz == 'left') align[0] = -1;
				if (tableAlignHoriz == 'center') align[0] = 0;
				if (tableAlignHoriz == 'right') align[0] = 1;
				if (tableAlignVert == 'top') align[1] = -1;
				if (tableAlignVert == 'middle') align[1] = 0;
				if (tableAlignVert == 'bottom') align[1] = 1;
				if (cell.align == 'left') align[0] = -1;
				if (cell.align == 'center') align[0] = 0;
				if (cell.align == 'right') align[0] = 1;
				if (cell.vertAlign == 'top') align[1] = -1;
				if (cell.vertAlign == 'middle') align[1] = 0;
				if (cell.vertAlign == 'bottom') align[1] = 1;
				if (typeof cell.align == 'object') align = cell.align;
				var font2 = def([cell.font, font]);
				var fontSize2 = def([cell.fontSize, fontSize]);
				var textColor2 = def([cell.textColor, textColor]);
				var italic2 = def([cell.italic, false]);
				var bold2 = def([cell.bold, false]);
				var paddingH2 = def([cell.paddingH, cell.padding, paddingH]);
				var paddingV2 = def([cell.paddingV, cell.padding, paddingV]);
				var fracScale = def([cell.fracScale, fracScale]);
				var algPadding = def([cell.algPadding, algPadding]);
				var marginLeft = def([cell.marginLeft, object.marginLeft, 0]);
				var marginRight = def([cell.marginRight, object.marginRight, 0]);
				var lineSpacingFactor = def([cell.lineSpacingFactor, object.lineSpacingFactor, 1.2]);
				var lineSpacingStyle = def([cell.lineSpacingStyle, cell.spacingStyle, object.lineSpacingStyle, object.spacingStyle, "variable"]);
				
				var backgroundColor = typeof cell.color !== 'undefined' && cell.color !== 'none' ? cell.color : '#FFF';
				var box = clone(cell.box);
				
				if (!un(box) && typeof isInputColor !== 'undefined') box.color = isInputColor;

				cellTextMeasure[i][j] = text({
					ctx: ctx,
					rect: [leftPos + paddingH2, topPos + paddingV2, cellWidth - 2 * paddingH2, heights[i] - 2 * paddingV2],
					text: txt,
					box: box,
					sf: sf,
					align: align,
					font: font2,
					fontSize: fontSize2,
					color: textColor2,
					italic: italic2,
					bold: bold2,
					selected: hl,
					backgroundColor: backgroundColor,
					fracScale:fracScale,
					algPadding:algPadding,
					marginLeft:marginLeft,
					marginRight:marginRight,
					lineSpacingFactor:lineSpacingFactor,
					lineSpacingStyle:lineSpacingStyle
				});
			}

			leftPos += cellWidth;
		}
		topPos += heights[i];
	}

	// draw outer border
	if (outerBorder.show == true) {
		/*ctx.strokeStyle = outerBorder.color;
		ctx.lineWidth = outerBorder.width;
		if (un(ctx.setLineDash)) {
			ctx.setLineDash = function () {}
		}
		ctx.setLineDash(outerBorder.dash);
		ctx.beginPath();
		ctx.strokeRect(left, top, totalWidth, totalHeight);*/
		var color = outerBorder.color || '#000';
		var width = outerBorder.width || 4;
		var radius = outerBorder.radius || 0;
		var dash = outerBorder.dash || [0,0];
		roundedRect(ctx,left,top,totalWidth,totalHeight,radius,width,color,'none',dash)
	}

	ctx.restore();

	return {
		cellTextMeasure: cellTextMeasure,
		cell: cellDims,
		xPos: horizPos,
		yPos: vertPos
	};
}
function createScrollTable(object) {
	var left = object.left;
	var top = object.top;
	var z = object.z || object.zIndex || 2;

	var padding = 2; // padding for canvas
	var fullRect = [0, 0, 100, 100];
	var visRect = [left, top, 100, 100];
	var topRowRect = [left, top, 100, 100];
	var scrollRect = [left, top, 25, 10];

	var ctxVis = newctx({
			rect: visRect,
			z: z
		});
	var ctxTopRow = newctx({
			rect: topRowRect,
			z: z
		});
	var ctxInvis = newctx({
			rect: fullRect,
			vis: false
		});

	var topRowFreeze = boolean(object.topRowFreeze, true);

	var scrollMax = 10;
	var scrollDiff = 5;

	var scroll = createScroller({
			rect: scrollRect,
			max: scrollMax,
			zIndex: z,
			funcMove: function (value) {
				this.table.scrollPos = (value / this.table.scrollMax) * this.table.scrollDiff;
				this.table.redraw();
			},
			funcStop: function (value) {
				this.table.scrollPos = (value / this.table.scrollMax) * this.table.scrollDiff;
				this.table.redraw();
			}
		});

	if (!un(object.funcMove)) {
		ctxVis.canvas.style.pointerEvents = 'auto';
		ctxVis.data[6] = true;
		ctxVis.data[106] = true;
		addListenerMove(ctxVis.canvas, function (e) {
			updateMouse(e);
			var r = -1,
			c = -1;
			for (var x = 0; x < this.table.xPos.length - 1; x++) {
				if (mouse.x >= this.table.xPos[x] + this.table.ctxVis.data[100] && mouse.x <= this.table.xPos[x + 1] + this.table.ctxVis.data[100]) {
					c = x;
					break;
				}
			}
			if (this.table.topRowFreeze && mouse.y <= this.table.yPos[1] + this.table.ctxVis.data[101]) {
				r = 0;
			} else {
				for (var y = 0; y < this.table.yPos.length - 1; y++) {
					if (mouse.y + this.table.scrollPos >= this.table.yPos[y] + this.table.ctxVis.data[101] && mouse.y + this.table.scrollPos <= this.table.yPos[y + 1] + this.table.ctxVis.data[101]) {
						r = y;
						break;
					}
				}
			}
			this.table.funcMove(r, c);
		});
	} else {
		object.funcMove = function () {};
	}
	if (!un(object.funcClick)) {
		ctxVis.canvas.style.pointerEvents = 'auto';
		ctxVis.data[6] = true;
		ctxVis.data[106] = true;
		addListener(ctxVis.canvas, function (e) {
			updateMouse(e);
			var r = -1,
			c = -1,
			xProp = 0,
			yProp = 0;
			for (var x = 0; x < this.table.xPos.length - 1; x++) {
				if (mouse.x >= this.table.xPos[x] + this.table.ctxVis.data[100] && mouse.x <= this.table.xPos[x + 1] + this.table.ctxVis.data[100]) {
					c = x;
					xProp = (mouse.x - (this.table.xPos[x] + this.table.ctxVis.data[100])) / (this.table.xPos[x + 1] - this.table.xPos[x]);
					break;
				}
			}
			if (this.table.topRowFreeze && mouse.y <= this.table.yPos[1] + this.table.ctxVis.data[101]) {
				r = 0;
			} else {
				for (var y = 0; y < this.table.yPos.length - 1; y++) {
					if (mouse.y + this.table.scrollPos >= this.table.yPos[y] + this.table.ctxVis.data[101] && mouse.y + this.table.scrollPos <= this.table.yPos[y + 1] + this.table.ctxVis.data[101]) {
						r = y;
						yProp = (mouse.y - (this.table.yPos[y] + this.table.ctxVis.data[101])) / (this.table.yPos[y + 1] - this.table.yPos[y]);
						break;
					}
				}
			}
			this.table.funcClick(r, c, xProp, yProp);
		});
	} else {
		object.funcClick = function () {};
	}

	object.ctxVis = ctxVis;
	object.ctxInvis = ctxInvis;
	object.ctxTopRow = ctxTopRow;
	object.padding = padding;
	object.scroller = scroll;
	object.scrollPos = 0;
	object.scrollMax = scrollMax;
	object.scrollDiff = scrollDiff;
	object.topRowFreeze = topRowFreeze;
	object.redraw = function () {
		this.ctxVis.clearRect(0, 0, this.ctxVis.canvas.data[102], this.ctxVis.canvas.data[103]);
		this.ctxVis.drawImage(this.ctxInvis.canvas, 0, -this.scrollPos);
	};

	object.scroller.table = object;
	object.ctxVis.canvas.table = object;

	if (!un(object.additionalDraw)) {
		object.additionalDraw();
	}
	object.refreshCells = function () {
		var sf = def([this.sf, 1]);

		var left = this.left * sf;
		var top = this.top * sf;
		var cells = this.cells;
		var z = this.z || this.zIndex || 2;

		var minCellWidth = this.minCellWidth * sf || 80 * sf;
		var maxCellWidth = this.maxCellWidth * sf || Math.max(1200 * sf, this.minCellWidth * sf);
		var minCellHeight = this.minCellHeight * sf || 100 * sf;
		var minCellPadding = this.minCellPadding * sf || 7 * sf;
		var paddingH = minCellPadding;
		var paddingV = minCellPadding;
		if (typeof this.paddingH == 'number')
			paddingH = this.paddingH * sf;
		if (typeof this.paddingV == 'number')
			paddingV = this.paddingV * sf;
		var horizAlign = this.horizAlign || this.align || 'center';
		if (typeof this.text == 'this') {
			var font = this.text.font || 'Arial';
			var fontSize = this.text.size || 32;
			var textColor = this.text.color || '#000';
		} else {
			var font = 'Arial';
			var fontSize = 32;
			var textColor = '#000';
		}
		if (typeof this.alpha == 'number') {
			var alpha = this.alpha;
		} else {
			var alpha = 1;
		}
		var lineJoin = this.lineJoin || this.lineCap || 'round';
		var lineCap = this.lineCap || this.lineJoin || 'round';
		var outerBorder = {};
		if (typeof this.outerBorder == 'object') {
			outerBorder.show = boolean(this.outerBorder.show, true);
			outerBorder.width = this.outerBorder.width * sf || 4 * sf;
			if (typeof this.outerBorder.color == 'undefined') {
				outerBorder.color = colorA('#000', alpha);
			} else {
				outerBorder.color = colorA(this.outerBorder.color, alpha);
			}
			outerBorder.dash = this.outerBorder.dash || [];
		} else {
			outerBorder.show = true;
			outerBorder.width = 4 * sf;
			outerBorder.color = colorA('#000', alpha);
			outerBorder.dash = [];
		}
		outerBorder.dash = enlargeDash(outerBorder.dash, sf);
		var innerBorder = {};
		if (typeof this.innerBorder == 'object') {
			innerBorder.show = boolean(this.innerBorder.show, true);
			innerBorder.width = this.innerBorder.width * sf || 4 * sf;
			if (typeof this.innerBorder.color == 'undefined') {
				innerBorder.color = colorA('#000', alpha);
			} else {
				innerBorder.color = colorA(this.innerBorder.color, alpha);
			}
			innerBorder.dash = this.innerBorder.dash || [];
		} else {
			innerBorder.show = true;
			innerBorder.width = 4 * sf;
			innerBorder.color = colorA('#000', alpha);
			innerBorder.dash = [20, 15];
		}
		innerBorder.dash = enlargeDash(innerBorder.dash, sf);
		var tableAlignHoriz = this.tableAlignHoriz || 'left'; // is the whole table centred on [left,top]?
		var tableAlignVert = this.tableAlignVert || 'top';

		var numRows = cells.length;
		var numCols = 0;
		for (var i = 0; i < cells.length; i++) {
			numCols = Math.max(cells[i].length, numCols);
		}
		var cellHeights = [];
		for (var i = 0; i < numRows; i++) {
			cellHeights[i] = minCellHeight;
		}
		var cellWidths = [];
		for (var j = 0; j < numCols; j++) {
			cellWidths[j] = minCellWidth;
		}
		var totalWidth = 0;
		var totalHeight = 0;

		var cellHeights = [];
		for (var i = 0; i < numRows; i++) {
			cellHeights[i] = minCellHeight;
		}
		var cellWidths = [];
		for (var j = 0; j < numCols; j++) {
			cellWidths[j] = minCellWidth;
		}
		var totalWidth = 0;
		var totalHeight = 0;

		if (typeof hiddenCanvas == 'undefined') {
			var hiddenCanvas = document.createElement('canvas');
			hiddenCanvas.width = mainCanvasWidth * sf;
			hiddenCanvas.height = mainCanvasHeight * sf;
			hiddenCanvas.ctx = hiddenCanvas.getContext('2d');
		}

		for (var r = 0; r < cells.length; r++) {
			var maxHeight = minCellHeight;
			for (var c = 0; c < cells[r].length; c++) {
				if (typeof cells[r][c] == 'this') {
					if (typeof cells[r][c].text !== 'this') {
						cells[r][c].text = [];
					} else {
						cells[r][c].text = clone(cells[r][c].text);
					}
					if (typeof cells[r][c].color !== 'string')
						cells[r][c].color = 'none';
					if (typeof cells[r][c].minWidth !== 'number')
						cells[r][c].minWidth = 0;
					if (typeof cells[r][c].minHeight !== 'number')
						cells[r][c].minHeight = 0;
					var font2 = font;
					var fontSize2 = fontSize;
					var textColor2 = textColor;
					if (!un(cells[r][c].font))
						font2 = cells[r][c].font;
					if (!un(cells[r][c].fontSize))
						fontSize2 = cells[r][c].fontSize;
					if (!un(cells[r][c].textColor))
						textColor2 = cells[r][c].textColor;
					if (un(cells[r][c].styled)) {
						cells[r][c].text.unshift('<<font:' + font2 + '>><<fontSize:' + fontSize2 + '>><<color:' + textColor2 + '>>');
						cells[r][c].styled = true;
					}
					//var dims = drawMathsText(ctx,cells[r][c].text,fontSize,0,0,false,[],horizAlign,'middle',text.color,'measure');
					//maxHeight = Math.max(dims[1]+2*minCellPadding,cells[r][c].minHeight,maxHeight);
					//cellWidths[c] = Math.max(dims[0]+2*minCellPadding,cells[r][c].minWidth,cellWidths[c]);

					var cellText = text({
							ctx: hiddenCanvas.ctx,
							left: 0,
							top: 0,
							width: maxCellWidth,
							textArray: cells[r][c].text,
							minTightWidth: 5,
							minTightHeight: 5,
							box: cells[r][c].box,
							sf: sf
						});
					maxHeight = Math.max(cellText.tightRect[3] + 2 * paddingV, cells[r][c].minHeight * sf, maxHeight);
					cellWidths[c] = Math.max(cellText.tightRect[2] + 3 * paddingH, cells[r][c].minWidth * sf, cellWidths[c]);
				}
			}
			cellHeights[r] = Math.max(maxHeight, cellHeights[r]);
			totalHeight += cellHeights[r];
		}
		for (var j = 0; j < cellWidths.length; j++) {
			totalWidth += cellWidths[j];
		}

		if (tableAlignHoriz == 'center') {
			left = left - totalWidth / 2;
		} else if (tableAlignHoriz == 'right') {
			left = left - totalWidth;
		}

		if (tableAlignVert == 'middle') {
			top = top - totalHeight / 2;
		} else if (tableAlignVert == 'bottom') {
			top = top - totalHeight;
		}

		var maxHeight = this.maxHeight;
		var padding = def([this.padding, this.outerBorder.width / 2]); // padding for canvas
		if (totalHeight + 2 * padding < maxHeight) {
			var hasScroll = true;
		} else {
			var hasScroll = false;
		}
		var fullRect = [0, 0, totalWidth + 2 * padding, totalHeight + 2 * padding];
		var visRect = [left, top, totalWidth + 2 * padding, maxHeight];
		var topRowRect = [left, top, totalWidth + 2 * padding, maxHeight];
		var scrollRect = [left + totalWidth + 4 * padding, top, 25, maxHeight];

		var ctxInvis = this.ctxInvis;
		var ctxVis = this.ctxVis;
		var ctxTopRow = this.ctxTopRow;
		ctxInvis.data[102] = fullRect[2];
		ctxInvis.canvas.width = fullRect[2];
		ctxInvis.data[103] = fullRect[3];
		ctxInvis.canvas.height = fullRect[3];
		ctxVis.data[100] = visRect[0];
		ctxVis.data[101] = visRect[1];
		ctxVis.data[102] = visRect[2];
		ctxVis.canvas.width = visRect[2];
		ctxVis.data[103] = visRect[3];
		ctxVis.canvas.height = visRect[3];
		ctxTopRow.data[100] = topRowRect[0];
		ctxTopRow.data[101] = topRowRect[1];
		ctxTopRow.data[102] = topRowRect[2];
		ctxTopRow.canvas.width = topRowRect[2];
		ctxTopRow.data[103] = topRowRect[3];
		ctxTopRow.canvas.height = topRowRect[3];
		resizeCanvas(ctxInvis.canvas, 0, 0, fullRect[2], fullRect[3]);
		resizeCanvas(ctxVis.canvas, visRect[0], visRect[1], visRect[2], visRect[3]);
		resizeCanvas(ctxTopRow.canvas, topRowRect[0], topRowRect[1], topRowRect[2], topRowRect[3]);
		ctxInvis.clear();
		ctxVis.clear();
		ctxTopRow.clear();

		var left = padding;
		var top = padding;

		ctxInvis.save();
		ctxInvis.lineCap = lineCap;
		ctxInvis.lineJoin = lineJoin;

		var cellDims = [];

		var horizPos = [left];
		for (var i = 0; i < cellWidths.length; i++) {
			horizPos.push(horizPos[horizPos.length - 1] + cellWidths[i])
		}

		var vertPos = [top];
		for (var i = 0; i < cellHeights.length; i++) {
			vertPos.push(vertPos[vertPos.length - 1] + cellHeights[i])
		}

		// write text to each cell
		var topPos = top;
		for (var i = 0; i < cells.length; i++) {
			var leftPos = left;
			cellDims[i] = [];
			for (var j = 0; j < cells[i].length; j++) {
				cellDims[i][j] = {
					left: leftPos + 2,
					top: topPos + 1,
					width: cellWidths[j] - 9,
					height: cellHeights[i] - 8,
					border: false,
					offset: [-40, 0.5 * (cellHeights[i] - 8) - 20],
					fontSize: fontSize,
					leftPoint: paddingH,
					textColor: textColor,
					textAlign: horizAlign,
					fontSize: fontSize
				};
				if (cells[i][j].highlight == true) {
					if (typeof cells[i][j].color !== 'undefined' && cells[i][j].color !== 'none') {
						ctxInvis.fillStyle = colorA(invertColor(cells[i][j].color), alpha);
					} else {
						ctxInvis.fillStyle = colorA(invertColor('#FFC'), alpha);
					}
					ctxInvis.fillRect(leftPos, topPos, cellWidths[j], cellHeights[i]);
				} else if (typeof cells[i][j].color !== 'undefined' && cells[i][j].color !== 'none') {
					ctxInvis.fillStyle = colorA(cells[i][j].color, alpha);
					ctxInvis.fillRect(leftPos, topPos, cellWidths[j], cellHeights[i]);
				}
				var align = horizAlign;
				if (!un(cells[i][j].align))
					align = cells[i][j].align;
				var cellText = text({
						ctx: ctxInvis,
						left: leftPos + paddingH,
						top: topPos + paddingV,
						width: cellWidths[j] - 2 * paddingH,
						height: cellHeights[i] - 2 * paddingV,
						textArray: cells[i][j].text,
						textAlign: align,
						vertAlign: 'middle',
						padding: 0.001,
						box: cells[i][j].box,
						sf: sf
					});
				/*console.log(cellText.tightRect[2],cellText.tightRect[3],{
				ctx:ctxInvis,
				left:leftPos+paddingH,
				top:topPos+paddingV,
				width:cellWidths[j]-2*paddingH,
				height:cellHeights[i]-2*paddingV,
				textArray:cells[i][j].text,
				textAlign:align,
				vertAlign:'middle',
				padding:0.001,
				box:cells[i][j].box,
				sf:sf
				});*/
				leftPos += cellWidths[j];
			}
			topPos += cellHeights[i];
		}

		// draw inner border
		if (innerBorder.show == true) {
			ctxInvis.strokeStyle = innerBorder.color;
			ctxInvis.lineWidth = innerBorder.width;
			if (!ctxInvis.setLineDash) {
				ctxInvis.setLineDash = function () {}
			}
			ctxInvis.setLineDash(innerBorder.dash);
			var leftPos = left;
			for (var i = 0; i < cellWidths.length - 1; i++) {
				leftPos += cellWidths[i];
				ctxInvis.beginPath();
				ctxInvis.moveTo(leftPos, top);
				ctxInvis.lineTo(leftPos, top + totalHeight);
				ctxInvis.stroke();
			}
			var topPos = top;
			for (var i = 0; i < cellHeights.length - 1; i++) {
				topPos += cellHeights[i];
				ctxInvis.beginPath();
				ctxInvis.moveTo(left, topPos);
				ctxInvis.lineTo(left + totalWidth, topPos);
				ctxInvis.stroke();
			}
		}

		// draw outer border
		if (outerBorder.show == true) {
			ctxInvis.strokeStyle = outerBorder.color;
			ctxInvis.lineWidth = outerBorder.width;
			if (!ctxInvis.setLineDash) {
				ctxInvis.setLineDash = function () {}
			}
			ctxInvis.setLineDash(outerBorder.dash);
			ctxInvis.beginPath();
			ctxInvis.strokeRect(left, top, totalWidth, totalHeight);
		}

		ctxInvis.restore();

		this.cell = cellDims;
		this.xPos = horizPos;
		this.yPos = vertPos;

		if (!un(this.additionalDraw)) {
			this.additionalDraw();
		}

		//this.scroller.max = totalHeight/maxHeight;
		//this.scroller.rect = scrollRect;
		this.scroller.reposition(totalHeight / maxHeight, scrollRect);
		setScrollerValue(this.scroller, 0, true);
		this.scrollPos = 0;
		this.scrollMax = scrollMax;
		this.scrollDiff = totalHeight - maxHeight + 2 * padding;

		this.redraw();

		if (totalHeight + 2 * padding > this.maxHeight) {
			this.hasScroll = true;
			//this.scrollPos = 0;
			//this.scrollMax = totalHeight/maxHeight;
			//this.scrollDiff = totalHeight-maxHeight+2*padding;
			//this.scroller.max = totalHeight/maxHeight;
			//this.scroller.value = 0;
			//this.scroller = updateScrollerDims(this.scroller);
			showScroller(this.scroller);
			if (this.topRowFreeze) {
				showObj(ctxTopRow.canvas);
				ctxTopRow.data[3] = ctxTopRow.data[103] = padding + vertPos[1];
				ctxTopRow.canvas.width = ctxTopRow.data[102];
				ctxTopRow.canvas.height = ctxTopRow.data[103];
				resize();
				ctxTopRow.drawImage(ctxInvis.canvas, 0, 0);
			} else {
				hideObj(ctxTopRow.canvas);
			}
		} else {
			this.hasScroll = false;
			hideScroller(this.scroller);
			hideObj(ctxTopRow.canvas);
		}
	}
	object.refreshCells();

	object.move = function (left, top) {
		var relLeft = this.scroller.rect[0] - this.ctxVis.canvas.data[100];
		this.left = left;
		this.top = top;
		this.ctxVis.canvas.data[100] = left;
		this.ctxVis.canvas.data[101] = top;
		resizeCanvas3(this.ctxVis.canvas);
		this.ctxTopRow.canvas.data[100] = left;
		this.ctxTopRow.canvas.data[101] = top;
		resizeCanvas3(this.ctxTopRow.canvas);
		this.scroller.rect[0] = left + relLeft;
		this.scroller.rect[1] = top;
		this.scroller.reposition();
	}

	return object;
}
function drawScrollTable(object) {
	/* EXAMPLE USAGE:
	var j0001table1 = drawScrollTable({
	left:100,
	top:150,
	minCellWidth:80,
	minCellHeight:50,
	horizAlign:'center',
	text:{font:'Arial',size:32,color:'#000'},
	outerBorder:{show:true,width:4,color:'#000'},
	innerBorder:{show:true,width:2,color:'#666'},
	cells:[
	[    // row 0{text:['<<fontSize:36>><<font:algebra>>x'],color:'#CCF',minWidth:100,minHeight:70},{text:['<<fontSize:36>><<font:algebra>>y'],color:'#CCF',minWidth:100,minHeight:70},{text:['<<fontSize:36>><<font:algebra>><<color:#F00>>z'],color:'#CCF',minWidth:100,minHeight:70},
	], [ // row 1{},{text:['2']},{text:['<<color:#F00>>3']},
	], [ // row 2{text:['4']},{},{text:['<<color:#F00>>6']},
	],
	],
	maxHeight:300,
	moveFunc:function(r,c) {console.log(r,c)),
	clickFunc:function(r,c) {console.log(r,c)),
	padding:2 // def: outerBorder.width/2
	});
	 */

	if (typeof object.sf !== 'undefined') {
		var sf = object.sf;
	} else {
		var sf = 1;
	}

	var left = object.left * sf;
	var top = object.top * sf;
	var cells = object.cells;
	var z = object.z || object.zIndex || 2;

	var minCellWidth = object.minCellWidth * sf || 80 * sf;
	var maxCellWidth = object.maxCellWidth * sf || Math.max(1200 * sf, object.minCellWidth * sf);
	var minCellHeight = object.minCellHeight * sf || 100 * sf;
	var minCellPadding = object.minCellPadding * sf || 7 * sf;
	var paddingH = minCellPadding;
	var paddingV = minCellPadding;
	if (typeof object.paddingH == 'number')
		paddingH = object.paddingH * sf;
	if (typeof object.paddingV == 'number')
		paddingV = object.paddingV * sf;
	var horizAlign = object.horizAlign || object.align || 'center';
	if (typeof object.text == 'object') {
		var font = object.text.font || 'Arial';
		var fontSize = object.text.size || 32;
		var textColor = object.text.color || '#000';
	} else {
		var font = 'Arial';
		var fontSize = 32;
		var textColor = '#000';
	}
	if (typeof object.alpha == 'number') {
		var alpha = object.alpha;
	} else {
		var alpha = 1;
	}
	var lineJoin = object.lineJoin || object.lineCap || 'round';
	var lineCap = object.lineCap || object.lineJoin || 'round';
	var outerBorder = {};
	if (typeof object.outerBorder == 'object') {
		outerBorder.show = boolean(object.outerBorder.show, true);
		outerBorder.width = object.outerBorder.width * sf || 4 * sf;
		if (typeof object.outerBorder.color == 'undefined') {
			outerBorder.color = colorA('#000', alpha);
		} else {
			outerBorder.color = colorA(object.outerBorder.color, alpha);
		}
		outerBorder.dash = object.outerBorder.dash || [];
	} else {
		outerBorder.show = true;
		outerBorder.width = 4 * sf;
		outerBorder.color = colorA('#000', alpha);
		outerBorder.dash = [];
	}
	outerBorder.dash = enlargeDash(outerBorder.dash, sf);
	var innerBorder = {};
	if (typeof object.innerBorder == 'object') {
		innerBorder.show = boolean(object.innerBorder.show, true);
		innerBorder.width = object.innerBorder.width * sf || 4 * sf;
		if (typeof object.innerBorder.color == 'undefined') {
			innerBorder.color = colorA('#000', alpha);
		} else {
			innerBorder.color = colorA(object.innerBorder.color, alpha);
		}
		innerBorder.dash = object.innerBorder.dash || [];
	} else {
		innerBorder.show = true;
		innerBorder.width = 4 * sf;
		innerBorder.color = colorA('#000', alpha);
		innerBorder.dash = [20, 15];
	}
	innerBorder.dash = enlargeDash(innerBorder.dash, sf);
	var tableAlignHoriz = object.tableAlignHoriz || 'left'; // is the whole table centred on [left,top]?
	var tableAlignVert = object.tableAlignVert || 'top';

	var numRows = cells.length;
	var numCols = 0;
	for (var i = 0; i < cells.length; i++) {
		numCols = Math.max(cells[i].length, numCols);
	}
	var cellHeights = [];
	for (var i = 0; i < numRows; i++) {
		cellHeights[i] = minCellHeight;
	}
	var cellWidths = [];
	for (var j = 0; j < numCols; j++) {
		cellWidths[j] = minCellWidth;
	}
	var totalWidth = 0;
	var totalHeight = 0;
	//calcTableDims(object);

	if (typeof hiddenCanvas == 'undefined') {
		var hiddenCanvas = document.createElement('canvas');
		hiddenCanvas.width = mainCanvasWidth * sf;
		hiddenCanvas.height = mainCanvasHeight * sf;
		hiddenCanvas.ctx = hiddenCanvas.getContext('2d');
	}

	for (var r = 0; r < cells.length; r++) {
		var maxHeight = minCellHeight;
		for (var c = 0; c < cells[r].length; c++) {
			if (typeof cells[r][c] == 'object') {
				if (typeof cells[r][c].text !== 'object') {
					cells[r][c].text = [];
				} else {
					cells[r][c].text = clone(cells[r][c].text);
				}
				if (typeof cells[r][c].color !== 'string')
					cells[r][c].color = 'none';
				if (typeof cells[r][c].minWidth !== 'number')
					cells[r][c].minWidth = 0;
				if (typeof cells[r][c].minHeight !== 'number')
					cells[r][c].minHeight = 0;
				var font2 = font;
				var fontSize2 = fontSize;
				var textColor2 = textColor;
				if (!un(cells[r][c].font))
					font2 = cells[r][c].font;
				if (!un(cells[r][c].fontSize))
					fontSize2 = cells[r][c].fontSize;
				if (!un(cells[r][c].textColor))
					textColor2 = cells[r][c].textColor;
				if (un(cells[r][c].styled)) {
					cells[r][c].text.unshift('<<font:' + font2 + '>><<fontSize:' + fontSize2 + '>><<color:' + textColor2 + '>>');
					cells[r][c].styled = true;
				}
				//var dims = drawMathsText(ctx,cells[r][c].text,fontSize,0,0,false,[],horizAlign,'middle',text.color,'measure');
				//maxHeight = Math.max(dims[1]+2*minCellPadding,cells[r][c].minHeight,maxHeight);
				//cellWidths[c] = Math.max(dims[0]+2*minCellPadding,cells[r][c].minWidth,cellWidths[c]);

				var cellText = text({
						ctx: hiddenCanvas.ctx,
						left: 0,
						top: 0,
						width: maxCellWidth,
						textArray: cells[r][c].text,
						minTightWidth: 5,
						minTightHeight: 5,
						box: cells[r][c].box,
						sf: sf
					});
				maxHeight = Math.max(cellText.tightRect[3] + 2 * paddingV, cells[r][c].minHeight * sf, maxHeight);
				cellWidths[c] = Math.max(cellText.tightRect[2] + 3 * paddingH, cells[r][c].minWidth * sf, cellWidths[c]);
			}
		}
		cellHeights[r] = Math.max(maxHeight, cellHeights[r]);
		totalHeight += cellHeights[r];
	}
	for (var j = 0; j < cellWidths.length; j++) {
		totalWidth += cellWidths[j];
	}

	if (tableAlignHoriz == 'center') {
		left = left - totalWidth / 2;
	} else if (tableAlignHoriz == 'right') {
		left = left - totalWidth;
	}

	if (tableAlignVert == 'middle') {
		top = top - totalHeight / 2;
	} else if (tableAlignVert == 'bottom') {
		top = top - totalHeight;
	}

	// now the table dims are known, create canvases
	var maxHeight = object.maxHeight;
	if (totalHeight + 2 * padding < maxHeight) {
		var hasScroll = true;
	} else {
		var hasScroll = false;
	}
	var padding = def([object.padding, object.outerBorder.width / 2]); // padding for canvas
	var fullRect = [0, 0, totalWidth + 2 * padding, totalHeight + 2 * padding];
	var visRect = [left, top, totalWidth + 2 * padding, maxHeight];
	var topRowRect = [left, top, totalWidth + 2 * padding, maxHeight];
	var scrollRect = [left + totalWidth + 4 * padding, top, 25, maxHeight];

	var ctxVis = newctx({
			rect: visRect,
			z: z
		});
	var ctxTopRow = newctx({
			rect: topRowRect,
			z: z
		});
	var ctxInvis = newctx({
			rect: fullRect,
			vis: false
		});

	var left = padding;
	var top = padding;

	ctxInvis.save();
	ctxInvis.lineCap = lineCap;
	ctxInvis.lineJoin = lineJoin;

	var cellDims = [];

	var horizPos = [left];
	for (var i = 0; i < cellWidths.length; i++) {
		horizPos.push(horizPos[horizPos.length - 1] + cellWidths[i])
	}

	var vertPos = [top];
	for (var i = 0; i < cellHeights.length; i++) {
		vertPos.push(vertPos[vertPos.length - 1] + cellHeights[i])
	}

	// write text to each cell
	var topPos = top;
	for (var i = 0; i < cells.length; i++) {
		var leftPos = left;
		cellDims[i] = [];
		for (var j = 0; j < cells[i].length; j++) {
			cellDims[i][j] = {
				left: leftPos + 2,
				top: topPos + 1,
				width: cellWidths[j] - 9,
				height: cellHeights[i] - 8,
				border: false,
				offset: [-40, 0.5 * (cellHeights[i] - 8) - 20],
				fontSize: fontSize,
				leftPoint: paddingH,
				textColor: textColor,
				textAlign: horizAlign,
				fontSize: fontSize
			};
			if (cells[i][j].highlight == true) {
				if (typeof cells[i][j].color == 'undefined' || cells[i][j].color !== 'none') {
					ctxInvis.fillStyle = colorA(invertColor(cells[i][j].color), alpha);
				} else {
					ctxInvis.fillStyle = colorA(invertColor('#FFC'), alpha);
				}
				ctxInvis.fillRect(leftPos, topPos, cellWidths[j], cellHeights[i]);
			} else if (typeof cells[i][j].color == 'undefined' || cells[i][j].color !== 'none') {
				ctxInvis.fillStyle = colorA(cells[i][j].color, alpha);
				ctxInvis.fillRect(leftPos, topPos, cellWidths[j], cellHeights[i]);
			}
			var align = horizAlign;
			if (!un(cells[i][j].align))
				align = cells[i][j].align;
			var cellText = text({
					ctx: ctxInvis,
					left: leftPos + paddingH,
					top: topPos + paddingV,
					width: cellWidths[j] - 2 * paddingH,
					height: cellHeights[i] - 2 * paddingV,
					textArray: cells[i][j].text,
					textAlign: align,
					vertAlign: 'middle',
					padding: 0.001,
					box: cells[i][j].box,
					sf: sf
				});
			//console.log(cellText.tightRect[2],cellText.tightRect[3]);
			leftPos += cellWidths[j];
		}
		topPos += cellHeights[i];
	}

	// draw inner border
	if (innerBorder.show == true) {
		ctxInvis.strokeStyle = innerBorder.color;
		ctxInvis.lineWidth = innerBorder.width;
		if (!ctxInvis.setLineDash) {
			ctxInvis.setLineDash = function () {}
		}
		ctxInvis.setLineDash(innerBorder.dash);
		var leftPos = left;
		for (var i = 0; i < cellWidths.length - 1; i++) {
			leftPos += cellWidths[i];
			ctxInvis.beginPath();
			ctxInvis.moveTo(leftPos, top);
			ctxInvis.lineTo(leftPos, top + totalHeight);
			ctxInvis.stroke();
		}
		var topPos = top;
		for (var i = 0; i < cellHeights.length - 1; i++) {
			topPos += cellHeights[i];
			ctxInvis.beginPath();
			ctxInvis.moveTo(left, topPos);
			ctxInvis.lineTo(left + totalWidth, topPos);
			ctxInvis.stroke();
		}
	}

	// draw outer border
	if (outerBorder.show == true) {
		ctxInvis.strokeStyle = outerBorder.color;
		ctxInvis.lineWidth = outerBorder.width;
		if (!ctxInvis.setLineDash) {
			ctxInvis.setLineDash = function () {}
		}
		ctxInvis.setLineDash(outerBorder.dash);
		ctxInvis.beginPath();
		ctxInvis.strokeRect(left, top, totalWidth, totalHeight);
	}

	ctxInvis.restore();

	var topRowFreeze = boolean(object.topRowFreeze, true);

	var scrollMax = totalHeight / maxHeight;
	var scrollDiff = totalHeight - maxHeight + 2 * padding;
	//console.log(scrollMax,scrollDiff);

	var scroll = createScroller({
			rect: scrollRect,
			max: scrollMax,
			zIndex: z,
			funcMove: function (value) {
				this.table.scrollPos = (value / this.table.scrollMax) * this.table.scrollDiff;
				this.table.redraw();
			},
			funcStop: function (value) {
				this.table.scrollPos = (value / this.table.scrollMax) * this.table.scrollDiff;
				this.table.redraw();
			}
		});

	if (!un(object.funcMove)) {
		ctxVis.canvas.style.pointerEvents = 'auto';
		ctxVis.data[6] = true;
		ctxVis.data[106] = true;
		addListenerMove(ctxVis.canvas, function (e) {
			updateMouse(e);
			var r = -1,
			c = -1;
			for (var x = 0; x < this.table.xPos.length - 1; x++) {
				if (mouse.x >= this.table.xPos[x] + this.table.ctxVis.data[100] && mouse.x <= this.table.xPos[x + 1] + this.table.ctxVis.data[100]) {
					c = x;
					break;
				}
			}
			if (this.table.topRowFreeze && mouse.y <= this.table.yPos[1] + this.table.ctxVis.data[101]) {
				r = 0;
			} else {
				for (var y = 0; y < this.table.yPos.length - 1; y++) {
					if (mouse.y + this.table.scrollPos >= this.table.yPos[y] + this.table.ctxVis.data[101] && mouse.y + this.table.scrollPos <= this.table.yPos[y + 1] + this.table.ctxVis.data[101]) {
						r = y;
						break;
					}
				}
			}
			this.table.funcMove(r, c);
		});
	} else {
		object.funcMove = function () {};
	}
	if (!un(object.funcClick)) {
		ctxVis.canvas.style.pointerEvents = 'auto';
		ctxVis.data[6] = true;
		ctxVis.data[106] = true;
		addListener(ctxVis.canvas, function (e) {
			updateMouse(e);
			var r = -1,
			c = -1,
			xProp = 0,
			yProp = 0;
			for (var x = 0; x < this.table.xPos.length - 1; x++) {
				if (mouse.x >= this.table.xPos[x] + this.table.ctxVis.data[100] && mouse.x <= this.table.xPos[x + 1] + this.table.ctxVis.data[100]) {
					c = x;
					xProp = (mouse.x - (this.table.xPos[x] + this.table.ctxVis.data[100])) / (this.table.xPos[x + 1] - this.table.xPos[x]);
					break;
				}
			}
			if (this.table.topRowFreeze && mouse.y <= this.table.yPos[1] + this.table.ctxVis.data[101]) {
				r = 0;
			} else {
				for (var y = 0; y < this.table.yPos.length - 1; y++) {
					if (mouse.y + this.table.scrollPos >= this.table.yPos[y] + this.table.ctxVis.data[101] && mouse.y + this.table.scrollPos <= this.table.yPos[y + 1] + this.table.ctxVis.data[101]) {
						r = y;
						yProp = (mouse.y - (this.table.yPos[y] + this.table.ctxVis.data[101])) / (this.table.yPos[y + 1] - this.table.yPos[y]);
						break;
					}
				}
			}
			this.table.funcClick(r, c, xProp, yProp);
		});
	} else {
		object.funcClick = function () {};
	}

	var returnObj = clone(object);

	returnObj.ctxVis = ctxVis;
	returnObj.ctxInvis = ctxInvis;
	returnObj.ctxTopRow = ctxTopRow;
	returnObj.cell = cellDims;
	returnObj.xPos = horizPos;
	returnObj.yPos = vertPos;
	returnObj.padding = padding;
	returnObj.hasScroll = hasScroll;
	returnObj.scroller = scroll;
	returnObj.scrollPos = 0;
	returnObj.scrollMax = scrollMax;
	returnObj.scrollDiff = scrollDiff;
	returnObj.topRowFreeze = topRowFreeze;
	returnObj.redraw = function () {
		this.ctxVis.clearRect(0, 0, this.ctxVis.canvas.data[102], this.ctxVis.canvas.data[103]);
		this.ctxVis.drawImage(this.ctxInvis.canvas, 0, -this.scrollPos);
	};

	returnObj.scroller.table = returnObj;
	returnObj.ctxVis.canvas.table = returnObj;

	if (!un(returnObj.additionalDraw)) {
		returnObj.additionalDraw();
	}

	returnObj.redraw();

	if (topRowFreeze) {
		ctxTopRow.data[3] = ctxTopRow.data[103] = padding + vertPos[1];
		ctxTopRow.canvas.width = ctxTopRow.data[102];
		ctxTopRow.canvas.height = ctxTopRow.data[103];
		resizeCanvas2(ctxTopRow.canvas, ctxTopRow.data[102], ctxTopRow.data[103]);
		resize();
		ctxTopRow.drawImage(ctxInvis.canvas, 0, 0);
	} else {
		hideObj(ctxTopRow.canvas);
	}

	return returnObj;
}
function updateScrollTable(object) { // update previously drawn scrollTable with changed cell data
	var sf = def([object.sf, 1]);

	var left = object.left * sf;
	var top = object.top * sf;
	var cells = object.cells;
	var z = object.z || object.zIndex || 2;

	///console.log(object);

	var minCellWidth = object.minCellWidth * sf || 80 * sf;
	var maxCellWidth = object.maxCellWidth * sf || Math.max(1200 * sf, object.minCellWidth * sf);
	var minCellHeight = object.minCellHeight * sf || 100 * sf;
	var minCellPadding = object.minCellPadding * sf || 7 * sf;
	var paddingH = minCellPadding;
	var paddingV = minCellPadding;
	if (typeof object.paddingH == 'number')
		paddingH = object.paddingH * sf;
	if (typeof object.paddingV == 'number')
		paddingV = object.paddingV * sf;
	var horizAlign = object.horizAlign || object.align || 'center';
	if (typeof object.text == 'object') {
		var font = object.text.font || 'Arial';
		var fontSize = object.text.size || 32;
		var textColor = object.text.color || '#000';
	} else {
		var font = 'Arial';
		var fontSize = 32;
		var textColor = '#000';
	}
	if (typeof object.alpha == 'number') {
		var alpha = object.alpha;
	} else {
		var alpha = 1;
	}
	var lineJoin = object.lineJoin || object.lineCap || 'round';
	var lineCap = object.lineCap || object.lineJoin || 'round';
	var outerBorder = {};
	if (typeof object.outerBorder == 'object') {
		outerBorder.show = boolean(object.outerBorder.show, true);
		outerBorder.width = object.outerBorder.width * sf || 4 * sf;
		if (typeof object.outerBorder.color == 'undefined') {
			outerBorder.color = colorA('#000', alpha);
		} else {
			outerBorder.color = colorA(object.outerBorder.color, alpha);
		}
		outerBorder.dash = object.outerBorder.dash || [];
	} else {
		outerBorder.show = true;
		outerBorder.width = 4 * sf;
		outerBorder.color = colorA('#000', alpha);
		outerBorder.dash = [];
	}
	outerBorder.dash = enlargeDash(outerBorder.dash, sf);
	var innerBorder = {};
	if (typeof object.innerBorder == 'object') {
		innerBorder.show = boolean(object.innerBorder.show, true);
		innerBorder.width = object.innerBorder.width * sf || 4 * sf;
		if (typeof object.innerBorder.color == 'undefined') {
			innerBorder.color = colorA('#000', alpha);
		} else {
			innerBorder.color = colorA(object.innerBorder.color, alpha);
		}
		innerBorder.dash = object.innerBorder.dash || [];
	} else {
		innerBorder.show = true;
		innerBorder.width = 4 * sf;
		innerBorder.color = colorA('#000', alpha);
		innerBorder.dash = [20, 15];
	}
	innerBorder.dash = enlargeDash(innerBorder.dash, sf);
	var tableAlignHoriz = object.tableAlignHoriz || 'left'; // is the whole table centred on [left,top]?
	var tableAlignVert = object.tableAlignVert || 'top';

	var numRows = cells.length;
	var numCols = 0;
	for (var i = 0; i < cells.length; i++) {
		numCols = Math.max(cells[i].length, numCols);
	}
	var cellHeights = [];
	for (var i = 0; i < numRows; i++) {
		cellHeights[i] = minCellHeight;
	}
	var cellWidths = [];
	for (var j = 0; j < numCols; j++) {
		cellWidths[j] = minCellWidth;
	}
	var totalWidth = 0;
	var totalHeight = 0;

	var cellHeights = [];
	for (var i = 0; i < numRows; i++) {
		cellHeights[i] = minCellHeight;
	}
	var cellWidths = [];
	for (var j = 0; j < numCols; j++) {
		cellWidths[j] = minCellWidth;
	}
	var totalWidth = 0;
	var totalHeight = 0;

	if (typeof hiddenCanvas == 'undefined') {
		var hiddenCanvas = document.createElement('canvas');
		hiddenCanvas.width = mainCanvasWidth * sf;
		hiddenCanvas.height = mainCanvasHeight * sf;
		hiddenCanvas.ctx = hiddenCanvas.getContext('2d');
	}

	for (var r = 0; r < cells.length; r++) {
		var maxHeight = minCellHeight;
		for (var c = 0; c < cells[r].length; c++) {
			if (typeof cells[r][c] == 'object') {
				if (typeof cells[r][c].text !== 'object') {
					cells[r][c].text = [];
				} else {
					cells[r][c].text = clone(cells[r][c].text);
				}
				if (typeof cells[r][c].color !== 'string')
					cells[r][c].color = 'none';
				if (typeof cells[r][c].minWidth !== 'number')
					cells[r][c].minWidth = 0;
				if (typeof cells[r][c].minHeight !== 'number')
					cells[r][c].minHeight = 0;
				var font2 = font;
				var fontSize2 = fontSize;
				var textColor2 = textColor;
				if (!un(cells[r][c].font))
					font2 = cells[r][c].font;
				if (!un(cells[r][c].fontSize))
					fontSize2 = cells[r][c].fontSize;
				if (!un(cells[r][c].textColor))
					textColor2 = cells[r][c].textColor;
				if (un(cells[r][c].styled)) {
					cells[r][c].text.unshift('<<font:' + font2 + '>><<fontSize:' + fontSize2 + '>><<color:' + textColor2 + '>>');
					cells[r][c].styled = true;
				}
				//var dims = drawMathsText(ctx,cells[r][c].text,fontSize,0,0,false,[],horizAlign,'middle',text.color,'measure');
				//maxHeight = Math.max(dims[1]+2*minCellPadding,cells[r][c].minHeight,maxHeight);
				//cellWidths[c] = Math.max(dims[0]+2*minCellPadding,cells[r][c].minWidth,cellWidths[c]);

				var cellText = text({
						ctx: hiddenCanvas.ctx,
						left: 0,
						top: 0,
						width: maxCellWidth,
						textArray: cells[r][c].text,
						minTightWidth: 5,
						minTightHeight: 5,
						box: cells[r][c].box,
						sf: sf
					});
				maxHeight = Math.max(cellText.tightRect[3] + 2 * paddingV, cells[r][c].minHeight * sf, maxHeight);
				cellWidths[c] = Math.max(cellText.tightRect[2] + 3 * paddingH, cells[r][c].minWidth * sf, cellWidths[c]);
			}
		}
		cellHeights[r] = Math.max(maxHeight, cellHeights[r]);
		totalHeight += cellHeights[r];
	}
	for (var j = 0; j < cellWidths.length; j++) {
		totalWidth += cellWidths[j];
	}

	if (tableAlignHoriz == 'center') {
		left = left - totalWidth / 2;
	} else if (tableAlignHoriz == 'right') {
		left = left - totalWidth;
	}

	if (tableAlignVert == 'middle') {
		top = top - totalHeight / 2;
	} else if (tableAlignVert == 'bottom') {
		top = top - totalHeight;
	}

	//update canvases
	var maxHeight = object.maxHeight;
	var padding = def([object.padding, object.outerBorder.width / 2]); // padding for canvas
	var fullRect = [0, 0, totalWidth + 2 * padding, totalHeight + 2 * padding];
	var visRect = [left, top, totalWidth + 2 * padding, maxHeight];
	var topRowRect = [left, top, totalWidth + 2 * padding, maxHeight];
	var scrollRect = [left + totalWidth + 4 * padding, top, 25, maxHeight];

	var ctxInvis = object.ctxInvis;
	var ctxVis = object.ctxVis;
	var ctxTopRow = object.ctxTopRow;
	ctxInvis.clear();
	ctxVis.clear();
	ctxTopRow.clear();
	ctxInvis.data[102] = fullRect[2];
	ctxInvis.data[103] = fullRect[3];
	ctxInvis.canvas.width = fullRect[2];
	ctxInvis.canvas.height = fullRect[3];
	ctxVis.data[100] = visRect[0];
	ctxVis.data[101] = visRect[1];
	ctxVis.data[102] = visRect[2];
	ctxVis.data[103] = visRect[3];
	ctxVis.canvas.width = visRect[2];
	ctxVis.canvas.height = visRect[3];
	ctxTopRow.data[100] = topRowRect[0];
	ctxTopRow.data[101] = topRowRect[1];
	ctxTopRow.data[102] = topRowRect[2];
	ctxTopRow.data[103] = topRowRect[3];
	ctxTopRow.canvas.width = visRect[2];
	ctxTopRow.canvas.height = visRect[3];
	resize();

	var left = padding;
	var top = padding;

	ctxInvis.save();
	ctxInvis.lineCap = lineCap;
	ctxInvis.lineJoin = lineJoin;

	var cellDims = [];

	var horizPos = [left];
	for (var i = 0; i < cellWidths.length; i++) {
		horizPos.push(horizPos[horizPos.length - 1] + cellWidths[i])
	}

	var vertPos = [top];
	for (var i = 0; i < cellHeights.length; i++) {
		vertPos.push(vertPos[vertPos.length - 1] + cellHeights[i])
	}

	// write text to each cell
	var topPos = top;
	for (var i = 0; i < cells.length; i++) {
		var leftPos = left;
		cellDims[i] = [];
		for (var j = 0; j < cells[i].length; j++) {
			cellDims[i][j] = {
				left: leftPos + 2,
				top: topPos + 1,
				width: cellWidths[j] - 9,
				height: cellHeights[i] - 8,
				border: false,
				offset: [-40, 0.5 * (cellHeights[i] - 8) - 20],
				fontSize: fontSize,
				leftPoint: paddingH,
				textColor: textColor,
				textAlign: horizAlign,
				fontSize: fontSize
			};
			if (cells[i][j].highlight == true) {
				if (typeof cells[i][j].color == 'undefined' || cells[i][j].color !== 'none') {
					ctxInvis.fillStyle = colorA(invertColor(cells[i][j].color), alpha);
				} else {
					ctxInvis.fillStyle = colorA(invertColor('#FFC'), alpha);
				}
				ctxInvis.fillRect(leftPos, topPos, cellWidths[j], cellHeights[i]);
			} else if (typeof cells[i][j].color == 'undefined' || cells[i][j].color !== 'none') {
				ctxInvis.fillStyle = colorA(cells[i][j].color, alpha);
				ctxInvis.fillRect(leftPos, topPos, cellWidths[j], cellHeights[i]);
			}
			var align = horizAlign;
			if (!un(cells[i][j].align))
				align = cells[i][j].align;
			var cellText = text({
					ctx: ctxInvis,
					left: leftPos + paddingH,
					top: topPos + paddingV,
					width: cellWidths[j] - 2 * paddingH,
					height: cellHeights[i] - 2 * paddingV,
					textArray: cells[i][j].text,
					textAlign: align,
					vertAlign: 'middle',
					padding: 0.001,
					box: cells[i][j].box,
					sf: sf
				});
			/*console.log(cellText.tightRect[2],cellText.tightRect[3],{
			ctx:ctxInvis,
			left:leftPos+paddingH,
			top:topPos+paddingV,
			width:cellWidths[j]-2*paddingH,
			height:cellHeights[i]-2*paddingV,
			textArray:cells[i][j].text,
			textAlign:align,
			vertAlign:'middle',
			padding:0.001,
			box:cells[i][j].box,
			sf:sf
			});*/
			leftPos += cellWidths[j];
		}
		topPos += cellHeights[i];
	}

	// draw inner border
	if (innerBorder.show == true) {
		ctxInvis.strokeStyle = innerBorder.color;
		ctxInvis.lineWidth = innerBorder.width;
		if (!ctxInvis.setLineDash) {
			ctxInvis.setLineDash = function () {}
		}
		ctxInvis.setLineDash(innerBorder.dash);
		var leftPos = left;
		for (var i = 0; i < cellWidths.length - 1; i++) {
			leftPos += cellWidths[i];
			ctxInvis.beginPath();
			ctxInvis.moveTo(leftPos, top);
			ctxInvis.lineTo(leftPos, top + totalHeight);
			ctxInvis.stroke();
		}
		var topPos = top;
		for (var i = 0; i < cellHeights.length - 1; i++) {
			topPos += cellHeights[i];
			ctxInvis.beginPath();
			ctxInvis.moveTo(left, topPos);
			ctxInvis.lineTo(left + totalWidth, topPos);
			ctxInvis.stroke();
		}
	}

	// draw outer border
	if (outerBorder.show == true) {
		ctxInvis.strokeStyle = outerBorder.color;
		ctxInvis.lineWidth = outerBorder.width;
		if (!ctxInvis.setLineDash) {
			ctxInvis.setLineDash = function () {}
		}
		ctxInvis.setLineDash(outerBorder.dash);
		ctxInvis.beginPath();
		ctxInvis.strokeRect(left, top, totalWidth, totalHeight);
	}

	ctxInvis.restore();

	object.cell = cellDims;
	object.xPos = horizPos;
	object.yPos = vertPos;

	if (!un(object.additionalDraw)) {
		object.additionalDraw();
	}

	object.redraw();

	if (totalHeight + 2 * padding > object.maxHeight) {
		moveScroller(object.scroller, object.left + object.xPos.last(), object.top + object.yPos[0]);
		object.hasScroll = true;
		object.scrollPos = 0;
		object.scrollMax = totalHeight / maxHeight;
		object.scrollDiff = totalHeight - maxHeight + 2 * padding;
		object.scroller.max = totalHeight / maxHeight;
		object.scroller.value = 0;
		object.scroller = updateScrollerDims(object.scroller);
		showScroller(object.scroller);
		if (object.topRowFreeze) {
			showObj(ctxTopRow.canvas);
			ctxTopRow.data[3] = ctxTopRow.data[103] = padding + vertPos[1];
			ctxTopRow.canvas.width = ctxTopRow.data[102];
			ctxTopRow.canvas.height = ctxTopRow.data[103];
			resizeCanvas3(ctxTopRow.canvas);
			ctxTopRow.drawImage(ctxInvis.canvas, 0, 0);
		} else {
			hideObj(ctxTopRow.canvas);
		}
	} else {
		object.hasScroll = false;
		hideScroller(object.scroller);
		hideObj(ctxTopRow.canvas);
	}

	return object;
}
function moveScrollTable(object, left, top) {
	var relLeft = object.scroller.rect[0] - object.ctxVis.canvas.data[100];
	object.left = left;
	object.top = top;
	object.ctxVis.canvas.data[100] = left;
	object.ctxVis.canvas.data[101] = top;
	resizeCanvas3(object.ctxVis.canvas);
	object.ctxTopRow.canvas.data[100] = left;
	object.ctxTopRow.canvas.data[101] = top;
	resizeCanvas3(object.ctxTopRow.canvas);
	object.scroller.rect[0] = left + relLeft;
	object.scroller.rect[1] = top;
	object.scroller.reposition();
}
function showScrollTable(object, includeTopRow) {
	showObj(object.ctxVis.canvas);
	if (boolean(includeTopRow, true))
		showObj(object.ctxTopRow.canvas);
	/*if (object.hasScroll == true)*/
	showScroller(object.scroller);
}
function hideScrollTable(object) {
	hideObj(object.ctxVis.canvas);
	hideObj(object.ctxTopRow.canvas);
	hideScroller(object.scroller);
}

function createSlider(object) {
	if (typeof slider[pageIndex] == 'undefined')
		slider[pageIndex] = [];
	var id = object.id || slider[pageIndex].length;
	if (typeof object.gridDetails == 'undefined')
		object.gridDetails = {};
	var left = object.left || object.l || (object.gridDetails.left - 10);
	var top = object.top || object.t || (object.gridDetails.top + object.gridDetails.height);
	var width = object.width || object.w || (object.gridDetails.width + 20);
	var height = object.height || object.h || 60;
	var bottom = top + height;
	var min,
	max;
	if (typeof object.min == 'number') {
		min = object.min;
	} else {
		min = object.gridDetails.xMin;
	}
	if (typeof object.max == 'number') {
		max = object.max;
	} else {
		max = object.gridDetails.xMax;
	}
	var vari = object.vari || "a";
	var linkedVar = object.linkedVar;
	var varChangeListener = object.varChangeListener;
	var onchange = object.onchange;
	var startNum = min;
	if (typeof object.startNum == 'number')
		startNum = object.startNum;
	var inc = object.inc || 1;
	var label = true;
	if (typeof object.label == 'boolean')
		label = object.label;
	var labelFont = object.labelFont || "24px Arial";
	var labelColor = object.labelColor || '#000';
	var visible = boolean(object.visible, true);
	var zIndex = object.zIndex || 2;
	var handleColor = object.handleColor || '#00F';
	var handleStyle = object.handleStyle || 'rect'; // rect or circle
	var discrete = false;
	if (typeof object.discrete == 'boolean')
		discrete = object.discrete;
	var stepNum = 1;
	if (typeof object.stepNum == 'number')
		stepNum = object.stepNum;
	var snap = false;
	if (typeof object.snap == 'boolean')
		snap = object.snap;
	var snapNum = 1;
	if (typeof object.snapNum == 'number')
		snapNum = object.snapNum;
	var vert = boolean(object.vertical, false);

	if (vert == false) {
		var sliderWidth = 20;
		if (handleStyle == 'circle')
			sliderWidth = 40;
		var sliderHeight = 40;
	} else {
		var sliderHeight = 20;
		if (handleStyle == 'circle')
			sliderHeight = 40;
		var sliderWidth = 40;
	}

	var backCanvas = document.createElement('canvas');
	backCanvas.width = width;
	backCanvas.height = height * 1.5;
	backCanvas.setAttribute('position', 'absolute');
	backCanvas.setAttribute('cursor', 'auto');
	backCanvas.setAttribute('draggable', 'false');
	backCanvas.setAttribute('class', 'buttonClass');
	backCanvas.style.pointerEvents = 'none';
	backCanvas.style.zIndex = zIndex;
	if (visible == true)
		container.appendChild(backCanvas);
	canvases[pageIndex].push(backCanvas);
	var backCtx = backCanvas.getContext('2d');
	var backCanvasData = [left, top, width, height * 1.5, visible, false, false, zIndex];
	for (var i = 0; i < 8; i++) {
		backCanvasData[100 + i] = backCanvasData[i];
	}
	backCanvasData[130] = visible;
	backCanvas.data = backCanvasData;

	backCtx.lineWidth = 5;
	backCtx.strokeStyle = object.backColor || '#666';
	backCtx.lineCap = 'round';
	backCtx.lineJoin = 'round';
	backCtx.beginPath();
	if (vert == false) {
		backCtx.moveTo(0.5 * sliderWidth, 0.5 * height);
		backCtx.lineTo(width - 0.5 * sliderWidth, 0.5 * height);
	} else {
		backCtx.moveTo(0.5 * width, 0.5 * sliderHeight);
		backCtx.lineTo(0.5 * width, height - 0.5 * sliderHeight);
	}
	backCtx.closePath();
	backCtx.stroke();
	if (!un(object.scale)) {
		var step = def([object.scale.step, 1]);
		var xInc = (width - 20) / ((max - min) / step);
		var color = def([object.scale.color, backCtx.strokeStyle]);
		backCtx.lineWidth = 2;
		backCtx.strokeStyle = color;
		backCtx.beginPath();
		var l = 10;
		for (var i = min; i <= max; i += step) {
			backCtx.moveTo(l, 0.5 * height);
			backCtx.lineTo(l, 0.85 * height);
			text({
				ctx: backCtx,
				left: l - 50,
				top: 0.85 * height,
				width: 100,
				height: height,
				align: 'center',
				color: color,
				textArray: ['<<fontSize:20>>' + i]
			});
			l += xInc;
		}
		backCtx.stroke();
	}

	var sliderCanvas = document.createElement('canvas');
	sliderCanvas.width = sliderWidth;
	sliderCanvas.height = sliderHeight;
	sliderCanvas.setAttribute('position', 'absolute');
	sliderCanvas.setAttribute('cursor', 'auto');
	sliderCanvas.setAttribute('draggable', 'false');
	sliderCanvas.setAttribute('class', 'buttonClass');
	sliderCanvas.style.zIndex = zIndex;
	if (visible == true)
		container.appendChild(sliderCanvas);
	canvases[pageIndex].push(sliderCanvas);
	var sliderCtx = sliderCanvas.getContext('2d');
	if (vert == false) {
		var leftPos = left + (startNum - min) * (width - sliderWidth) / (max - min);
		var sliderCanvasData = [leftPos, top + 0.5 * height - 0.5 * sliderHeight, sliderWidth, sliderHeight, visible, false, true, zIndex];
	} else {
		var topPos = bottom - sliderHeight - (startNum - min) * (height - sliderHeight) / (max - min);
		var sliderCanvasData = [left + 0.5 * width - 0.5 * sliderWidth, topPos, sliderWidth, sliderHeight, visible, false, true, zIndex];
	}
	for (var i = 0; i < 8; i++) {
		sliderCanvasData[100 + i] = sliderCanvasData[i];
	}
	sliderCanvasData[130] = visible;
	sliderCanvas.data = sliderCanvasData;
	addListenerStart(sliderCanvas, sliderDragStart);

	sliderCtx.fillStyle = handleColor;
	if (handleStyle == 'rect') {
		sliderCtx.fillRect(0, 0, sliderWidth, sliderHeight);
	} else if (handleStyle == 'circle') {
		sliderCtx.beginPath();
		sliderCtx.arc(0.5 * sliderWidth, 0.5 * sliderHeight, 0.5 * sliderHeight - 2, 0, 2 * Math.PI);
		sliderCtx.closePath();
		sliderCtx.fill();
	}

	var labelCanvas = document.createElement('canvas');
	labelCanvas.width = width;
	labelCanvas.height = parseInt(labelFont) * 2;
	labelCanvas.setAttribute('position', 'absolute');
	labelCanvas.setAttribute('cursor', 'auto');
	labelCanvas.setAttribute('draggable', 'false');
	labelCanvas.setAttribute('class', 'buttonClass');
	labelCanvas.style.pointerEvents = 'none';
	labelCanvas.style.zIndex = zIndex;
	if (label == true && visible == true) {
		container.appendChild(labelCanvas);
	}
	canvases[pageIndex].push(labelCanvas);
	var labelCtx = labelCanvas.getContext('2d');
	var labelCanvasData = [left, top + height, width, height, visible, false, false, zIndex];
	for (var i = 0; i < 8; i++) {
		labelCanvasData[100 + i] = labelCanvasData[i];
	}
	labelCanvasData[130] = visible;
	labelCanvas.data = labelCanvasData;

	if (label == true) {
		labelCtx.fillStyle = labelColor;
		labelCtx.font = "24px Arial";
		labelCtx.textAlign = 'center';
		labelCtx.textBaseline = 'middle';
		labelCtx.fillText(vari + " = " + startNum, 0.5 * width, parseInt(labelFont));
	}

	resize();

	slider[pageIndex][id] = {
		id: id,
		backCanvas: backCanvas,
		backctx: backCtx,
		backData: backCanvasData,
		sliderCanvas: sliderCanvas,
		sliderctx: sliderCtx,
		sliderData: sliderCanvasData,
		labelCanvas: labelCanvas,
		labelctx: labelCtx,
		labelData: labelCanvasData,
		left: left,
		top: top,
		width: width,
		height: height,
		bottom: bottom,
		sliderWidth: sliderWidth,
		sliderHeight: sliderHeight,
		min: min,
		max: max,
		startNum: startNum,
		currNum: startNum,
		vari: vari,
		linkedVar: linkedVar,
		varChangeListener: varChangeListener,
		onchange: onchange,
		inc: inc,
		label: label,
		labelFont: labelFont,
		labelColor: labelColor,
		visible: visible,
		zIndex: zIndex,
		discrete: discrete,
		stepNum: stepNum,
		snap: snap,
		snapNum: snapNum,
		vert: vert
	};

	return slider[pageIndex][id];
}
function showSlider(slider) {
	showObj(slider.backCanvas, slider.backData);
	showObj(slider.sliderCanvas, slider.sliderData);
	showObj(slider.labelCanvas, slider.labelData);
}
function hideSlider(slider) {
	hideObj(slider.backCanvas, slider.backData);
	hideObj(slider.sliderCanvas, slider.sliderData);
	hideObj(slider.labelCanvas, slider.labelData);
}
function setSliderValue(slider, value) {
	var val = Math.min(Math.max(slider.min, value), slider.max);
	if (slider.vert == false) {
		var left = slider.left + ((val - slider.min) / (slider.max - slider.min)) * (slider.width - slider.sliderWidth);
		slider.sliderData[100] = left;
	} else {
		var top = slider.bottom - slider.sliderHeight - ((val - slider.min) / (slider.max - slider.min)) * (slider.height - slider.sliderHeight);
		slider.sliderData[101] = top;
	}
	slider.currNum = val;
	if (slider.label == true) {
		slider.labelctx.clearRect(0, 0, slider.width, mainCanvasHeight);
		slider.labelctx.fillStyle = slider.labelColor;
		slider.labelctx.font = slider.labelFont;
		slider.labelctx.textAlign = 'center';
		slider.labelctx.textBaseline = 'middle';
		slider.labelctx.fillText(slider.vari + " = " + roundToNearest(val, 0.01), 0.5 * slider.width, parseInt(slider.labelFont));
	}
	resizeCanvas2(slider.sliderCanvas, slider.sliderData[100], slider.sliderData[101]);
	if (!un(slider.linkedVar))
		eval(slider.linkedVar + "=" + val);
	if (!un(slider.varChangeListener))
		eval(slider.varChangeListener + "()");
	if (!un(slider.onchange))
		slider.onchange(val);
}
function sliderDragStart(e) {
	for (var i = 0; i < slider[pageIndex].length; i++) {
		if (slider[pageIndex][i].sliderCanvas == e.target) {
			currSlider = i;
			break;
		}
	}
	removeListenerStart(e.target, sliderDragStart)
	addListenerMove(window, sliderDragMove);
	addListenerEnd(window, sliderDragStop);
}
function sliderDragMove(e) {
	var s = slider[pageIndex][currSlider];
	if (s.vert == false) {
		var left = Math.min(Math.max(mouse.x, s.left), s.left + s.width - s.sliderWidth);
		slider[pageIndex][currSlider].sliderData[100] = left;
		var val = s.min + (left - s.left) * (s.max - s.min) / (s.width - s.sliderWidth);
	} else {
		var top = Math.min(Math.max(mouse.y, s.top), s.bottom - s.sliderHeight);
		slider[pageIndex][currSlider].sliderData[101] = top;
		var val = s.min + (s.bottom - s.sliderHeight - top) * (s.max - s.min) / (s.height - s.sliderHeight);
	}
	if (s.discrete == true) {
		val = roundToNearest(val, s.stepNum);
	}
	s.currNum = val;
	if (!un(s.linkedVar))
		eval(s.linkedVar + "=" + val);
	if (!un(s.varChangeListener))
		eval(s.varChangeListener + "()");
	if (!un(s.onchange))
		s.onchange(val);
	if (s.label == true) {
		s.labelctx.clearRect(0, 0, s.width, mainCanvasHeight);
		s.labelctx.fillStyle = s.labelColor;
		s.labelctx.font = s.labelFont;
		s.labelctx.textAlign = 'center';
		s.labelctx.textBaseline = 'middle';
		s.labelctx.fillText(s.vari + " = " + roundToNearest(val, 0.01), 0.5 * s.width, parseInt(s.labelFont));
	}
	resize();
}
function sliderDragStop(e) {
	removeListenerMove(window, sliderDragMove);
	removeListenerEnd(window, sliderDragStop);
	// snap slider to position
	var s = slider[pageIndex][currSlider];
	if (s.snap == true) {
		if (s.vert == false) {
			var left = Math.min(Math.max(mouse.x, s.left), s.left + s.width - s.sliderWidth);
			var val = s.min + (left - s.left) * (s.max - s.min) / (s.width - s.sliderWidth);
		} else {
			var top = Math.min(Math.max(mouse.y, s.top), s.bottom - s.sliderHeight);
			var val = s.min + (s.bottom - s.sliderHeight - top) * (s.max - s.min) / (s.height - s.sliderHeight);
		}
		if (s.discrete == true) {
			val = roundToNearest(val, s.stepNum);
		} else if (s.snap == true) {
			val = roundToNearest(val, s.snapNum);
		} else {
			val = roundToNearest(val, s.inc);
		}
		s.currNum = val;
		eval(s.linkedVar + "=" + val);
		eval(s.varChangeListener + "()");
		if (s.vert == false) {
			var leftSnap = s.left + (val - s.min) * (s.width - s.sliderWidth) / (s.max - s.min);
			slider[pageIndex][currSlider].sliderData[100] = leftSnap;
		} else {
			var topSnap = s.bottom - s.sliderHeight - (val - s.min) * (s.height - s.sliderHeight) / (s.max - s.min);
			slider[pageIndex][currSlider].sliderData[101] = topSnap;
		}
		resize();
	}
	addListenerStart(slider[pageIndex][currSlider].sliderCanvas, sliderDragStart)
}

var currScroller;
function createScroller(obj) {
	var rect = obj.rect;
	var z = obj.zIndex || obj.z || 2;
	var vis = boolean(obj.visible, boolean(obj.vis, true));
	var min = obj.min || 0;
	var max = obj.max;
	//var colors = obj.colors || ['#3FF','#00F','#333','#CCC','#333'];
	var colors = obj.colors || {
		buttons: '#3FF',
		slider: '#00F',
		border: '#333',
		back: '#CCC',
		buttonsBorder: '#333',
		arrows: '#333'
	};
	var sliderHeight = obj.sliderHeight || (rect[3] - rect[2] * 2) / (max - min);
	var inc = obj.inc || 1;
	var incDist = (rect[3] - 2 * rect[2] - sliderHeight) / ((max - min) / inc);
	var sliderRect = [rect[0], rect[1] + rect[2], rect[2], sliderHeight];
	var radius = def([obj.radius, 0]);
	var scroller = {
		rect: rect,
		zIndex: z,
		min: min,
		max: max,
		value: min,
		colors: colors,
		sliderRect: sliderRect,
		sliderHeight: sliderHeight,
		inc: inc,
		incDist: incDist,
		radius: radius
	};
	if (typeof obj.funcMove == 'function')
		scroller.funcMove = obj.funcMove;
	if (typeof obj.funcStop == 'function')
		scroller.funcStop = obj.funcStop;
	scroller.canvas = newctx({
			rect: scroller.rect,
			pE: true,
			z: scroller.zIndex
		}).canvas;
	scroller.canvas.scroller = scroller;
	scroller.ctx = scroller.canvas.ctx;
	scroller.slider = {};
	scroller.sliderCanvas = newctx({
			rect: sliderRect,
			pE: true,
			z: scroller.zIndex + 1
		}).canvas;
	scroller.sliderCanvas.scroller = scroller;
	scroller.sliderctx = scroller.sliderCanvas.ctx;
	scroller.sliderctx.fillStyle = colors[1];
	scroller.sliderctx.fillRect(0, 0, sliderRect[2], sliderRect[3]);
	scroller.reposition = function (newMax, newRect, sliderHeight) {
		if (!un(newMax))
			this.max = newMax;
		if (!un(newRect))
			this.rect = newRect;
		this.canvas.data[100] = this.rect[0];
		this.canvas.data[101] = this.rect[1];
		this.canvas.data[102] = this.rect[2];
		this.canvas.data[103] = this.rect[3];
		resizeCanvas(this.canvas, this.rect[0], this.rect[1], this.rect[2], this.rect[3]);
		this.canvas.width = this.rect[2];
		this.canvas.height = this.rect[3];
		if (!un(sliderHeight)) {
			this.sliderHeight = sliderHeight;
		} else {
			this.sliderHeight = (this.rect[3] - this.rect[2] * 2) / (this.max - this.min);
		}
		this.sliderRect = [this.rect[0], this.rect[1] + this.rect[2], this.rect[2], this.sliderHeight];
		this.sliderCanvas.data[100] = this.sliderRect[0];
		this.sliderCanvas.data[101] = this.sliderRect[1];
		this.sliderCanvas.data[102] = this.sliderRect[2];
		this.sliderCanvas.data[103] = this.sliderRect[3];
		resizeCanvas(this.sliderCanvas, this.sliderRect[0], this.sliderRect[1], this.sliderRect[2], this.sliderRect[3]);
		this.sliderCanvas.width = this.sliderRect[2];
		this.sliderCanvas.height = this.sliderRect[3];
		this.draw();
		this.value = 0;
		this.sliderRect[1] = this.rect[1] + this.rect[2] + (this.rect[3] - 2 * this.rect[2] - this.sliderHeight) * ((this.value - this.min) / (this.max - this.min));
		resizeCanvas(this.sliderCanvas, this.sliderRect[0], this.sliderRect[1]);
	}
	scroller.draw = function () {
		var ctx = this.ctx;
		var w = this.rect[2];
		var h = this.rect[3];
		ctx.clearRect(0, 0, w, h);
		var lineWidth = this.lineWidth || 4;
		var radius = this.radius;
		roundedRect(ctx, lineWidth / 2, lineWidth / 2, w - lineWidth, h - lineWidth, radius, lineWidth, this.colors.border, this.colors.back);
		roundedRect(ctx, lineWidth / 2, lineWidth / 2, w - lineWidth, w - lineWidth, radius, lineWidth, this.colors.buttonsBorder, this.colors.buttons);
		roundedRect(ctx, lineWidth / 2, h - w, w - lineWidth, w - lineWidth, radius, lineWidth, this.colors.buttonsBorder, this.colors.buttons);
		ctx.fillStyle = this.colors.arrows;
		ctx.lineCap = 'round';
		ctx.lineJoin = 'round';
		ctx.beginPath();
		ctx.moveTo(w * 14 / 50, w * 34 / 50);
		ctx.lineTo(w * 25 / 50, w * 16 / 50);
		ctx.lineTo(w * 36 / 50, w * 34 / 50);
		ctx.lineTo(w * 14 / 50, w * 34 / 50);
		ctx.fill();
		ctx.beginPath();
		ctx.moveTo(w * 14 / 50, h - w + w * 16 / 50);
		ctx.lineTo(w * 25 / 50, h - w + w * 34 / 50);
		ctx.lineTo(w * 36 / 50, h - w + w * 16 / 50);
		ctx.lineTo(w * 14 / 50, h - w + w * 16 / 50);
		ctx.fill();
		this.sliderctx.fillStyle = this.colors.slider;
		this.sliderctx.fillRect(0, 0, this.sliderRect[2], this.sliderHeight);
	}
	scroller.draw();
	addListener(scroller.canvas, function (e) {
		updateMouse(e);
		var scroller = this.scroller;
		if (mouse.y < scroller.sliderRect[1]) {
			scroller.update(-1);
		} else if (mouse.y > scroller.sliderRect[1] + scroller.sliderRect[3]) {
			scroller.update(1);
		}
	});
	addListenerStart(scroller.sliderCanvas, scrollerMoveStart);
	scroller.update = function (change) {
		var newValue = Math.min(this.max, Math.max(this.min, this.value + change));
		if (newValue == this.value)
			return;
		this.value = newValue;
		this.sliderRect[1] = this.rect[1] + this.rect[2] + (this.rect[3] - 2 * this.rect[2] - this.sliderHeight) * ((this.value - this.min) / (this.max - this.min));
		resizeCanvas(this.sliderCanvas, this.sliderRect[0], this.sliderRect[1]);
		if (typeof this.funcStop == 'function') {
			this.funcStop(this.value);
		} else if (typeof this.funcMove == 'function') {
			this.funcMove(this.value);
		}
	}
	return scroller;
}
function updateScrollerDims(s) { // update max
	s.sliderHeight = (s.rect[3] - s.rect[2] * 2) / (s.max - s.min);
	s.incDist = (s.rect[3] - 2 * s.rect[2] - s.sliderHeight) / ((s.max - s.min) / s.inc);
	s.sliderRect[3] = s.sliderHeight;
	s.sliderCanvas.data[100] = s.sliderRect[0];
	s.sliderCanvas.data[101] = s.sliderRect[1];
	s.sliderCanvas.data[102] = s.sliderRect[2];
	s.sliderCanvas.data[103] = s.sliderRect[3];
	resizeCanvas3(s.sliderCanvas);
	setScrollerValue(s, s.value, true);
	return s;
}
function scrollerMoveStart(e) {
	updateMouse(e);
	currScroller = e.target.scroller;
	currScroller.dragStartPos = mouse.y;
	currScroller.dragStartValue = currScroller.value;
	currScroller.dragStartY = currScroller.sliderRect[1];
	currScroller.dragOffset = mouse.y - currScroller.sliderRect[1];
	currScroller.dragMinY = currScroller.rect[1] + currScroller.rect[2];
	currScroller.dragMaxY = currScroller.rect[1] + currScroller.rect[3] - currScroller.rect[2] - currScroller.sliderRect[3];
	addListenerMove(window, scrollerMoveMove);
	addListenerEnd(window, scrollerMoveStop);
}
function scrollerMoveMove(e) {
	updateMouse(e);
	var dy = mouse.y - currScroller.dragStartPos;
	var newY = Math.min(Math.max(currScroller.dragStartY + dy, currScroller.dragMinY), currScroller.dragMaxY);
	if (newY == currScroller.sliderRect[1])
		return;
	currScroller.sliderRect[1] = newY;
	resizeCanvas(currScroller.sliderCanvas, currScroller.sliderRect[0], currScroller.sliderRect[1]);
	currScroller.value = currScroller.min + (currScroller.max - currScroller.min) * (currScroller.sliderRect[1] - currScroller.dragMinY) / (currScroller.dragMaxY - currScroller.dragMinY);
	if (typeof currScroller.funcMove == 'function')
		currScroller.funcMove(currScroller.value);
};
function scrollerMoveStop(e) {
	if (typeof currScroller.funcStop == 'function')
		currScroller.funcStop(currScroller.value);
	currScroller = null;
	removeListenerMove(window, scrollerMoveMove);
	removeListenerEnd(window, scrollerMoveStop);
};
function setScrollerValue(scroller, value, applyFunc) {
	var newValue = Math.min(Math.max(scroller.min, value), scroller.max);
	//if (newValue == scroller.value) return;
	scroller.value = newValue;
	scroller.sliderRect[1] = scroller.rect[1] + scroller.rect[2] + (scroller.rect[3] - 2 * scroller.rect[2] - scroller.sliderHeight) * ((scroller.value - scroller.min) / (scroller.max - scroller.min));
	resizeCanvas(scroller.sliderCanvas, scroller.sliderRect[0], scroller.sliderRect[1]);
	scroller.update(0);
	if (!applyFunc && applyFunc == false)
		return;
	if (typeof scroller.funcStop == 'function') {
		scroller.funcStop(scroller.value);
	} else if (typeof scroller.funcMove == 'function') {
		scroller.funcMove(scroller.value);
	}
}
function moveScroller(scroller, left, top) {
	var relTop = scroller.sliderCanvas.data[101] - scroller.canvas.data[100];
	scroller.sliderRect[0] = left;
	scroller.sliderRect[1] = top + relTop;
	scroller.rect[0] = left;
	scroller.rect[1] = top;
	scroller.canvas.data[100] = left;
	scroller.canvas.data[101] = top;
	resizeCanvas3(scroller.canvas);
	scroller.sliderCanvas.data[100] = left;
	scroller.sliderCanvas.data[101] = top + relTop;
	resizeCanvas3(scroller.sliderCanvas);
}
function hideScroller(scroller) {
	if (un(scroller))
		return;
	hideObj(scroller.canvas);
	hideObj(scroller.sliderCanvas);
}
function showScroller(scroller) {
	if (un(scroller))
		return;
	showObj(scroller.canvas);
	showObj(scroller.sliderCanvas);
}

function drawArrow(object) {
	var context = object.context || object.ctx;
	var startX = object.startX;
	var startY = object.startY;
	var finX = object.finX || startX;
	var finY = object.finY || startY;

	var doubleEnded;
	if (typeof object.doubleEnded == 'boolean') {
		doubleEnded = object.doubleEnded
	} else {
		doubleEnded = false
	}
	var arrowLength = object.arrowLength || 30;
	var angleBetweenLinesRads = object.angleBetweenLinesRads || 0.5;
	var fillArrow = boolean(object.fillArrow, false);
	var showLine = boolean(object.showLine, true);
	var dash = object.dash || [];

	context.save();
	context.strokeStyle = object.color || '#000';
	context.fillStyle = object.color || '#000';
	context.lineWidth = object.lineWidth || 4;

	if (showLine == true) {
		//draw line
		if (typeof context.setLineDash == 'undefined')
			context.setLineDash = function () {};
		context.setLineDash(dash);
		context.beginPath();
		context.moveTo(startX, startY);
		context.lineTo(finX, finY);
		context.stroke();
	}

	context.lineWidth = object.arrowLineWidth || object.lineWidth || 4;
	context.beginPath();
	if (typeof context.setLineDash == 'undefined')
		context.setLineDash = function () {};
	context.setLineDash([]);
	context.lineJoin = 'round';
	context.lineCap = 'round';

	var posX;
	var posY;
	var otherX;
	var otherY;
	var endToDraw = "fin";

	do {
		if (endToDraw == "fin") {
			posX = finX;
			posY = finY;
			otherX = startX;
			otherY = startY;
		} else if (endToDraw == "start") {
			posX = startX;
			posY = startY;
			otherX = finX;
			otherY = finY;
		}

		var nGradient = (-1 * (posY - otherY)) / (posX - otherX);

		var angleToHorizontal = Math.abs(Math.atan(nGradient));
		var remainingAngle = Math.PI / 2 - angleBetweenLinesRads - angleToHorizontal;

		var narrowX1,
		narrowX2,
		narrowY1,
		narrowY2;

		if (nGradient == Infinity) {
			//first half of arrow
			narrowX1 = Math.sin(remainingAngle) * arrowLength;
			narrowY1 = Math.cos(remainingAngle) * arrowLength;
			context.moveTo(posX, posY);
			context.lineTo(posX + narrowX1, posY + narrowY1);

			// second half of arrow
			narrowX2 = Math.cos(angleBetweenLinesRads - angleToHorizontal) * arrowLength;
			narrowY2 = Math.sin(angleBetweenLinesRads - angleToHorizontal) * arrowLength;
			context.moveTo(posX, posY);
			context.lineTo(posX + narrowX2, posY - narrowY2);

			if (fillArrow == true)
				context.lineTo(posX + narrowX1, posY + narrowY1);
		} else if (nGradient == -Infinity) {
			//first half of arrow
			narrowX1 = Math.sin(remainingAngle) * arrowLength;
			narrowY1 = Math.cos(remainingAngle) * arrowLength;
			context.moveTo(posX, posY);
			context.lineTo(posX + narrowX1, posY - narrowY1);

			// second half of arrow
			narrowX2 = Math.cos(angleBetweenLinesRads - angleToHorizontal) * arrowLength;
			narrowY2 = Math.sin(angleBetweenLinesRads - angleToHorizontal) * arrowLength;
			context.moveTo(posX, posY);
			context.lineTo(posX + narrowX2, posY + narrowY2);

			if (fillArrow == true)
				context.lineTo(posX + narrowX1, posY - narrowY1);
		} else

			///case 1 - arrow is pointing up and to the left
			if (nGradient < 0 && posY < otherY) {

				//first half of arrow
				narrowX1 = Math.sin(remainingAngle) * arrowLength;
				narrowY1 = Math.cos(remainingAngle) * arrowLength;
				context.moveTo(posX, posY);
				context.lineTo(posX + narrowX1, posY + narrowY1);

				// second half of arrow
				narrowX2 = Math.cos(angleBetweenLinesRads - angleToHorizontal) * arrowLength;
				narrowY2 = Math.sin(angleBetweenLinesRads - angleToHorizontal) * arrowLength;
				context.moveTo(posX, posY);
				context.lineTo(posX + narrowX2, posY - narrowY2);

				if (fillArrow == true)
					context.lineTo(posX + narrowX1, posY + narrowY1);
			} else

				///case 2 - arrow is pointing up and to the right
				if (nGradient > 0 && posY < otherY) {

					//first half of arrow
					narrowX1 = Math.sin(remainingAngle) * arrowLength;
					narrowY1 = Math.cos(remainingAngle) * arrowLength;
					context.moveTo(posX, posY);
					context.lineTo(posX - narrowX1, posY + narrowY1);

					// second half of arrow
					narrowX2 = Math.cos(angleBetweenLinesRads - angleToHorizontal) * arrowLength;
					narrowY2 = Math.sin(angleBetweenLinesRads - angleToHorizontal) * arrowLength;
					context.moveTo(posX, posY);
					context.lineTo(posX - narrowX2, posY - narrowY2);

					if (fillArrow == true)
						context.lineTo(posX - narrowX1, posY + narrowY1);
				} else

					//gradient is 0 and pointing right
					if (nGradient == 0 && posX > otherX) {

						//first half of arrow
						narrowX1 = Math.sin(remainingAngle) * arrowLength
							narrowY1 = Math.cos(remainingAngle) * arrowLength
							context.moveTo(posX, posY)
							context.lineTo(posX - narrowX1, posY + narrowY1)

							// second half of arrow
							narrowX2 = Math.cos(angleBetweenLinesRads - angleToHorizontal) * arrowLength
							narrowY2 = Math.sin(angleBetweenLinesRads - angleToHorizontal) * arrowLength
							context.moveTo(posX, posY)
							context.lineTo(posX - narrowX2, posY - narrowY2)

							if (fillArrow == true)
								context.lineTo(posX - narrowX1, posY + narrowY1);
					} else

						// gradient is 0 and pointing left
						if (nGradient == 0 && posX < otherX) {

							//first half of arrow
							narrowX1 = Math.sin(remainingAngle) * arrowLength
								narrowY1 = Math.cos(remainingAngle) * arrowLength
								context.moveTo(posX, posY)
								context.lineTo(posX + narrowX1, posY + narrowY1)

								// second half of arrow
								narrowX2 = Math.cos(angleBetweenLinesRads - angleToHorizontal) * arrowLength
								narrowY2 = Math.sin(angleBetweenLinesRads - angleToHorizontal) * arrowLength
								context.moveTo(posX, posY)
								context.lineTo(posX + narrowX2, posY - narrowY2)

								if (fillArrow == true)
									context.lineTo(posX + narrowX1, posY + narrowY1);
						} else

							///case 3 - arrow is pointing down and to the right
							if (nGradient < 0 && posY > otherY) {

								angleBetweenLinesRads = Math.PI - angleBetweenLinesRads
									remainingAngle = Math.PI / 2 - angleBetweenLinesRads - angleToHorizontal;

								//first half of arrow
								narrowX1 = Math.sin(remainingAngle) * arrowLength
									narrowY1 = Math.cos(remainingAngle) * arrowLength
									context.moveTo(posX, posY)
									context.lineTo(posX + narrowX1, posY + narrowY1)

									// second half of arrow
									narrowX2 = Math.cos(angleBetweenLinesRads - angleToHorizontal) * arrowLength
									narrowY2 = Math.sin(angleBetweenLinesRads - angleToHorizontal) * arrowLength
									context.moveTo(posX, posY)
									context.lineTo(posX + narrowX2, posY - narrowY2)

									if (fillArrow == true)
										context.lineTo(posX + narrowX1, posY + narrowY1);
							} else

								///case 4 - arrow is pointing down and to the left
								if (nGradient > 0 && posY > otherY) {

									angleBetweenLinesRads = Math.PI - angleBetweenLinesRads
										remainingAngle = Math.PI / 2 - angleBetweenLinesRads - angleToHorizontal;

									//first half of arrow
									narrowX1 = Math.sin(remainingAngle) * arrowLength
										narrowY1 = Math.cos(remainingAngle) * arrowLength
										context.moveTo(posX, posY)
										context.lineTo(posX - narrowX1, posY + narrowY1)

										// second half of arrow
										narrowX2 = Math.cos(angleBetweenLinesRads - angleToHorizontal) * arrowLength
										narrowY2 = Math.sin(angleBetweenLinesRads - angleToHorizontal) * arrowLength
										context.moveTo(posX, posY)
										context.lineTo(posX - narrowX2, posY - narrowY2)

										if (fillArrow == true)
											context.lineTo(posX - narrowX1, posY + narrowY1);
								}

		if (doubleEnded == true && endToDraw == "fin") {
			endToDraw = "start";
		} else {
			endToDraw = "none";
		}
	} while (endToDraw !== "none");

	context.closePath();
	context.stroke();
	if (fillArrow == true)
		context.fill();
	context.restore();

}
function drawVector(vectorCtx, lineEndPointX1, lineEndPointY1, lineEndPointX2, lineEndPointY2, arrowLength, angleBetweenLinesInRadians, opt_color, opt_lineWidth) {

	if (typeof opt_color == 'undefined') {
		vectorCtx.strokeStyle = "#000";
	}
	if (typeof opt_lineWidth == 'undefined') {
		vectorCtx.lineWidth = 5;
	}

	//draw line

	vectorCtx.beginPath();
	vectorCtx.moveTo(lineEndPointX1, lineEndPointY1);
	vectorCtx.lineTo(lineEndPointX2, lineEndPointY2);

	//draw Arrow
	var nMidpointX = (lineEndPointX1 + lineEndPointX2) / 2
	var nMidpointY = (lineEndPointY1 + lineEndPointY2) / 2

	var nGradient = (-1 * (lineEndPointY2 - lineEndPointY1)) / (lineEndPointX2 - lineEndPointX1);

	var angleToHorizontal = Math.abs(Math.atan(nGradient));
	var remainingAngle = Math.PI / 2 - angleBetweenLinesInRadians - angleToHorizontal;

	var narrowX;
	var narrowY;

	///case 1 - arrow is pointing up and to the left
	if (nGradient < 0 && lineEndPointY2 < lineEndPointY1) {

		//first half of arrow

		narrowX = Math.sin(remainingAngle) * arrowLength
			narrowY = Math.cos(remainingAngle) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX + narrowX, nMidpointY + narrowY)

			// second half of arrow

			narrowX = Math.cos(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength
			narrowY = Math.sin(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX + narrowX, nMidpointY - narrowY)

	}

	///case 2 - arrow is pointing up and to the right
	if (nGradient > 0 && lineEndPointY2 < lineEndPointY1) {

		//first half of arrow

		narrowX = Math.sin(remainingAngle) * arrowLength
			narrowY = Math.cos(remainingAngle) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX - narrowX, nMidpointY + narrowY)

			// second half of arrow

			narrowX = Math.cos(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength
			narrowY = Math.sin(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX - narrowX, nMidpointY - narrowY)

	}

	//gradient is 0 and pointing right


	if (nGradient == 0 && lineEndPointX2 > lineEndPointX1) {

		//first half of arrow

		narrowX = Math.sin(remainingAngle) * arrowLength
			narrowY = Math.cos(remainingAngle) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX - narrowX, nMidpointY + narrowY)

			// second half of arrow

			narrowX = Math.cos(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength
			narrowY = Math.sin(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX - narrowX, nMidpointY - narrowY)

	}

	// gradient is - and pointing left

	if (nGradient == 0 && lineEndPointX2 < lineEndPointX1) {

		//first half of arrow

		narrowX = Math.sin(remainingAngle) * arrowLength
			narrowY = Math.cos(remainingAngle) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX + narrowX, nMidpointY + narrowY)

			// second half of arrow

			narrowX = Math.cos(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength
			narrowY = Math.sin(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX + narrowX, nMidpointY - narrowY)

	}

	///case 3 - arrow is pointing down and to the right
	if (nGradient < 0 && lineEndPointY2 > lineEndPointY1) {

		angleBetweenLinesInRadians = Math.PI - angleBetweenLinesInRadians
			remainingAngle = Math.PI / 2 - angleBetweenLinesInRadians - angleToHorizontal;

		//first half of arrow

		narrowX = Math.sin(remainingAngle) * arrowLength
			narrowY = Math.cos(remainingAngle) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX + narrowX, nMidpointY + narrowY)

			// second half of arrow

			narrowX = Math.cos(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength
			narrowY = Math.sin(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX + narrowX, nMidpointY - narrowY)

	}

	///case 4 - arrow is pointing down and to the left
	if (nGradient > 0 && lineEndPointY2 > lineEndPointY1) {

		angleBetweenLinesInRadians = Math.PI - angleBetweenLinesInRadians
			remainingAngle = Math.PI / 2 - angleBetweenLinesInRadians - angleToHorizontal;

		//first half of arrow

		narrowX = Math.sin(remainingAngle) * arrowLength
			narrowY = Math.cos(remainingAngle) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX - narrowX, nMidpointY + narrowY)

			// second half of arrow

			narrowX = Math.cos(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength
			narrowY = Math.sin(angleBetweenLinesInRadians - angleToHorizontal) * arrowLength

			vectorCtx.moveTo(nMidpointX, nMidpointY)
			vectorCtx.lineTo(nMidpointX - narrowX, nMidpointY - narrowY)

	}

	vectorCtx.closePath();
	vectorCtx.stroke();

}
function measureAngle(object) {
	// REQUIRED
	var aPos = object.a; // array: [x,y]
	var bPos = object.b; // array: [x,y]
	var cPos = object.c; // array: [x,y]

	// OPTIONAL
	var angleType = object.angleType || 'radians';

	// Work out the angles seperately - measured in radians anti-clockwise from north
	var m1 = (bPos[1] - aPos[1]) / (aPos[0] - bPos[0]);
	var angle1 = (Math.PI / 2 - Math.atan(m1));
	if (aPos[0] <= bPos[0])
		angle1 += Math.PI;
	if (aPos[0] == bPos[0]) { // if infinite gradient
		if (aPos[1] < bPos[1]) {
			angle1 = 0;
		} else {
			angle1 = Math.PI;
		}
	}

	var m2 = (cPos[1] - bPos[1]) / (bPos[0] - cPos[0]);
	var angle2 = (Math.PI / 2 - Math.atan(m2));
	if (bPos[0] >= cPos[0])
		angle2 += Math.PI;
	if (bPos[0] == cPos[0]) { // if infinite gradient
		if (bPos[1] > cPos[1]) {
			angle2 = 0;
		} else {
			angle2 = Math.PI;
		}
	}

	var angleDiff = angle2 - angle1;
	if (angle1 > angle2)
		angleDiff = angle2 - (angle1 - 2 * Math.PI);
	if (angleType == 'degrees')
		angleDiff = angleDiff * 180 / Math.PI;

	return angleDiff;
}
function drawAngle(obj) {
	// REQUIRED
	var ctx = obj.ctx || obj.context;
	var aPos = obj.a; // array: [x,y]
	var bPos = obj.b; // array: [x,y]
	var cPos = obj.c; // array: [x,y]

	// OPTIONAL
	if (typeof obj.sf !== 'undefined') {
		var sf = obj.sf;
	} else {
		var sf = 1;
	}
	if (sf !== 1) {
		aPos = [aPos[0] * sf, aPos[1] * sf];
		bPos = [bPos[0] * sf, bPos[1] * sf];
		cPos = [cPos[0] * sf, cPos[1] * sf];
	}
	var labelCtx = obj.labelCtx || ctx;
	var radius = obj.angleRadius * sf || obj.radius * sf || 35 * sf;
	var forceRightAngle = boolean(obj.forceRightAngle, false);
	var squareForRight = boolean(obj.squareForRight, true);
	var labelIfRight = boolean(obj.labelIfRight, false);

	var drawLines = boolean(obj.drawLines, false);
	var lineWidth = obj.lineWidth * sf || 4 * sf;
	var armWidth = obj.armWidth * sf || lineWidth;
	var lineColor = obj.lineColor || '#000';
	var armColor = obj.armColor || lineColor;

	var numOfCurves = obj.numOfCurves || 1;
	var curveGap = obj.curveGap || 4 * sf + lineWidth;

	var drawCurve = boolean(obj.drawCurve, true);
	var curveWidth = obj.curveWidth * sf || lineWidth;
	var curveColor = obj.curveColor || lineColor;

	var fill = boolean(obj.fill, false);
	var fillColor = obj.fillColor || '#CCF';
	if (fillColor == 'none')
		fill = false;

	var label = obj.label || [''];
	var labelFont = obj.labelFont || 'Arial';
	var labelFontSize = obj.labelFontSize * sf || 30 * sf;
	var labelColor = obj.labelColor || '#000';
	var labelRadius = obj.labelRadius * sf || radius * 1.1;
	var labelBox = obj.labelBox || {
		type: 'none'
	};
	if (boolean(obj.labelBackFill, false) === true) {
		labelBox = {
			type: 'tight',
			color: mainCanvasFillStyle,
			borderColor: mainCanvasFillStyle,
			padding: 0.1
		};
	}

	var labelMeasure = boolean(obj.labelMeasure, false);
	var measureRoundTo = obj.measureRoundTo || 1;
	var angleType = obj.angleType || 'degrees';

	function lowerCaseTest(string) {
		var upperCase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789lkhfdb'.split('');
		for (var i = 0; i < upperCase.length; i++) {
			if (string.indexOf(upperCase[i]) > -1)
				return false;
		}
		return true;
	}

	// Work out the angles required - measured in radians anti-clockwise from north
	var m1 = (bPos[1] - aPos[1]) / (aPos[0] - bPos[0]);
	var angle1 = (Math.PI / 2 - Math.atan(m1));
	if (aPos[0] <= bPos[0])
		angle1 += Math.PI;
	if (aPos[0] == bPos[0]) { // if infinite gradient
		if (aPos[1] < bPos[1]) {
			angle1 = 0;
		} else {
			angle1 = Math.PI;
		}
	}

	var m2 = (cPos[1] - bPos[1]) / (bPos[0] - cPos[0]);
	var angle2 = (Math.PI / 2 - Math.atan(m2));
	if (bPos[0] >= cPos[0])
		angle2 += Math.PI;
	if (bPos[0] == cPos[0]) { // if infinite gradient
		if (bPos[1] > cPos[1]) {
			angle2 = 0;
		} else {
			angle2 = Math.PI;
		}
	}

	var angleDiff = angle2 - angle1;
	if (angle1 > angle2) angleDiff = angle2 - (angle1 - 2 * Math.PI);

	// test if right-angled
	if (forceRightAngle == true || (squareForRight == true && roundToNearest(angleDiff * 180 / Math.PI, measureRoundTo) == 90)) {
		var dAngle = angle1 + 0.5 * angleDiff;
		if (angle1 > angle2) {
			dAngle = (angle1 - 2 * Math.PI) + 0.5 * angleDiff;
		}
		var dPos = [bPos[0] + radius * Math.cos(dAngle - Math.PI / 2), bPos[1] + radius * Math.sin(dAngle - Math.PI / 2)];

		// other vertices of the square
		var abLength = Math.sqrt(Math.pow(bPos[0] - aPos[0], 2) + Math.pow(bPos[1] - aPos[1], 2));
		var aPos2 = [bPos[0] + (aPos[0] - bPos[0]) * radius / (abLength * Math.sqrt(2)), bPos[1] + (aPos[1] - bPos[1]) * radius / (abLength * Math.sqrt(2))];

		var bcLength = Math.sqrt(Math.pow(bPos[0] - cPos[0], 2) + Math.pow(bPos[1] - cPos[1], 2));
		var cPos2 = [bPos[0] + (cPos[0] - bPos[0]) * radius / (bcLength * Math.sqrt(2)), bPos[1] + (cPos[1] - bPos[1]) * radius / (bcLength * Math.sqrt(2))];

		if (fill == true) {
			ctx.fillStyle = fillColor;
			ctx.beginPath();
			ctx.moveTo(bPos[0], bPos[1]);
			ctx.lineTo(aPos2[0], aPos2[1]);
			ctx.lineTo(dPos[0], dPos[1]);
			ctx.lineTo(cPos2[0], cPos2[1]);
			ctx.closePath();
			ctx.fill();
		}

		if (drawLines == true) {
			ctx.strokeStyle = armColor;
			ctx.lineWidth = armWidth;
			ctx.beginPath();
			ctx.joinCap = 'round';
			ctx.moveTo(aPos[0], aPos[1]);
			ctx.lineTo(bPos[0], bPos[1]);
			ctx.lineTo(cPos[0], cPos[1]);
			ctx.stroke();
		}

		if (drawCurve == true) {
			ctx.strokeStyle = curveColor;
			ctx.lineWidth = curveWidth;
			ctx.beginPath();
			ctx.moveTo(aPos2[0], aPos2[1]);
			ctx.lineTo(dPos[0], dPos[1]);
			ctx.lineTo(cPos2[0], cPos2[1]);
			ctx.stroke();
		}

		if (labelIfRight == true) {
			if (labelMeasure == true) {
				var angleDiff2 = angleDiff;
				if (angleType == 'degrees')
					angleDiff2 = angleDiff2 * 180 / Math.PI;
				angleDiff2 = roundToNearest(angleDiff2, measureRoundTo);
				label = [String(angleDiff2)];
				if (angleType == 'degrees') {
					label = [String(angleDiff2) + String.fromCharCode(0x00B0)]
				};
			}

			// work out label position
			// d is midPoint of ac
			var dAngle = angle1 + 0.5 * angleDiff;
			if (angle1 > angle2) {
				dAngle = (angle1 - 2 * Math.PI) + 0.5 * angleDiff;
			}
			var dPos = [bPos[0] + 1.85 * radius * Math.cos(dAngle - Math.PI / 2), bPos[1] + 1.85 * radius * Math.sin(dAngle - Math.PI / 2)];

			if (labelCtx == ctx) {
				drawMathsText(labelCtx, label, labelFontSize, dPos[0], dPos[1] + 0.5 * labelFontSize, true, [], 'center', 'bottom');
			} else {
				var labelCanvas = labelCtx.canvas;
				var labelWidth = labelCanvas.width;
				var labelHeight = labelCanvas.height;
				//console.log(taskObject,pageIndex);
				//var canvasNum = taskObject.indexOf(labelCanvas);
				//var labelData = taskObjectData[canvasNum];

				labelCtx.clearRect(0, 0, labelWidth, labelHeight);

				drawMathsText(labelCtx, label, labelFontSize, 0.5 * labelWidth, 0.5 * labelHeight + 0.5 * labelFontSize, true, [], 'center', 'bottom');
				labelCanvas.data[100] = dPos[0] - 0.5 * labelWidth;
				labelCanvas.data[101] = dPos[1] - 0.5 * labelHeight;
				resizeCanvas3(labelCanvas);
			}
		} else if (labelCtx !== ctx) {
			var labelCanvas = labelCtx.canvas;
			var labelWidth = labelCanvas.width;
			var labelHeight = labelCanvas.height;
			labelCtx.clearRect(0, 0, labelWidth, labelHeight);
		}

	} else {
		// points at the end of the arc drawn for the angle
		var abLength = Math.sqrt(Math.pow(bPos[0] - aPos[0], 2) + Math.pow(bPos[1] - aPos[1], 2));
		var aPos2 = [bPos[0] + (aPos[0] - bPos[0]) * radius / abLength, bPos[1] + (aPos[1] - bPos[1]) * radius / abLength];

		var bcLength = Math.sqrt(Math.pow(bPos[0] - cPos[0], 2) + Math.pow(bPos[1] - cPos[1], 2));
		var cPos2 = [bPos[0] + (cPos[0] - bPos[0]) * radius / bcLength, bPos[1] + (cPos[1] - bPos[1]) * radius / bcLength];

		if (labelMeasure == true) {
			var angleDiff2 = angleDiff;
			if (angleType == 'degrees')
				angleDiff2 = angleDiff2 * 180 / Math.PI;
			angleDiff2 = roundToNearest(angleDiff2, measureRoundTo);
			label = [String(angleDiff2)];
			if (angleType == 'degrees') {
				label = [String(angleDiff2) + String.fromCharCode(0x00B0)]
			};
		}

		// work out label position
		// d is midPoint of ac
		var dAngle = angle1 + 0.5 * angleDiff;
		if (angle1 > angle2) {
			dAngle = (angle1 - 2 * Math.PI) + 0.5 * angleDiff;
		}

		var labelRadiusFactor = 1.5 + 0.11 * (removeTags(label[0]).length - 1);
		var lowerCaseOnly = lowerCaseTest(removeTags(label[0]));
		var lcHeightAdjust = 0;
		if (lowerCaseOnly == true)
			lcHeightAdjust = labelFontSize / 5;

		if (dAngle < Math.PI / 6 || dAngle > 11 * Math.PI / 6 || (dAngle > 5 * Math.PI / 6 && dAngle < 7 * Math.PI / 6)) {
			labelRadiusFactor = labelRadiusFactor * 0.9;
		} else if (dAngle < Math.PI / 4 || dAngle > 7 * Math.PI / 4 || (dAngle > 3 * Math.PI / 4 && dAngle < 5 * Math.PI / 4)) {
			labelRadiusFactor = labelRadiusFactor * 0.95;
		}

		var dPos = [bPos[0] + labelRadiusFactor * labelRadius * Math.cos(dAngle - Math.PI / 2), bPos[1] + labelRadiusFactor * labelRadius * Math.sin(dAngle - Math.PI / 2) - lcHeightAdjust];

		/* draw a dot at dPos (for testing angle label position
		ctx.fillStyle = '#F00';
		ctx.beginPath();
		ctx.arc(dPos[0],dPos[1],8,0,2*Math.PI);
		ctx.closePath();
		ctx.fill();
		//*/

		label.unshift('<<color:' + labelColor + '>><<fontSize:' + labelFontSize + '>><<font:' + labelFont + '>>');

		if (fill == true && boolean(obj.measureOnly, true) == true) {
			ctx.fillStyle = fillColor;
			ctx.beginPath();
			ctx.moveTo(bPos[0], bPos[1]);
			ctx.lineTo(aPos2[0], aPos2[1]);
			ctx.arc(bPos[0], bPos[1], radius, angle1 - 0.5 * Math.PI, angle2 - 0.5 * Math.PI);
			ctx.lineTo(cPos2[0], cPos2[1]);
			ctx.closePath();
			ctx.fill();
		}
		
		if (drawLines == true && boolean(obj.measureOnly, true) == true) {
			ctx.strokeStyle = armColor;
			ctx.lineWidth = armWidth;
			ctx.joinCap = 'round';
			ctx.beginPath();
			ctx.moveTo(aPos[0], aPos[1]);
			ctx.lineTo(bPos[0], bPos[1]);
			ctx.lineTo(cPos[0], cPos[1]);
			ctx.stroke();
		}
		
		if (drawCurve == true && boolean(obj.measureOnly, true) == true) {
			ctx.strokeStyle = curveColor;
			ctx.lineWidth = curveWidth;
			if (numOfCurves == 1) {
				ctx.beginPath();
				ctx.moveTo(aPos2[0], aPos2[1]);
				ctx.arc(bPos[0], bPos[1], Math.abs(radius), angle1 - 0.5 * Math.PI, angle2 - 0.5 * Math.PI);
				ctx.stroke();
			} else if (numOfCurves == 2) {
				ctx.beginPath();
				ctx.arc(bPos[0], bPos[1], Math.abs(radius - curveGap / 2), angle1 - 0.5 * Math.PI, angle2 - 0.5 * Math.PI);
				ctx.stroke();
				ctx.beginPath();
				ctx.arc(bPos[0], bPos[1], Math.abs(radius + curveGap / 2), angle1 - 0.5 * Math.PI, angle2 - 0.5 * Math.PI);
				ctx.stroke();
			} else if (numOfCurves == 3) {
				ctx.beginPath();
				ctx.arc(bPos[0], bPos[1], Math.abs(radius - curveGap), angle1 - 0.5 * Math.PI, angle2 - 0.5 * Math.PI);
				ctx.stroke();
				ctx.beginPath();
				ctx.arc(bPos[0], bPos[1], Math.abs(radius), angle1 - 0.5 * Math.PI, angle2 - 0.5 * Math.PI);
				ctx.stroke();
				ctx.beginPath();
				ctx.arc(bPos[0], bPos[1], Math.abs(radius + curveGap), angle1 - 0.5 * Math.PI, angle2 - 0.5 * Math.PI);
				ctx.stroke();
			}
		}

		if (labelCtx == ctx) {
			if (boolean(obj.measureLabelOnly, false) == true) {
				var angleLabelPos = [dPos[0] - 57.8 / 2, dPos[1] - 25, 57.8, 50];
			} else {
				var angleLabelPos = text({
						ctx: labelCtx,
						left: dPos[0] - 200,
						top: dPos[1] - 200,
						width: 400,
						height: 400,
						textArray: label,
						align: 'center',
						vertAlign: 'middle',
						box: labelBox,
						minTightWidth: 1,
						minTightHeight: 1
					}).tightRect;
			}
		} else {
			var labelCanvas = labelCtx.canvas;
			var labelWidth = labelCanvas.width;
			var labelHeight = labelCanvas.height;
			//var canvasNum = taskObject[pageIndex].indexOf(labelCanvas);
			//var labelData = taskObjectData[pageIndex][canvasNum];

			labelCtx.clearRect(0, 0, labelWidth, labelHeight);

			drawMathsText(labelCtx, label, labelFontSize, 0.5 * labelWidth, 0.5 * labelHeight + 0.5 * labelFontSize, true, [], 'center', 'bottom');
			labelCanvas.data[100] = dPos[0] - 0.5 * labelWidth;
			labelCanvas.data[101] = dPos[1] - 0.5 * labelHeight;
			resizeCanvas3(labelCanvas);
			//resize();
		}
	}
	return angleLabelPos;

}
function getAngleMidAngle(obj) {
	// Work out the angles required - measured in radians anti-clockwise from north
	var m1 = (obj.b[1] - obj.a[1]) / (obj.a[0] - obj.b[0]);
	var angle1 = (Math.PI / 2 - Math.atan(m1));
	if (obj.a[0] <= obj.b[0])
		angle1 += Math.PI;
	if (obj.a[0] == obj.b[0]) { // if infinite gradient
		if (obj.a[1] < obj.b[1]) {
			angle1 = 0;
		} else {
			angle1 = Math.PI;
		}
	}

	var m2 = (obj.c[1] - obj.b[1]) / (obj.b[0] - obj.c[0]);
	var angle2 = (Math.PI / 2 - Math.atan(m2));
	if (obj.b[0] >= obj.c[0])
		angle2 += Math.PI;
	if (obj.b[0] == obj.c[0]) { // if infinite gradient
		if (obj.b[1] > obj.c[1]) {
			angle2 = 0;
		} else {
			angle2 = Math.PI;
		}
	}
	
	if (angle1 > angle2) {
		var angleDiff = angle2 - (angle1 - 2 * Math.PI);
	} else {
		var angleDiff = angle2 - angle1;
	}
	
	var dAngle = angle1 + 0.5 * angleDiff;
	if (angle1 > angle2) {
		dAngle = (angle1 - 2 * Math.PI) + 0.5 * angleDiff;
	}
	return dAngle - Math.PI / 2;
}
function getAngleLabelPos(obj,radius) {
	var angle = getAngleMidAngle(obj);
	return [obj.b[0]+radius*Math.cos(angle),obj.b[1]+radius*Math.sin(angle)]
}
function drawStar(obj) {
	var ctx = obj.ctx;
	var c = obj.center || obj.c;
	var r = obj.radius || obj.r;
	var p = obj.points || obj.p || 5;
	var s = obj.step || obj.s || 2;
	var vertices = [];
	for (var i = 0; i < p; i++) {
		var angle = -Math.PI / 2 + i * (2 * Math.PI) / p;
		vertices.push([c[0] + r * Math.cos(angle), c[1] + r * Math.sin(angle)]);
	}
	ctx.moveTo(vertices[0][0], vertices[0][1]);
	for (var i = p; i >= 0; i--) {
		ctx.lineTo(vertices[(i * s) % p][0], vertices[(i * s) % p][1]);
	}
}
function drawAnglesAroundPoint(obj) {
	/* eg.
	drawAnglesAroundPoint({
	ctx:ctx1,
	center:[400,300],
	points:[[300,300],[400,200],[450,250],[480,320]],
	lineColor:'#000',
	thickness:4,
	angles:[{fill:true,fillColor:"#CFC",lineWidth:2,labelFontSize:25,labelMeasure:true,labelRadius:33,radius:30},{fill:false,fillColor:"#CFC",lineWidth:2,labelFontSize:25,labelMeasure:true,labelRadius:33,radius:30},{fill:true,fillColor:"#CFC",lineWidth:2,labelFontSize:25,labelMeasure:true,labelRadius:33,radius:30},{fill:false,fillColor:"#CFC",lineWidth:2,labelFontSize:25,labelMeasure:true,labelRadius:33,radius:30}
	]
	});
	 */

	// required
	var ctx = obj.ctx;
	var points = obj.points;
	var center = obj.center;

	// optional
	var lineColor = obj.lineColor || obj.color || false;
	var lineWidth = obj.lineWidth || obj.thickness || false;
	var angles = obj.angles || [];

	ctx.save();
	ctx.lineJoin = 'round';
	ctx.lineCap = 'round';
	ctx.lineWidth = lineWidth;
	ctx.strokeStye = lineColor;

	var angleLabelPos = [];

	for (var i = 0; i < points.length; i++) {
		if (typeof angles[i] == 'object' && angles[i] !== null) {
			angles[i].ctx = ctx;
			angles[i].b = center;
			angles[i].a = points[i];
			if (i == points.length - 1) {
				angles[i].c = points[0];
			} else {
				angles[i].c = points[i + 1];
			}
			angles[i].drawLines = false;
			if (typeof angles[i].lineWidth == 'undefined')
				angles[i].lineWidth = ctx.lineWidth;
			if (typeof angles[i].lineColor == 'undefined')
				angles[i].lineColor = ctx.lineWidth;
			if (typeof angles[i].labelColor == 'undefined')
				angles[i].labelColor = ctx.strokeStyle;
			angleLabelPos[i] = drawAngle(angles[i]);
		}
	}

	ctx.lineWidth = lineWidth;
	ctx.strokeStye = lineColor;
	ctx.beginPath();
	for (var p = 0; p < points.length; p++) {
		ctx.moveTo(center[0], center[1]);
		ctx.lineTo(points[p][0], points[p][1]);
	}
	ctx.stroke();
	ctx.restore();

	return angleLabelPos;
}
function drawCylinder(obj) {
	var ctx = obj.ctx;
	var pos = obj.pos; // position of centre of base
	var h = obj.h || obj.height;
	var r = obj.r || obj.radius;

	var direction = obj.direction || obj.dir || 'vert'; // 'vert', 'horiz1' or 'horiz2'
	var angle = obj.angle || Math.PI / 6; // for 'horiz2' only

	var lineWidth = obj.lineWidth || obj.thickness || false;
	var lineColor = obj.lineColor || obj.color || false;
	var lineDash = obj.lineDash || [];

	ctx.save();
	if (lineWidth !== false)
		ctx.lineWidth = lineWidth;
	if (lineColor !== false)
		ctx.strokeStyle = lineColor;
	ctx.lineJoin = 'round';
	ctx.lineCap = 'round';

	var transparent = boolean(obj.transparent, true);
	var backLineWidth = obj.lineWidth;
	var backLineColor = obj.backLineWidth || getShades(ctx.strokeStyle)[8];
	var backLineDash = obj.backLineDash || [7, 10];

	var fill = boolean(obj.fill, false);
	if (typeof obj.fillColors !== 'undefined') {
		var fillColors = obj.fillColors;
	} else if (typeof obj.fillColor !== 'undefined') {
		var fillColors = [obj.fillColor, obj.fillColor];
	} else {
		var fillColors = ['#FCC', '#CFC'];
	}

	ctx.translate(pos[0], pos[1]);

	if (direction == 'vert') {
		ctx.scale(1, 0.4);

		// draw back of bottom ellipse
		if (transparent == true && fill == false) {
			ctx.save();
			ctx.lineWidth = backLineWidth;
			ctx.strokeStyle = backLineColor;
			ctx.setLineDash(backLineDash);
			ctx.beginPath();
			ctx.arc(0, 0, r, Math.PI, 2 * Math.PI);
			ctx.stroke();
			ctx.restore();
		}

		// draw front
		ctx.beginPath();
		ctx.moveTo(r, 0);
		ctx.arc(0, 0, r, 0, Math.PI);
		ctx.lineTo(-r, -h / 0.4);
		ctx.arc(0, -h / 0.4, r, Math.PI, 0, true);
		ctx.lineTo(r, 0);
		if (fill == true) {
			ctx.fillStyle = fillColors[0];
			ctx.fill();
		}
		ctx.stroke();

		// draw top
		ctx.beginPath();
		ctx.arc(0, -h / 0.4, r, 0, 2 * Math.PI);
		if (fill == true && typeof fillColors[1] !== 'undefined' && fillColors[1] !== 'none' && fillColors[1] !== false) {
			ctx.fillStyle = fillColors[1];
			ctx.fill();
		}
		ctx.stroke();
	} else if (direction == 'horiz1') {
		ctx.scale(0.4, 1);

		// draw back of right ellipse
		if (transparent == true && fill == false) {
			ctx.save();
			ctx.lineWidth = backLineWidth;
			ctx.strokeStyle = backLineColor;
			ctx.setLineDash(backLineDash);
			ctx.beginPath();
			ctx.arc(0, 0, r, 0.5 * Math.PI, 1.5 * Math.PI);
			ctx.stroke();
			ctx.restore();
		}

		// draw front
		ctx.beginPath();
		ctx.moveTo(0, r);
		ctx.arc(0, 0, r, 0.5 * Math.PI, 1.5 * Math.PI, true);
		ctx.lineTo(-h / 0.4, -r);
		ctx.arc(-h / 0.4, 0, r, 1.5 * Math.PI, 0.5 * Math.PI);
		ctx.lineTo(0, r);
		if (fill == true) {
			ctx.fillStyle = fillColors[0];
			ctx.fill();
		}
		ctx.stroke();

		// draw left ellipse
		ctx.beginPath();
		ctx.arc(-h / 0.4, 0, r, 0, 2 * Math.PI);
		if (fill == true && typeof fillColors[1] !== 'undefined' && fillColors[1] !== 'none' && fillColors[1] !== false) {
			ctx.fillStyle = fillColors[1];
			ctx.fill();
		}
		ctx.stroke();
	} else if (direction == 'horiz2') {
		var pos2 = [h * Math.cos(angle), -h * Math.sin(angle)];
		var angle1 = Math.PI / 2 - angle;
		var angle2 = -angle - 0.5 * Math.PI;
		var a = [r * Math.cos(angle1), r * Math.sin(angle1)];
		var b = [r * Math.cos(angle2), r * Math.sin(angle2)];
		var c = [pos2[0] + r * Math.cos(angle1), pos2[1] + r * Math.sin(angle1)];
		var d = [pos2[0] + r * Math.cos(angle2), pos2[1] + r * Math.sin(angle2)];

		// draw back of right circle
		if (transparent == true && fill == false) {
			ctx.save();
			ctx.lineWidth = backLineWidth;
			ctx.strokeStyle = backLineColor;
			ctx.setLineDash(backLineDash);
			ctx.beginPath();
			ctx.arc(pos2[0], pos2[1], r, angle1, angle2);
			ctx.stroke();
			ctx.restore();
		}

		// front
		ctx.beginPath();
		ctx.moveTo(d[0], d[1]);
		ctx.arc(pos2[0], pos2[1], r, angle2, angle1);
		ctx.lineTo(a[0], a[1]);
		ctx.arc(0, 0, r, angle1, angle2, true);
		ctx.lineTo(d[0], d[1]);
		if (fill == true) {
			ctx.fillStyle = fillColors[0];
			ctx.fill();
		}
		ctx.stroke();

		// front circle
		ctx.beginPath();
		ctx.arc(0, 0, r, 0, 2 * Math.PI);
		if (fill == true && typeof fillColors[1] !== 'undefined' && fillColors[1] !== 'none' && fillColors[1] !== false) {
			ctx.fillStyle = fillColors[1];
			ctx.fill();
		}
		ctx.stroke();
	}

	ctx.restore();
}
function drawCuboid(obj) {
	var ctx = obj.ctx;
	var x = obj.x || obj.pos[0];
	var y = obj.y || obj.pos[1];
	var z = obj.z || obj.pos[2];
	var xd = obj.xd || obj.dims[0];
	var yd = obj.yd || obj.dims[1];
	var zd = obj.zd || obj.dims[2];

	var labels = obj.labels;
	var unitBaseVectors = obj.unitBaseVectors || [[Math.sqrt(3) / 2, -1 / 2], [-Math.sqrt(3) / 2, -1 / 2], [0, -1]];
	var unitLength = obj.unitLength || 15;
	var baseVector = obj.baseVector || obj.baseVectors || [[unitLength * unitBaseVectors[0][0], unitLength * unitBaseVectors[0][1]], [unitLength * unitBaseVectors[1][0], unitLength * unitBaseVectors[1][1]], [unitLength * unitBaseVectors[2][0], unitLength * unitBaseVectors[2][1]]];
	var origin = obj.origin || [0, 700];
	var mag = obj.mag || 15;

	var lineWidth = obj.lineWidth || obj.thickness || false;
	var lineColor = obj.lineColor || obj.color || false;
	var lineDash = obj.lineDash || [];

	var showUnitCubes = boolean(obj.showUnitCubes, false);

	ctx.save();
	if (lineWidth !== false)
		ctx.lineWidth = lineWidth;
	if (lineColor !== false)
		ctx.strokeStyle = lineColor;
	ctx.lineJoin = 'round';
	ctx.lineCap = 'round';

	var transparent = boolean(obj.transparent, true);
	var backLineWidth = obj.lineWidth;
	var backLineColor = obj.backLineWidth || getShades(ctx.strokeStyle)[8];
	var backLineDash = obj.backLineDash || [7, 10];

	var fill = boolean(obj.fill, false);
	if (typeof obj.fillColors !== 'undefined') {
		var fillColors = obj.fillColors
	} else if (typeof obj.fillColor !== 'undefined') {
		var fillColors = [obj.fillColor, obj.fillColor, obj.fillColor];
	} else {
		var fillColors = ['#FCC', '#CFC', '#CCF'];
	}

	var cuboid = [[x, y, z], [x + xd, y, z], [x + xd, y + yd, z], [x, y + yd, z], [x, y, z + zd], [x + xd, y, z + zd], [x + xd, y + yd, z + zd], [x, y + yd, z + zd]];
	var cuboidPos = [];
	for (var v = 0; v < cuboid.length; v++) {
		cuboidPos[v] = [];

		cuboidPos[v][0] = origin[0];
		cuboidPos[v][0] += cuboid[v][0] * baseVector[0][0];
		cuboidPos[v][0] += cuboid[v][1] * baseVector[1][0];
		cuboidPos[v][0] += cuboid[v][2] * baseVector[2][0];

		cuboidPos[v][1] = origin[1];
		cuboidPos[v][1] += cuboid[v][0] * baseVector[0][1];
		cuboidPos[v][1] += cuboid[v][1] * baseVector[1][1];
		cuboidPos[v][1] += cuboid[v][2] * baseVector[2][1];
	}

	if (fill == true) {
		ctx.fillStyle = fillColors[0];
		if (baseVector[0][0] * baseVector[2][1] - baseVector[0][1] * baseVector[2][0] > 0) {
			ctx.beginPath();
			ctx.moveTo(cuboidPos[3][0], cuboidPos[3][1]);
			ctx.lineTo(cuboidPos[2][0], cuboidPos[2][1]);
			ctx.lineTo(cuboidPos[6][0], cuboidPos[6][1]);
			ctx.lineTo(cuboidPos[7][0], cuboidPos[7][1]);
			ctx.lineTo(cuboidPos[3][0], cuboidPos[3][1]);
			ctx.closePath();
			ctx.fill();
			ctx.stroke();
		} else {
			ctx.beginPath();
			ctx.moveTo(cuboidPos[0][0], cuboidPos[0][1]);
			ctx.lineTo(cuboidPos[1][0], cuboidPos[1][1]);
			ctx.lineTo(cuboidPos[5][0], cuboidPos[5][1]);
			ctx.lineTo(cuboidPos[4][0], cuboidPos[4][1]);
			ctx.lineTo(cuboidPos[0][0], cuboidPos[0][1]);
			ctx.closePath();
			ctx.fill();
			ctx.stroke();
		}

		ctx.fillStyle = fillColors[1];
		if (baseVector[0][0] * baseVector[1][1] - baseVector[0][1] * baseVector[1][0] > 0) {
			ctx.beginPath();
			ctx.moveTo(cuboidPos[0][0], cuboidPos[0][1]);
			ctx.lineTo(cuboidPos[1][0], cuboidPos[1][1]);
			ctx.lineTo(cuboidPos[2][0], cuboidPos[2][1]);
			ctx.lineTo(cuboidPos[3][0], cuboidPos[3][1]);
			ctx.lineTo(cuboidPos[0][0], cuboidPos[0][1]);
			ctx.closePath();
			ctx.fill();
			ctx.stroke();
		} else {
			ctx.beginPath();
			ctx.moveTo(cuboidPos[4][0], cuboidPos[4][1]);
			ctx.lineTo(cuboidPos[5][0], cuboidPos[5][1]);
			ctx.lineTo(cuboidPos[6][0], cuboidPos[6][1]);
			ctx.lineTo(cuboidPos[7][0], cuboidPos[7][1]);
			ctx.lineTo(cuboidPos[4][0], cuboidPos[4][1]);
			ctx.closePath();
			ctx.fill();
			ctx.stroke();
		}

		ctx.fillStyle = fillColors[2];
		if (baseVector[2][0] * baseVector[1][1] - baseVector[2][1] * baseVector[1][0] > 0) {
			ctx.beginPath();
			ctx.moveTo(cuboidPos[2][0], cuboidPos[2][1]);
			ctx.lineTo(cuboidPos[1][0], cuboidPos[1][1]);
			ctx.lineTo(cuboidPos[5][0], cuboidPos[5][1]);
			ctx.lineTo(cuboidPos[6][0], cuboidPos[6][1]);
			ctx.lineTo(cuboidPos[2][0], cuboidPos[2][1]);
			ctx.closePath();
			ctx.fill();
			ctx.stroke();
		} else {
			ctx.beginPath();
			ctx.moveTo(cuboidPos[0][0], cuboidPos[0][1]);
			ctx.lineTo(cuboidPos[3][0], cuboidPos[3][1]);
			ctx.lineTo(cuboidPos[7][0], cuboidPos[7][1]);
			ctx.lineTo(cuboidPos[4][0], cuboidPos[4][1]);
			ctx.lineTo(cuboidPos[0][0], cuboidPos[0][1]);
			ctx.closePath();
			ctx.fill();
			ctx.stroke();
		}
	}

	if (fill == false && transparent == true) {
		ctx.save();
		ctx.lineWidth = backLineWidth;
		ctx.strokeStyle = backLineColor;
		ctx.setLineDash(backLineDash);
		ctx.beginPath();
		ctx.moveTo(cuboidPos[1][0], cuboidPos[1][1]);
		ctx.lineTo(cuboidPos[2][0], cuboidPos[2][1]);
		ctx.moveTo(cuboidPos[2][0], cuboidPos[2][1]);
		ctx.lineTo(cuboidPos[3][0], cuboidPos[3][1]);
		ctx.moveTo(cuboidPos[2][0], cuboidPos[2][1]);
		ctx.lineTo(cuboidPos[6][0], cuboidPos[6][1]);
		ctx.stroke();
		ctx.restore();
	}

	ctx.beginPath();
	//base
	ctx.moveTo(cuboidPos[0][0], cuboidPos[0][1]);
	ctx.lineTo(cuboidPos[1][0], cuboidPos[1][1]);
	ctx.moveTo(cuboidPos[0][0], cuboidPos[0][1]);
	ctx.lineTo(cuboidPos[3][0], cuboidPos[3][1]);
	//sides
	ctx.moveTo(cuboidPos[0][0], cuboidPos[0][1]);
	ctx.lineTo(cuboidPos[4][0], cuboidPos[4][1]);
	ctx.moveTo(cuboidPos[1][0], cuboidPos[1][1]);
	ctx.lineTo(cuboidPos[5][0], cuboidPos[5][1]);
	ctx.moveTo(cuboidPos[3][0], cuboidPos[3][1]);
	ctx.lineTo(cuboidPos[7][0], cuboidPos[7][1]);
	//top
	ctx.moveTo(cuboidPos[4][0], cuboidPos[4][1]);
	ctx.lineTo(cuboidPos[5][0], cuboidPos[5][1]);
	ctx.lineTo(cuboidPos[6][0], cuboidPos[6][1]);
	ctx.lineTo(cuboidPos[7][0], cuboidPos[7][1]);
	ctx.lineTo(cuboidPos[4][0], cuboidPos[4][1]);
	ctx.closePath();
	ctx.stroke();

	/*
	ctx.fillStyle = '#FFC';
	ctx.fillRect(0.5*(cuboidPos[0][0]+cuboidPos[1][0])+8,0.5*(cuboidPos[0][1]+cuboidPos[1][1])-5,19,40);
	ctx.fillRect(0.5*(cuboidPos[0][0]+cuboidPos[3][0])-8,0.5*(cuboidPos[0][1]+cuboidPos[3][1])-5,-19,40);
	ctx.fillRect(0.5*(cuboidPos[3][0]+cuboidPos[7][0])-8,0.5*(cuboidPos[3][1]+cuboidPos[7][1])-5,-79,40);
	 */

	if (showUnitCubes == true) {
		ctx.beginPath();

		for (var i = 1; i < xd; i++) {
			var pos1 = interpolateTwoPoints(cuboidPos[0], cuboidPos[1], i / xd);
			var pos2 = interpolateTwoPoints(cuboidPos[4], cuboidPos[5], i / xd);
			ctx.moveTo(pos1[0], pos1[1]);
			ctx.lineTo(pos2[0], pos2[1]);

			var pos1 = interpolateTwoPoints(cuboidPos[4], cuboidPos[5], i / xd);
			var pos2 = interpolateTwoPoints(cuboidPos[7], cuboidPos[6], i / xd);
			ctx.moveTo(pos1[0], pos1[1]);
			ctx.lineTo(pos2[0], pos2[1]);
		}

		for (var i = 1; i < yd; i++) {
			var pos1 = interpolateTwoPoints(cuboidPos[3], cuboidPos[0], i / yd);
			var pos2 = interpolateTwoPoints(cuboidPos[7], cuboidPos[4], i / yd);
			ctx.moveTo(pos1[0], pos1[1]);
			ctx.lineTo(pos2[0], pos2[1]);

			var pos1 = interpolateTwoPoints(cuboidPos[6], cuboidPos[5], i / yd);
			var pos2 = interpolateTwoPoints(cuboidPos[7], cuboidPos[4], i / yd);
			ctx.moveTo(pos1[0], pos1[1]);
			ctx.lineTo(pos2[0], pos2[1]);
		}

		for (var i = 1; i < zd; i++) {
			var pos1 = interpolateTwoPoints(cuboidPos[0], cuboidPos[4], i / zd);
			var pos2 = interpolateTwoPoints(cuboidPos[1], cuboidPos[5], i / zd);
			ctx.moveTo(pos1[0], pos1[1]);
			ctx.lineTo(pos2[0], pos2[1]);

			var pos1 = interpolateTwoPoints(cuboidPos[0], cuboidPos[4], i / zd);
			var pos2 = interpolateTwoPoints(cuboidPos[3], cuboidPos[7], i / zd);
			ctx.moveTo(pos1[0], pos1[1]);
			ctx.lineTo(pos2[0], pos2[1]);
		}

		ctx.stroke();
	}

	if (typeof labels !== 'undefined') {
		text({
			ctx: ctx,
			left: 0.5 * (cuboidPos[0][0] + cuboidPos[1][0]) + 10,
			top: 0.5 * (cuboidPos[0][1] + cuboidPos[1][1]) - 5,
			width: 200,
			textArray: labels[0]
		});

		text({
			ctx: ctx,
			left: 0.5 * (cuboidPos[0][0] + cuboidPos[3][0]) - 210,
			top: 0.5 * (cuboidPos[0][1] + cuboidPos[3][1]) - 5,
			width: 200,
			align: 'right',
			textArray: labels[1]
		});

		text({
			ctx: ctx,
			left: 0.5 * (cuboidPos[3][0] + cuboidPos[7][0]) - 210,
			top: 0.5 * (cuboidPos[3][1] + cuboidPos[7][1]) - 5,
			width: 200,
			align: 'right',
			textArray: labels[2]
		});
	}
	ctx.restore();
}
function drawTreeDiagram(obj) {
	var ctx = obj.ctx;
	var left = obj.left;
	var top = obj.top;
	var width = obj.width;
	var height = obj.height;
	var branches = obj.branches || [2, 2];

	/*
	var endLabelFontSize = obj.endLabelFontSize || obj.fontSize || width/20;
	var midLabelFontSize = obj.midLabelFontSize || obj.fontSize || width/20
	var labels = obj.labels || [[['win','lose']],[['win','lose],['win','lose']]];
	var probabilities = obj.probabilities || [[[[1,2],[1,2]]],[[[1,3],[2,3]],[[3,4],[1,4]]]];
	var branchColors = obj.branchColors || [[['#000','#000']],[[['#F00','#00F'],['#000','#000']]]];
	var endLabelColors = obj.endLabelColors || [[['#000','#000']],[[['#F00','#00F'],['#000','#000']]]];
	var midLabelColors = obj.midLabelColors || [[['#000','#000']],[[['#F00','#00F'],['#000','#000']]]];
	var branchLineWidths = obj.branchLineWidths || [[[3]],[[3,3],[3,3]]];
	 */

	var labels = obj.labels || [['<<fontSize:30>>win'], ['<<fontSize:30>>draw'], ['<<fontSize:30>>lose']]
		var probabilities = obj.probabilities || [['<<fontSize:30>>', ['frac', ['1'], ['4']]], ['<<fontSize:30>>', ['frac', ['1'], ['2']]], ['<<fontSize:30>>', ['frac', ['1'], ['4']]]];

	var hiddenCanvas = document.createElement('canvas');
	var ctx2 = hiddenCanvas.getContext('2d');
	var labelTightRects = [];
	var maxLabelWidth = 0;
	for (var i = 0; i < labels.length; i++) {
		labelTightRects[i] = text({
				ctx: ctx2,
				textArray: labels[i],
				measureOnly: true
			}).tightRect;
		maxLabelWidth = Math.max(maxLabelWidth, labelTightRects[i][2] + 15);
	}

	var branchWidth = (width - maxLabelWidth * branches.length) / branches.length;

	ctx.save();
	ctx.lineWidth = 3;
	ctx.lineCap = 'round';
	ctx.lineJoin = 'round';

	for (var i = 0; i < branches.length; i++) { // each vertical set of branches
		var forkPoints = 1;
		if (i > 0) {
			for (var j = 0; j < i; j++) {
				forkPoints = forkPoints * branches[j];
			}
		}
		var startX = left + i * branchWidth + i * maxLabelWidth;
		var finX = startX + branchWidth;
		var h = height / forkPoints; // height of surrouding rect for this fork point;
		for (var j = 0; j < forkPoints; j++) {
			var t = top + j * h;
			var startY = t + 0.5 * h;
			for (var k = 0; k < branches[i]; k++) { // each branch emanating from the fork point
				if (branches[i] == 2) {
					var finY = t + ((2 * k + 1) / 4) * h;
				} else if (branches[i] == 3) {
					var finY = t + ((2 * k + 1) / 6) * h;
				}
				//draw branch
				ctx.beginPath();
				ctx.moveTo(startX, startY);
				ctx.lineTo(finX, finY);
				ctx.stroke();
				//draw endLabel
				text({
					ctx: ctx,
					textArray: labels[k],
					left: finX,
					top: finY - labelTightRects[k][3] / 2,
					width: maxLabelWidth,
					height: labelTightRects[k][3],
					align: 'center',
					horizAlign: 'middle',
					box: {
						type: 'none',
						borderColor: '#00F',
						padding: 0.001
					}
				});
				//draw midLabel
				var prob = probabilities[k];
				var measure = text({
						ctx: ctx2,
						textArray: prob,
						measureOnly: true
					}).tightRect;
				var l2 = (startX + finX) / 2 - measure[2] / 2;
				if (k < branches[i] - 1) {
					var t2 = (startY + finY) / 2 - measure[3] * 1.1;
				} else {
					var t2 = (startY + finY) / 2; ;
				}
				text({
					ctx: ctx,
					textArray: prob,
					left: l2,
					top: t2,
					width: measure[2],
					height: measure[3],
					align: 'center',
					horizAlign: 'middle',
					box: {
						type: 'none',
						borderColor: '#F00',
						padding: 0.001
					}
				});
			}
		}
	}
	ctx.restore();
}
function drawSpinner(context, center, radius, sectorAngles, sectorColors, arrowAngle, showArrow) {
	if (typeof arrowAngle == 'undefined')
		arrowAngle = -Math.PI / 4;
	var show = boolean(showArrow, true);

	//work out angles in radians;
	var vals = [];
	var total = 0;
	for (var val = 0; val < sectorAngles.length; val++) {
		total += sectorAngles[val];
	}
	var angles = [0]; // cumulative angle array
	for (var val = 0; val < sectorAngles.length; val++) {
		angles.push(angles[val] + (sectorAngles[val] / total) * 2 * Math.PI);
	}

	context.lineWidth = 4;
	context.strokeStyle = '#000';
	for (var val = 0; val < sectorAngles.length; val++) {
		// draw a sector
		context.fillStyle = sectorColors[val];
		context.beginPath();
		context.moveTo(center[0], center[1]);
		context.arc(center[0], center[1], radius, angles[val], angles[val + 1]);
		context.lineTo(center[0], center[1]);
		context.closePath();
		context.fill();
		context.stroke();
	}

	if (show == true) {
		context.strokeStyle = "#000";
		context.lineWidth = 4;
		context.beginPath();
		context.moveTo(center[0], center[1]);
		context.lineTo(center[0] + 0.75 * radius * Math.cos(arrowAngle), center[1] + 0.75 * radius * Math.sin(arrowAngle));
		context.stroke();
		drawArrow({
			context: context,
			startX: center[0],
			startY: center[1],
			finX: center[0] + 0.75 * radius * Math.cos(arrowAngle),
			finY: center[1] + 0.75 * radius * Math.sin(arrowAngle),
			arrowLength: 13,
			color: "#000000",
			lineWidth: 4,
			arrowLineWidth: 4,
			fillArrow: true
		});
		context.fillStyle = "#000";
		context.beginPath();
		context.arc(center[0], center[1], 5, 0, 2 * Math.PI);
		context.fill();
	}
}
function vennDiagram(obj) {
	var ctx = obj.ctx;
	var l = obj.left || obj.l || 0;
	var t = obj.top || obj.t || 0;
	var w = obj.width || obj.w || 400;
	var h = obj.height || obj.h || w * 0.65;
	var radius = obj.radius || obj.r || w * 0.25;
	var centerA = obj.centerA || [l + w * 0.35, t + h / 2];
	var centerB = obj.centerB || [l + w * 0.65, t + h / 2];
	var lineWidth = obj.lineWidth || 4;
	var lineDash = obj.lineDash || [];
	var strokeStyle = obj.strokeStyle || '#000';
	var colorA = obj.colorA || strokeStyle;
	var colorB = obj.colorB || strokeStyle;
	var labelA = obj.labelA || ['<<fontSize:' + (w / 12) + '>>A'];
	var labelB = obj.labelB || ['<<fontSize:' + (w / 12) + '>>B'];
	var fillStyle = obj.fillStyle || '#FCF';
	var shade = obj.shade || [false, false, false, false];

	ctx.save();
	if (typeof ctx.setLineDash == 'undefined')
		ctx.setLineDash = function () {};
	ctx.setLineDash(lineDash);
	ctx.strokeStyle = strokeStyle;
	ctx.lineWidth = lineWidth;
	ctx.strokeRect(l, t, w, h);

	ctx.beginPath();
	ctx.strokeStyle = colorA;
	ctx.arc(centerA[0], centerA[1], radius, 0, 2 * Math.PI);
	ctx.stroke();

	ctx.beginPath();
	ctx.strokeStyle = colorB;
	ctx.arc(centerB[0], centerB[1], radius, 0, 2 * Math.PI);
	ctx.stroke();

	var xy = [centerA[0] - (radius * 1.25) * Math.cos(Math.PI / 4), centerA[1] - (radius * 1.25) * Math.cos(Math.PI / 4)];
	text({
		ctx: ctx,
		textArray: labelA,
		left: xy[0] - 100,
		width: 200,
		top: xy[1] - 100,
		height: 200,
		textAlign: 'center',
		vertAlign: 'middle',
		padding: 0.1, /*box:{type:'tight',color:mainCanvasFillStyle,borderColor:mainCanvasFillStyle}*/
	});

	var xy = [centerB[0] + (radius * 1.25) * Math.cos(Math.PI / 4), centerB[1] - (radius * 1.25) * Math.cos(Math.PI / 4)];
	text({
		ctx: ctx,
		textArray: labelB,
		left: xy[0] - 100,
		width: 200,
		top: xy[1] - 100,
		height: 200,
		textAlign: 'center',
		vertAlign: 'middle',
		padding: 0.1, /*box:{type:'tight',color:mainCanvasFillStyle,borderColor:mainCanvasFillStyle}*/
	});

	ctx.restore();

	return {
		ctx: ctx,
		left: l,
		top: t,
		width: w,
		height: h,
		radius: radius,
		centerA: centerA,
		centerB: centerB,
		lineWidth: lineWidth,
		lineDash: lineDash,
		strokeStyle: strokeStyle,
		labelA: labelA,
		labelB: labelB,
		fillStyle: fillStyle,
		shade: shade
	};
}
function vennDiagram3(obj) {
	var ctx = obj.ctx;
	var l = obj.left || obj.l || 0;
	var t = obj.top || obj.t || 0;
	var w = obj.width || obj.w || 400;
	var h = obj.height || obj.h || w;
	var radius = obj.radius || obj.r || w * 0.27;
	var centerA = obj.centerA || [l + w * 0.5 + 0.6 * radius * Math.cos(Math.PI * (1 / 2 + 2 / 3)), t + h * 0.47 + 0.6 * radius * Math.sin(Math.PI * (1 / 2 + 2 / 3))];
	var centerB = obj.centerB || [l + w * 0.5 + 0.6 * radius * Math.cos(Math.PI * (1 / 2 + 4 / 3)), t + h * 0.47 + 0.6 * radius * Math.sin(Math.PI * (1 / 2 + 4 / 3))];
	var centerC = obj.centerC || [l + w * 0.5 + 0.6 * radius * Math.cos(Math.PI * (1 / 2)), t + h * 0.47 + 0.6 * radius * Math.sin(Math.PI * (1 / 2))];
	var lineWidth = obj.lineWidth || 4;
	var lineDash = obj.lineDash || [];
	var strokeStyle = obj.strokeStyle || '#000';
	var colorA = obj.colorA || strokeStyle;
	var colorB = obj.colorB || strokeStyle;
	var colorC = obj.colorC || strokeStyle;
	var labelA = obj.labelA || ['<<fontSize:' + (w / 10) + '>>A'];
	var labelB = obj.labelB || ['<<fontSize:' + (w / 10) + '>>B'];
	var labelC = obj.labelC || ['<<fontSize:' + (w / 10) + '>>C'];
	var fillStyle = obj.fillStyle || '#FCF';
	var shade = obj.shade || [false, false, false, false, false, false, false, false];

	ctx.save();
	if (typeof ctx.setLineDash == 'undefined')
		ctx.setLineDash = function () {};
	ctx.setLineDash(lineDash);
	ctx.strokeStyle = strokeStyle;
	ctx.lineWidth = lineWidth;
	ctx.strokeRect(l, t, w, h);

	ctx.beginPath();
	ctx.strokeStyle = colorA;
	ctx.arc(centerA[0], centerA[1], radius, 0, 2 * Math.PI);
	ctx.stroke();

	ctx.beginPath();
	ctx.strokeStyle = colorB;
	ctx.arc(centerB[0], centerB[1], radius, 0, 2 * Math.PI);
	ctx.stroke();

	ctx.beginPath();
	ctx.strokeStyle = colorC;
	ctx.arc(centerC[0], centerC[1], radius, 0, 2 * Math.PI);
	ctx.stroke();

	var xy = [centerA[0] - (radius * 1.25) * Math.cos(Math.PI / 4), centerA[1] - (radius * 1.25) * Math.cos(Math.PI / 4)];
	text({
		ctx: ctx,
		textArray: labelA,
		left: xy[0] - 100,
		width: 200,
		top: xy[1] - 100,
		height: 200,
		textAlign: 'center',
		vertAlign: 'middle',
		padding: 0.1, /*box:{type:'tight',color:mainCanvasFillStyle,borderColor:mainCanvasFillStyle}*/
	});

	var xy = [centerB[0] + (radius * 1.25) * Math.cos(Math.PI / 4), centerB[1] - (radius * 1.25) * Math.cos(Math.PI / 4)];
	text({
		ctx: ctx,
		textArray: labelB,
		left: xy[0] - 100,
		width: 200,
		top: xy[1] - 100,
		height: 200,
		textAlign: 'center',
		vertAlign: 'middle',
		padding: 0.1, /*box:{type:'tight',color:mainCanvasFillStyle,borderColor:mainCanvasFillStyle}*/
	});

	var xy = [centerC[0] + (radius * 1.25) * Math.cos(Math.PI / 4), centerC[1] + (radius * 1.25) * Math.cos(Math.PI / 4)];
	text({
		ctx: ctx,
		textArray: labelC,
		left: xy[0] - 100,
		width: 200,
		top: xy[1] - 100,
		height: 200,
		textAlign: 'center',
		vertAlign: 'middle',
		padding: 0.1, /*box:{type:'tight',color:mainCanvasFillStyle,borderColor:mainCanvasFillStyle}*/
	});

	ctx.restore();

	return {
		ctx: ctx,
		left: l,
		top: t,
		width: w,
		height: h,
		radius: radius,
		centerA: centerA,
		centerB: centerB,
		centerC: centerC,
		lineWidth: lineWidth,
		lineDash: lineDash,
		strokeStyle: strokeStyle,
		labelA: labelA,
		labelB: labelB,
		labelC: labelC,
		fillStyle: fillStyle,
		shade: shade
	};
}
function drawIsometricDotty(object) {
	// required
	var ctx = object.ctx || object.context;

	// options
	var left = object.left || object.l || 0;
	var top = object.top || object.t || 100;
	var width = object.width || object.w || 1200;
	var height = object.height || object.h || 700;
	var spacingFactor = object.spacingFactor || 15;
	var color = object.color || '#AAA';
	var origin = object.origin || [left + 0.5 * width, top + 0.5 * height];
	var radius = object.radius || 5;

	if (object.direction == 1) {
		var baseVector = [
			[-5 * (1 / 2),5 * (Math.sqrt(3) / 2)],
			[-5 * (1 / 2),-5 * (Math.sqrt(3) / 2)],
			[5, 0]
		];
	} else {
		var baseVector = [
			[5 * (Math.sqrt(3) / 2), -5 * (1 / 2)],
			[-5 * (Math.sqrt(3) / 2), -5 * (1 / 2)],
			[0, -5]
		];
	}
	var points = [];
	var x,
	y;

	for (var i = 0; i < 2; i++) {
		x = origin[0];
		y = origin[1];
		while (x >= left && y >= top && x <= left + width && y <= top + height) {
			points.push([x, y]);
			x += spacingFactor * baseVector[i][0];
			y += spacingFactor * baseVector[i][1];
		}
	}

	for (var i = 0, lim = points.length; i < lim; i++) {
		x = points[i][0];
		y = points[i][1];
		while (x >= left && y >= top && x <= left + width && y <= top + height) {
			points.push([x, y]);
			x += spacingFactor * baseVector[2][0];
			y += spacingFactor * baseVector[2][1];
		}
		x = points[i][0];
		y = points[i][1];
		while (x >= left && y >= top && x <= left + width && y <= top + height) {
			points.push([x, y]);
			x -= spacingFactor * baseVector[2][0];
			y -= spacingFactor * baseVector[2][1];
		}
	}

	// remove out-of-range and duplicate points
	for (var i = points.length - 1; i >= 0; i--) {
		for (var j = i - 1; j >= 0; j--) {
			if (arraysEqual(points[i], points[j]) == true) {
				points.splice(i, 1);
				break;
			}
		}
	}

	ctx.save();
	ctx.fillStyle = color;
	for (var i = 0; i < points.length; i++) {
		ctx.beginPath();
		ctx.arc(points[i][0], points[i][1], radius, 0, 2 * Math.PI);
		ctx.fill();
	}
	ctx.restore();
	return points;
}

function drawSquareDotty(object) {
	// required
	var ctx = object.ctx || object.context;

	// options
	var left = object.left || object.l || 0;
	var top = object.top || object.t || 100;
	var width = object.width || object.w || 1200;
	var height = object.height || object.h || 700;
	var spacingFactor = object.spacingFactor || 80;
	var color = object.color || '#AAA';
	var origin = object.origin || [left + 0.5 * width, top + 0.5 * height];
	var radius = object.radius || 5;

	var points = [];
	var x,
	y;

	x = origin[0];
	y = origin[1];
	while (x >= left && y >= top && x <= left + width && y <= top + height) {
		points.push([x, y]);
		x += spacingFactor;
	}

	x = origin[0] - spacingFactor;
	while (x >= left && y >= top && x <= left + width && y <= top + height) {
		points.push([x, y]);
		x -= spacingFactor;
	}

	for (var i = 0, lim = points.length; i < lim; i++) {
		x = points[i][0];
		y = points[i][1] + spacingFactor;
		while (x >= left && y >= top && x <= left + width && y <= top + height) {
			points.push([x, y]);
			y += spacingFactor;
		}
		y = points[i][1] - spacingFactor;
		while (x >= left && y >= top && x <= left + width && y <= top + height) {
			points.push([x, y]);
			y -= spacingFactor;
		}
	}

	// remove duplicate points
	for (var i = points.length - 1; i >= 0; i--) {
		for (var j = i - 1; j >= 0; j--) {
			if (arraysEqual(points[i], points[j]) == true) {
				points.splice(i, 1);
				break;
			}
		}
	}

	ctx.save();
	ctx.fillStyle = color;
	for (var i = 0; i < points.length; i++) {
		ctx.beginPath();
		ctx.arc(points[i][0], points[i][1], radius, 0, 2 * Math.PI);
		ctx.fill();
	}
	ctx.restore();
	return points;
}
function drawNumberLine(object) {
	var context = object.context;
	var left = object.left;
	var top = object.top;
	var width = object.width;
	var height = object.height;
	var min = object.min;
	var max = object.max;
	var majorStep = object.majorStep;
	var minorStep = object.minorStep;

	var minorYPos = [0.5, 0.75];
	if (typeof object.minorYPos == 'object')
		minorYPos = object.minorYPos;
	var majorYPos = [0.25, 0.75];
	if (typeof object.majorYPos == 'object')
		majorYPos = object.majorYPos;
	var minorWidth = object.minorWidth || 1.2;
	var majorWidth = object.majorWidth || 2;
	var minorColor = object.minorColor || '#CCC';
	var majorColor = object.majorColor || '#000';
	var lineWidth = object.lineWidth || 4;
	var lineColor = object.lineColor || '#000';

	var autoLabel = boolean(object.autoLabel, true);
	var labels = object.labels;
	var font = object.font || 'Arial';
	var fontSize = object.fontSize || 24;
	var textColor = object.textColor || majorColor;

	var minorSpacing = (width * minorStep) / (max - min);
	var majorSpacing = (width * majorStep) / (max - min);

	var x0 = left - (min * width) / (max - min);

	// draw minor markings
	context.strokeStyle = minorColor;
	context.lineWidth = minorWidth;
	context.beginPath();
	var startValue = Math.abs(min % minorStep);
	var axisPos = left;
	while (axisPos - (left + width) <= 0.1) {
		context.moveTo(axisPos, top + minorYPos[0] * height);
		context.lineTo(axisPos, top + minorYPos[1] * height);
		axisPos += minorSpacing;
	}
	context.stroke();
	// draw major markings
	context.strokeStyle = majorColor;
	context.lineWidth = majorWidth;
	var startValue = Math.abs(min % majorStep);
	var axisPos = left + startValue * majorSpacing;
	var num = min + startValue;
	var count = 0;
	while (axisPos - (left + width) <= 0.1) {
		context.moveTo(axisPos, top + majorYPos[0] * height);
		context.lineTo(axisPos, top + majorYPos[1] * height);
		if (autoLabel == true) {
			text({
				context: context,
				left: axisPos - 100,
				width: 200,
				top: top + 0.75 * height,
				textArray: ['<<align:center>><<font:' + font + '>><<fontSize:' + fontSize + '>><<color:' + textColor + '>>' + num]
			})
		} else if (typeof labels == 'object' && typeof labels[count] !== 'undefined') {
			text({
				context: context,
				left: axisPos - 100,
				width: 200,
				top: top + 0.75 * height,
				textArray: ['<<align:center>><<font:' + font + '>><<fontSize:' + fontSize + '>><<color:' + textColor + '>>' + labels[count]]
			})
		}
		count++;
		num += majorStep;
		axisPos += majorSpacing;
	}
	context.stroke();
	context.strokeStyle = lineColor;
	context.lineWidth = lineWidth;
	context.moveTo(left, top + 0.5 * height);
	context.lineTo(left + width, top + 0.5 * height);
	context.stroke();
}
function drawNumberLine2(obj) {
	var ctx = obj.ctx || obj.context;
	ctx.save();
	ctx.lineJoin = 'round';
	ctx.lineCap = 'round';
	var vertical = boolean(obj.vertical, false);

	if (un(obj.rect))
		obj.rect = [];
	var left = obj.left || obj.rect[0];
	var top = obj.top || obj.rect[1];
	var width = obj.width || obj.rect[2];
	var height = obj.height || obj.rect[3];
	if (vertical == true) {
		if (width > height) {
			var temp = width;
			width = height;
			height = temp;
		}
	}
	var min = Math.min(obj.min, obj.max);
	var max = Math.max(obj.min, obj.max);
	if (min >= max) {
		console.log('Check numberline min & max.');
		return;
	}
	var minorStep = obj.minorStep;
	var majorStep = obj.majorStep;

	var scaleOffset = obj.scaleOffset || 15;

	var minorYPos = [0.5, 0.75];
	if (typeof obj.minorYPos == 'object')
		minorYPos = obj.minorYPos;
	var majorYPos = [0.25, 0.75];
	if (typeof obj.majorYPos == 'object')
		majorYPos = obj.majorYPos;
	var minorWidth = obj.minorWidth || 1.2;
	var majorWidth = obj.majorWidth || 2;
	var minorColor = obj.minorColor || '#CCC';
	var majorColor = obj.majorColor || '#000';
	var lineWidth = obj.lineWidth || 4;
	var lineColor = obj.lineColor || '#000';
	var backColor = obj.backColor || mainCanvasFillStyle;

	var autoLabel = boolean(obj.autoLabel, true);
	var labels = obj.labels;
	var font = obj.font || 'Arial';
	var fontSize = obj.fontSize || 24;
	var textColor = obj.textColor || majorColor;

	if (vertical == true) {
		drawNumberlineVertical();
	} else {
		drawNumberlineHorizontal();
	}

	ctx.restore();

	function drawNumberlineHorizontal() {
		if (typeof obj.arrows == 'number') {
			left += obj.arrows;
			width -= 2 * obj.arrows;
		}
		var minorSpacing = (width * minorStep) / (max - min);
		var majorSpacing = (width * majorStep) / (max - min);
		var x0 = left - (min * width) / (max - min);

		if (boolean(obj.showMinorPos, true) == true) {
			ctx.strokeStyle = minorColor;
			ctx.lineWidth = minorWidth;
			ctx.beginPath();
			var xAxisPoint = x0 + minorSpacing;
			while (Math.round(xAxisPoint) <= Math.round(left + width)) {
				if (Math.round(xAxisPoint) >= Math.round(left)) {
					ctx.moveTo(xAxisPoint, top + minorYPos[0] * height);
					ctx.lineTo(xAxisPoint, top + minorYPos[1] * height);
					//console.log(xAxisPoint);
				}
				xAxisPoint += minorSpacing;
			}
			var xAxisPoint = x0 - minorSpacing;
			while (Math.round(xAxisPoint) >= Math.round(left)) {
				if (Math.round(xAxisPoint) <= Math.round(left + width)) {
					ctx.moveTo(xAxisPoint, top + minorYPos[0] * height);
					ctx.lineTo(xAxisPoint, top + minorYPos[1] * height);
					//console.log(xAxisPoint);
				}
				xAxisPoint -= minorSpacing;
			}
			ctx.closePath();
			ctx.stroke();
		}

		// draw major lines
		ctx.strokeStyle = majorColor;
		ctx.lineWidth = majorWidth;
		ctx.beginPath();
		var xAxisPoint = x0;
		while (Math.round(xAxisPoint) <= Math.round(left + width)) {
			if (Math.round(xAxisPoint) >= Math.round(left)) {
				ctx.moveTo(xAxisPoint, top + majorYPos[0] * height);
				ctx.lineTo(xAxisPoint, top + majorYPos[1] * height);
			}
			xAxisPoint += majorSpacing;
		}
		var xAxisPoint = x0 - majorSpacing;
		while (Math.round(xAxisPoint) >= Math.round(left)) {
			if (Math.round(xAxisPoint) <= Math.round(left + width)) {
				ctx.moveTo(xAxisPoint, top + majorYPos[0] * height);
				ctx.lineTo(xAxisPoint, top + majorYPos[1] * height);
			}
			xAxisPoint -= majorSpacing;
		}
		ctx.closePath();
		ctx.stroke();

		if (boolean(obj.showScales, true) == true) {
			// draw axes numbers
			ctx.font = fontSize + 'px Arial';
			ctx.textAlign = "center";
			ctx.textBaseline = "top";

			var xAxisPoint = x0;
			var major = 0;
			var placeValue = Math.pow(10, Math.floor(Math.log(majorStep) / Math.log(10)));
			while (roundToNearest(xAxisPoint, 0.001) <= roundToNearest(left + width, 0.001)) {
				if (xAxisPoint >= left) {
					var value = roundToNearest(major * majorStep, placeValue);
					var axisValue = [String(value)];
					var textWidth = ctx.measureText(String(axisValue)).width;
					ctx.fillStyle = backColor;
					ctx.fillRect(xAxisPoint - textWidth / 2, top + 0.5 * height + scaleOffset - 1, textWidth, fontSize * 1.1);
					var labelText = drawMathsText(ctx, axisValue, fontSize, xAxisPoint, top + 0.5 * height + scaleOffset + 0.5 * fontSize, true, [], 'center', 'middle', majorColor);
				}
				major += 1;
				xAxisPoint += majorSpacing;
			}

			var xAxisPoint = x0 - majorSpacing;
			var major = -1;
			while (roundToNearest(xAxisPoint, 0.001) >= roundToNearest(left, 0.001)) {
				if (xAxisPoint < left + width) {
					var value = roundToNearest(major * majorStep, placeValue);
					var axisValue = [String(value)];
					var textWidth = ctx.measureText(String(axisValue)).width;
					ctx.fillStyle = backColor;
					ctx.fillRect(xAxisPoint - textWidth / 2, top + 0.5 * height + scaleOffset - 1, textWidth, fontSize * 1.1);
					var labelText = drawMathsText(ctx, axisValue, fontSize, xAxisPoint, top + 0.5 * height + scaleOffset + 0.5 * fontSize, true, [], 'center', 'middle', majorColor);
				}
				major -= 1;
				xAxisPoint -= majorSpacing;
			}
		}

		if (typeof obj.arrows == 'number') {
			drawArrow({
				ctx: ctx,
				startX: left - obj.arrows,
				startY: top + 0.5 * height,
				finX: left + width + obj.arrows,
				finY: top + 0.5 * height,
				doubleEnded: true,
				color: lineColor,
				lineWidth: lineWidth,
				fillArrow: true,
				arrowLength: 12
			});
		} else {
			// draw line
			ctx.beginPath();
			ctx.strokeStyle = lineColor;
			ctx.lineWidth = lineWidth;
			ctx.moveTo(left, top + 0.5 * height);
			ctx.lineTo(left + width, top + 0.5 * height);
			ctx.closePath();
			ctx.stroke();
		}

	}
	function drawNumberlineVertical() {
		if (typeof obj.arrows == 'number') {
			top += obj.arrows;
			height -= 2 * obj.arrows;
		}
		var minorSpacing = (height * minorStep) / (max - min);
		var majorSpacing = (height * majorStep) / (max - min);
		var y0 = top - (min * height) / (max - min);

		if (boolean(obj.showMinorPos, true) == true) {
			ctx.strokeStyle = minorColor;
			ctx.lineWidth = minorWidth;
			ctx.beginPath();
			var yAxisPoint = y0 + minorSpacing;
			while (Math.round(yAxisPoint) <= Math.round(top + height)) {
				if (Math.round(yAxisPoint) >= Math.round(top)) {
					ctx.moveTo(left + minorYPos[0] * width, yAxisPoint);
					ctx.lineTo(left + minorYPos[1] * width, yAxisPoint);
				}
				yAxisPoint += minorSpacing;
			}
			var yAxisPoint = y0 - minorSpacing;
			while (Math.round(yAxisPoint) >= Math.round(top)) {
				if (Math.round(yAxisPoint) <= Math.round(top + height)) {
					ctx.moveTo(left + minorYPos[0] * width, yAxisPoint);
					ctx.lineTo(left + minorYPos[1] * width, yAxisPoint);
				}
				yAxisPoint -= minorSpacing;
			}
			ctx.closePath();
			ctx.stroke();
		}

		// draw major lines
		ctx.strokeStyle = majorColor;
		ctx.lineWidth = majorWidth;
		ctx.beginPath();
		var yAxisPoint = y0;
		while (Math.round(yAxisPoint) <= Math.round(top + height)) {
			if (Math.round(yAxisPoint) >= Math.round(top)) {
				ctx.moveTo(left + majorYPos[0] * width, yAxisPoint);
				ctx.lineTo(left + majorYPos[1] * width, yAxisPoint);
			}
			yAxisPoint += majorSpacing;
		}
		var yAxisPoint = y0 - majorSpacing;
		while (Math.round(yAxisPoint) >= Math.round(top)) {
			if (Math.round(yAxisPoint) <= Math.round(top + height)) {
				ctx.moveTo(left + majorYPos[0] * width, yAxisPoint);
				ctx.lineTo(left + majorYPos[1] * width, yAxisPoint);
			}
			yAxisPoint -= majorSpacing;
		}
		ctx.closePath();
		ctx.stroke();
		
		if (boolean(obj.showScales, true) == true) {
			ctx.font = fontSize + 'px Arial';
			ctx.textBaseline = "middle";
			ctx.textAlign = "right";

			// positive y numbers
			var yAxisPoint = y0;
			var major = 0;
			while (roundToNearest(yAxisPoint, 0.001) >= roundToNearest(top, 0.001)) {
				if (yAxisPoint <= top + height) {
					var axisValue = Number(roundToNearest(major * majorStep, 0.00001));
					var textWidth = ctx.measureText(String(axisValue)).width
					var labelText = drawMathsText(ctx, String(axisValue), fontSize, left + majorYPos[0] * width - 10, yAxisPoint - 2, true, [], 'right', 'middle', '#000');
				}
				major += 1;
				yAxisPoint -= majorSpacing;
			}

			// negative y numbers
			var yAxisPoint = y0 + majorSpacing;
			var major = -1;
			while (roundToNearest(yAxisPoint, 0.001) <= roundToNearest(top + height, 0.001)) {
				if (yAxisPoint >= top) {
					var axisValue = Number(roundToNearest(major * majorStep, 0.00001));
					var textWidth = ctx.measureText(String(axisValue)).width
						var labelText = drawMathsText(ctx, String(axisValue), fontSize, left + majorYPos[0] * width - 10, yAxisPoint - 2, true, [], 'right', 'middle', '#000');
				}
				major -= 1;
				yAxisPoint += majorSpacing;

			}
		}

		if (typeof obj.arrows == 'number') {
			drawArrow({
				ctx: ctx,
				startX: left + 0.5 * width,
				startY: top - obj.arrows,
				finX: left + 0.5 * width,
				finY: top + height + obj.arrows,
				doubleEnded: true,
				color: lineColor,
				lineWidth: lineWidth,
				fillArrow: true,
				arrowLength: 12
			});
		} else {
			// draw line
			ctx.beginPath();
			ctx.strokeStyle = lineColor;
			ctx.lineWidth = lineWidth;
			ctx.moveTo(left + 0.5 * width, top);
			ctx.lineTo(left + 0.5 * width, top + height);
			ctx.closePath();
			ctx.stroke();
		}

	}

}

function isPointBetweenAngles(center, p1, p2, p3, cw) {
	var a1 = posToAngle(p1[0], p1[1], center[0], center[1]);
	var a2 = posToAngle(p2[0], p2[1], center[0], center[1]);
	var a3 = posToAngle(p3[0], p3[1], center[0], center[1]);
	if (anglesInOrder(a1, a2, a3), cw) {
		return false;
	} else {
		return true;
	}
}
function anglesInOrder(a1, a2, a3, cw) { // test if three angles are in order
	while (a1 < 0)
		a1 += 2 * Math.PI;
	while (a2 < 0)
		a2 += 2 * Math.PI;
	while (a3 < 0)
		a3 += 2 * Math.PI;
	while (a1 > 2 * Math.PI)
		a1 -= 2 * Math.PI;
	while (a2 > 2 * Math.PI)
		a2 -= 2 * Math.PI;
	while (a3 > 2 * Math.PI)
		a3 -= 2 * Math.PI;
	if (boolean(cw, true) == true) {
		if ((a1 <= a2 && a2 <= a3) || //123
			(a2 <= a3 && a3 <= a1) || //231
			(a3 <= a1 && a1 <= a2)) { //312
			return true;
		} else {
			return false;
		}
	} else {
		if ((a3 <= a2 && a2 <= a1) || //321
			(a2 <= a1 && a1 <= a3) || //213
			(a1 <= a3 && a3 <= a2)) { //132
			return true;
		} else {
			return false;
		}
	}
}

function roundedRect(context, left, top, width, height, roundingSize, lineThickness, lineColor, fillColor, dash) {
	context.save();
	if (lineThickness) {
		context.lineWidth = lineThickness
	};
	if (lineColor) {
		context.strokeStyle = lineColor
	};
	if (fillColor) {
		context.fillStyle = fillColor
	};
	if (typeof dash == 'undefined')
		dash = [];
	if (typeof dash == 'object') {
		if (!context.setLineDash) {
			context.setLineDash = function () {}
		}
		context.setLineDash(dash);
	}
	context.beginPath();
	context.moveTo(left + roundingSize, top);
	context.lineTo(left + width - roundingSize, top);
	context.arc(left + width - roundingSize, top + roundingSize, roundingSize, 1.5 * Math.PI, 2 * Math.PI);
	context.lineTo(left + width, top + height - roundingSize);
	context.arc(left + width - roundingSize, top + height - roundingSize, roundingSize, 0, 0.5 * Math.PI);
	context.lineTo(left + roundingSize, top + height);
	context.arc(left + roundingSize, top + height - roundingSize, roundingSize, 0.5 * Math.PI, Math.PI);
	context.lineTo(left, top + roundingSize);
	context.arc(left + roundingSize, top + roundingSize, roundingSize, Math.PI, 1.5 * Math.PI);
	context.closePath();
	if (typeof lineColor == 'string' && lineColor !== 'none')
		context.stroke();
	if (typeof fillColor == 'string' && fillColor !== 'none')
		context.fill();
	context.restore();
}
function roundedRect2(context, left, top, width, height, roundingSize, lineThickness, lineColor, fillColor, dash) {
	context.save();
	if (lineThickness)
		context.lineWidth = lineThickness;
	if (lineColor)
		context.strokeStyle = lineColor;
	if (fillColor)
		context.fillStyle = fillColor;
	if (typeof dash == 'undefined')
		dash = [];
	if (typeof dash == 'object') {
		if (!context.setLineDash) {
			context.setLineDash = function () {}
		}
		context.setLineDash(dash);
	}
	context.beginPath();
	context.moveTo(left + roundingSize, top);
	context.lineTo(left + width - roundingSize, top);
	context.arc(left + width - roundingSize, top + roundingSize, roundingSize, 1.5 * Math.PI, 2 * Math.PI);
	context.lineTo(left + width, top + height - roundingSize);
	context.arc(left + width - roundingSize, top + height - roundingSize, roundingSize, 0, 0.5 * Math.PI);
	context.lineTo(left + roundingSize, top + height);
	context.arc(left + roundingSize, top + height - roundingSize, roundingSize, 0.5 * Math.PI, Math.PI);
	context.lineTo(left, top + roundingSize);
	context.arc(left + roundingSize, top + roundingSize, roundingSize, Math.PI, 1.5 * Math.PI);
	context.closePath();
	if (typeof fillColor == 'string' && fillColor !== 'none')
		context.fill();
	if (typeof lineColor == 'string' && lineColor !== 'none')
		context.stroke();
	context.restore();
}
function roundedRect3(context, left, top, width, height, roundingSize, lineThickness, lineColor, fillColor, dash) {
	context.save();
	if (lineThickness) {
		context.lineWidth = lineThickness
	};
	if (lineColor) {
		context.strokeStyle = lineColor
	};
	if (fillColor) {
		context.fillStyle = fillColor
	};
	if (typeof dash == 'undefined')
		dash = [];
	if (typeof dash == 'object') {
		if (!context.setLineDash) {
			context.setLineDash = function () {}
		}
		context.setLineDash(dash);
	}
	context.beginPath();
	context.moveTo(left + roundingSize[0], top);
	context.lineTo(left + width - roundingSize[1], top);
	context.arc(left + width - roundingSize[1], top + roundingSize[1], roundingSize[1], 1.5 * Math.PI, 2 * Math.PI);
	context.lineTo(left + width, top + height - roundingSize[2]);
	context.arc(left + width - roundingSize[2], top + height - roundingSize[2], roundingSize[2], 0, 0.5 * Math.PI);
	context.lineTo(left + roundingSize[3], top + height);
	context.arc(left + roundingSize[3], top + height - roundingSize[3], roundingSize[3], 0.5 * Math.PI, Math.PI);
	context.lineTo(left, top + roundingSize[0]);
	context.arc(left + roundingSize[0], top + roundingSize[0], roundingSize[0], Math.PI, 1.5 * Math.PI);
	context.closePath();
	if (typeof fillColor == 'string' && fillColor !== 'none') {
		context.fill()
	};
	context.stroke();
	context.restore();
}
function drawPath(object) {
	var ctx = object.ctx;
	var path = object.path;
	ctx.save();
	if (typeof object.lineColor !== 'undefined') {
		ctx.strokeStyle = object.lineColor
	};
	if (typeof object.lineWidth !== 'undefined') {
		ctx.lineWidth = object.lineWidth
	};
	ctx.lineCap = 'round';
	ctx.lineJoin = 'round';
	ctx.beginPath();
	ctx.moveTo(path[0][0], path[0][1]);
	for (var i = 1; i < path.length; i++) {
		ctx.lineTo(path[i][0], path[i][1]);
	}
	if (typeof object.fillColor !== 'undefined' || object.closed == true) {
		ctx.closePath()
	};
	if (typeof object.fillColor !== 'undefined') {
		ctx.fillStyle = object.fillColor;
		ctx.fill();
	}
	ctx.stroke();
	ctx.restore();
}
function dashedLine(object) {
	var context = object.context;
	var startX = object.startX;
	var startY = object.startY;
	var finX = object.finX;
	var finY = object.finY;

	if (startX > finX) {
		var x1 = startX;
		var y1 = startY;
		var x2 = finX;
		var y2 = finY;
		startX = x2;
		startY = y2;
		finX = x1;
		finY = y1;
	}

	var dashSize = object.dashSize || 20;
	var gapSize = object.gapSize || 10;
	var color = object.color || '#000';
	var lineWidth = object.lineWidth || 2;

	var totalLength = Math.sqrt(Math.pow((finX - startX), 2) + Math.pow((finY - startY), 2));
	var numOfIncs = totalLength / (dashSize + gapSize);

	var dx = (finX - startX) / numOfIncs;
	var dxDash = dx * dashSize / (dashSize + gapSize);
	var dxGap = dx * gapSize / (dashSize + gapSize);

	var dy = (finY - startY) / numOfIncs;
	var dyDash = dy * dashSize / (dashSize + gapSize);
	var dyGap = dy * gapSize / (dashSize + gapSize);

	var xPos = startX;
	var yPos = startY;
	var incCount = 0;

	context.save();
	context.strokeStyle = color;
	context.lineWidth = lineWidth;
	context.beginPath();
	do {
		context.moveTo(xPos, yPos);
		xPos += dxDash;
		yPos += dyDash;
		context.lineTo(xPos, yPos);
		xPos += dxGap;
		yPos += dyGap;
		incCount++;
	} while (incCount <= numOfIncs - 1)
	if ((startX < finX && xPos < finX) || (startX > finX && xPos > finX) || (startY < finY && yPos < finY) || (startY > finY && yPos > finY)) {
		context.moveTo(xPos, yPos);
		context.lineTo(finX, finY);
	}
	context.closePath();
	context.stroke();
	context.restore();
}
function drawParallelArrow(object) {
	// required
	var context = object.context || object.ctx;
	var startX = object.startX;
	var startY = object.startY;
	var finX = object.finX;
	var finY = object.finY;

	// optional
	var numOfArrows = object.numOfArrows || 1;
	var arrowLength = object.arrowLength || 25;
	var arrowAngle = object.arrowAngle || 0.5;
	var color = object.color || '#000';
	var lineWidth = object.lineWidth || 2;
	var fillArrow = boolean(object.fillArrow, false);

	context.save();
	if (numOfArrows == 1) {

		var fracPos = 0.5 + 0.5 * arrowLength * Math.cos(arrowAngle) / Math.sqrt(Math.pow((finX - startX), 2) + Math.pow((finY - startY), 2))
			drawArrow({
				context: context,
				startX: startX,
				startY: startY,
				finX: startX + fracPos * (finX - startX),
				finY: startY + fracPos * (finY - startY),
				arrowLength: arrowLength,
				angleBetweenLinesRads: arrowAngle,
				color: color,
				lineWidth: 0.1,
				arrowLineWidth: lineWidth
			});

	} else if (numOfArrows == 2) {

		var fracPos1 = 0.5 + 0.75 * arrowLength * (Math.cos(arrowAngle) + 0.5) / Math.sqrt(Math.pow((finX - startX), 2) + Math.pow((finY - startY), 2))
			var fracPos2 = fracPos1 - 1 * arrowLength / Math.sqrt(Math.pow((finX - startX), 2) + Math.pow((finY - startY), 2))

			drawArrow({
				context: context,
				startX: startX,
				startY: startY,
				finX: startX + fracPos1 * (finX - startX),
				finY: startY + fracPos1 * (finY - startY),
				arrowLength: arrowLength,
				angleBetweenLinesRads: arrowAngle,
				color: color,
				lineWidth: 0.1,
				showLine: false,
				arrowLineWidth: lineWidth
			});
		drawArrow({
			context: context,
			startX: startX,
			startY: startY,
			finX: startX + fracPos2 * (finX - startX),
			finY: startY + fracPos2 * (finY - startY),
			arrowLength: arrowLength,
			angleBetweenLinesRads: arrowAngle,
			color: color,
			lineWidth: 0.1,
			showLine: false,
			arrowLineWidth: lineWidth
		});
	}
	context.restore();
}
function labelLine(posA, posB, obj) {
	var ctx = obj.ctx;
	if (typeof hiddenCanvas == 'undefined')
		hiddenCanvas = newcanvas({
				vis: false
			});
	obj.ctx = hiddenCanvas.ctx;
	obj.measureOnly = true;
	var textDims = text(obj);
	var w = textDims.tightRect[2];
	var h = textDims.tightRect[3];
	if (typeof obj.box == 'undefined' || obj.box.type !== 'tight')
		w += 20;
	var x1 = posA[0],
	y1 = posA[1],
	x2 = posB[0],
	y2 = posB[1],
	x4,
	y4;
	var x3 = (x1 + x2) / 2;
	var y3 = (y1 + y2) / 2;
	if (y1 == y2) {
		x4 = x3 - w / 2;
		if (x1 < x2) {
			y4 = y3;
		} else {
			y4 = y3 - h;
		}
	} else if (x1 == x2) {
		y4 = y3 - h / 2;
		if (y1 < y2) {
			x4 = x3 - w;
		} else {
			x4 = x3;
		}
	} else if (x1 < x2) {
		if (y1 < y2) {
			x4 = x3 - w;
			y4 = y3;
		} else {
			x4 = x3;
			y4 = y3;
		}
	} else if (x3 > x2) {
		if (y3 < y2) {
			x4 = x3 - w;
			y4 = y3 - h;
		} else {

			x4 = x3;
			y4 = y3 - h;
		}
	}
	obj.ctx = ctx;
	obj.measureOnly = false;
	obj.left = x4 - 10;
	obj.top = y4 - 10;
	obj.width = w + 20;
	obj.height = h + 20;
	obj.align = 'center';
	obj.vertAlign = 'middle';
	text(obj);
}
function drawDash(context, x1, y1, x2, y2, length) {
	if (typeof length !== 'number')
		length = 10;
	var grad =  - (x2 - x1) / (y2 - y1);
	var midX = (x1 + x2) / 2;
	var midY = (y1 + y2) / 2;
	var end1X = midX - length * Math.cos(Math.atan(grad));
	var end1Y = midY - length * Math.sin(Math.atan(grad));
	var end2X = midX + length * Math.cos(Math.atan(grad));
	var end2Y = midY + length * Math.sin(Math.atan(grad));

	context.beginPath();
	context.moveTo(end1X, end1Y);
	context.lineTo(end2X, end2Y);
	context.stroke();
}
function drawDoubleDash(context, x1, y1, x2, y2, length, separation) {
	if (typeof length !== 'number')
		length = 10;
	var sep = separation / 2 || context.lineWidth + 2 || 4;
	var grad =  - (x2 - x1) / (y2 - y1);

	// [unitX,unitY] is a unit vector in the direction of the line
	var unitX = (x2 - x1) / Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
	var unitY = (y2 - y1) / Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));

	var midX = (x1 + x2) / 2;
	var midY = (y1 + y2) / 2;

	var dashX1 = midX - sep * unitX;
	var dashX2 = midX + sep * unitX;
	var dashY1 = midY - sep * unitY;
	var dashY2 = midY + sep * unitY;

	var end1X = dashX1 - length * Math.cos(Math.atan(grad));
	var end1Y = dashY1 - length * Math.sin(Math.atan(grad));
	var end2X = dashX1 + length * Math.cos(Math.atan(grad));
	var end2Y = dashY1 + length * Math.sin(Math.atan(grad));

	var end3X = dashX2 - length * Math.cos(Math.atan(grad));
	var end3Y = dashY2 - length * Math.sin(Math.atan(grad));
	var end4X = dashX2 + length * Math.cos(Math.atan(grad));
	var end4Y = dashY2 + length * Math.sin(Math.atan(grad));

	context.beginPath();
	context.moveTo(end1X, end1Y);
	context.lineTo(end2X, end2Y);
	context.moveTo(end3X, end3Y);
	context.lineTo(end4X, end4Y);
	context.stroke();
}
function drawPrintIcon(ctx,rect,backColor) {
	var w = rect[2];
	ctx.save();
	ctx.translate(rect[0],rect[1]);
		ctx.lineJoin = 'round';
		ctx.lineCap = 'round';
		ctx.strokeStyle = '#000';
		ctx.fillStyle = '#000';
		ctx.lineWidth = 0.1*w;
		
		
		roundedRect(ctx,0,0.3*w,w,0.45*w,0.1*w,0.1*w,'#000','#000');
		ctx.beginPath();
		ctx.fillStyle = backColor;
		ctx.fillRect(0.22*w,0.65*w,0.56*w,0.15*w);
		
		roundedRect(ctx,0.22*w,0,0.56*w,w,0.1*w,0.1*w,'#000');
		
		roundedRect(ctx,0.35*w,0.70*w,0.3*w,0.05*w,0,0.01*w,'#000','#000');
		roundedRect(ctx,0.35*w,0.82*w,0.2*w,0.05*w,0,0.01*w,'#000','#000');
		
		ctx.beginPath();
		ctx.fillStyle = backColor;
		ctx.arc(0.86*w,0.4*w,0.085*w,0,2*Math.PI);
		ctx.fill();
		
	ctx.translate(-rect[0],-rect[1]);
	ctx.restore();
}

CanvasRenderingContext2D.prototype.setStroke = function (obj) {
	var lineWidth = obj.lineWidth || obj.width || obj.w || obj.thickness || this.lineWidth;
	var strokeStyle = obj.color || obj.strokeStyle || obj.style || this.strokeStyle;
	var dash = obj.dash || obj.lineDash || this.getLineDash();
	var lineCap = obj.lineCap || obj.cap || 'round';
	var lineJoin = obj.lineJoin || obj.join || obj.cap || 'round';
	this.lineWidth = lineWidth;
	this.strokeStyle = strokeStyle;
	this.setLineDash(dash);
	this.lineCap = lineCap;
	this.lineJoin = lineJoin;
}
CanvasRenderingContext2D.prototype.setFill = function (obj) {
	var color = obj.color || this.fillStyle;
	this.fillStyle = obj.color;
}
CanvasRenderingContext2D.prototype.path = function (pathArray, close, obj) {
	if (typeof obj == 'undefined')
		obj = {};
	this.beginPath();
	this.moveTo(pathArray[0][0], pathArray[0][1]);
	for (var i = 1; i < pathArray.length; i++) {
		this.lineTo(pathArray[i][0], pathArray[i][1]);
	}
	if (boolean(close, false) === true) {
		this.lineTo(pathArray[0][0], pathArray[0][1]);
	}
	if (typeof obj.fill !== 'undefined') {
		this.setFill(obj.fill);
		this.fill();
	}
	if (typeof obj.lineDec !== 'undefined') {}
	if (typeof obj.intAngles !== 'undefined') {
		if (typeof obj.intAngles.show == 'undefined') {
			obj.intAngles.show = [];
			for (var i = 0; i < pathArray.length; i++)
				obj.intAngles.show.push(true);
		}
		var angle = {
			ctx: this
		};
		angle.radius = obj.intAngles.radius || obj.intAngles.r || undefined;
		angle.squareForRight = boolean(obj.intAngles.squareForRight, true);
		angle.labelIfRight = boolean(obj.intAngles.labelIfRight, false);
		angle.drawLines = boolean(obj.intAngles.drawLines, false);
		angle.lineWidth = obj.intAngles.lineWidth || obj.intAngles.width || obj.intAngles.w || undefined;
		angle.lineColor = obj.intAngles.lineColor || obj.intAngles.color || undefined;
		angle.drawCurve = boolean(obj.intAngles.drawCurve, true);
		angle.curveWidth = obj.intAngles.curveWidth || angle.lineWidth;
		angle.curveColor = obj.intAngles.curveColor || angle.lineColor;
		if (typeof obj.intAngles.fill == 'string') {
			angle.fill = true;
			angle.fillColor = obj.intAngles.fill;
		} else {
			angle.fill = boolean(obj.intAngles.fill, false);
			angle.fillColor = obj.intAngles.fillColor || undefined;
		}
		angle.label = obj.intAngles.label || obj.intAngles.text || undefined;
		angle.labelFont = obj.intAngles.labelFont || obj.intAngles.font || undefined;
		angle.labelFontSize = obj.intAngles.labelFontSize || obj.intAngles.fontSize || undefined;
		angle.labelColor = obj.intAngles.labelColor || angle.lineColor || undefined;
		angle.labelRadius = obj.intAngles.labelRadius || undefined;
		angle.labelMeasure = boolean(obj.intAngles.labelMeasure, false);
		angle.measureRoundTo = obj.intAngles.measureRoundTo || obj.intAngles.roundTo || undefined;
		angle.angleType = obj.intAngles.angleType || undefined;
		for (var i = 0; i < pathArray.length; i++) {
			if (obj.intAngles.show[i] === true) {
				if (i === 0) {
					angle.a = pathArray[pathArray.length - 1]
				} else {
					angle.a = pathArray[i - 1]
				};
				angle.b = pathArray[i];
				if (i === pathArray.length - 1) {
					angle.c = pathArray[0]
				} else {
					angle.c = pathArray[i + 1]
				};
				if (typeof obj.intAngles.r == 'object')
					angle.radius = obj.intAngles.r[i];
				if (typeof obj.intAngles.radius == 'object')
					angle.radius = obj.intAngles.radius[i];
				if (typeof obj.intAngles.squareForRight == 'object')
					angle.squareForRight = boolean(obj.intAngles.squareForRight[i], true);
				if (typeof obj.intAngles.labelIfRight == 'object')
					angle.labelIfRight = boolean(obj.intAngles.labelIfRight[i], false);
				if (typeof obj.intAngles.drawLines == 'object')
					angle.drawLines = boolean(obj.intAngles.drawLines[i], false);
				if (typeof obj.intAngles.lineWidth == 'object')
					angle.lineWidth = obj.intAngles.lineWidth[i];
				if (typeof obj.intAngles.width == 'object')
					angle.lineWidth = obj.intAngles.width[i];
				if (typeof obj.intAngles.w == 'object')
					angle.lineWidth = obj.intAngles.w[i];
				if (typeof obj.intAngles.lineColor == 'object')
					angle.lineColor = obj.intAngles.lineColor[i];
				if (typeof obj.intAngles.color == 'object')
					angle.lineWidth = obj.intAngles.color[i];
				if (typeof obj.intAngles.drawCurve == 'object')
					angle.drawCurve = boolean(obj.intAngles.drawCurve[i], true);
				if (typeof obj.intAngles.lineWidth == 'object')
					angle.curveWidth = obj.intAngles.lineWidth[i];
				if (typeof obj.intAngles.curveWidth == 'object')
					angle.curveWidth = obj.intAngles.curveWidth[i];
				if (typeof obj.intAngles.curveColor == 'object')
					angle.curveColor = obj.intAngles.curveColor[i];
				if (typeof obj.intAngles.fill == 'object') {
					if (typeof obj.intAngles.fill[i] == 'string') {
						angle.fill = true;
						angle.fillColor = obj.intAngles.fill[i];
					} else {
						angle.fill = boolean(obj.intAngles.fill[i], false);
						if (typeof obj.intAngles.fillColor == 'object')
							angle.fillColor = obj.intAngles.fillColor[i];
					}
				}
				if (typeof obj.intAngles.label == 'object')
					angle.label = obj.intAngles.label[i];
				if (typeof obj.intAngles.text == 'object')
					angle.label = obj.intAngles.text[i];
				if (typeof obj.intAngles.labelFont == 'object')
					angle.labelFont = obj.intAngles.curveColor[i];
				if (typeof obj.intAngles.font == 'object')
					angle.labelFont = obj.intAngles.font[i];
				if (typeof obj.intAngles.labelFontSize == 'object')
					angle.labelFontSize = obj.intAngles.labelFontSize[i];
				if (typeof obj.intAngles.fontSize == 'object')
					angle.labelFontSize = obj.intAngles.fontSize[i];
				if (typeof obj.intAngles.lineColor == 'object')
					angle.labelColor = obj.intAngles.lineColor[i];
				if (typeof obj.intAngles.labelColor == 'object')
					angle.labelColor = obj.intAngles.labelColor[i];
				if (typeof obj.intAngles.labelRadius == 'object')
					angle.labelRadius = obj.intAngles.labelRadius[i];
				if (typeof obj.intAngles.labelMeasure == 'object')
					angle.labelMeasure = boolean(obj.intAngles.labelMeasure[i], false);
				if (typeof obj.intAngles.measureRoundTo == 'object')
					angle.measureRoundTo = obj.intAngles.measureRoundTo[i];
				if (typeof obj.intAngles.roundTo == 'object')
					angle.measureRoundTo = obj.intAngles.roundTo[i];
				drawAngle(angle);
			}
		}
	}
	if (typeof obj.vertexLabels !== 'undefined') {
		if (typeof obj.vertexLabels.show == 'undefined') {
			obj.vertexLabels.show = [];
			for (var i = 0; i < pathArray.length; i++)
				obj.vertexLabels.show.push(true);
		}
		var angle = {
			ctx: this
		};
		angle.labelIfRight = true;
		angle.drawLines = false;
		angle.drawCurve = false;
		angle.fill = false;
		angle.label = obj.vertexLabels.label || obj.vertexLabels.text || undefined;
		angle.labelFont = obj.vertexLabels.labelFont || obj.vertexLabels.font || undefined;
		angle.labelFontSize = obj.vertexLabels.labelFontSize || obj.vertexLabels.fontSize || undefined;
		angle.labelColor = obj.vertexLabels.labelColor || angle.lineColor || undefined;
		angle.labelRadius = obj.vertexLabels.labelRadius || obj.vertexLabels.radius || obj.vertexLabels.r || undefined;
		angle.labelMeasure = false;
		for (var i = 0; i < pathArray.length; i++) {
			if (obj.vertexLabels.show[i] === true) {
				if (i === 0) {
					angle.c = pathArray[pathArray.length - 1]
				} else {
					angle.c = pathArray[i - 1]
				};
				angle.b = pathArray[i];
				if (i === pathArray.length - 1) {
					angle.a = pathArray[0]
				} else {
					angle.a = pathArray[i + 1]
				};
				if (typeof obj.vertexLabels.label == 'object')
					angle.label = obj.vertexLabels.label[i];
				if (typeof obj.vertexLabels.text == 'object')
					angle.label = obj.vertexLabels.text[i];
				if (typeof obj.vertexLabels.labelFont == 'object')
					angle.labelFont = obj.vertexLabels.curveColor[i];
				if (typeof obj.vertexLabels.font == 'object')
					angle.labelFont = obj.vertexLabels.font[i];
				if (typeof obj.vertexLabels.labelFontSize == 'object')
					angle.labelFontSize = obj.vertexLabels.labelFontSize[i];
				if (typeof obj.vertexLabels.fontSize == 'object')
					angle.labelFontSize = obj.vertexLabels.fontSize[i];
				if (typeof obj.vertexLabels.lineColor == 'object')
					angle.labelColor = obj.vertexLabels.lineColor[i];
				if (typeof obj.vertexLabels.labelColor == 'object')
					angle.labelColor = obj.vertexLabels.labelColor[i];
				if (typeof obj.vertexLabels.radius == 'object')
					angle.labelRadius = obj.vertexLabels.radius[i];
				if (typeof obj.vertexLabels.r == 'object')
					angle.labelRadius = obj.vertexLabels.r[i];
				if (typeof obj.vertexLabels.labelRadius == 'object')
					angle.labelRadius = obj.vertexLabels.labelRadius[i];
				drawAngle(angle);
			}
		}
	}
	if (typeof obj.edgeLabels !== 'undefined') {
		if (typeof obj.edgeLabels.show == 'undefined') {
			obj.edgeLabels.show = [];
			for (var i = 0; i < pathArray.length; i++)
				obj.edgeLabels.show.push(true);
		}
		var label = {
			ctx: this
		};
		label.font = obj.edgeLabels.font || undefined;
		label.fontSize = obj.edgeLabels.fontSize || undefined;
		label.width = 1200;
		for (var i = 0; i < pathArray.length; i++) {
			if (obj.edgeLabels.show[i] === true) {
				var a = pathArray[i];
				var b = pathArray[(i + 1) % pathArray.length];
				label.textArray = obj.edgeLabels.text[i];
				labelLine(a, b, label);
			}
		}
	}
	if (typeof obj.stroke !== 'undefined') {
		this.beginPath();
		this.moveTo(pathArray[0][0], pathArray[0][1]);
		for (var i = 1; i < pathArray.length; i++) {
			this.lineTo(pathArray[i][0], pathArray[i][1]);
		}
		if (boolean(close, false) === true) {
			this.lineTo(pathArray[0][0], pathArray[0][1]);
		}
		this.setStroke(obj.stroke);
		this.stroke();
	}
}
CanvasRenderingContext2D.prototype.rect2 = function (obj) {
	var obj = clone(obj);
	if (un(obj.sf))
		obj.sf = 1;
	this.save();
	var line = true;
	this.lineWidth = def([obj.lineWidth, obj.thickness, this.lineWidth]) * obj.sf;
	this.strokeStyle = def([obj.lineColor, obj.color, obj.strokeStyle, this.strokeStyle]);
	if (obj.lineColor == 'none' || obj.color == 'none' || obj.strokeStyle == 'none')
		line = false;
	var fill = false;
	if (!un(obj.fillColor) && obj.fillColor !== 'none') {
		fill = true;
		this.fillStyle = obj.fillColor;
	} else if (!un(obj.fillStyle) && obj.fillStyle !== 'none') {
		fill = true;
		this.fillStyle = obj.fillStyle;
	}
	var dash = enlargeDash(def([obj.dash, this.getLineDash(), []]), this.sf);
	if (!this.setLineDash) {
		this.setLineDash = function () {}
	}
	this.setLineDash(dash);
	if (!un(obj.rect)) {
		obj.left = obj.rect[0];
		obj.top = obj.rect[1];
		obj.width = obj.rect[2];
		obj.height = obj.rect[3];
	}
	var left = (obj.left || obj.l) * obj.sf;
	var top = (obj.top || obj.t) * obj.sf;
	var width = (obj.width || obj.w) * obj.sf;
	var height = (obj.height || obj.h) * obj.sf;
	this.beginPath();
	if (!un(obj.radius)) {
		var radius = obj.radius * obj.sf;
		this.moveTo(left + radius, top);
		this.lineTo(left + width - radius, top);
		this.arc(left + width - radius, top + radius, radius, 1.5 * Math.PI, 2 * Math.PI);
		this.lineTo(left + width, top + height - radius);
		this.arc(left + width - radius, top + height - radius, radius, 0, 0.5 * Math.PI);
		this.lineTo(left + radius, top + height);
		this.arc(left + radius, top + height - radius, radius, 0.5 * Math.PI, Math.PI);
		this.lineTo(left, top + radius);
		this.arc(left + radius, top + radius, radius, Math.PI, 1.5 * Math.PI);
		this.closePath();
		if (fill == true)
			this.fill();
		if (line == true)
			this.stroke();
	} else {
		if (fill == true)
			this.fillRect(left, top, width, height);
		if (line == true)
			this.strokeRect(left, top, width, height);
	}
	this.restore();
}
CanvasRenderingContext2D.prototype.clear = function () {
	this.clearRect(0, 0, this.data[102], this.data[103]);
}
HTMLCanvasElement.prototype.setLeft = function (left) {
	this.data[100] = left;
	resizeCanvas2(this, this.data[100], this.data[101]);
}
HTMLCanvasElement.prototype.setTop = function (top) {
	this.data[101] = top;
	resizeCanvas2(this, this.data[100], this.data[101]);
}
HTMLCanvasElement.prototype.setPos = function (left, top) {
	this.data[100] = left;
	this.data[101] = top;
	resizeCanvas2(this, this.data[100], this.data[101]);
}
HTMLCanvasElement.prototype.setWidth = function (width) {
	this.data[102] = width;
	resizeCanvas(this, this.data[100], this.data[101], this.data[102], this.data[103]);
}
HTMLCanvasElement.prototype.setHeight = function (height) {
	this.data[103] = height;
	resizeCanvas(this, this.data[100], this.data[101], this.data[102], this.data[103]);
}
HTMLCanvasElement.prototype.setDims = function (width, height) {
	this.data[102] = width;
	this.data[103] = height;
	resizeCanvas(this, this.data[100], this.data[101], this.data[102], this.data[103]);
}
HTMLCanvasElement.prototype.setVis = function (vis) {
	if (typeof vis == 'undefined') {
		this.data[104] = !this.data[104];
	} else {
		this.data[104] = vis;
	}
	if (this.data[104] == true) {
		showObj(this);
	} else {
		hideObj(this);
	}
}
HTMLCanvasElement.prototype.setPE = function (point) {
	if (typeof point == 'undefined') {
		this.data[106] = !this.data[106];
	} else {
		this.data[106] = point;
	}
	if (this.data[106] == true) {
		this.style.pointerEvents = 'auto';
	} else {
		this.style.pointerEvents = 'none';
	}
}
HTMLCanvasElement.prototype.setZ = function (z) {
	this.data[107] = z;
	this.style.zIndex = z;
}
HTMLCanvasElement.prototype.setCursor = function (cursor) {
	this.style.cursor = cursor || 'pointer';
}
HTMLCanvasElement.prototype.setOpacity = function (opacity) {
	this.style.opacity = opacity;
}

function playButton(left, top, width, func, options) {
	//visible,zIndex,fillColor,lineColor,lineWidth,radiusx
	if (typeof options == 'undefined')
		var options = {};
	var zIndex = options.zIndex || 2;
	var button = createCanvas(left, top, width, width, boolean(options.visible, true), false, true, zIndex);
	button.lineColor = options.lineColor || '#000';
	button.lineWidth = options.lineWidth || 4;
	button.fillColor = options.fillColor || '#3FF';
	button.radius = options.radius || 8;
	button.direction = 'right';
	if (options.dir == 'left')
		button.direction = 'left';
	button.width = width;
	button.left = left;
	button.top = top;
	button.draw = function () {
		var ctx = this.ctx;
		roundedRect2(ctx, this.lineWidth / 2, this.lineWidth / 2, this.width - this.lineWidth, this.width - this.lineWidth, this.radius, this.lineWidth, this.lineColor, this.fillColor);
		ctx.fillStyle = this.lineColor;
		ctx.lineCap = 'round';
		ctx.lineJoin = 'round';
		ctx.beginPath();
		if (this.direction == 'right') {
			ctx.moveTo(this.width * 16 / 50, this.width * 14 / 50);
			ctx.lineTo(this.width * 34 / 50, this.width * 25 / 50);
			ctx.lineTo(this.width * 16 / 50, this.width * 36 / 50);
			ctx.lineTo(this.width * 16 / 50, this.width * 14 / 50);
		} else {
			ctx.moveTo(this.width * 34 / 50, this.width * 14 / 50);
			ctx.lineTo(this.width * 16 / 50, this.width * 25 / 50);
			ctx.lineTo(this.width * 34 / 50, this.width * 36 / 50);
			ctx.lineTo(this.width * 34 / 50, this.width * 14 / 50);
		}
		ctx.fill();
	}
	button.draw();
	if (typeof func !== 'undefined') {
		addListener(button, func);
	}
	return button;
}
function drawCalcAllowedButton(ctx, l, t, size, allowed, backColor) {
	var w = size || 20;
	var h = size || 20;
	var color = backColor || '#FFC';
	ctx.save();
	ctx.strokeStyle = '#000';
	ctx.fillStyle = '#000';
	roundedRect(ctx, l, t, w, h, 2, 3, '#000', color);
	roundedRect(ctx, l + 0.3 * w, t + 0.2 * h, w * 0.4, h * 0.6, 1, 3, '#000', '#000');
	roundedRect(ctx, l + 0.35 * w, t + 0.25 * h, w * 0.3, h * 0.15, 0.01, 3, '#000', color);
	for (var i = 0; i < 3; i++) {
		for (var j = 0; j < 3; j++) {
			roundedRect(ctx, l + 0.35 * w + 0.12 * j * w, t + 0.45 * h + 0.12 * i * h, w * 0.08, h * 0.08, 0.01, 3, '#000', color);
		}
	}
	if (boolean(allowed, true) == false) {
		ctx.lineWidth = 0.1 * w;
		ctx.lineCap = 'round';
		ctx.lineJoin = 'round';
		ctx.beginPath();
		ctx.strokeStyle = '#F00';
		ctx.moveTo(l + 0.85 * w, t + 0.15 * h);
		ctx.lineTo(l + 0.15 * w, t + 0.85 * h);
		ctx.stroke();
	}
	ctx.restore();
}
function drawCalcAllowedButton2(ctx, l, t, size, allowed, backColor, calcColor) {
	var w = size || 20;
	var h = size || 20;
	var color = backColor || '#FFC';
	var color2 = calcColor || '#333';
	ctx.save();
	ctx.strokeStyle = color2;
	ctx.fillStyle = color2;
	roundedRect(ctx, l, t, w, h, 2, 3, '#000', color);
	roundedRect(ctx, l + 0.3 * w, t + 0.2 * h, w * 0.4, h * 0.6, 1, 3, color2, color2);
	roundedRect(ctx, l + 0.35 * w, t + 0.25 * h, w * 0.3, h * 0.15, 0.01, 3, color2, color);
	for (var i = 0; i < 3; i++) {
		for (var j = 0; j < 3; j++) {
			roundedRect(ctx, l + 0.35 * w + 0.12 * j * w, t + 0.45 * h + 0.12 * i * h, w * 0.08, h * 0.08, 0.01, 3, color2, color);
		}
	}
	if (boolean(allowed, true) == false) {
		ctx.lineWidth = 0.08 * w;
		ctx.lineCap = 'round';
		ctx.lineJoin = 'round';
		ctx.beginPath();
		ctx.strokeStyle = '#900';
		ctx.arc(l + 0.5 * w, t + 0.5 * h, 0.45 * w, 0, 2 * Math.PI);
		ctx.stroke();
		ctx.beginPath();
		ctx.lineWidth = 0.12 * w;
		ctx.moveTo(l + 0.5 * w + (1 / Math.sqrt(2)) * 0.42 * w, t + 0.5 * h - (1 / Math.sqrt(2)) * 0.42 * h);
		ctx.lineTo(l + 0.5 * w - (1 / Math.sqrt(2)) * 0.42 * w, t + 0.5 * h + (1 / Math.sqrt(2)) * 0.42 * h);
		//ctx.moveTo(l+0.15*w,t+0.15*h);
		//ctx.lineTo(l+0.85*w,t+0.85*h);
		ctx.stroke();

	}
	ctx.restore();
}
function drawRefreshButton(ctx, l, t, size, backColor) {
	var w = size || 20;
	var h = size || 20;
	var color = backColor || '#FFC';
	ctx.save();
	ctx.strokeStyle = '#000';
	ctx.fillStyle = '#000';
	ctx.lineCap = 'round';
	ctx.lineJoin = 'round';
	roundedRect(ctx, l, t, w, h, 8, 8, '#000', color);
	ctx.lineWidth = 0.08 * w;
	ctx.beginPath();
	ctx.arc(l + 0.5 * w, t + 0.5 * h, 0.22 * w, -1.8 * Math.PI, -0.2 * Math.PI);
	ctx.stroke();
	ctx.beginPath();
	var l2 = l + 0.77 * w;
	var t2 = t + 0.47 * h;
	var arrowLength = 0.28 * w;
	ctx.moveTo(l2, t2);
	ctx.lineTo(l2 + arrowLength * Math.sin(1.06 * Math.PI), t2 + arrowLength * Math.cos(1.06 * Math.PI));
	ctx.lineTo(l2 + arrowLength * Math.cos(1.03 * Math.PI), t2 - arrowLength * Math.sin(1.03 * Math.PI));
	ctx.lineTo(l2, t2);
	ctx.fill();
	ctx.restore();
}
function drawRangeLabel(ctx, l, t, w, h, direction) {
	var dir = 'bottom'; // default;
	if (typeof direction == 'string')
		dir = direction;
	switch (dir) {
	case 'bottom':
		var p1 = [l, t];
		var p2 = [l + w / 2, t + h];
		var p3 = [l + w, t];
		var c1 = [l + w * (1 / 12), t + h * 1.3];
		var c2 = [l + w * (13 / 40), t + h * (-0.7)];
		var c3 = [l + w * (27 / 40), t + h * (-0.7)];
		var c4 = [l + w * (11 / 12), t + h * 1.3];
		break;
	case 'top':
		var p1 = [l, t + h];
		var p2 = [l + w / 2, t];
		var p3 = [l + w, t + h];
		var c1 = [l + w * (1 / 12), t + h - h * 1.3];
		var c2 = [l + w * (13 / 40), t + h - h * (-0.7)];
		var c3 = [l + w * (27 / 40), t + h - h * (-0.7)];
		var c4 = [l + w * (11 / 12), t + h - h * 1.3];
		break;
	case 'right':
		var p1 = [l, t];
		var p2 = [l + w, t + h / 2];
		var p3 = [l, t + h];
		var c1 = [l + w * 1.3, t + h * (1 / 12)];
		var c2 = [l + w * (-0.7), t + h * (13 / 40)];
		var c3 = [l + w * (-0.7), t + h * (27 / 40)];
		var c4 = [l + w * 1.3, t + h * (11 / 12)];
		break;
	case 'left':
		var p1 = [l + w, t];
		var p2 = [l, t + h / 2];
		var p3 = [l + w, t + h];
		var c1 = [l + w - w * 1.3, t + h * (1 / 12)];
		var c2 = [l + w - w * (-0.7), t + h * (13 / 40)];
		var c3 = [l + w - w * (-0.7), t + h * (27 / 40)];
		var c4 = [l + w - w * 1.3, t + h * (11 / 12)];
		break;
	}
	ctx.beginPath();
	ctx.moveTo(p1[0], p1[1]);
	ctx.bezierCurveTo(c1[0], c1[1], c2[0], c2[1], p2[0], p2[1]);
	ctx.bezierCurveTo(c3[0], c3[1], c4[0], c4[1], p3[0], p3[1]);
	ctx.stroke();
}

var JSONfn = {};
(function () {
	JSONfn.stringify = function (obj) {
		return JSON.stringify(obj, function (key, value) {
			return (typeof value === 'function') ? value.toString() : value;
		});
	}
	JSONfn.parse = function (str) {
		return JSON.parse(str, function (key, value) {
			if (typeof value != 'string')
				return value;
			return (value.substring(0, 8) == 'function') ? eval('(' + value + ')') : value;
		});
	}
}
	());

function replaceAll(string, find, replace) {
	return string.replace(new RegExp(escapeRegExp(find), 'g'), replace);
}
function escapeRegExp(string) {
	return string.replace(/([.*+?^=!:${}()|\[\]\/\\])/g, "\\$1");
}
function removeSpaces(string, opt_mathsInput) {
	string = string.replace(/\s/g, "");
	if (typeof opt_mathsInput !== 'undefined')
		setMathsInputText(opt_mathsInput, string, 0);
	return string;
}
function stringTo2dArray(string, elemType) {
	if (!elemType)
		elemType = 'string';
	var start = string.indexOf("[");

	// replace commas with semi-colons inside array (level 1)
	var bracket = 0;
	for (j = start; j < string.length; j++) {
		if (string.charAt(j) == "[")
			bracket++;
		if (string.charAt(j) == "]")
			bracket--;
		if (string.charAt(j) == "," && bracket == 1) {
			string = string.slice(0, j) + ";" + string.slice(j + 1);
		}
	}

	var bracket = 0;
	var fin;
	for (j = start; j < string.length; j++) {
		if (string.charAt(j) == "[")
			bracket++;
		if (string.charAt(j) == "]")
			bracket--;
		if (bracket == 0) {
			fin = j + 1;
			break;
		}
	}

	string = string.slice(start + 1, fin - 1);
	var array = string.split(";");

	for (j = 0; j < array.length; j++) {
		var str = array[j];
		array[j] = array[j].slice(1, -1);
		array[j] = array[j].split(',');
		for (k = 0; k < array[j].length; k++) {
			if (elemType == 'number')
				array[j][k] = Number(array[j][k]);
		}
	}

	return array;
}
function textArrayReplace(textArray, findStr, replaceStr) {
	if (typeof replaceStr == 'object') {
		return textArrayReplace2(textArray, findStr, replaceStr);
	}
	replaceStr = String(replaceStr);
	for (var i = 0; i < textArray.length; i++) {
		if (typeof textArray[i] == 'string') {
			textArray[i] = textStringReplace(textArray[i], findStr, replaceStr);
		} else if (typeof textArray[i] == 'object') {
			textArray[i] = textArrayReplace(textArray[i], findStr, replaceStr);
		}
	}
	return textArray;
}
function textStringReplace(string, findStr, replaceStr) {
	var re = new RegExp(findStr, "gi");
	return string.replace(re, replaceStr);
}
function textArrayReplace2(textArray, findStr, replacement) {
	// replace string with array
	for (var i = 0; i < textArray.length; i++) {
		if (typeof textArray[i] == 'string') {
			var pos = textArray[i].indexOf(findStr);
			if (pos > -1) {
				var newElems = clone(replacement);
				newElems.unshift(textArray[i].slice(0, pos));
				newElems.push(textArray[i].slice(pos + findStr.length));
				textArray.splice(i, 1);
				textArray.splice.apply(textArray, [i, 0].concat(newElems));
				break;
			}
		} else if (typeof textArray[i] == 'object') {
			textArray[i] = textArrayReplace2(textArray[i], findStr, replacement);
		}
	}
	return textArray;
}

function getArrayCount(testArray, testValue) {
	var count = 0;
	for (var j = 0; j < testArray.length; j++) {
		if (testArray[j] == testValue) {
			count++;
		}
	}
	return count;
}
function getArrayLessThanCount(testArray, testValue) {
	var count = 0;
	for (var j = 0; j < testArray.length; j++) {
		if (testArray[j] < testValue) {
			count++;
		}
	}
	return count;
}
function shuffleArray(array) {
	var newArray = [];
	do {
		var randomPos = Math.floor(Math.random() * array.length);
		newArray.push(array[randomPos]);
		array.splice(randomPos, 1);
	} while (array.length > 0);
	return newArray;
}
function buildArray(array, dim0, dim1, dim2, dim3, dim4, dim5) {
	if ((typeof dim0 !== 'undefined') && (typeof array[dim0] == 'undefined')) {
		array[dim0] = [];
	}
	if ((typeof dim1 !== 'undefined') && (typeof array[dim0][dim1] == 'undefined')) {
		array[dim0][dim1] = [];
	}
	if ((typeof dim2 !== 'undefined') && (typeof array[dim0][dim1][dim2] == 'undefined')) {
		array[dim0][dim1][dim2] = [];
	}
	if ((typeof dim3 !== 'undefined') && (typeof array[dim0][dim1][dim2][dim3] == 'undefined')) {
		array[dim0][dim1][dim2][dim3] = [];
	}
	if ((typeof dim4 !== 'undefined') && (typeof array[dim0][dim1][dim2][dim3][dim4] == 'undefined')) {
		array[dim0][dim1][dim2][dim3][dim4] = [];
	}
	if ((typeof dim5 !== 'undefined') && (typeof array[dim0][dim1][dim2][dim3][dim4][dim5] == 'undefined')) {
		array[dim0][dim1][dim2][dim3][dim4][dim5] = [];
	}
}
function arraySum(array) {
	var sum = 0;
	if (!un(array)) {
		for (var a = 0, aMax = array.length; a < aMax; a++) {
			sum += Number(array[a]);
		}
	}
	return sum;
}
Array.prototype.alphanumSort = function (caseInsensitive) {
	for (var z = 0, t; t = this[z]; z++) {
		this[z] = [],
		x = 0,
		y = -1,
		n = 0,
		i,
		j;
		while (i = (j = t.charAt(x++)).charCodeAt(0)) {
			var m = (i == 46 || (i >= 48 && i <= 57));
			if (m !== n) {
				this[z][++y] = "";
				n = m;
			}
			this[z][y] += j;
		}
	}

	this.sort(function (a, b) {
		for (var x = 0, aa, bb; (aa = a[x]) && (bb = b[x]); x++) {
			if (caseInsensitive) {
				aa = aa.toLowerCase();
				bb = bb.toLowerCase();
			}
			if (aa !== bb) {
				var c = Number(aa),
				d = Number(bb);
				if (c == aa && d == bb) {
					return c - d;
				} else
					return (aa > bb) ? 1 : -1;
			}
		}
		return a.length - b.length;
	});

	for (var z = 0; z < this.length; z++)
		this[z] = this[z].join("");
}
function compareVersion(data0, data1, levels) {
	function getVersionHash(version) {
		var value = 0;
		version = version.split(".").map(function (a) {
				var n = parseInt(a);
				var letter = a.replace(n, "");
				if (letter) {
					return n + letter[0].charCodeAt() / 0xFF;
				} else {
					return n;
				}
			});
		for (var i = 0; i < version.length; ++i) {
			if (levels === i)
				break;
			value += version[i] / 0xFF * Math.pow(0xFF, levels - i + 1);
		}
		return value;
	};
	var v1 = getVersionHash(data0);
	var v2 = getVersionHash(data1);
	return v1 === v2 ? -1 : v1 > v2 ? 0 : 1;
};

function mouseHitRect(l, t, w, h) {
	var x = mouse.x;
	var y = mouse.y;
	if (x >= l && x <= (l + w) && y >= t && y <= (t + h)) {
		return true;
	} else {
		return false;
	}
}
function hitTestMouseOver(obj) {
	if (un(obj))
		return;
	var objBoundingRect = obj.getBoundingClientRect();
	var x = xCanvasToWindow(mouse.x);
	var y = yCanvasToWindow(mouse.y);
	if (x > objBoundingRect.left && x < objBoundingRect.right && y > objBoundingRect.top && y < objBoundingRect.bottom) {
		return true;
	} else {
		return false;
	}
}
function hitTestTwoObjects(obj1, obj2) {
	var obj1BoundingRect = obj1.getBoundingClientRect();
	var obj2BoundingRect = obj2.getBoundingClientRect();
	if (obj1BoundingRect.left < obj2BoundingRect.right && obj1BoundingRect.top < obj2BoundingRect.bottom && obj1BoundingRect.right > obj2BoundingRect.left && obj1BoundingRect.bottom > obj2BoundingRect.top) {
		return true
	} else {
		if (obj1BoundingRect.right > obj2BoundingRect.left && obj1BoundingRect.top < obj2BoundingRect.bottom && obj1BoundingRect.left < obj2BoundingRect.right && obj1BoundingRect.bottom > obj2BoundingRect.top) {
			return true;
		} else {
			if (obj2BoundingRect.left < obj1BoundingRect.right && obj2BoundingRect.top < obj1BoundingRect.bottom && obj2BoundingRect.right > obj1BoundingRect.left && obj2BoundingRect.bottom > obj1BoundingRect.top) {
				return true
			} else {
				if (obj2BoundingRect.right > obj1BoundingRect.left && obj2BoundingRect.top < obj1BoundingRect.bottom && obj2BoundingRect.left < obj1BoundingRect.right && obj2BoundingRect.bottom > obj1BoundingRect.top) {
					return true;
				} else {
					return false
				}
			}
		}
	}
}
function hitTestRect(obj, left, top, width, height) {
	var objBoundingRect = obj.getBoundingClientRect();
	var right = left + width;
	var bottom = top + height;
	left = xCanvasToWindow(left);
	right = xCanvasToWindow(right);
	top = yCanvasToWindow(top);
	bottom = yCanvasToWindow(bottom);
	if (objBoundingRect.left < right && objBoundingRect.top < bottom && objBoundingRect.right > left && objBoundingRect.bottom > top) {
		return true;
	} else {
		if (objBoundingRect.right > left && objBoundingRect.top < bottom && objBoundingRect.left < right && objBoundingRect.bottom > top) {
			return true;
		} else {
			if (left < objBoundingRect.right && top < objBoundingRect.bottom && right > objBoundingRect.left && bottom > objBoundingRect.top) {
				return true;
			} else {
				if (right > objBoundingRect.left && top < objBoundingRect.bottom && left < objBoundingRect.right && bottom > objBoundingRect.top) {
					return true;
				} else {
					return false;
				}
			}
		}
	}
}
function hitTestRect2(obj, left, top, width, height) { // tests if center of obj is in rect
	var objBoundingRect = obj.getBoundingClientRect();
	var objX = objBoundingRect.left + 0.5 * (objBoundingRect.right - objBoundingRect.left);
	var objY = objBoundingRect.top + 0.5 * (objBoundingRect.bottom - objBoundingRect.top);
	var right = left + width;
	var bottom = top + height;
	left = xCanvasToWindow(left);
	right = xCanvasToWindow(right);
	top = yCanvasToWindow(top);
	bottom = yCanvasToWindow(bottom);
	if (objX < right && objY < bottom && objX > left && objY > top) {
		return true;
	} else {
		return false;
	}
}
function hitTestTwoRects(rect1, rect2) {
	var xHit = false;
	var yHit = false;
	if (
		(rect2[0] <= rect1[0] && rect2[0] + rect2[2] >= rect1[0]) ||
		(rect2[0] <= rect1[0] + rect1[2] && rect2[0] + rect2[2] >= rect1[0] + rect1[2]) ||
		(rect2[0] >= rect1[0] && rect2[0] + rect2[2] <= rect1[0] + rect1[2])) {
		xHit = true;
	};
	if (
		(rect2[1] <= rect1[1] && rect2[1] + rect2[3] >= rect1[1]) ||
		(rect2[1] <= rect1[1] + rect1[3] && rect2[1] + rect2[3] >= rect1[1] + rect1[3]) ||
		(rect2[1] >= rect1[1] && rect2[1] + rect2[3] <= rect1[1] + rect1[3])) {
		yHit = true;
	};
	return (xHit && yHit);
}
function hitTestMouseOverRect(left, top, width, height) { // tests if mouse is in rect - REQUIRES mouse coords to have been updated
	if (mouse.x < left + width && mouse.y < top + height && mouse.x > left && mouse.y > top) {
		return true;
	} else {
		return false;
	}
}
function hitTestCircle(obj, centreX, centreY, radius) {
	var objBoundingRect = obj.getBoundingClientRect();
	centreX = xCanvasToWindow(centreX);
	centreY = yCanvasToWindow(centreY);
	if ((window.innerWidth / window.innerHeight) > (12 / 7)) {
		radius = (radius / canvas.height) * window.innerHeight;
	} else {
		radius = (radius / canvas.width) * window.innerWidth;
	}
	var testPoint = [];
	testPoint[0] = Math.pow((objBoundingRect.left - centreX), 2) + Math.pow((objBoundingRect.top - centreY), 2);
	testPoint[1] = Math.pow((objBoundingRect.left - centreX), 2) + Math.pow((objBoundingRect.bottom - centreY), 2);
	testPoint[2] = Math.pow((objBoundingRect.right - centreX), 2) + Math.pow((objBoundingRect.top - centreY), 2);
	testPoint[3] = Math.pow((objBoundingRect.right - centreX), 2) + Math.pow((objBoundingRect.bottom - centreY), 2);
	testPoint[4] = Math.pow((objBoundingRect.left - centreX), 2) + Math.pow(((objBoundingRect.top + objBoundingRect.bottom) / 2 - centreY), 2);
	testPoint[5] = Math.pow((objBoundingRect.right - centreX), 2) + Math.pow(((objBoundingRect.top + objBoundingRect.bottom) / 2 - centreY), 2);
	testPoint[6] = Math.pow(((objBoundingRect.left + objBoundingRect.right) / 2 - centreX), 2) + Math.pow((objBoundingRect.top - centreY), 2);
	testPoint[7] = Math.pow(((objBoundingRect.left + objBoundingRect.right) / 2 - centreX), 2) + Math.pow((objBoundingRect.bottom - centreY), 2);

	if (getArrayLessThanCount(testPoint, Math.pow(radius, 2)) > 0) {
		return true
	} else {
		return false
	}
}
function hitTestCircle2(obj, centreX, centreY, radius) { // this one just requires the center of the object to be within the circle
	var objBoundingRect = obj.getBoundingClientRect();
	centreX = xCanvasToWindow(centreX);
	centreY = yCanvasToWindow(centreY);
	if ((window.innerWidth / window.innerHeight) > (12 / 7)) {
		radius = (radius / canvas.height) * window.innerHeight;
	} else {
		radius = (radius / canvas.width) * window.innerWidth;
	}
	var objX = objBoundingRect.left + 0.5 * objBoundingRect.width;
	var objY = objBoundingRect.top + 0.5 * objBoundingRect.height;
	if (Math.pow((objX - centreX), 2) + Math.pow((objY - centreY), 2) <= Math.pow(radius, 2)) {
		return true
	} else {
		return false
	}
}
function hitTestMouseOverPolygon(verticesArray) {
	var x = mouse.x;
	var y = mouse.y;

	// split n-agon into (n-2) triangles and test if (x,y) is in each triangle
	var x1 = verticesArray[0][0];
	var y1 = verticesArray[0][1];

	for (var i = 1; i <= verticesArray.length - 2; i++) {
		var x2 = verticesArray[i][0];
		var y2 = verticesArray[i][1];
		var x3 = verticesArray[i + 1][0];
		var y3 = verticesArray[i + 1][1];
		// work out the barycentric coordinates for the triangle
		// iff all are positive, (x, y) is in the triangle
		var alpha = ((y2 - y3) * (x - x3) + (x3 - x2) * (y - y3)) / ((y2 - y3) * (x1 - x3) + (x3 - x2) * (y1 - y3));
		var beta = ((y3 - y1) * (x - x3) + (x1 - x3) * (y - y3)) / ((y2 - y3) * (x1 - x3) + (x3 - x2) * (y1 - y3));
		var gamma = 1 - alpha - beta;
		if (alpha > 0 && beta > 0 && gamma > 0) {
			return true;
		}
	}
	return false;
}
function hitTestPolygon(point, verticesArray, includePerimeter) {
	var x = point[0];
	var y = point[1];
	
	// split n-agon into (n-2) triangles and test if (x,y) is in each triangle
	var x1 = verticesArray[0][0];
	var y1 = verticesArray[0][1];

	for (var i = 1; i <= verticesArray.length - 2; i++) {
		var x2 = verticesArray[i][0];
		var y2 = verticesArray[i][1];
		var x3 = verticesArray[i + 1][0];
		var y3 = verticesArray[i + 1][1];
		// work out the barycentric coordinates for the triangle
		// iff all are positive, (x, y) is in the triangle
		var alpha = ((y2 - y3) * (x - x3) + (x3 - x2) * (y - y3)) / ((y2 - y3) * (x1 - x3) + (x3 - x2) * (y1 - y3));
		var beta = ((y3 - y1) * (x - x3) + (x1 - x3) * (y - y3)) / ((y2 - y3) * (x1 - x3) + (x3 - x2) * (y1 - y3));
		var gamma = 1 - alpha - beta;
		if (boolean(includePerimeter, true) == true) {
			if (alpha >= 0 && beta >= 0 && gamma >= 0)
				return true;
		} else {
			if (alpha > 0 && beta > 0 && gamma > 0)
				return true;
		}
	}
	return false;
}
function hitTestPolygon2(point,pos) {
	//https://stackoverflow.com/questions/8721406/how-to-determine-if-a-point-is-inside-a-2d-convex-polygon/23223947#23223947
	var result = false;
	for (var i = 0, j = pos.length - 1; i < pos.length; j = i++) {
		if ((pos[i][1] > point[1]) != (pos[j][1] > point[1]) &&
		(point[0] < (pos[j][0] - pos[i][0]) * (point[1] - pos[i][1]) / (pos[j][1]-pos[i][1]) + pos[i][0])) {
			result = !result;
		}
	}
	return result;
}
function hitTestPolygonBoundary(point,pos,tol) {
	if (un(tol)) tol = 0.01;
	for (var p = 0; p < pos.length; p++) {
		var pos1 = pos[p];
		var pos2 = pos[(p+1)%pos.length];
		if (isPointOnLineSegment(point, pos1, pos2, tol) == true) return true;
	}
	return false;
}

function motionPath(canvasData, startX, startY, finX, finY, rateType, rate) { // eg. rateType='time', rate=2000 (time in ms to complete motion) or rateType='speed', rate=200 (speed of motion in (canvas) pixels per second)
	var xDistance = finX - startX;
	var yDistance = finY - startY;
	var distance = Math.sqrt(Math.pow(xDistance, 2) + Math.pow(yDistance, 2));
	var time;
	if (rateType == 'speed') {
		time = 1000 * distance / rate
	};
	if (rateType == 'time') {
		time = rate
	};
	var dx = xDistance * 40 / time;
	var dy = yDistance * 40 / time;
	var frameCount = 0;
	var totalFrames = Math.floor(time / 40);
	var motion = setInterval(function () {
			canvasData[100] += dx;
			canvasData[101] += dy;
			resize();
			frameCount++;
			if (frameCount >= totalFrames) {
				canvasData[100] = finX;
				canvasData[101] = finY;
				resize();
				clearInterval(motion)
			};
		}, 40);
}
function motionResize(canvasData, newWidth, newHeight, time, coeX, coeY) {
	//if not present, the coe will default to the centre of the object
	if (!coeX) {
		coeX = canvasData[100] + 0.5 * canvasData[102]
	};
	if (!coeY) {
		coeY = canvasData[101] + 0.5 * canvasData[103]
	};
	var dw = (newWidth - canvasData[102]) * 40 / time;
	var dh = (newHeight - canvasData[103]) * 40 / time;
	var dx = 0.5 * (canvasData[102] - newWidth) * 40 / time;
	var dy = 0.5 * (canvasData[103] - newHeight) * 40 / time;
	var finX = canvasData[100] + 0.5 * (canvasData[102] - newWidth);
	var finY = canvasData[101] + 0.5 * (canvasData[103] - newHeight);
	var frameCount = 0;
	var totalFrames = Math.floor(time / 40);
	var motion = setInterval(function () {
			canvasData[100] += dx;
			canvasData[101] += dy;
			canvasData[102] += dw;
			canvasData[103] += dh;
			resize();
			frameCount++;
			if (frameCount >= totalFrames) {
				canvasData[100] = finX;
				canvasData[101] = finY;
				canvasData[102] = newWidth;
				canvasData[103] = newHeight;
				resize();
				clearInterval(motion)
			};
		}, 40);
}

function ceiling(number, toNearest) {
	// get the place value of toNearest
	var decPointPos;
	if (String(toNearest).indexOf('.') !== -1) {
		decPointPos = String(toNearest).indexOf('.');
	} else {
		decPointPos = String(toNearest).length - 1;
	}
	var placeValue;
	for (ii = 0; ii < String(toNearest).length; ii++) {
		if (String(toNearest).charAt(ii) !== "0" && String(toNearest).charAt(ii) !== ".") {
			placeValue = decPointPos - ii;
		}
	}
	// divide number and toNearesr by 10^placevalue
	number = number / (Math.pow(10, placeValue));
	toNearest = toNearest / (Math.pow(10, placeValue));
	// divide number by toNearest
	number = number / toNearest;
	number = Math.ceil(number);
	number = number * toNearest;
	number = number * (Math.pow(10, placeValue));
	number = Math.round(number * 1000000000) / 1000000000;
	return number;
}
function truncate(number, decPlaces) {
	return  + (Math.floor(number * Math.pow(10, decPlaces)) / Math.pow(10, decPlaces)).toFixed(decPlaces);
}
function round2(number, decPlaces) {
	return  + (Math.round(number * Math.pow(10, decPlaces)) / Math.pow(10, decPlaces)).toFixed(decPlaces);
}
function roundToNearest(number, toNearest) {
	var testLog = Math.log(toNearest) / Math.log(10);
	if (Math.abs(testLog - Math.round(testLog)) < 0.000001) { // powers of 10
		return round(number, toNearest);
	} else {
		// get the place value of toNearest
		var decPointPos;
		if (String(toNearest).indexOf('.') !== -1) {
			decPointPos = String(toNearest).indexOf('.');
		} else {
			decPointPos = String(toNearest).length - 1;
		}
		var placeValue;
		for (var i = 0; i < String(toNearest).length; i++) {
			if (String(toNearest).charAt(i) !== "0" && String(toNearest).charAt(i) !== ".") {
				placeValue = decPointPos - i;
			}
		}
		number = number / (Math.pow(10, placeValue));
		toNearest = toNearest / (Math.pow(10, placeValue));
		number = number / toNearest;
		number = Math.round(number);
		number = number * toNearest;
		number = number * (Math.pow(10, placeValue));
		number = Math.round(number * 1000000000) / 1000000000;
		return number;
	}
}
function roundSF(number, sigFigs, showAllZeros) {
	if (un(sigFigs)) sigFigs = 1;
	var negative = number < 0 ? true : false;
	number = Math.abs(number);
	var pv = Math.floor(Math.log(number)/Math.log(10)) - (sigFigs-1);
	var toNearest = Math.pow(10,pv);
	var rounded = String(roundToNearest(number,toNearest));
	
	var sfCount = 0; // check number of sf in answer
	var dpPassed = false;
	for (var d = 0; d < rounded.length; d++) {
		if (rounded[d] == '-') continue;
		if (rounded[d] == '.') {
			if (sfCount >= sigFigs) {
				rounded = rounded.slice(0,d);
				break;
			} else {
				dpPassed = true;
				continue;
			}
		}
		if (sfCount == 0 && rounded[d] == '0') continue;
		sfCount++;
		if (dpPassed == true && sfCount == sigFigs) {
			rounded = rounded.slice(0,d+1);
			break;
		}
	}
	if (negative == true) rounded = '-'+rounded;
	return rounded;
}
function round(number, toNearest, returnAsString) { // toNearest must be a power of 10
	var sign = number < 0 ? '-' : '';
	var str = String(Math.abs(number));
	var decPos = str.indexOf('.') > -1 ? str.indexOf('.') : str.length;
	var digits = [];
	for (var n = 0; n < str.length; n++) {
		if (isNaN(Number(str[n])))
			continue;
		digits.push(Number(str[n]));
	}
	var roundPV = Math.round(Math.log(toNearest) / Math.log(10));
	var roundPos = Math.round(decPos - roundPV - 1);
	if (roundPos >= digits.length) {
		var addDigits = roundPos - digits.length;
		for (var p = 0; p <= addDigits; p++)
			digits.push(0);
	} else {
		if (roundPos == -1) {
			if (digits[0] >= 5) {
				digits.unshift(1);
				roundPos++;
				decPos++;
			} else {
				return 0;
			}
		} else if (digits[roundPos + 1] >= 5) {
			if (digits[roundPos] < 9) {
				digits[roundPos]++;
			} else {
				digits[roundPos] = 0;
				var done = false;
				var pos = roundPos - 1;
				var count = 0;
				while (done == false && count < 50) {
					count++
					if (pos == -1) {
						digits.unshift(1);
						roundPos++;
						decPos++;
						done = true;
					} else if (digits[pos] < 9) {
						digits[pos]++;
						done = true;
					} else {
						digits[pos] = 0;
						pos--;
					}
				}
			}
		}
		for (var p = roundPos + 1; p < digits.length; p++)
			digits[p] = 0;
	}
	var str2 = sign;
	for (var p = 0; p < digits.length; p++) {
		if (p == decPos) {
			if (roundPV < 0) {
				str2 += '.';
			} else {
				break;
			}
		}
		if (p == roundPos + 1 && p > decPos)
			break;
		str2 += String(digits[p]);
	}
	if (Number(str2) == 0)
		str2 = '0';

	if (boolean(returnAsString, false) == true) {
		return str2;
	} else {
		return Number(str2);
	}
	//console.log(sign,str,toNearest,decPos,digits,roundPV,roundPos,str2);
}

function nthroot(x, n) {
	try {
		var negate = n % 2 == 1 && x < 0;
		if (negate)
			x = -x;
		var possible = Math.pow(x, 1 / n);
		n = Math.pow(possible, n);
		if (Math.abs(x - n) < 1 && (x > 0 == n > 0))
			return negate ? -possible : possible;
	} catch (e) {}
}
function hcf(x, y) {
	x = Math.abs(x);
	y = Math.abs(y);
	// Apply Euclid's algorithm to the two numbers.
	while (Math.max(x, y) % Math.min(x, y) != 0) {
		if (x > y) {
			x %= y;
		} else {
			y %= x;
		}
	}
	// When the while loop finishes the minimum of x and y is the HCF.
	return Math.min(x, y);
}
function ran(minNum, maxNum) {
	return Math.floor((maxNum - minNum + 1) * Math.random()) + minNum;
}

function clickToHide(canvas, canvasctx, canvasData, font, textColor) {
	if (!font) {
		font = '12px Arial'
	};
	if (!textColor) {
		textColor = '#333'
	};
	canvasctx.font = font;
	canvasctx.fillStyle = textColor;
	canvasctx.textBaseline = 'bottom';
	canvasctx.textAlign = 'center';
	canvasctx.fillText('Click to close', canvasData[2] / 2, canvasData[3] - 3);
	canvas.style.pointerEvents = 'auto';
	canvas.onclick = function () {
		hideObj(canvas, canvasData);
	}
}

// rotates coordinates about the origin (or a given center) and rounds to nearest integer
function rotateCoords(x, y, degrees, opt_direction, opt_centerX, opt_centerY, opt_round) {
	var round = true;
	if (typeof opt_round == 'boolean') {
		round = opt_round
	}
	var direction = opt_direction || 'anti-cw'; // use 'cw' or 'anti-cw'
	var centerX = opt_centerX || 0; //optional centre of rotation
	var centerY = opt_centerY || 0;
	// convert to anti-cw and radians
	if (direction == 'cw')
		degrees = 360 - degrees;
	var angleRads = degrees / 180 * Math.PI;
	// transpose to origin
	x -= centerX;
	y -= centerY;
	// apply matrix
	if (round == true) {
		var newX = Math.round(Math.cos(angleRads) * x - Math.sin(angleRads) * y);
		var newY = Math.round(Math.sin(angleRads) * x + Math.cos(angleRads) * y);
	} else {
		var newX = Math.cos(angleRads) * x - Math.sin(angleRads) * y;
		var newY = Math.sin(angleRads) * x + Math.cos(angleRads) * y;
	}
	// un-transpose
	newX += centerX;
	newY += centerY;
	return {
		x: newX,
		y: newY
	};
}

var variArray = ['a', 'b', 'c', 'd', 'g', 'h', 'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'y', 'y'];
function equivExpressions(string1, string2) { // checks if two algebraic expressions (as strings in x only) are equivalent
	if (string1 == '' || string2 == '') {
		return false;
	}
	var equivalent = true;
	// select 100 * 2 random numbers of different magnitudes
	for (mag = 0; mag < 10; mag++) {
		for (num = 0; num < 10; num++) {
			var x = Math.random() * Math.pow(10, mag);
			var val1 = eval(string1);
			var val2 = eval(string2);
			// get percentage error between values
			var pError = 0;
			if (val1 !== 0) {
				pError = Math.abs((val1 - val2) / val1);
			} else if (val2 !== 0) {
				pError = Math.abs((val1 - val2) / val2);
			}
			if (pError > 0.00001) {
				equivalent = false;
			}
			x = -1 * x;
			val1 = eval(string1);
			val2 = eval(string2);
			pError = 0;
			if (val1 !== 0) {
				pError = Math.abs((val1 - val2) / val1);
			} else if (val2 !== 0) {
				pError = Math.abs((val1 - val2) / val2);
			}
			if (pError > 0.00001) {
				equivalent = false;
			}
		}
	}
	return equivalent
}

function buildQuadraticExp(d, e, f, g, h, vari) {
	if (un(h))
		h = 1;
	var a = h * d * f;
	var b = h * (d * g + e * f);
	var c = h * e * g;
	return buildQuadratic(a, b, c, d, e, f, g, h, vari);
}
function buildQuadratic(a, b, c, d, e, f, g, h, vari) {
	// ax^2 + bx + c = h(dx + e)(fx + g)
	if (!vari) {
		var variNum = ran(0, 50);
		vari = 'x';
		if (variNum < 19)
			vari = variArray[variNum];
	}
	var p,
	q,
	r,
	exp,
	fac,
	compSq,
	disc,
	qText,
	rText,
	root1Text,
	root2Text,
	vertexText,
	expJS,
	factors = [],
	factorisedForms = [],
	expandedTerms = [],
	expandedForms = [];

	// create the expanded form text
	var aSign = '';
	var aFirstSign = '';
	var aTerm = String(Math.abs(a)) + vari;
	var aTermJS = String(Math.abs(a)) + '*Math.pow(' + vari + ',2)';
	if (a > 0)
		aSign = ' + ';
	if (a < 0)
		aSign = ' - ';
	if (a < 0)
		aFirstSign = '-';
	if (a == 1 || a == -1)
		aTerm = vari;
	if (a == 1)
		aTermJS = 'Math.pow(' + vari + ',2)';
	if (a == -1)
		aTermJS = '-Math.pow(' + vari + ',2)';
	if (a == 0)
		aTerm = '';

	var bSign = '';
	var bFirstSign = '';
	var bTerm = String((Math.abs(b))) + vari;
	var bTermJS = String((Math.abs(b))) + '*' + vari;
	if (b > 0)
		bSign = ' + ';
	if (b < 0)
		bSign = ' - ';
	if (b < 0)
		bFirstSign = '-';
	if (b == 1 || b == -1)
		bTerm = vari;
	if (b == 1 || b == -1)
		bTermJS = vari;
	if (b == -1)
		bTermJS = vari;
	if (b == 0)
		bTerm = '';
	if (b == 0)
		bTermJS = '';

	var cSign = '';
	var cFirstSign = '';
	var cTerm = String(Math.abs(c));
	var cTermJS = String(Math.abs(c));
	if (c > 0)
		cSign = ' + ';
	if (c < 0)
		cSign = ' - ';
	if (c < 0)
		cFirstSign = '-';
	if (c == 0)
		cTermJS = '';
	if (c == 0)
		cTerm = '';

	var expTermsMathsText = [[aFirstSign, aTerm], [bFirstSign, bTerm], [cFirstSign, cTerm]];
	var expFormsMathsText = [
		[aFirstSign + aTerm, ['power', false, '2'], bSign, bTerm, cSign, cTerm],
		[aFirstSign + aTerm, ['power', false, '2'], cSign, cTerm, bSign, bTerm],
		[bFirstSign + bTerm + aSign + aTerm, ['power', false, '2'], cSign + cTerm],
		[bFirstSign + bTerm + cSign + cTerm + aSign + aTerm, ['power', false, '2']],
		[cFirstSign + cTerm + aSign + aTerm, ['power', false, '2'], bSign + bTerm],
		[cFirstSign + cTerm + bSign + bTerm + aSign + aTerm, ['power', false, '2']]
	];
	var expTermsJS = [aTermJS, bTermJS, cTermJS];
	var expFormsJS = [
		aFirstSign + aTermJS + bSign + bTermJS + cSign + cTermJS,
		aFirstSign + aTermJS + cSign + cTermJS + bSign + bTermJS,
		bFirstSign + bTermJS + aSign + aTermJS + cSign + cTermJS,
		bFirstSign + bTermJS + cSign + cTermJS + aSign + aTermJS,
		cFirstSign + cTermJS + aSign + aTermJS + bSign + bTermJS,
		cFirstSign + cTermJS + bSign + bTermJS + aSign + aTermJS,
	]

	if (a > 0 || (a < 0 && b < 0 && c < 0)) {
		exp = expFormsMathsText[0];
		expJS = expFormsJS[0];
	} else if (c > 0) {
		exp = expFormsMathsText[5];
		expJS = expFormsJS[5];
	} else {
		exp = expFormsMathsText[3];
		expJS = expFormsJS[3];
	}

	// create the factorised forms
	var factors = constructFactors(h, d, e, f, g, vari);
	var factorisedForms = constructFactorisedForms(factors);

	var hFactors = [];
	for (var hF = h; hF > 1; hF--) {
		if (h % hF == 0)
			hFactors.push(hF);
	}

	var compositeFactors = [];
	var partiallyFactorisedForms = [];

	//construct sets of factors;

	if (typeof d !== 'undefined' && typeof e !== 'undefined' && typeof f !== 'undefined' && typeof g !== 'undefined') {
		if (d < 0) {
			bracket1 = '(' + e + " - ";
			var dText = Math.abs(d);
			if (d == -1)
				dText = '';
			bracket1 += dText + vari + ')'
		} else {
			var eSign = " + ";
			if (e < 0) {
				eSign = " - "
			};
			var dText = d;
			if (d == 1)
				dText = "";
			if (d == -1)
				dText = "-";
			bracket1 = "(" + dText + vari + eSign + Math.abs(e) + ")";
		}

		if (f < 0) {
			bracket2 = '(' + g + " - ";
			var fText = Math.abs(f);
			if (f == -1)
				fText = '';
			bracket2 += fText + vari + ')'
		} else {
			var gSign = " + ";
			if (g < 0) {
				gSign = " - "
			};
			var fText = f;
			if (f == 1)
				fText = "";
			if (f == -1)
				fText = "-";
			bracket2 = "(" + fText + vari + gSign + Math.abs(g) + ")";
		}

		fac = bracket1 + bracket2;
		if (Math.random() < 0.5)
			fac = bracket2 + bracket1;
		if (bracket1 == bracket2) {
			fac = bracket1 + String.fromCharCode(0x00B2)
		};

		if (e == 0) {
			var dText = d;
			if (d == 1)
				dText = '';
			if (d == -1)
				dText = '-';
			bracket1 = dText + vari;

		}

		if (g == 0) {
			var fText = f;
			if (f == 1)
				fText = '';
			if (f == -1)
				fText = '-';
			bracket2 = fText + vari;
			fac = bracket2 + bracket1;
		}

		if (typeof h !== 'undefined') {
			var hTerm = h;
			if (h == 1)
				hTerm = '';
			if (h == -1)
				hTerm = '-';
			fac = hTerm + fac;

		}
	}

	// create the completed square form text
	p = a;
	q = b / (2 * a);
	r = c - (b * b) / (4 * a);
	compSq = '';
	if (p > 0 || p < 0 && r <= 0) {
		var pTerm = String(p);
		if (p == 1)
			pTerm = '';
		if (p == -1)
			pTerm = '-';
		var qSign = " + ";
		if (q < 0)
			qSign = " - ";
		var qTerm = toMathsText(b, 2 * a);
		var rSign = " + ";
		if (r < 0)
			rSign = " - ";
		var rTerm = toMathsText(4 * a * c - b * b, 4 * a);
		if (r == 0) {
			rSign = '';
			rTerm = '';
		}
		compSq = [pTerm + '(' + vari + qSign, qTerm, ')', ['pow', '', '2'], rSign, rTerm];
	} else if (p < 0 && r > 0) { // r - p(x +- q)^2
		var rTerm = toMathsText(4 * a * c - b * b, 4 * a);
		var qSign = " + ";
		if (q < 0)
			qSign = " - ";
		var qTerm = toMathsText(b, 2 * a);
		var pTerm = toMathsText(p);
		if (p == -1)
			pTerm = '';
		compSq = [rTerm, ' - ' + pTerm + '(' + vari + qSign, qTerm, ')', ['pow', '', '2']];
	}

	// makes qText, rText and vertexText
	if (q < 0) {
		qText = ["-", qTerm];
		if (r < 0) {
			rText = ["-", rTerm];
			vertexText = ['(', qTerm, ', -', rTerm, ')'];
		} else {
			rText = rTerm;
			vertexText = ['(', qTerm, ', ', rTerm, ')'];
		}
	} else {
		qText = qTerm;
		if (r < 0) {
			rText = ["-", rTerm];
			vertexText = ['(-', qTerm, ', -', rTerm, ')'];
		} else {
			rText = rTerm;
			vertexText = ['(-', qTerm, ', ', rTerm, ')'];
		}
	}

	disc = b * b - 4 * a * c;

	// solves ax^2 + bx + c = 0
	var root1 = (-1 * b + Math.pow(b * b - 4 * a * c, 0.5)) / (2 * a);
	var root2 = (-1 * b - Math.pow(b * b - 4 * a * c, 0.5)) / (2 * a);

	// makes root1text and root2text
	// if non-surd solutions
	if (Math.pow(b * b - 4 * a * c, 0.5) == Math.round(Math.pow(b * b - 4 * a * c, 0.5))) {
		var root1sign = '';
		if ((-1 * b + Math.pow(b * b - 4 * a * c, 0.5)) / (2 * a) < 0)
			root1sign = '-';
		root1text = [root1sign, toMathsText((-1 * b + Math.pow(b * b - 4 * a * c, 0.5)), (2 * a))];
		var root2sign = '';
		if ((-1 * b - Math.pow(b * b - 4 * a * c, 0.5)) / (2 * a) < 0)
			root2sign = '-';
		root2text = [root2sign, toMathsText((-1 * b - Math.pow(b * b - 4 * a * c, 0.5)), (2 * a))];
	} else {
		var surd = simpSurd(b * b - 4 * a * c, 0.5);
		root1text = [toMathsText((-1 * b), (2 * a)), ' + ', toMathsText(1, (2 * a)), surd.mathsText];
		root2text = [toMathsText((-1 * b), (2 * a)), ' - ', toMathsText(1, (2 * a)), surd.mathsText];
	}

	return {
		exp: exp,
		fac: fac,
		compSq: compSq,
		disc: disc,
		a: a,
		b: b,
		c: c,
		d: d,
		e: e,
		f: f,
		g: g,
		h: h,
		p: p,
		q: q,
		r: r,
		vari: vari,
		root1: root1,
		root2: root2,
		qText: qText,
		rText: rText,
		vertexText: vertexText,
		root1text: root1text,
		root2text: root2text,
		factors: factors,
		factorisedForms: factorisedForms,
		expTermsMathsText: expTermsMathsText,
		expFormsMathsText: expFormsMathsText,
		expTermsJS: expTermsJS,
		expFormsJS: expFormsJS,
		expJS: expJS
	}
}
function quadratic(level, vari) {
	if (!vari) {
		var variNum = ran(0, 50);
		vari = 'x';
		if (variNum < 19)
			vari = variArray[variNum];
	}
	// quadratic is (dx + e)(fx + g) = ax^2 + bx + c
	var a,
	b,
	c,
	d,
	e,
	f,
	g,
	h,
	p,
	q,
	r,
	exp,
	fac,
	compSq,
	disc,
	qText,
	rText,
	root1Text,
	root2Text,
	vertexText,
	expJS;
	var factors = [];
	var factorisedForms = [];
	var expandedTerms = [];
	var expandedForms = [];
	switch (level) {
	case 1:
		// (x +- e)(x +- g) || dx(fx +- g)
		do {
			d = 1;
			e = ran(-10, 10);
			f = 1;
			g = ran(-10, 10);
		} while (g == 0)

		if (e == 0) {
			d = ran(1, 3);
			do {
				f = ran(1, 3);
			} while (hcf(f, g) !== 1)
		}

		a = d * f;
		b = d * g + e * f;
		c = e * g;
		h = 1;

		break;
	case 2:
		// h(x +- e)(x +- g), where h > 1
		do {
			d = 1;
			e = ran(-10, 10);
			f = 1;
			g = ran(-10, 10);
		} while (e == 0 || g == 0)

		a = d * f;
		b = d * g + e * f;
		c = e * g;
		h = [2, 2, 3, 4, 5, 10][ran(0, 5)];
		break;
	case 3:
		// h(dx +- e)(fx +- g)  where d = 1 or f = 1 but not both
		do {
			d = ran(1, 6);
			e = ran(-10, 10);
			f = ran(1, 6);
			g = ran(-10, 10);
			h = Math.max(1, ran(-15, 5));
		} while (e == 0 || g == 0 || (d == 1 && f == 1) || (d !== 1 && f !== 1) || hcf(d, e) > 1 || hcf(f, g) > 1)

		a = h * d * f;
		b = h * (d * g + e * f);
		c = h * e * g;

		break;
	case 4:
		// h(dx +- e)(fx +- g)  where d >= 1 and f >= 1
		do {
			d = ran(1, 6);
			e = ran(-10, 10);
			f = ran(1, 6);
			g = ran(-10, 10);
			h = Math.max(1, ran(-15, 5));
		} while (e == 0 || g == 0 || (d == 1 && f == 1) || hcf(d, e) > 1 || hcf(f, g) > 1)

		a = h * d * f;
		b = h * (d * g + e * f);
		c = h * e * g;

		break;
	case 5:
		// h(e - dx)(fx +- g)
		do {
			d = ran(-6, -1);
			e = ran(1, 10);
			f = ran(1, 6);
			g = ran(-10, 10);
			h = Math.max(1, ran(-15, 5));
		} while (g == 0 || hcf(d, e) > 1 || hcf(f, g) > 1)

		a = h * d * f;
		b = h * (d * g + e * f);
		c = h * e * g;

		break;
	case 6:
		// +-h(+-dx +- e)(+-fx +- g)  where d >= 1 and f >= 1
		do {
			d = ran(-3, 3);
			e = ran(-10, 10);
			f = ran(-3, 3);
			g = ran(-10, 10);
			h = ran(-3, 3);
		} while (e == 0 || g == 0 || d == 0 || f == 0 || h == 0 || (d == 1 && f == 1) || hcf(d, e) > 1 || hcf(f, g) > 1)

		if (d < 0 && e < 0) {
			d = -d;
			e = -e;
			h = -h;
		}
		if (f < 0 && g < 0) {
			f = -f;
			g = -g;
			h = -h;
		}

		a = h * d * f;
		b = h * (d * g + e * f);
		c = h * e * g;

		break;
	case 7:
		// generates a quadratic ax^2 +- bx +- c that doesn't factorise
		do {
			a = ran(1, 5);
			b = ran(-100, 100);
			c = ran(-100, 100);
			var disc = Math.pow(b * b - 4 * a * c, 0.5);
		} while (disc == Math.round(disc));
		h = 1;

		break;
	case 8:
		// generates a quadratic +-ax^2 +- bx +- c that doesn't factorise
		do {
			a = ran(-10, 10);
			b = ran(-100, 100);
			c = ran(-100, 100);
			var disc = Math.pow(b * b - 4 * a * c, 0.5);
		} while (a == 0 || disc == Math.round(disc) || (b == 0 && c == 0));
		h = 1;

		break;

	}

	return buildQuadratic(a, b, c, d, e, f, g, h, vari);
}
function sketchQuad(context, quad, gridLeft, gridTop, gridWidth, gridHeight, xMin, xMax, yMin, yMax, yIntLabel, xIntLabel, vertexLabel, opt_fontSize) {
	// draws a sketch of the graph of a quadratic
	if (typeof yIntLabel !== 'boolean')
		yIntLabel = false;
	if (typeof xIntLabel !== 'boolean')
		xIntLabel = false;
	if (typeof vertexLabel !== 'boolean')
		vertexLabel = false;
	if (quad.q == 0 && vertexLabel == true)
		yIntLabel = true;
	var fontSize = opt_fontSize || (Math.min(gridWidth, gridHeight) / 13);

	if (quad.a > 0) {
		// need to solve ax^2 + bx + c = yMax
		var maxVal = solveQuad(quad.a, quad.b, quad.c - yMax);
	} else {
		// need to solve ax^2 + bx + c = yMin
		var maxVal = solveQuad(quad.a, quad.b, quad.c - yMin);
	}
	var xStart = Math.max(xMin, maxVal.x2);
	var yStart = quad.a * xStart * xStart + quad.b * xStart + quad.c;
	var xFin = Math.min(xMax, maxVal.x1);
	var yFin = quad.a * xFin * xFin + quad.b * xFin + quad.c;

	var controlPoint = getBezierCurveForQuad(quad.a, quad.b, quad.c, xStart, yStart, xFin, yFin);

	var minPoint = {
		x: -1 * quad.q,
		y: quad.r
	}

	var gridSta = convertGridCoordsToCanvas(xStart, yStart, gridLeft, gridTop, gridWidth, gridHeight, xMin, xMax, yMin, yMax);
	var gridFin = convertGridCoordsToCanvas(xFin, yFin, gridLeft, gridTop, gridWidth, gridHeight, xMin, xMax, yMin, yMax);
	var gridCon = convertGridCoordsToCanvas(controlPoint.x, controlPoint.y, gridLeft, gridTop, gridWidth, gridHeight, xMin, xMax, yMin, yMax);
	var gridMin = convertGridCoordsToCanvas(minPoint.x, minPoint.y, gridLeft, gridTop, gridWidth, gridHeight, xMin, xMax, yMin, yMax);
	var gridRoot1 = convertGridCoordsToCanvas(quad.root1, 0, gridLeft, gridTop, gridWidth, gridHeight, xMin, xMax, yMin, yMax);
	var gridRoot2 = convertGridCoordsToCanvas(quad.root2, 0, gridLeft, gridTop, gridWidth, gridHeight, xMin, xMax, yMin, yMax);
	var gridYInt = convertGridCoordsToCanvas(0, quad.c, gridLeft, gridTop, gridWidth, gridHeight, xMin, xMax, yMin, yMax);

	context.lineWidth = 1;
	context.strokeStyle = '#666';
	context.beginPath();
	context.moveTo(gridLeft, gridTop + 0.5 * gridHeight);
	context.lineTo(gridLeft + gridWidth, gridTop + 0.5 * gridHeight);
	context.moveTo(gridLeft + gridWidth * 0.5, gridTop);
	context.lineTo(gridLeft + gridWidth * 0.5, gridTop + gridHeight);
	context.stroke();
	context.strokeStyle = '#000';
	context.beginPath()
	context.moveTo(gridSta.x, gridSta.y);
	context.quadraticCurveTo(gridCon.x, gridCon.y, gridFin.x, gridFin.y);
	if (vertexLabel == true) {
		context.moveTo(gridMin.x - 5, gridMin.y - 5);
		context.lineTo(gridMin.x + 5, gridMin.y + 5);
		context.moveTo(gridMin.x - 5, gridMin.y + 5);
		context.lineTo(gridMin.x + 5, gridMin.y - 5);
	}
	context.stroke();

	context.font = "14px Arial";
	context.textBaseline = "middle";
	context.fillStyle = "#000";
	context.textAlign = 'center';
	if (quad.disc == 0) {
		if (xIntLabel == true || vertexLabel == true)
			drawMathsText(context, quad.root1text, fontSize, gridRoot1.x, gridRoot1.y + 15, true, '', 'center', 'middle', '#000', 'draw', '#000');
		if (yIntLabel == true)
			drawMathsText(context, [String(quad.c)], fontSize, gridYInt.x + 5, gridYInt.y, true, '', 'left', 'middle', '#000', 'draw', '#000');

	} else if (quad.a > 0) {
		if (xIntLabel == true)
			drawMathsText(context, quad.root1text, fontSize, gridRoot1.x + 4, gridRoot1.y + 12, true, '', 'left', 'middle', '#000', 'draw');
		if (xIntLabel == true)
			drawMathsText(context, quad.root2text, fontSize, gridRoot2.x - 4, gridRoot1.y + 12, true, '', 'right', 'middle', '#000', 'draw');
		if (quad.b !== 0) {
			var vertexY = gridMin.y + 20;
			if (xIntLabel == true && vertexY - (gridTop + 0.5 * gridHeight) < 40)
				vertexY = gridTop + 0.5 * gridHeight + 40;
			if (vertexLabel == true)
				drawMathsText(context, quad.vertexText, fontSize, gridMin.x, vertexY, true, '', 'center', 'middle', '#000', 'draw');
		}
		if (quad.c !== 0) {
			if (quad.q <= 0) {
				if (quad.b !== 0) {
					if (yIntLabel == true)
						drawMathsText(context, [String(quad.c)], fontSize, gridYInt.x - 5, gridYInt.y, true, '', 'right', 'middle', '#000', 'draw');
				} else {
					if (yIntLabel == true)
						drawMathsText(context, [String(quad.c)], fontSize, gridYInt.x - 5, gridYInt.y + 15, true, '', 'right', 'middle', '#000', 'draw');
				}
			} else {
				if (quad.b !== 0) {
					if (yIntLabel == true)
						drawMathsText(context, [String(quad.c)], fontSize, gridYInt.x + 5, gridYInt.y, true, '', 'left', 'middle', '#000', 'draw');
				} else {
					if (yIntLabel == true)
						drawMathsText(context, [String(quad.c)], fontSize, gridYInt.x + 5, gridYInt.y + 15, true, '', 'left', 'middle', '#000', 'draw');
				}
			}
		}
	} else {
		// quads with a < 0

	}
}
function constructFactors(z0, z1, z2, z3, z4, vari) {
	// z0 is h
	var hSign = '+';
	var hOppSign = '-';
	var hFirstSign = '';
	var hOppFirstSign = '-';
	if (z0 < 0) {
		hSign = '-';
		hOppSign = '+';
		hFirstSign = '-';
		hOppFirstSign = '';
	}
	var hTerm = String(Math.abs(z0));
	if (z0 == 1 || z0 == -1)
		hTerm = '';

	// z1 is d (ie.dx)
	var dSign = '+';
	var dOppSign = '-';
	var dFirstSign = '';
	var dOppFirstSign = '-';
	if (z1 < 0) {
		dSign = '-';
		dOppSign = '+';
		dFirstSign = '-';
		dOppFirstSign = '';
	}
	var dTerm = String(Math.abs(z1)) + vari;
	if (z1 == 1 || z1 == -1)
		dTerm = vari;

	// z2 is e
	var eSign = '+';
	var eOppSign = '-';
	var eFirstSign = '';
	var eOppFirstSign = '-';
	if (z2 < 0) {
		eSign = '-';
		eOppSign = '+';
		eFirstSign = '-';
		eOppFirstSign = '';
	}
	var eTerm = String(Math.abs(z2));
	if (z2 == 0) {
		eSign = '';
		eOppSign = '';
		eFirstSign = '';
		eOppFirstSign = '';
		eTerm = '';
	}

	// z3 is f (ie.fx)
	var fSign = '+';
	var fOppSign = '-';
	var fFirstSign = '';
	var fOppFirstSign = '-';
	if (z3 < 0) {
		fSign = '-';
		fOppSign = '+';
		fFirstSign = '-';
		fOppFirstSign = '';
	}
	var fTerm = String(Math.abs(z3)) + vari;
	if (z3 == 1 || z3 == -1)
		fTerm = vari;

	// z4 is g
	var gSign = '+';
	var gOppSign = '-';
	var gFirstSign = '';
	var gOppFirstSign = '-';
	if (z4 < 0) {
		gSign = '-';
		gOppSign = '+';
		gFirstSign = '-';
		gOppFirstSign = '';
	}
	var gTerm = String(Math.abs(z4));
	if (z4 == 0) {
		gSign = '';
		gOppSign = '';
		gFirstSign = '';
		gOppFirstSign = '';
		gTerm = '';
	}

	return [

		[hFirstSign + hTerm, dFirstSign + dTerm + eSign + eTerm, fFirstSign + fTerm + gSign + gTerm],
		[hFirstSign + hTerm, eFirstSign + eTerm + dSign + dTerm, fFirstSign + fTerm + gSign + gTerm],
		[hFirstSign + hTerm, dFirstSign + dTerm + eSign + eTerm, gFirstSign + gTerm + fSign + fTerm],
		[hFirstSign + hTerm, eFirstSign + eTerm + dSign + dTerm, gFirstSign + gTerm + fSign + fTerm],

		[hOppFirstSign + hTerm, dOppFirstSign + dTerm + eOppSign + eTerm, fFirstSign + fTerm + gSign + gTerm],
		[hOppFirstSign + hTerm, eOppFirstSign + eTerm + dOppSign + dTerm, fFirstSign + fTerm + gSign + gTerm],
		[hOppFirstSign + hTerm, dOppFirstSign + dTerm + eOppSign + eTerm, gFirstSign + gTerm + fSign + fTerm],
		[hOppFirstSign + hTerm, eOppFirstSign + eTerm + dOppSign + dTerm, gFirstSign + gTerm + fSign + fTerm],

		[hOppFirstSign + hTerm, dFirstSign + dTerm + eSign + eTerm, fOppFirstSign + fTerm + gOppSign + gTerm],
		[hOppFirstSign + hTerm, eFirstSign + eTerm + dSign + dTerm, fOppFirstSign + fTerm + gOppSign + gTerm],
		[hOppFirstSign + hTerm, dFirstSign + dTerm + eSign + eTerm, gOppFirstSign + gTerm + fOppSign + fTerm],
		[hOppFirstSign + hTerm, eFirstSign + eTerm + dSign + dTerm, gOppFirstSign + gTerm + fOppSign + fTerm],

		[hFirstSign + hTerm, dOppFirstSign + dTerm + eOppSign + eTerm, fOppFirstSign + fTerm + gOppSign + gTerm],
		[hFirstSign + hTerm, eOppFirstSign + eTerm + dOppSign + dTerm, fOppFirstSign + fTerm + gOppSign + gTerm],
		[hFirstSign + hTerm, dOppFirstSign + dTerm + eOppSign + eTerm, gOppFirstSign + gTerm + fOppSign + fTerm],
		[hFirstSign + hTerm, eOppFirstSign + eTerm + dOppSign + dTerm, gOppFirstSign + gTerm + fOppSign + fTerm],

	]

}
function constructFactorisedForms(factorsArray) {
	var returnArray = [];
	for (var set = 0; set < factorsArray.length; set++) {
		var fac = [factorsArray[set][0], factorsArray[set][1], factorsArray[set][2]];
		var facBrac = ['(' + fac[0] + ')', '(' + fac[1] + ')', '(' + fac[2] + ')'];
		var bracReqFirst = [false, true, true];
		var bracReq = [true, true, true];

		for (br = 0; br < fac.length; br++) {
			if (fac[br] == '-')
				facBrac[br] = '(-1)';
			// if the factor doesn't contain + or -, no bracket required
			if (fac[br].indexOf('-') == -1 && fac[br].indexOf('+') == -1)
				bracReq[br] = false;
		}

		var first;
		var second;
		var third;

		for (br1 = 0; br1 < 3; br1++) {
			first = facBrac[br1];
			if (bracReqFirst[br1] == false)
				first = fac[br1];
			for (br2 = 0; br2 < 3; br2++) {
				if (br2 !== br1) {
					second = facBrac[br2];
					if (bracReq[br2] == false)
						second = fac[br2];
					for (br3 = 0; br3 < 3; br3++) {
						if (br3 !== br1 && br3 !== br2) {
							third = facBrac[br3];
							if (bracReq[br3] == false)
								third = fac[br3];

							if (returnArray.indexOf(first + second + third) == -1) {
								returnArray.push(first + second + third);
							}
							if (first == second && second == third && first !== '') {
								if (returnArray.indexOf('Math.pow(' + first + ',3)') == -1)
									returnArray.push('Math.pow(' + first + ',3)');
							}
							if (first == second && first !== '') {
								if (returnArray.indexOf('Math.pow(' + first + ',2)' + second) == -1)
									returnArray.push('Math.pow(' + first + ',2)' + second);
							}
							if (second == third && second !== '') {
								if (returnArray.indexOf(first + 'Math.pow(' + second + ',2)') == -1)
									returnArray.push(first + 'Math.pow(' + second + ',2)');
							}
						}
					}
				}
			}
		}
	}
	return returnArray;
}
function toMathsText(num, num2) {
	if (typeof num2 == 'undefined') {
		num = Math.abs(num);
		if (num == Math.round(num)) {
			return String(num);
		} else {
			// if num is negative?
			var frac = decToFrac(num);
			return ['frac', String(frac.num), String(frac.denom)];
		}
	} else {
		if (num == 0)
			return '0';
		var pos = true;
		if (num / num2 < 0)
			pos = false;
		num = Math.abs(num)
			num2 = Math.abs(num2);
		var divisor = hcf(num, num2);
		num = num / divisor;
		num2 = num2 / divisor;
		if (num2 == 1) {
			if (pos == true) {
				return String(num);
			} else {
				return "-" + String(num);
			}
		} else {
			if (pos == true) {
				return ['frac', [String(num)], [String(num2)]];
			} else {
				return ['-', ['frac', [String(num)], [String(num2)]]];
			}
		}
	}
}
function addFracs(num1, denom1, num2, denom2) {
	var denom = denom1 * denom2 / hcf(denom1, denom2);
	var num = num1 * (denom / denom1) + num2 * (denom / denom2);
	//console.log(num,denom);
	return toMathsText(num, denom);
}
function simplifyFrac(object, textArrayOrObject) {
	var textArray = boolean(textArrayOrObject, true);

	var positive = true;
	if (object.num / object.denom < 0)
		positive = false;
	if (object.num == 0) {
		if (textArray == true) {
			return ["0"];
		} else {
			return {
				num: 0,
				denom: 1
			};
		}
	}
	while (Math.round(object.num) !== object.num || Math.round(object.denom) !== object.denom) {
		object.num = object.num * 10;
		object.denom = object.denom * 10;
	}

	var num = Math.abs(object.num);
	var denom = Math.abs(object.denom);
	var multOfPi = false;
	if (typeof object.multOfPi == 'boolean')
		multOfPi = object.multOfPi;
	var newNum = num / hcf(num, denom);
	var newDenom = denom / hcf(num, denom);

	if (textArray == true) { // if returning a textArray
		if (multOfPi == false) {
			if (newDenom == 1) {
				if (positive == true) {
					return String(newNum);
				} else {
					return "-" + String(newNum);
				}
			} else {
				if (positive == true) {
					return ['frac', [String(newNum)], [String(newDenom)]]
				} else {
					return ['-', ['frac', [String(newNum)], [String(newDenom)]]]
				}
			}
		} else {
			if (newDenom == 1) {
				if (positive == true) {
					if (newNum == 1) {
						return String.fromCharCode(0x03C0);
					} else {
						return String(newNum) + String.fromCharCode(0x03C0);
					}
				} else {
					if (newNum == 1) {
						return "-" + String.fromCharCode(0x03C0);
					} else {
						return "-" + String(newNum) + String.fromCharCode(0x03C0);
					}
				}
			} else {
				if (positive == true) {
					if (newNum == 1) {
						return ['frac', [String.fromCharCode(0x03C0)], [String(newDenom)]];
					} else {
						return ['frac', [String(newNum) + String.fromCharCode(0x03C0)], [String(newDenom)]];
					}
				} else {
					if (newNum == 1) {
						return ["-", ['frac', [String.fromCharCode(0x03C0)], [String(newDenom)]]];
					} else {
						return ["-", ['frac', [String(newNum) + String.fromCharCode(0x03C0)], [String(newDenom)]]];
					}
				}
			}
		}
	} else { // if returning an object
		if (positive == true) {
			return {
				num: newNum,
				denom: newDenom
			};
		} else {
			return {
				num: -1 * newNum,
				denom: newDenom
			};
		}
	}
}
function simplifyFrac2(frac) {
	var positive = true;
	if (frac[0] / frac[1] < 0)
		positive = false;
	if (frac[0] == 0)
		return [0, 1];
	while (Math.round(frac[0]) !== frac[0] || Math.round(frac[1]) !== frac[1]) {
		frac[0] = frac[0] * 10;
		frac[1] = frac[1] * 10;
	}

	var num = Math.abs(frac[0]);
	var denom = Math.abs(frac[1]);
	var newNum = num / hcf(num, denom);
	var newDenom = denom / hcf(num, denom);
	if (positive == true) {
		return [newNum, newDenom];
	} else {
		return [-1 * newNum, newDenom];
	}
}
function addFracs2(frac1, frac2) {
	var denom = frac1[1] * frac2[1] / hcf(frac1[1], frac2[1]);
	var num = frac1[0] * (denom / frac1[1]) + frac2[0] * (denom / frac2[1]);
	return [num, denom];
}
function simpSurd(c) {
	//takes sqrt(c) and returns simplified: a*sqrt(b)
	var a,
	b,
	mathsTextSurd;

	for (fac = 1; fac <= c; fac++) {
		if (Math.sqrt(c / fac) == Math.round(Math.sqrt(c / fac))) {
			a = Math.sqrt(c / fac);
			b = fac;
			break;
		}
	}

	var aTerm = String(a);
	mathsTextSurd = [String(a), ['sqrt', [String(b)]]];
	if (a == 1 && b > 1)
		mathsTextSurd = [['sqrt', [String(b)]]]
		if (b == 1)
			mathsTextSurd = [String(a)];

	return {
		a: a,
		b: b,
		mathsText: mathsTextSurd
	};
}
function primeFactors(num) {
	var primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131];
	if (num == 1)
		return ['1'];
	if (num > 131)
		return ['']; // too big!
	if (primes.indexOf(num) > -1)
		return [String(num)];
	var primeFactors = [];
	do {
		for (var i = 0; i < primes.length; i++) {
			if (num % primes[i] == 0) {
				primeFactors.push(primes[i]);
				num = num / primes[i];
				break;
			}
		}
	} while (num > 1);
	var returnArray = [];
	for (var i = 0; i < primeFactors.length; i++) {
		var repeated = 1;
		for (var j = i + 1; j < primeFactors.length; j++) {
			if (primeFactors[i] == primeFactors[j])
				repeated++;
		}
		if (i > 0)
			returnArray.push(String.fromCharCode(0x00D7))
			returnArray.push(String(primeFactors[i]));
		if (repeated > 1) {
			returnArray.push(['power', false, [String(repeated)]]);
			i += repeated - 1;
		}
	}
	return returnArray;
}
function cuberoot(x) {
	var y = Math.pow(Math.abs(x), 1 / 3);
	return x < 0 ? -y : y;
}
function solveCubic(a, b, c, d) {
	if (Math.abs(a) < 1e-8) { // Quadratic case, ax^2+bx+c=0
		a = b;
		b = c;
		c = d;
		if (Math.abs(a) < 1e-8) { // Linear case, ax+b=0
			a = b;
			b = c;
			if (Math.abs(a) < 1e-8) // Degenerate case
				return [];
			return [-b / a];
		}

		var D = b * b - 4 * a * c;
		if (Math.abs(D) < 1e-8)
			return [-b / (2 * a)];
		else if (D > 0)
			return [(-b + Math.sqrt(D)) / (2 * a), (-b - Math.sqrt(D)) / (2 * a)];
		return [];
	}

	// Convert to depressed cubic t^3+pt+q = 0 (subst x = t - b/3a)
	var p = (3 * a * c - b * b) / (3 * a * a);
	var q = (2 * b * b * b - 9 * a * b * c + 27 * a * a * d) / (27 * a * a * a);
	var roots;

	if (Math.abs(p) < 1e-8) { // p = 0 -> t^3 = -q -> t = -q^1/3
		roots = [cuberoot(-q)];
	} else if (Math.abs(q) < 1e-8) { // q = 0 -> t^3 + pt = 0 -> t(t^2+p)=0
		roots = [0].concat(p < 0 ? [Math.sqrt(-p), -Math.sqrt(-p)] : []);
	} else {
		var D = q * q / 4 + p * p * p / 27;
		if (Math.abs(D) < 1e-8) { // D = 0 -> two roots
			roots = [-1.5 * q / p, 3 * q / p];
		} else if (D > 0) { // Only one real root
			var u = cuberoot(-q / 2 - Math.sqrt(D));
			roots = [u - p / (3 * u)];
		} else { // D < 0, three roots, but needs to use complex numbers/trigonometric solution
			var u = 2 * Math.sqrt(-p / 3);
			var t = Math.acos(3 * q / p / u) / 3; // D < 0 implies p < 0 and acos argument in [-1..1]
			var k = 2 * Math.PI / 3;
			roots = [u * Math.cos(t), u * Math.cos(t - k), u * Math.cos(t - 2 * k)];
		}
	}

	// Convert back from depressed cubic
	for (var i = 0; i < roots.length; i++)
		roots[i] -= b / (3 * a);

	return roots;
}

function hitAndAlign(object, firstArray, secondArray, offsetX, offsetY) {
	//this function aligns a dragged object to the x and y position of another object
	//first array is draggable buttons
	//second array is the things they are going to hit
	//this works for buttons
	if (typeof offsetX == 'undefined') {
		offsetX = 0
	} else {
		offsetX = Number(offsetX)
	}
	if (typeof offsetY == 'undefined') {
		offsetY = 0
	} else {
		offsetY = Number(offsetY)
	}
	var alreadyHitMe = false
		for (var j = 0; j < firstArray.length; j++) {

			if (hitTestTwoObjects(object, firstArray[j]) == true && object !== firstArray[j]) {
				alreadyHitMe = true
			}

		}

		for (var j = 0; j < secondArray.length; j++) {

			if (hitTestTwoObjects(object, secondArray[j]) == true && alreadyHitMe == false) {

				var buttonArray = eval(String(taskTag) + 'button')
					var buttonArrayData = eval(String(taskTag) + 'buttonData')

					var butNum = buttonArray.indexOf(object)
					var butNum2 = buttonArray.indexOf(secondArray[j])

					buttonArrayData[butNum][100] = buttonArrayData[butNum2][100] + Number(offsetX)
					buttonArrayData[butNum][101] = buttonArrayData[butNum2][101] + Number(offsetY)
					resize()
			}

		}

}
function hitAndAlignImages(object, firstArray, secondArray, offsetX, offsetY) {

	if (typeof offsetX == 'undefined') {
		offsetX = 0
	} else {
		offsetX = Number(offsetX)
	}
	if (typeof offsetY == 'undefined') {
		offsetY = 0
	} else {
		offsetY = Number(offsetY)
	}

	var alreadyHitMe = false
		for (var j = 0; j < firstArray.length; j++) {

			if (hitTestTwoObjects(object, firstArray[j]) == true && object !== firstArray[j]) {
				alreadyHitMe = true
			}

		}

		for (var j = 0; j < secondArray.length; j++) {

			if (hitTestTwoObjects(object, secondArray[j]) == true && alreadyHitMe == false) {

				var buttonArray = eval(String(taskTag) + 'imageCanvas')
					var buttonArrayData = eval(String(taskTag) + 'imageCanvasData')

					var butNum = buttonArray.indexOf(object)
					var butNum2 = buttonArray.indexOf(secondArray[j])

					buttonArrayData[butNum][100] = buttonArrayData[butNum2][100] + Number(offsetX)
					buttonArrayData[butNum][101] = buttonArrayData[butNum2][101] + Number(offsetY)
					resize()
			}

		}

}
function shuffleImagePositions(arrayOfObjects) {

	var buttonArray = eval(String(taskTag) + 'imageCanvas')
		var buttonArrayData = eval(String(taskTag) + 'imageCanvasData')

		currentX = []
		currentY = []

		//get current x and y positions of all objects in array

		for (n201i = 0; n201i < arrayOfObjects.length; n201i++) {
			var object = arrayOfObjects[n201i]

				var butNum = buttonArray.indexOf(object)

				currentX[n201i] = buttonArrayData[butNum][100]
				currentY[n201i] = buttonArrayData[butNum][101]

		}
		var mixedNumbers = []
		for (n201i = 0; n201i < arrayOfObjects.length; n201i++) {
			mixedNumbers[n201i] = n201i
		}
		mixedNumbers = shuffleArray(mixedNumbers)

		for (n201i = 0; n201i < arrayOfObjects.length; n201i++) {

			//arrayOfObjects = shuffleArray(arrayOfObjects)
			//choose random object from array

			var objectN = arrayOfObjects[mixedNumbers[n201i]]
				var butNumN = buttonArray.indexOf(objectN)

				buttonArrayData[butNumN][100] = currentX[n201i]
				buttonArrayData[butNumN][101] = currentY[n201i]
				//arrayOfObjects = arrayOfObjects.splice(ran,1)
		}

		resize()
}
function shuffleObjectPositions(arrayOfObjects) {

	var buttonArray = eval(String(taskTag) + 'button')
		var buttonArrayData = eval(String(taskTag) + 'buttonData')

		currentX = []
		currentY = []

		//get current x and y positions of all objects in array

		for (n201i = 0; n201i < arrayOfObjects.length; n201i++) {
			var object = arrayOfObjects[n201i]

				var butNum = buttonArray.indexOf(object)

				currentX[n201i] = buttonArrayData[butNum][100]
				currentY[n201i] = buttonArrayData[butNum][101]

		}
		var mixedNumbers = []
		for (n201i = 0; n201i < arrayOfObjects.length; n201i++) {
			mixedNumbers[n201i] = n201i
		}
		mixedNumbers = shuffleArray(mixedNumbers)

		for (n201i = 0; n201i < arrayOfObjects.length; n201i++) {

			//arrayOfObjects = shuffleArray(arrayOfObjects)
			//choose random object from array

			var objectN = arrayOfObjects[mixedNumbers[n201i]]
				var butNumN = buttonArray.indexOf(objectN)

				buttonArrayData[butNumN][100] = currentX[n201i]
				buttonArrayData[butNumN][101] = currentY[n201i]
				//arrayOfObjects = arrayOfObjects.splice(ran,1)
		}

		resize()
}

// array sorting function for key values
// use is:   array = array.sort(keySort('/*key*/'));
function keySort(key, desc) {
	return function (a, b) {
		return desc ? ~~(a[key] < b[key]) : ~~(a[key] > b[key]);
	}
}
function arrayMin(array) {
	var min = array[0];
	for (var i = 1; i < array.length; i++) {
		min = Math.min(min, array[i]);
	}
	return min;
}
function arrayMax(array) {
	var max = array[0];
	for (var i = 1; i < array.length; i++) {
		max = Math.max(max, array[i]);
	}
	return max;
}
function cloneArray(array) {
	var newArray = [];
	for (var i = 0; i < array.length; i++) {
		newArray[i] = array[i].slice(0);
	}
	return newArray
}

function hexToRgb(color) {
	if (color.indexOf('rgba') > -1) { // if an rgba string
		var result = color.substring(5, color.length - 1).replace(/ /g, '').split(',');
		return result ? {
			r: parseInt(result[0]),
			g: parseInt(result[1]),
			b: parseInt(result[2])
		}
		 : null;
	} else if (color.indexOf('rgb') > -1) { // if an rgb string
		var result = color.substring(5, color.length - 1).replace(/ /g, '').split(',');
		return result ? {
			r: parseInt(result[0]),
			g: parseInt(result[1]),
			b: parseInt(result[2])
		}
		 : null;
	} else if (color.indexOf('#') > -1) { // if a hex string
		// Expand shorthand form (e.g. "03F") to full form (e.g. "0033FF")
		var shorthandRegex = /^#?([a-f\d])([a-f\d])([a-f\d])$/i;
		color = color.replace(shorthandRegex, function (m, r, g, b) {
				return r + r + g + g + b + b;
			});
		var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(color);
		return result ? {
			r: parseInt(result[1], 16),
			g: parseInt(result[2], 16),
			b: parseInt(result[3], 16)
		}
		 : null;
	} else {
		return color;
	}
}
function colorA(color, alpha) {
	var colorRGB = hexToRgb(color);
	return "rgba(" + colorRGB.r + "," + colorRGB.g + "," + colorRGB.b + "," + alpha + ")";
}
function invertColor(color) {
	if (/^(#)((?:[A-Fa-f0-9]{3}){1,2})$/i.test(color) == true)
		color = hexToRgb(color); // if hex, change to rgba
	color.r = 255 - color.r;
	color.g = 255 - color.g;
	color.b = 255 - color.b;
	var a = 1;
	if (typeof color.a == 'number')
		a = color.a;
	return "rgba(" + color.r + "," + color.g + "," + color.b + "," + a + ")";
}
function getShades(color, invert) {
	var invert = boolean(invert, false);
	if (invert == true) {
		var color2 = hexToRgb(invertColor(color));
	} else {
		var color2 = hexToRgb(color);
	}
	var r = color2.r;
	var g = color2.g;
	var b = color2.b;

	//var rgb = [];
	var hex = [];

	if (r == 0 && g == 0 && b == 0) { // if the color is black, switch it to white
		r = 255;
		g = 255;
		b = 255;
	}

	// get brightest shade of rgb
	if (Math.max(r, g, b) < 255) {
		var m = 255 / Math.max(r, g, b);
		r = r * m;
		g = g * m;
		b = b * m;
	}

	for (var i = 0; i < 16; i++) {
		var r2 = roundToNearest((i / 15) * r, 1);
		var g2 = roundToNearest((i / 15) * g, 1);
		var b2 = roundToNearest((i / 15) * b, 1);
		//rgb[i] = "rgb("+String(r2)+","+String(g2)+","+String(b2)+")";
		var r3 = decToHex2Digits(r2);
		var g3 = decToHex2Digits(g2);
		var b3 = decToHex2Digits(b2);
		hex[i] = "#" + r3 + g3 + b3;
	}

	return hex;
}
function decToHex2Digits(num) {
	num2 = num.toString(16);
	if (num2.length == 1) {
		num2 = "0" + num2;
	} else if (num2.indexOf('.') == 1) {
		num2 = "0" + num2.slice(0, 1);
	} else {
		num2 = num2.slice(0, 2);
	}
	return num2;
}
function testShades(ctx, color, invert) {
	var colors = getShades(color, invert);
	var ctx = draw.drawctx;
	ctx.strokeStyle = '#000';
	for (var i = 0; i < 16; i++) {
		ctx.fillStyle = colors[i];
		ctx.fillRect(50 + i * 50, 50, 50, 50);
		ctx.strokeRect(50 + i * 50, 50, 50, 50);
	}
}
function getColor(r, g, b, a) {
	if (un(a))
		a = 1;
	return 'rgba(' + r + ',' + g + ',' + b + ',' + a + ')';
}
function getScaleColor(value,max,saturation) {
	if (un(saturation)) saturation = 1;
	var perc = Math.round((value / max) * 100);
	var h = Math.floor(perc * 1.2);
    var s = saturation;
    var v = 1;
	return hsv2rgb(h, s, v);
}
function hsv2rgb (h, s, v) {
  // adapted from http://schinckel.net/2012/01/10/hsv-to-rgb-in-javascript/
  var rgb, i, data = [];
  if (s === 0) {
    rgb = [v,v,v];
  } else {
    h = h / 60;
    i = Math.floor(h);
    data = [v*(1-s), v*(1-s*(h-i)), v*(1-s*(1-(h-i)))];
    switch(i) {
      case 0:
        rgb = [v, data[2], data[0]];
        break;
      case 1:
        rgb = [data[1], v, data[0]];
        break;
      case 2:
        rgb = [data[0], v, data[2]];
        break;
      case 3:
        rgb = [data[0], data[1], v];
        break;
      case 4:
        rgb = [data[2], data[0], v];
        break;
      default:
        rgb = [v, data[0], data[1]];
        break;
    }
  }
  return '#' + rgb.map(function(x){
    return ("0" + Math.round(x*255).toString(16)).slice(-2);
  }).join('');
};

function collapseLines(lineArray) {
	// collapses lines in an array such as:
	// [ [[x1,y1],[x2,y2]], [[x3,y3],[x4,y4]], [[x5,y5],[x6,y6]] ]
	do {
		var joinFound = false;
		for (var i = 0; i < lineArray.length; i++) {
			if (joinFound == false) {
				for (var j = i + 1; j < lineArray.length; j++) {
					var x1 = lineArray[i][0][0];
					var y1 = lineArray[i][0][1];
					var x2 = lineArray[i][1][0];
					var y2 = lineArray[i][1][1];
					var x3 = lineArray[j][0][0];
					var y3 = lineArray[j][0][1];
					var x4 = lineArray[j][1][0];
					var y4 = lineArray[j][1][1];
					var m1 = (y2 - y1) / (x2 - x1);
					var m2 = (y4 - y3) / (x4 - x3);
					// if gradients are equal and point from line 1 is on line 2
					//console.log('x1,y1,x2,y2,x3,y3,x4,y4');
					//console.log('grad/grad: ',mMax/mMin);
					//console.log('pointOnLine: ',isPointOnLine([x1,y1],[x3,y3],[x4,y4],3.5));
					if (((Math.abs(m1) == 'Infinity' && Math.abs(m2) == 'Infinity') || Math.abs(m1 - m2) < 0.0001) && isPointOnLine([x1, y1], [x3, y3], [x4, y4], 0.25) == true) {
						// if one of the points is between the two points on the other line
						if ((x1 >= Math.min(x3, x4) && x1 <= Math.max(x3, x4) && y1 >= Math.min(y3, y4) && y1 <= Math.max(y3, y4)) || (x2 >= Math.min(x3, x4) && x2 <= Math.max(x3, x4) && y2 >= Math.min(y3, y4) && y2 <= Math.max(y3, y4)) || (x3 >= Math.min(x1, x2) && x3 <= Math.max(x1, x2) && y3 >= Math.min(y1, y2) && y3 <= Math.max(y1, y2)) || (x4 >= Math.min(x1, x2) && x4 <= Math.max(x1, x2) && y4 >= Math.min(y1, y2) && y4 <= Math.max(y1, y2))) {
							var xMin = Math.min(x1, x2, x3, x4);
							var xMax = Math.max(x1, x2, x3, x4);
							if (xMin == x1)
								var yMin = y1;
							if (xMin == x2)
								var yMin = y2;
							if (xMin == x3)
								var yMin = y3;
							if (xMin == x4)
								var yMin = y4;
							if (xMax == x1)
								var yMax = y1;
							if (xMax == x2)
								var yMax = y2;
							if (xMax == x3)
								var yMax = y3;
							if (xMax == x4)
								var yMax = y4;
							if (xMin == xMax) {
								var yMin = Math.min(y1, y2, y3, y4);
								var yMax = Math.max(y1, y2, y3, y4);
							}
							joinFound = true;
							lineArray[i][0] = [xMin, yMin];
							lineArray[i][1] = [xMax, yMax];
							lineArray.splice(j, 1);
							break;
						}
					}
				}
			}
		}
	} while (joinFound == true);
	return lineArray;
}

function drawBarChart(object) {
	/* EXAMPLE USAGE:
	drawBarChart({
	ctx:j324buttonctx[0],
	left:200,
	top:240,
	width:500,
	height:370,
	data:[{value:['0'],	freq:17},{value:['1'],	freq:6},{value:['2'],	freq:3},{value:['3'],	freq:1},{value:['4'],	freq:2},{value:['5'],	freq:0},{value:['6'],	freq:1},
	],
	barWidth:[2,1], // bar width to gap width ratio
	barColor:'#FCF',
	barOutlineColor:'#000',
	barOutlineWidth:4,
	xLabel:['number of days'],
	yLabel:['frequency'],
	title:['Number of days absent in a month for a class'],
	titlePos:[450,260,200,90],
	yMinor:{show:true,step:1,color:'#AAA',width:1,dash:[3,5]},
	yMajor:{show:true,step:2,color:'#888',width:2,dash:[]},
	yMin:0,
	yMax:18,
	});
	 */

	var ctx = object.ctx || object.context;
	var left = object.left;
	var top = object.top;
	var width = object.width;
	var height = object.height;
	var data = object.data;

	var barWidth = object.barWidth || [2, 1];
	var barColor = object.barColor || '#FCF';
	var barOutlineColor = object.barOutlineColor || '#000';
	var barOutlineWidth = object.barOutlineWidth || 2;
	var xLabel = object.xLabel || [''];
	var yLabel = object.yLabel || [''];
	var title = object.title || [''];
	var titlePos = object.titlePos || [left + 0.5 * width, top + 0.03 * height, 0.4 * width, 0.2 * height];

	if (typeof object.yMinor == 'object') {
		var yMinorShow = boolean(object.yMinor.show, false);
		var yMinorStep = object.yMinor.step || 1;
		var yMinorColor = object.yMinor.color || '#AAA';
		var yMinorWidth = object.yMinor.width || 1;
		var yMinorDash = object.yMinor.dash || [];
	} else {
		var yMinorShow = false;
		var yMinorStep = 1;
		var yMinorColor = '#AAA';
		var yMinorWidth = 1;
		var yMinorDash = [];
	}

	if (typeof object.yMajor == 'object') {
		var yMajorShow = boolean(object.yMajor.show, false);
		var yMajorStep = object.yMajor.step || 1;
		var yMajorColor = object.yMajor.color || '#888';
		var yMajorWidth = object.yMajor.width || 2;
		var yMajorDash = object.yMajor.dash || [];
	} else {
		var yMajorShow = false;
		var yMajorStep = 1;
		var yMajorColor = '#888';
		var yMajorWidth = 2;
		var yMajorDash = [];
	}

	if (object.yMin == 'number') {
		var yMin = object.yMin;
	} else {
		var yMin = 0;
	}

	if (object.yMax == 'number') {
		var yMax = object.yMax;
	} else {
		var yMax = 0;
		for (var i = 0; i < data.length; i++) {
			yMax = Math.max(yMax, data[i].freq + 1);
		}
		var steps = Math.floor(yMax / yMajorStep);
		while (yMax % yMajorStep > 0 || yMax / yMajorStep < steps + 1) {
			yMax++;
		}
	}

	// work out the spacing for minor and major steps
	var yMinorSpacing = (height * yMinorStep) / (yMax - yMin);
	var yMajorSpacing = (height * yMajorStep) / (yMax - yMin);

	// work out the coordinates of the origin
	var x0 = left;
	var y0 = top + (yMax * height) / (yMax - yMin);

	// work out the actual display position of the origin (ie. at the edge if it is off the grid)
	var x0DisplayPos = left;
	var y0DisplayPos = top + height;

	ctx.save();
	ctx.lineJoin = 'round';
	ctx.lineCap = 'round';
	if (yMinorShow == true) {
		ctx.beginPath();
		ctx.strokeStyle = yMinorColor;
		ctx.lineWidth = yMinorWidth;
		if (!ctx.setLineDash) {
			ctx.setLineDash = function () {}
		}
		ctx.setLineDash(yMinorDash);
		var yAxisPoint = y0 - yMinorSpacing;
		while (yAxisPoint > top) {
			if (yAxisPoint < top + height) {
				ctx.moveTo(left, yAxisPoint);
				ctx.lineTo(left + width, yAxisPoint);
			}
			yAxisPoint -= yMinorSpacing;
		}
		var yAxisPoint = y0 + yMinorSpacing;
		while (yAxisPoint <= top + height) {
			if (yAxisPoint >= top) {
				ctx.moveTo(left, yAxisPoint);
				ctx.lineTo(left + width, yAxisPoint);
			}
			yAxisPoint += yMinorSpacing;
		}
		ctx.stroke();
	}

	if (yMajorShow == true) {
		ctx.beginPath();
		ctx.strokeStyle = yMajorColor;
		ctx.lineWidth = yMajorWidth;
		if (!ctx.setLineDash) {
			ctx.setLineDash = function () {}
		}
		ctx.setLineDash(yMajorDash);
		var yAxisPoint = y0 - yMajorSpacing;
		while (yAxisPoint > top - 0.00001) {
			if (yAxisPoint < (top + height + 0.00001)) {
				ctx.moveTo(left, yAxisPoint);
				ctx.lineTo(left + width, yAxisPoint);
			}
			yAxisPoint -= yMajorSpacing;
		}
		var yAxisPoint = y0 + yMajorSpacing;
		while (yAxisPoint < top + height + 0.00001) {
			if (yAxisPoint > top - 0.00001) {
				ctx.moveTo(left, yAxisPoint);
				ctx.lineTo(left + width, yAxisPoint);
			}
			yAxisPoint += yMajorSpacing;
		}
		ctx.stroke();
	}

	// draw axes
	ctx.beginPath();
	ctx.strokeStyle = '#000';
	ctx.lineWidth = 3;
	if (!ctx.setLineDash) {
		ctx.setLineDash = function () {}
	}
	ctx.setLineDash([]);
	// if neccesary, draw x-Axis
	if (y0 >= top && y0 <= top + height) {
		ctx.moveTo(left, y0);
		ctx.lineTo(left + width, y0);
	}
	ctx.stroke();
	ctx.beginPath();
	ctx.strokeStyle = '#000';
	ctx.lineWidth = 3;
	// if neccesary, draw y-Axis
	if (x0 >= left && x0 <= left + width) {
		ctx.moveTo(x0, top);
		ctx.lineTo(x0, top + height);
	}
	ctx.stroke();

	// draw yAxes numbers
	ctx.font = '24px Arial';
	ctx.textAlign = "center";
	ctx.textBaseline = "top";
	ctx.lineWidth = 2;
	ctx.strokeStyle = yMajorColor;
	ctx.textBaseline = "middle";
	ctx.textAlign = "right";
	ctx.fillStyle = '#000';
	var fontSize = 24;

	// positive y numbers
	var yAxisPoint = y0;
	var major = 0;
	var placeValue = Math.pow(10, Math.floor(Math.log(yMajorStep) / Math.log(10)));
	while (yAxisPoint >= top - 0.0001) {
		if (yAxisPoint <= top + height) {
			var axisValue = Number(roundSF(major * yMajorStep, 5));
			var textWidth = ctx.measureText(String(axisValue)).width
				ctx.clearRect(x0DisplayPos - textWidth - 16, yAxisPoint - fontSize * 0.5, textWidth + 3, fontSize);
			ctx.beginPath();
			ctx.moveTo(x0DisplayPos, yAxisPoint);
			ctx.lineTo(x0DisplayPos - 8, yAxisPoint);
			ctx.stroke();
			wrapText(ctx, String(axisValue), x0DisplayPos - 7, yAxisPoint - 2, 50, 40, fontSize + 'px Arial');
		}
		major += 1;
		yAxisPoint -= yMajorSpacing;
	}
	// negative y numbers
	var yAxisPoint = y0 + yMajorSpacing;
	var major = -1;
	while (yAxisPoint <= top + height + 0.0001) {
		if (yAxisPoint >= top) {
			var axisValue = Number(roundSF(major * yMajorStep, 5));
			var textWidth = ctx.measureText(String(axisValue)).width
				ctx.clearRect(x0DisplayPos - textWidth - 16, yAxisPoint - fontSize * 0.5, textWidth + 3, fontSize);
			ctx.beginPath();
			ctx.moveTo(x0DisplayPos, yAxisPoint);
			ctx.lineTo(x0DisplayPos - 8, yAxisPoint);
			ctx.stroke();
			wrapText(ctx, String(axisValue), x0DisplayPos - 7, yAxisPoint - 2, 50, 40, fontSize + 'px Arial');
		}
		major -= 1;
		yAxisPoint += yMajorSpacing;
	}

	// draw axes
	ctx.strokeStyle = '#000';
	ctx.lineWidth = 4;
	ctx.beginPath();
	ctx.moveTo(left, top);
	ctx.lineTo(left, top + height);
	ctx.lineTo(left + width, top + height);
	ctx.stroke();

	var ySpacing = height / (yMax - yMin);
	var xSpacing = width / (data.length * barWidth[0] + (data.length + 1) * barWidth[1]);
	var l = [];

	ctx.beginPath();
	for (var i = 0; i < data.length; i++) {
		l[i] = left + i * barWidth[0] * xSpacing + (i + 1) * barWidth[1] * xSpacing;
		drawMathsText(ctx, data[i].value, 24, l[i] + 0.5 * xSpacing * barWidth[0], top + height + 5, false, [], 'center', 'top', '#000');
		//ctx.moveTo(l[i]+0.5*xSpacing*barWidth[0],top+height);
		//ctx.lineTo(l[i]+0.5*xSpacing*barWidth[0],top+height+5);
	}
	ctx.stroke();

	ctx.lineWidth = barOutlineWidth;
	ctx.strokeStyle = barOutlineColor;
	ctx.fillStyle = barColor;
	ctx.beginPath();

	for (var i = 0; i < data.length; i++) {
		var t = top + height - ySpacing * data[i].freq;
		var h = ySpacing * data[i].freq;
		ctx.fillRect(l[i], t, xSpacing * barWidth[0], h);
		ctx.strokeRect(l[i], t, xSpacing * barWidth[0], h);
	}

	if (arraysEqual(xLabel, ['']) == false) {
		text({
			context: ctx,
			textArray: ['<<align:center>><<font:Arial>><<fontSize:24>><<color:#000>>' + xLabel],
			left: left + width - 200,
			width: 200,
			top: top + height + 30,
		});
	}

	if (arraysEqual(yLabel, ['']) == false) {
		text({
			context: ctx,
			textArray: ['<<align:right>><<font:Arial>><<fontSize:24>><<color:#000>>' + yLabel],
			left: left - 50 - 200,
			width: 200,
			top: top + height * 0.03,
		});
	}

	if (arraysEqual(title, ['']) == false) {
		text({
			context: ctx,
			textArray: ['<<align:center>><<font:Arial>><<fontSize:24>><<color:#000>>' + title],
			left: titlePos[0],
			top: titlePos[1],
			width: titlePos[2],
			maxHeight: titlePos[3],
			box: {
				color: '#FFC',
				dash: [],
				border: '#000',
				borderWidth: 3,
				radius: 5,
				pos: [titlePos[0] - 10, titlePos[1] - 5, titlePos[2] + 12, titlePos[3] + 10]
			}
			// box.pos may need tweaking when text has been improved
		});
	}
}

function isNode(o) { //Returns true if it is a DOM node
	return (
		typeof Node === "object" ? o instanceof Node :
		o && typeof o === "object" && typeof o.nodeType === "number" && typeof o.nodeName === "string");
}
function isElement(o) { //Returns true if it is a DOM element
	return (
		typeof HTMLElement === "object" ? o instanceof HTMLElement : //DOM2
		o && typeof o === "object" && o !== null && o.nodeType === 1 && typeof o.nodeName === "string");
}

/***************************/
/*     VECTOR GEOMETRY     */
/***************************/

function getVectorAB(a, b) {
	return [b[0] - a[0], b[1] - a[1]];
}
function getUnitVector(vector) {
	var mag = Math.sqrt(Math.pow(vector[0], 2) + Math.pow(vector[1], 2));
	return [vector[0] / mag, vector[1] / mag];
}
function setVectorMag(vector, mag) {
	var unit = getUnitVector(vector);
	return [unit[0] * mag, unit[1] * mag];
}
function getDist(a, b) {
	return Math.sqrt(Math.pow(b[0] - a[0], 2) + Math.pow(b[1] - a[1], 2));
}
function getPerpVector(vector, dir) {
	if (un(dir))
		dir = 1;
	if (dir == 1) {
		return [-1 * vector[1], vector[0]];
	} else {
		return [vector[1], -1 * vector[0]];
	}
}
function pointAddVector(point, vector, scalarMult) {
	if (un(scalarMult))
		scalarMult = 1;
	return [point[0] + scalarMult * vector[0], point[1] + scalarMult * vector[1]];
}
function getVectorMag(vector) {
	return Math.sqrt(Math.pow(vector[0], 2) + Math.pow(vector[1], 2));
}
function getVectorAngle(vector) {
	var angle = Math.atan(vector[1] / vector[0]);
	if (vector[0] >= 0 && vector[1] >= 0)
		return angle;
	if (vector[0] >= 0 && vector[1] < 0)
		return angle + 2 * Math.PI;
	if (vector[0] < 0)
		return angle + Math.PI;
}
function angleToVector(angle, mag) {
	if (un(mag)) mag = 1;
	return [mag*Math.cos(angle),mag*Math.sin(angle)];
}
function rotateVector(vector, angle) {
	var mag = Math.sqrt(Math.pow(vector[0], 2) + Math.pow(vector[1], 2));
	var theta = getVectorAngle(vector) + angle;
	return [mag * Math.cos(theta), mag * Math.sin(theta)];
}
function getVectorLinesIntersection(p1, v1, p2, v2) {
	var lambda = (p1[1] * v2[0] + p2[0] * v2[1] - p1[0] * v2[1] - p2[1] * v2[0]) / (v1[0] * v2[1] - v1[1] * v2[0]);
	return pointAddVector(p1, v1, lambda);
}
function getMidpoint(p1, p2) {
	return [(p1[0] + p2[0]) / 2, (p1[1] + p2[1]) / 2];
}
function getFootOfPerp(p, v, q) { // foot of perp from point q to line p + kv
	var lambda = (q[0] * v[0] + q[1] * v[1] - p[0] * v[0] - p[1] * v[1]) / (v[0] * v[0] + v[1] * v[1]);
	return pointAddVector(p, v, lambda);
}
function getPerpDist(p, v, q) { // shortest dist from point q to line p + kv
	var foot = getFootOfPerp(p, v, q);
	return getDist(q, foot);
}

var vector = { // generalised 3d versions
	getVectorAB: function (a, b) {
		if (a.length !== b.length) return null;
		var v = [];
		for (var i = 0; i < a.length; i++) v[i] = b[i] - a[i];
		return v;
	},
	scalarMult: function (a, k) {
		var r = [];
		for (var i = 0; i < a.length; i++)
			r[i] = a[i] * k;
		return r;
	},
	dotProduct: function (a, b) {
		if (a.length !== b.length)
			return null;
		var p = 0;
		for (var i = 0; i < a.length; i++)
			p += b[i] * a[i];
		return p;
	},
	crossProduct: function (a, b) {
		if (a.length !== 3 || b.length !== 3)
			return null;
		return [
			a[1] * b[2] - a[2] * b[1],
			a[2] * b[0] - a[0] * b[2],
			a[0] * b[1] - a[1] * b[0]
		];
	},
	getMagnitude: function (a) {
		var m = 0;
		for (var i = 0; i < a.length; i++)
			m += a[i] * a[i];
		return Math.sqrt(m);
	},
	getUnitVector: function (a) {
		var u = [];
		var m = vector.getMagnitude(a);
		for (var i = 0; i < a.length; i++)
			u[i] = a[i] / m;
		return u;
	},
	setMagnitude: function (a, m) {
		var b = [];
		var unitVector = vector.getUnitVector(a);
		for (var i = 0; i < a.length; i++)
			b[i] = unitVector[i] * m;
		return b;
	},
	addVectors: function (a, b, k) {
		if (a.length !== b.length)
			return null;
		if (un(k))
			k = 1;
		var r = [];
		for (var i = 0; i < a.length; i++)
			r[i] = a[i] + b[i] * k;
		return r;
	},
	getAngleBetweenVectors: function (a, b) {
		if (a.length !== b.length)
			return null;
		var dot = vector.dotProduct(a, b);
		var mag1 = vector.getMagnitude(a);
		var mag2 = vector.getMagnitude(b);
		return Math.acos(dot / (mag1 * mag2));
	}
};

/***************************/
/*     	   POLYGONS        */
/***************************/

function drawPolygon(obj) {
	// required
	var ctx = obj.ctx;
	var points = obj.points;

	// optional
	var fillColor = obj.fillColor || obj.fillStyle || false;
	var lineColor = obj.lineColor || obj.color || obj.strokeStyle || false;
	var lineWidth = obj.lineWidth || obj.thickness || false;
	var closed = boolean(obj.closed, true);
	var lineDecoration = obj.lineDecoration || [];
	var angles = obj.angles || [];
	var outerAngles = obj.outerAngles || [];
	var exteriorAngles = obj.exteriorAngles || [];
	var clockwise = boolean(obj.clockwise, true)
	var sf = obj.sf || 1;
	var calcTextSnapPos = boolean(obj.calcTextSnapPos, false)

	//console.log(ctx,points,lineColor,lineWidth,closed);

	var angleLabelPos = [];
	var outerAngleLabelPos = [];
	var exteriorAngleLabelPos = [];
	var prismPoints = [];
	var textSnapPos = [];

	ctx.save();
	ctx.lineJoin = 'round';
	ctx.lineCap = 'round';

	ctx.beginPath();

	if (!un(obj.solidType)) {
		if (obj.solidType == 'prism') {
			var prismVector = obj.prismVector || [40, -40];
			var vectorAngle = getVectorAngle(prismVector);
			var points2 = [];
			var points2Vis = [];
			var angles2 = [];
			for (var p = 0; p < points.length; p++) {
				points2[p] = pointAddVector(points[p], prismVector);
				prismPoints[p] = points2[p];
				var prev = p - 1;
				if (prev < 0)
					prev = obj.points.length - 1;
				var next = p + 1;
				if (next > obj.points.length - 1)
					next = 0;
				angles2[p] = [
					posToAngle(obj.points[prev][0], obj.points[prev][1], obj.points[p][0], obj.points[p][1]),
					posToAngle(obj.points[next][0], obj.points[next][1], obj.points[p][0], obj.points[p][1])
				];
				if (anglesInOrder(angles2[p][1], vectorAngle, angles2[p][0]) == true) {
					points2Vis[p] = false;
				} else {
					points2Vis[p] = true;
				}
			}
			
			if (closed == true && fillColor !== false && fillColor !== 'none') {
				for (var p = 0; p < points.length; p++) { // fill polygons
					var next = (p + 1) % (points.length);
					ctx.moveTo(points[p][0], points[p][1]);
					ctx.lineTo(points2[p][0], points2[p][1]);
					ctx.lineTo(points2[next][0], points2[next][1]);
					ctx.lineTo(points[next][0], points[next][1]);
					ctx.closePath();
					ctx.fillStyle = fillColor;
					ctx.fill();
				}
			}
			
			for (var p = 0; p < points.length; p++) { // draw lines
				ctx.save();
				if (points2Vis[p] == false || points2Vis[(p + 1) % (points.length)] == false) {
					if (obj.solidShowAllLines == false) continue;
					ctx.strokeStyle = getShades(ctx.strokeStyle)[12];
				}
				ctx.beginPath();
				ctx.moveTo(points2[p][0], points2[p][1]);
				ctx.lineTo(points2[(p + 1) % (points.length)][0], points2[(p + 1) % (points.length)][1]);
				ctx.stroke();
				ctx.restore();
			}
			
			for (var p = 0; p < points.length; p++) { // draw lines
				ctx.save();
				if (points2Vis[p] == false) {
					if (obj.solidShowAllLines == false) continue;					
					ctx.strokeStyle = getShades(ctx.strokeStyle)[12];
				}
				ctx.beginPath();
				ctx.moveTo(points[p][0], points[p][1]);
				ctx.lineTo(points2[p][0], points2[p][1]);
				ctx.stroke();
				ctx.restore();
			}

		}
	}

	if (closed == true && fillColor !== false && fillColor !== 'none') {
		ctx.moveTo(points[0][0], points[0][1]);
		for (var i = 1; i < points.length; i++) {
			ctx.lineTo(points[i][0], points[i][1]);
		}
		ctx.closePath();
		ctx.fillStyle = fillColor;
		ctx.fill();
	}

	for (var i = 0; i < points.length; i++) {
		var p1 = i == 0 ? points.last() : points[i-1];
		var p2 = points[i];
		var p3 = points[(i+1)%points.length];
		
		var a1 = getAngleFromAToB(p2,p1);
		var a2 = getAngleFromAToB(p2,p3);
		if (a2 > a1) {
			var a3 = (a1+a2)/2;
		} else {
			var a3 = (a1+a2+2*Math.PI)/2;
			while (a3 > 2*Math.PI) {
				a3 -= 2*Math.PI;
			}
		}
		var n = Math.PI/8;
		var align = [0,0];
		if (a3 < n || a3 >= 15*n) {
			align = [-1,0];
		} else if (a3 < 3*n) {
			align = [-1,-1];
		} else if (a3 < 5*n) {
			align = [0,-1];
		} else if (a3 < 7*n) {
			align = [1,-1];
		} else if (a3 < 9*n) {
			align = [1,0];
		} else if (a3 < 11*n) {
			align = [1,1];
		} else if (a3 < 13*n) {
			align = [0,1];
		} else if (a3 < 15*n) {
			align = [-1,1];
		}
		
		var vector = angleToVector(a3,5);
		var labelPos = pointAddVector(p2,vector);
		
		if (calcTextSnapPos == true) textSnapPos.push({type:'polygonVertex',pos:labelPos,align:align,angle:a3,vertex:i,polygon:obj});
		
		// side labels
		var mid = midpoint(p2[0],p2[1],p3[0],p3[1]);
		var ang = a2-0.5*Math.PI;
		while (ang < 0) ang += 2*Math.PI;
		
		var align = [0,0];
		if (ang < n || ang >= 15*n) {
			align = [-1,0];
		} else if (ang < 3*n) {
			align = [-1,-1];
		} else if (ang < 5*n) {
			align = [0,-1];
		} else if (ang < 7*n) {
			align = [1,-1];
		} else if (ang < 9*n) {
			align = [1,0];
		} else if (ang < 11*n) {
			align = [1,1];
		} else if (ang < 13*n) {
			align = [0,1];
		} else if (ang < 15*n) {
			align = [-1,1];
		}
		
		var margin = align.indexOf(0) > -1 ? 10 : 5;
		var vector = angleToVector(ang,margin);
		var labelPos = pointAddVector(mid,vector);
		
		if (calcTextSnapPos == true) textSnapPos.push({type:'polygonSide',pos:labelPos,align:align,angle:ang,vertex:i,polygon:obj});		
	}
	
	for (var i = 0; i < points.length; i++) {
		if (typeof angles[i] == 'object' && angles[i] !== null) {
			angle = clone(angles[i]);
		} else {
			continue;
			angle = {
				labelMeasure: true,
				measureLabelOnly: true,
				measureOnly: true
			};
		}
		angle.ctx = ctx;
		angle.b = points[i];
		if (clockwise == false) {
			angle.a = points[(i + 1) % (points.length)];
			if (i == 0) {
				angle.c = points[points.length - 1];
			} else {
				angle.c = points[i - 1];
			}
		} else {
			angle.c = points[(i + 1) % (points.length)];
			if (i == 0) {
				angle.a = points[points.length - 1];
			} else {
				angle.a = points[i - 1];
			}
		}
		angle.drawLines = false;
		if (typeof angle.lineWidth == 'undefined')
			angle.lineWidth = ctx.lineWidth;
		if (typeof angle.lineColor == 'undefined')
			angle.lineColor = ctx.lineWidth;
		if (typeof angle.labelColor == 'undefined')
			angle.labelColor = ctx.strokeStyle;
		angleLabelPos[i] = drawAngle(angle);
	}

	if (obj.anglesMode == 'outer' && (un(obj.solidType) || obj.solidType !== 'prism')) {
		for (var i = 0; i < outerAngles.length; i++) {
			if (typeof outerAngles[i] == 'object' && outerAngles[i] !== null) {
				outerAngles[i].ctx = ctx;
				outerAngles[i].b = points[i];
				if (clockwise == true) {
					outerAngles[i].a = points[(i + 1) % (points.length)];
					if (i == 0) {
						outerAngles[i].c = points[points.length - 1];
					} else {
						outerAngles[i].c = points[i - 1];
					}
				} else {
					outerAngles[i].c = points[(i + 1) % (points.length)];
					if (i == 0) {
						outerAngles[i].a = points[points.length - 1];
					} else {
						outerAngles[i].a = points[i - 1];
					}
				}
				outerAngles[i].drawLines = false;
				if (typeof outerAngles[i].lineWidth == 'undefined')
					outerAngles[i].lineWidth = ctx.lineWidth;
				if (typeof outerAngles[i].lineColor == 'undefined')
					outerAngles[i].lineColor = ctx.lineWidth;
				if (typeof outerAngles[i].labelColor == 'undefined')
					outerAngles[i].labelColor = ctx.strokeStyle;
				outerAngleLabelPos[i] = drawAngle(outerAngles[i]);
			}
		}
	}

	ctx.lineJoin = 'round';
	ctx.lineCap = 'round';

	if (lineColor !== false) {
		ctx.strokeStyle = lineColor;
	}
	if (lineWidth !== false) {
		ctx.lineWidth = lineWidth;
	}

	if (obj.anglesMode == 'exterior' && (un(obj.solidType) || obj.solidType !== 'prism')) {
		for (var i = 0; i < exteriorAngles.length; i++) {
			if (typeof exteriorAngles[i] == 'object') {
				exteriorAngleLabelPos[i] = [];
				var ext = exteriorAngles[i];
				if (!un(ext.a1) && ext.a1 !== null) {
					ext.a1.ctx = ctx;
					ext.a1.c = points[(i + 1) % (points.length)];
					ext.a1.b = points[i];
					ext.a1.a = ext.line2.pos;
					ext.a1.drawLines = false;
					if (un(ext.a1.lineWidth))
						ext.a1.lineWidth = ctx.lineWidth;
					if (un(ext.a1.lineColor))
						ext.a1.lineColor = ctx.lineWidth;
					if (un(ext.a1.labelColor))
						ext.a1.labelColor = ctx.strokeStyle;
					exteriorAngleLabelPos[i][0] = drawAngle(ext.a1);
				}
				if (!un(ext.a2) && ext.a2 !== null) {
					ext.a2.ctx = ctx;
					ext.a2.c = ext.line2.pos;
					ext.a2.b = points[i];
					ext.a2.a = ext.line1.pos;
					ext.a2.drawLines = false;
					if (un(ext.a2.lineWidth))
						ext.a2.lineWidth = ctx.lineWidth;
					if (un(ext.a2.lineColor))
						ext.a2.lineColor = ctx.lineWidth;
					if (un(ext.a2.labelColor))
						ext.a2.labelColor = ctx.strokeStyle;
					exteriorAngleLabelPos[i][1] = drawAngle(ext.a2);
				}
				if (!un(ext.a3) && ext.a3 !== null) {
					ext.a3.ctx = ctx;
					ext.a3.c = ext.line1.pos;
					ext.a3.b = points[i];
					if (i > 0) {
						ext.a3.a = points[i - 1];
					} else {
						ext.a3.a = points[points.length - 1];
					}
					ext.a3.drawLines = false;
					if (un(ext.a3.lineWidth))
						ext.a3.lineWidth = ctx.lineWidth;
					if (un(ext.a3.lineColor))
						ext.a3.lineColor = ctx.lineWidth;
					if (un(ext.a3.labelColor))
						ext.a3.labelColor = ctx.strokeStyle;
					exteriorAngleLabelPos[i][2] = drawAngle(ext.a3);
				}
				if (boolean(ext.line1.show, false)) {
					ctx.save();
					ctx.lineWidth = lineWidth;
					ctx.moveTo(points[i][0], points[i][1]);
					ctx.lineTo(ext.line1.pos[0], ext.line1.pos[1]);
					ctx.stroke();
					ctx.restore();
				}
				if (boolean(ext.line2.show, false)) {
					ctx.save();
					ctx.lineWidth = lineWidth;
					ctx.moveTo(points[i][0], points[i][1]);
					ctx.lineTo(ext.line2.pos[0], ext.line2.pos[1]);
					ctx.stroke();
					ctx.restore();
				}
			}
		}
	}

	ctx.beginPath();
	ctx.moveTo(points[0][0], points[0][1]);
	for (var i = 1; i < points.length; i++) {
		ctx.lineTo(points[i][0], points[i][1]);
	}
	if (closed == true) {
		ctx.closePath();
	}
	ctx.lineWidth = lineWidth;
	if (obj.strokeStyle !== 'none')
		ctx.stroke();

	for (var i = 0; i < lineDecoration.length; i++) {
		if (typeof lineDecoration[i] == 'object' && lineDecoration[i] !== null) {
			switch (lineDecoration[i].type) {
			case 'dash':
				var dashLength = lineDecoration[i].length || 8 * sf;
				var number = lineDecoration[i].number || 1;
				if (number == 1) {
					drawDash(ctx, points[i][0], points[i][1], points[(i + 1) % (points.length)][0], points[(i + 1) % (points.length)][1], dashLength);
				} else if (number == 2) {
					drawDoubleDash(ctx, points[i][0], points[i][1], points[(i + 1) % (points.length)][0], points[(i + 1) % (points.length)][1], dashLength);
				}
				break;
			case 'arrow':
				var arrowLength = lineDecoration[i].length || 12 * sf;
				var number = lineDecoration[i].number || 1;
				var direction = lineDecoration[i].direction || 1;
				ctx.save();
				if (direction == 1) {
					drawParallelArrow({
						context: ctx,
						startX: points[i][0],
						startY: points[i][1],
						finX: points[(i + 1) % (points.length)][0],
						finY: points[(i + 1) % (points.length)][1],
						arrowLength: arrowLength,
						lineWidth: ctx.lineWidth,
						numOfArrows: number,
						color: ctx.strokeStyle
					});
				} else if (direction == -1) {
					drawParallelArrow({
						context: ctx,
						finX: points[i][0],
						finY: points[i][1],
						startX: points[(i + 1) % (points.length)][0],
						startY: points[(i + 1) % (points.length)][1],
						arrowLength: arrowLength,
						lineWidth: ctx.lineWidth,
						numOfArrows: number,
						color: ctx.strokeStyle
					});
				}
				ctx.restore();
				break;
			default:
				break;
			};
		}
	}

	ctx.restore();
	return {
		angleLabelPos: angleLabelPos,
		outerAngleLabelPos: outerAngleLabelPos,
		exteriorAngleLabelPos: exteriorAngleLabelPos,
		prismPoints: prismPoints,
		textSnapPos: textSnapPos
	};
}
function checkLinesForPolygon(lines, allowSelfIntersect) {
	if (typeof allowSelfIntersect == 'undefined') allowSelfIntersect = false;
	if (lines.length < 3) return false;
	var lines = clone(lines);
	lines = reduceLineSegments(lines);

	// remove lines with zero length
	for (var l = lines.length - 1; l >= 0; l--) {
		if (arraysEqual(lines[l][0], lines[l][1])) lines.splice(l, 1);
	}

	var gradients = [];
	for (var l = 0; l < lines.length; l++) {
		var line = lines[l];
		gradients[l] = (line[1][1] - line[0][1]) / (line[1][0] - line[0][0]);
	}

	function pointsEqual(p1, p2) {
		if (p1[0] == p2[0] && p1[1] == p2[1]) return true;
		return false;
	}

	//console.clear();
	//console.log('lines:',clone(lines),lines.length);
	//console.log('gradients:',gradients);
	// test for overlapping parallel lines
	for (var a = 0; a < lines.length - 1; a++) {
		var lineA = lines[a];
		for (var b = a + 1; b < lines.length; b++) {
			var lineB = lines[b];
			if (gradients[a] !== gradients[b]) continue;
			var test1 = isPointOnLineSegment(lineB[0], lineA[0], lineA[1]);
			var test2 = isPointOnLineSegment(lineB[1], lineA[0], lineA[1]);
			var test3 = (pointsEqual(lineA[0], lineB[0]) || pointsEqual(lineA[0], lineB[1]) || pointsEqual(lineA[1], lineB[0]) || pointsEqual(lineA[1], lineB[1])) ? true : false;
			if (test1 == false && test2 == false && test3 == false) continue;

			//console.log('a:',a,lineA[0],lineA[1],'b:',b,lineB[0],lineB[1],'gradient:',gradients[a],gradients[b]);	//console.log(pointsEqual(lineA[0],lineB[0]),pointsEqual(lineA[0],lineB[1]),pointsEqual(lineA[1],lineB[0]),pointsEqual(lineA[1],lineB[1]));
			//console.log(test1,test2,test3);

			// lines overlap - find most extreme of the 4 points
			var pos = lineA.concat(lineB);
			var min = pos[0];
			var max = pos[0];
			if (gradients[a] == Infinity || gradients[a] == -Infinity) {
				for (var p = 1; p < pos.length; p++) {
					if (pos[p][1] < min[1])
						min = pos[p];
					if (pos[p][1] > max[1])
						max = pos[p];
				}
			} else {
				for (var p = 1; p < pos.length; p++) {
					if (pos[p][0] < min[0])
						min = pos[p];
					if (pos[p][0] > max[0])
						max = pos[p];
				}
			}
			lines[a] = [min, max];
			lines.splice(b, 1);
		}
	}

	var pos = [];
	//console.log('reduced lines:');
	for (var l = 0; l < lines.length; l++) {
		var line = lines[l];
		//console.log('('+line[0][0]+','+line[0][1]+')','('+line[1][0]+','+line[1][1]+')');
		var found = [false, false];
		for (var p = 0; p < pos.length; p++) {
			if (pos[p].pos[0] == line[0][0] && pos[p].pos[1] == line[0][1]) {
				pos[p].count++;
				found[0] = true;
			}
			if (pos[p].pos[0] == line[1][0] && pos[p].pos[1] == line[1][1]) {
				pos[p].count++;
				found[1] = true;
			}
		}
		if (found[0] == false)
			pos.push({
				pos: clone(line[0]),
				count: 1
			});
		if (found[1] == false)
			pos.push({
				pos: clone(line[1]),
				count: 1
			});
		//console.log(found,clone(pos));
	}
	//console.log('pos:',pos);

	for (var p = 0; p < pos.length; p++) {
		if (pos[p].count !== 2) return false;
	}

	var polygon = [lines.shift()];
	while (lines.length > 0) {
		var pos = polygon.last()[1];
		var found = false;
		for (var l = 0; l < lines.length; l++) {
			var line = lines[l];
			if (arraysEqual(line[0], pos)) {
				polygon.push(line);
				lines.splice(l, 1);
				found = true;
				break;
			} else if (arraysEqual(line[1], pos)) {
				polygon.push(line.reverse());
				lines.splice(l, 1);
				found = true;
				break;
			}
		}
		//console.log(clone(polygon),clone(lines),found);
		if (found == false)
			return false;
	}
	for (var p = 0; p < polygon.length; p++) polygon[p] = polygon[p][0];
	//console.log('polygon:',polygon);
	//if (allowSelfIntersect == false && polygonSelfIntersect2(polygon) == false) return false;

	return polygon;
}
/*function reduceLineSegments(lines) {
	var lines = clone(lines);

	// remove lines with zero length
	for (var l = lines.length - 1; l >= 0; l--) {
		if (pointsEqual(lines[l][0], lines[l][1])) lines.splice(l, 1);
	}

	var gradients = [];
	for (var l = 0; l < lines.length; l++) {
		var line = lines[l];
		gradients[l] = (line[1][1] - line[0][1]) / (line[1][0] - line[0][0]);
	}

	function pointsEqual(p1, p2) {
		if (p1[0] == p2[0] && p1[1] == p2[1]) return true;
		return false;
	}

	// test for overlapping parallel lines
	for (var a = 0; a < lines.length - 1; a++) {
		var lineA = lines[a];
		for (var b = a + 1; b < lines.length; b++) {
			var lineB = lines[b];
			if (gradients[a] !== gradients[b]) continue;
			var test1 = isPointOnLineSegment(lineB[0], lineA[0], lineA[1]);
			var test2 = isPointOnLineSegment(lineB[1], lineA[0], lineA[1]);
			var test3 = (pointsEqual(lineA[0], lineB[0]) || pointsEqual(lineA[0], lineB[1]) || pointsEqual(lineA[1], lineB[0]) || pointsEqual(lineA[1], lineB[1])) ? true : false;
			if (test1 == false && test2 == false && test3 == false) continue;

			// lines overlap - find most extreme of the 4 points
			var pos = lineA.concat(lineB);
			var min = pos[0];
			var max = pos[0];
			if (gradients[a] == Infinity || gradients[a] == -Infinity) {
				for (var p = 1; p < pos.length; p++) {
					if (pos[p][1] < min[1])
						min = pos[p];
					if (pos[p][1] > max[1])
						max = pos[p];
				}
			} else {
				for (var p = 1; p < pos.length; p++) {
					if (pos[p][0] < min[0])
						min = pos[p];
					if (pos[p][0] > max[0])
						max = pos[p];
				}
			}
			lines[a] = [min, max];
			lines.splice(b, 1);
		}
	}

	return lines;
}*/
function reduceLineSegments(lines) {
	var keepGoing = true;
	while (keepGoing === true) {
		keepGoing = false;
		for (var l1 = 0; l1 < lines.length-1; l1++) {
			var line1 = lines[l1];
			for (var l2 = l1+1; l2 < lines.length; l2++) {
				var line2 = lines[l2];
				var x1 = line1[0][0];
				var y1 = line1[0][1];
				var x2 = line1[1][0];
				var y2 = line1[1][1];
				var x3 = line2[0][0];
				var y3 = line2[0][1];
				var x4 = line2[1][0];
				var y4 = line2[1][1];
				
				if ((x1 === x2 && x1 === x3 && x1 === x4) || (Math.abs((y2 - y1) / (x2 - x1) - (y4 - y3) / (x4 - x3))) < 0.01) { // vertical or gradients equal
					// if one of the points is between the two points on the other line
					if ((x1 >= Math.min(x3,x4) && x1 <= Math.max(x3,x4) && y1 >= Math.min(y3,y4) && y1 <= Math.max(y3,y4)) || 
						(x2 >= Math.min(x3,x4) && x2 <= Math.max(x3,x4) && y2 >= Math.min(y3,y4) && y2 <= Math.max(y3,y4)) || 
						(x3 >= Math.min(x1,x2) && x3 <= Math.max(x1,x2) && y3 >= Math.min(y1,y2) && y3 <= Math.max(y1,y2)) || 
						(x4 >= Math.min(x1,x2) && x4 <= Math.max(x1,x2) && y4 >= Math.min(y1,y2) && y4 <= Math.max(y1,y2))) {
						var x5 = Math.min(x1,x2,x3,x4);
						var x6 = Math.max(x1,x2,x3,x4);
						var y5 = x5 === x6 ? Math.min(y1,y2,y3,y4) : x5 === x1 ? y1 : x5 === x2 ? y2 : x5 === x3 ? y3 : y4;
						var y6 = x5 === x6 ? Math.max(y1,y2,y3,y4) : x6 === x1 ? y1 : x6 === x2 ? y2 : x6 === x3 ? y3 : y4;
						lines[l1] = [[x5,y5],[x6,y6]];
						lines.splice(l2, 1);
						l2--;
						keepGoing = true;
					}
				}
			}
		}
	}
	return lines;
}
function polygonConvexTest(polygon) {
	var polygon = clone(polygon);
	if (polygonClockwiseTest(polygon) == false)
		polygon.reverse();
	for (var p = 0; p < polygon.length; p++) {
		var angle = measureAngle({
				a: polygon[p],
				b: polygon[(p + 1) % polygon.length],
				c: polygon[(p + 2) % polygon.length]
			});
		if (angle > Math.PI)
			return false;
	}
	return true;
}
function polygonClockwiseTest(pos) {
	if (pos.length < 3)
		return null;
	var sum = (pos[0][0] - pos.last()[0]) * (pos[0][1] + pos.last()[1]);
	for (var i = 0; i < pos.length - 1; i++) {
		sum += (pos[i + 1][0] - pos[i][0]) * (pos[i + 1][1] + pos[i][1]);
	}
	if (sum > 0)
		return true;
	return false;
};
function getPolygonSideLabelPoints(polygon, gap) {
	if (un(gap))
		gap = 25;
	var points = [];
	for (var i = 0; i < polygon.length; i++) {
		var j = (i + 1) % polygon.length;
		var mid = [(polygon[i][0] + polygon[j][0]) / 2, (polygon[i][1] + polygon[j][1]) / 2];
		var vec = getVectorAB(polygon[i], polygon[j]);
		var perp = getPerpVector(vec);
		var perpDist = setVectorMag(perp, gap);
		var point = pointAddVector(mid, perpDist);
		points.push(point);
	}
	return points;
}
function drawRegularPolygon(obj) {
	var ctx = obj.ctx;
	var c = obj.center || obj.c;
	var r = obj.radius || obj.r;
	var p = obj.points || obj.p || 3;
	var s = obj.step || obj.s || 1;
	var startAngle = -Math.PI / 2;
	if (typeof obj.startAngle == 'number')
		startAngle = obj.startAngle;
	var vertices = [];
	for (var i = 0; i < p; i++) {
		var angle = startAngle + i * (2 * Math.PI) / p;
		vertices.push([c[0] + r * Math.cos(angle), c[1] + r * Math.sin(angle)]);
	}
	ctx.moveTo(vertices[0][0], vertices[0][1]);
	for (var i = p; i >= 0; i--) {
		ctx.lineTo(vertices[(i * s) % p][0], vertices[(i * s) % p][1]);
	}
}
function drawRegularPolygonEllipse(ctx, obj) {
	var c = obj.center;
	var rX = obj.radiusX;
	var rY = obj.radiusY;
	var p = obj.points;
	var s = obj.step || 1;
	var startAngle = -Math.PI / 2;
	if (typeof obj.startAngle == 'number')
		startAngle = obj.startAngle;

	var vertices = [];
	for (var i = 0; i < p; i++) {
		var angle = startAngle + i * (2 * Math.PI) / p;
		vertices.push([c[0] + rX * Math.cos(angle), c[1] + rY * Math.sin(angle), angle]);
	}

	ctx.beginPath();
	ctx.moveTo(vertices[0][0], vertices[0][1]);
	for (var i = p; i >= 0; i--) {
		ctx.lineTo(vertices[(i * s) % p][0], vertices[(i * s) % p][1]);
	}
	ctx.stroke();

	return vertices;
}
function polygonIntersections(p1, p2) {
	var intersections = [];
	for (var i = 0; i < p1.length; i++) {
		var line1 = [p1[i], p1[(i + 1) % p1.length]];
		for (var j = 0; j < p2.length; j++) {
			var line2 = [p2[j], p2[(j + 1) % p2.length]];
			if (lineSegmentsIntersectionTest(line1, line2)) {
				intersections.push({
					edges: [i, j],
					intersection: linesIntersection(line1, line2)
				});
			}
		}
	}
	if (intersections.length == 0)
		return false;
	return intersections
}
function isPolygonInPolygon(p1, p2, includePerimeter) {
	if (hitTestPolygon2(p1[0], p2) == false) return false;
	for (var i = 0; i < p1.length; i++) {
		var line1 = [p1[i], p1[(i + 1) % p1.length]];
		for (var j = 0; j < p2.length; j++) {
			var line2 = [p2[j], p2[(j + 1) % p2.length]];
			if (lineSegmentsIntersectionTest(line1, line2) == true) {
				if (includePerimeter == false) return false;
				var p3 = isPointOnLineSegment(line1[0],line2[0],line2[1]);
				var p4 = isPointOnLineSegment(line1[1],line2[0],line2[1]);
				if (p3 == false && p4 == false) return false;
				if (p3 == true && p4 == true) continue; // edge is part of edge
				if (p3 == true && p4 == false && hitTestPolygon2(line1[1],p2) == false) return false;
				if (p3 == false && p4 == true && hitTestPolygon2(line1[0],p2) == false) return false;
			}
		}
	}
	return true;
}
function polygonsIntersectionPolygon(p1, p2) {
	var p = []; // polygon of intersecting region

	// add all edge-edge intersections
	for (var i = 0; i < p1.length; i++) {
		var line1 = [p1[i], p1[(i + 1) % p1.length]];
		for (var j = 0; j < p2.length; j++) {
			var line2 = [p2[j], p2[(j + 1) % p2.length]];
			if (lineSegmentsIntersectionTest(line1, line2)) {
				p.push(linesIntersection(line1, line2));
			}
		}
	}

	// get all vertices of p1 that are inside p2
	for (var i = 0; i < p1.length; i++) {
		if (hitTestPolygon(p1[i], p2, false))
			p.push(p1[i]);
	}

	// get all vertices of p1 that are inside p2
	for (var i = 0; i < p2.length; i++) {
		if (hitTestPolygon(p2[i], p1, false))
			p.push(p2[i]);
	}

	// get centre of p
	var center = [0, 0];
	for (var i = 0; i < p.length; i++) {
		center[0] += p[i][0];
		center[1] += p[i][1];
	}
	center[0] = center[0] / p.length;
	center[1] = center[1] / p.length;

	// order p
	p.sort(function (a, b) {
		var a1 = getAngleFromAToB(center, a);
		var a2 = getAngleFromAToB(center, b);
		return a2 - a1;
	});

	console.log(p, polygonClockwiseTest(p));

	return p;
}
function polygonArea(verticesArray) {
	verticesArray.push(verticesArray[0]);
	var area = 0;
	for (var i = 0; i < verticesArray.length - 1; i++) {
		area += (verticesArray[i][0] * verticesArray[i + 1][1]) - (verticesArray[i][1] * verticesArray[i + 1][0]);
	}
	area = 0.5 * Math.abs(area);
	return area;
}
function polygonCountSides(verticesArray) {
	// collapses polygon (ie. finds any three points that are on a straight line and reduces to single line)
	// returns number of sides/vertices of collapsed polygon
	var verticesNum = verticesArray.length - 1; // given number of vertices
	if (verticesNum < 3)
		return verticesNum;
	verticesArray.push(verticesArray[0]);
	verticesArray.push(verticesArray[1]);
	var verticesCount = 0; // return number of vertices
	for (var i = 0; i <= verticesNum; i++) {
		var point1 = verticesArray[i];
		var point2 = verticesArray[i + 1];
		var point3 = verticesArray[i + 2];
		var m1 = (point2[1] - point1[1]) / (point2[0] - point1[0]);
		var m2 = (point3[1] - point2[1]) / (point3[0] - point2[0]);
		var error = false;
		if (point1[0] == point2[0] && point1[1] == point2[1])
			error = true;
		if (point1[0] == point3[0] && point1[1] == point3[1])
			error = true;
		if (point3[0] == point2[0] && point3[1] == point2[1])
			error = true;
		if (m1 !== m2 && error == false)
			verticesCount++;
	}
	verticesArray.splice(-2, 2);
	logMe("verticesArray:", verticesArray, "polygon");
	return verticesCount;
}
function polygonSelfIntersect(verticesArray) {
	// vertices array such as [[], [], [], []]
	verticesArray = clone(verticesArray);
	verticesArray.push(verticesArray[0]); // duplicate first vertex to last vertex
	var segmentArray = [];
	var events = [];

	// create segments array [[x1,y1,x2,y2],[...],...] where x1 <= x2
	for (var i = 0; i < verticesArray.length - 1; i++) {
		segmentArray.push([verticesArray[i][0], verticesArray[i][1], verticesArray[i + 1][0], verticesArray[i + 1][1]]);

		// choose left-most end of segment to be 'start'
		var order;
		if (verticesArray[i][0] < verticesArray[i + 1][0]) {
			order = 1;
		} else if (verticesArray[i][0] > verticesArray[i + 1][0]) {
			order = 2;
		} else {
			if (verticesArray[i][1] < verticesArray[i + 1][1]) {
				order = 1;
			} else {
				order = 2;
			}
		}

		if (order == 1) {
			events.push([verticesArray[i][0], verticesArray[i][1], i, 'start']);
			events.push([verticesArray[i + 1][0], verticesArray[i + 1][1], i, 'end']);
		} else {
			events.push([verticesArray[i][0], verticesArray[i][1], i, 'end']);
			events.push([verticesArray[i + 1][0], verticesArray[i + 1][1], i, 'start']);
		}
	}

	// sort the events by x value
	events.sort(function (a, b) {
		return a[0] - b[0]
	});

	var sweepLine = [];

	for (var j = 0; j < events.length; j++) {
		if (events[j][3] == 'start') {
			sweepLine.push([events[j][0], events[j][1], events[j][2]]); // x-value, y-value, lineSegmentId
			sweepLine.sort(function (a, b) {
				return a[1] - b[1]
			}); // sort sweepLine by y-value
		} else if (events[j][3] == 'end') {
			// get position in sweepline (pos1) and segment id (seg1)
			var pos1,
			seg1;
			for (var k = 0; k < sweepLine.length; k++) {
				if (sweepLine[k][2] == events[j][2]) {
					pos1 = k;
					seg1 = segmentArray[k];
					break;
				}
			}
			// if not the lowest line, check for intersection with line below
			if (pos1 > 0) {
				var pos2 = sweepLine[pos1 - 1][2];
				var seg2 = segmentArray[pos2];
				if (intersects(seg1[0], seg1[1], seg1[2], seg1[3], seg2[0], seg2[1], seg2[2], seg2[3]) == true)
					return true;
			}
			if (pos1 < sweepLine.length - 1) {
				var pos2 = sweepLine[pos1 + 1][2];
				var seg2 = segmentArray[pos2];
				if (intersects(seg1[0], seg1[1], seg1[2], seg1[3], seg2[0], seg2[1], seg2[2], seg2[3]) == true)
					return true;
			}
		}
	}

	return false;
}
function polygonSelfIntersect2(polygon) {
	var edges = [];
	for (var i = 0; i < polygon.length; i++)
		edges.push([polygon[i], polygon[(i + 1) % polygon.length]]);
	for (var i = 0; i < edges.length - 1; i++) {
		for (var j = i + 1; j < edges.length; j++) {
			if (
				arraysEqual(edges[i][0], edges[j][0]) ||
				arraysEqual(edges[i][0], edges[j][1]) ||
				arraysEqual(edges[i][1], edges[j][0]) ||
				arraysEqual(edges[i][1], edges[j][1])) {
				continue;
			}
			if (intersects(edges[i][0][0], edges[i][0][1], edges[i][1][0], edges[i][1][1], edges[j][0][0], edges[j][0][1], edges[j][1][0], edges[j][1][1]) == true) {
				return true;
			}
		}
	}
	return false;
}
function findMinPolygon(edgeVertices, lines, point) {
	var edges = [];
	var lines2 = [];

	edgeVertices.push(edgeVertices[0].slice());
	// split edges into smaller vectors according to intersection points with lines
	for (var i = 0; i < edgeVertices.length - 1; i++) {
		edges[i] = [{
				point: edgeVertices[i].slice(0),
				dist: 0
			}, {
				point: edgeVertices[i + 1].slice(0),
				dist: dist(edgeVertices[i][0], edgeVertices[i][1], edgeVertices[i + 1][0], edgeVertices[i + 1][1])
			}
		];
		for (var j = 0; j < lines.length; j++) {
			//console.log('edgeVertices:',edgeVertices[i][0],edgeVertices[i][1],edgeVertices[i+1][0],edgeVertices[i+1][1]);
			//			console.log('lineVertices:',lines[j][0][0],lines[j][0][1],lines[j][1][0],lines[j][1][1]);
			//			console.log('intersects2:',intersects2(lines[j][0][0],lines[j][0][1],lines[j][1][0],lines[j][1][1],edgeVertices[i][0],edgeVertices[i][1],edgeVertices[i+1][0],edgeVertices[i+1][1]));
			if (intersects2(lines[j][0][0], lines[j][0][1], lines[j][1][0], lines[j][1][1], edgeVertices[i][0], edgeVertices[i][1], edgeVertices[i + 1][0], edgeVertices[i + 1][1])) {

				var int = intersection(edgeVertices[i][0], edgeVertices[i][1], edgeVertices[i + 1][0], edgeVertices[i + 1][1], lines[j][0][0], lines[j][0][1], lines[j][1][0], lines[j][1][1]);

				// check that the intersection point is not one of the end points of the edge
				if ((int[0] == edgeVertices[i][0] && int[1] == edgeVertices[i][1]) || (int[0] == edgeVertices[i + 1][0] && int[1] == edgeVertices[i + 1][1])) {
					//console.log('corner');
				} else {
					edges[i].push({
						point: int,
						dist: dist(edges[i][0].point[0], edges[i][0].point[1], int[0], int[1])
					});
				}

				if (typeof lines2[j] == 'undefined') {
					lines2[j] = [{
							point: int.slice(0),
							dist: 0
						}
					];
				} else {
					lines2[j].push({
						point: int.slice(0),
						dist: dist(int[0], int[1], lines2[j][0].point[0], lines2[j][0].point[1])
					});
				}

			}
		}
	}
	for (var i = 0; i < lines.length - 1; i++) {
		for (var j = i + 1; j < lines.length; j++) {
			var int = intersection(lines[i][0][0], lines[i][0][1], lines[i][1][0], lines[i][1][1], lines[j][0][0], lines[j][0][1], lines[j][1][0], lines[j][1][1]);
			if (hitTestPolygon(int, edgeVertices)) {
				lines2[i].push({
					point: int.slice(0),
					dist: dist(int[0], int[1], lines2[i][0].point[0], lines2[i][0].point[1])
				});
				lines2[j].push({
					point: int.slice(0),
					dist: dist(int[0], int[1], lines2[j][0].point[0], lines2[j][0].point[1])
				});
			}
		}
	}

	for (var i = 0; i < edges.length; i++) {
		edges[i].sortOn('dist');
	}
	for (var i = 0; i < lines2.length; i++) {
		lines2[i].sortOn('dist');
	}

	//console.log('edges:',edges.slice(0));
	//console.log('lines2:',lines2.slice(0));

	// find duplicate points in lines2 and remove
	for (var i = 0; i < lines2.length; i++) {
		for (var j = 1; j < lines2[i].length; ) {
			if (lines2[i][j - 1].dist == lines2[i][j].dist) {
				lines2[i].splice(j, 1);
			} else {
				j++;
			}
		}
	}

	var vectors = [];

	for (var i = 0; i < edges.length; i++) {
		for (var j = 0; j < edges[i].length - 1; j++) {
			vectors.push([edges[i][j].point.slice(0), edges[i][j + 1].point.slice(0)]);
		}
	}

	for (var i = 0; i < lines2.length; i++) {
		for (var j = 0; j < lines2[i].length - 1; j++) {
			vectors.push([lines2[i][j].point.slice(0), lines2[i][j + 1].point.slice(0)]);
		}
	}

	//console.log('vectors:',vectors.slice(0));
	//console.log('point:',point);

	var minDist = [];
	// work out whish vector is closest to the point
	for (var i = 0; i < vectors.length; i++) {
		minDist[i] = distancePointToLineSegment(point, vectors[i][0], vectors[i][1]);
	}
	//console.log('minDist:',minDist);

	// start the polygon vertices array
	var vertices = [];
	var currVector = vectors[minDist.indexOf(minDist.min())];

	// put the closest vector vertices into the array
	if (measureAngle({
			a: point,
			b: currVector[0],
			c: currVector[1]
		}) < measureAngle({
			a: point,
			b: currVector[1],
			c: currVector[0]
		})) {
		vertices.push(currVector[0].slice(0), currVector[1].slice(0));
	} else {
		vertices.push(currVector[1].slice(0), currVector[0].slice(0));
	}
	vectors.splice(minDist.indexOf(minDist.min()), 1);
	//console.log('first vertices:',vertices[0],vertices[1]);

	// until the path is completed
	do {
		var currPoint = vertices[vertices.length - 1].slice(0);
		// find all poss vectors from the current point
		var possVectors = [];
		var possVectorsAngle = [];
		var possVectorsIndex = [];
		for (var i = 0; i < vectors.length; i++) {
			if (arraysEqual(vectors[i][0], currPoint)) {
				//console.log('---possVector:',vectors[i].slice(0));
				possVectors.push(vectors[i].slice(0));
				possVectorsIndex.push(i);
				possVectorsAngle.push(measureAngle({
						a: vertices[vertices.length - 2],
						b: vertices[vertices.length - 1],
						c: vectors[i][1]
					}));
				//console.log('angle:',measureAngle({a:vertices[vertices.length-2],b:vertices[vertices.length-1],c:vectors[i][1]}));
			} else if (arraysEqual(vectors[i][1], currPoint)) {
				//console.log('+++possVector:',[vectors[i][1].slice(0),vectors[i][0].slice(0)]);
				possVectors.push([vectors[i][1].slice(0), vectors[i][0].slice(0)]);
				possVectorsIndex.push(i);
				possVectorsAngle.push(measureAngle({
						a: vertices[vertices.length - 2],
						b: vertices[vertices.length - 1],
						c: vectors[i][0]
					}));
				//console.log('angle:',measureAngle({a:vertices[vertices.length-2],b:vertices[vertices.length-1],c:vectors[i][0]}));
			}
		}
		//console.log('possVectors:',possVectors);
		//console.log('possVectorsAngle:',possVectorsAngle);
		//console.log('possVectorsIndex:',possVectorsIndex);
		// chose the vector with the smallest angle
		var selVectorPos = possVectorsAngle.indexOf(possVectorsAngle.min());
		vertices.push(possVectors[selVectorPos][1].slice(0));
		selVectorPos = possVectorsIndex[selVectorPos];
		vectors.splice(selVectorPos, 1);

		//console.log('vertex:',vertices[vertices.length-1]);
	} while (arraysEqual(vertices[0], vertices[vertices.length - 1]) == false);

	//console.log('vertices:',vertices);

	return vertices;
}
function samePolygons(verticesArray1, verticesArray2) {
	var a = verticesArray1;
	var b = verticesArray2;
	if (a.length !== b.length)
		return false;
	for (var i = 0; i < a.length; i++) {
		var found = false;
		for (var j = 0; j < b.length; j++) {
			if (roundToNearest(a[i][0], 0.0001) == roundToNearest(b[j][0], 0.0001) && roundToNearest(a[i][1], 0.0001) == roundToNearest(b[j][1], 0.0001)) {
				found = true;
				break;
			}
		}
		if (found == false)
			return false;
	}
	return true;
}
function polygonCongruenceTest(p1, p2, mode) { // mode 0 = any congruent shape, 1 = rotations allowed but not reflections, 2 = no rotations or reflectons allowed
	if (typeof mode == 'undefined')
		mode = 0
			if (p1.length !== p2.length)
				return false;
			var p1 = clone(p1);
	var p2 = clone(p2);
	if (polygonClockwiseTest(p1) == false)
		p1.reverse();
	if (polygonClockwiseTest(p2) == false)
		p2.reverse();
	if (mode == 2) { // test edge vectors are congruent
		var vectors1 = [],
		vectors2 = [];
		for (var p = 0; p < p1.length; p++) {
			var b = p1[p];
			var c = p == p1.length - 1 ? p1[0] : p1[p + 1];
			vectors1[p] = [c[0] - b[0], c[1] - b[1]];
			var b = p2[p];
			var c = p == p2.length - 1 ? p2[0] : p2[p + 1];
			vectors2[p] = [c[0] - b[0], c[1] - b[1]];
		}
		//console.log(vectors1,vectors2);

		for (var p = 0; p < p1.length; p++) {
			if (arraysEqual(vectors1[0], vectors2[p])) {
				//console.log(p,vectors1[0],vectors2[p]);
				var match = true;
				for (var q = 1; q < p2.length; q++) {
					var r = (p + q) % p2.length;
					//console.log(q,vectors1[q],vectors2[r]);
					if (arraysEqual(vectors1[q], vectors2[r]) == false) {
						match = false;
						break;
					}
				}
				if (match == true)
					return true;
			}
		}
		return false;
	} else { // test edge lengths and angles are congruent
		var lengths1 = [],
		lengths2 = [];
		var angles1 = [],
		angles2 = [];
		for (var p = 0; p < p1.length; p++) {
			var a = p == 0 ? p1.last() : p1[p - 1];
			var b = p1[p];
			var c = p == p1.length - 1 ? p1[0] : p1[p + 1];
			lengths1[p] = dist(b[0], b[1], c[0], c[1]);
			angles1[p] = measureAngle({
					a: a,
					b: b,
					c: c
				});
		}
		for (var p = 0; p < p2.length; p++) {
			var a = p == 0 ? p2.last() : p2[p - 1];
			var b = p2[p];
			var c = p == p2.length - 1 ? p2[0] : p2[p + 1];
			lengths2[p] = dist(b[0], b[1], c[0], c[1]);
			angles2[p] = measureAngle({
					a: a,
					b: b,
					c: c
				});
		}

		for (var p = 0; p < p1.length; p++) {
			if (Math.abs(lengths1[0] - lengths2[p]) < 0.001 && Math.abs(angles1[0] - angles2[p]) < 0.001) {
				var match = true;
				for (var q = 1; q < p2.length; q++) {
					var r = (p + q) % p2.length;
					if (Math.abs(lengths1[q] - lengths2[r]) > 0.001 || Math.abs(angles1[q] - angles2[r]) > 0.001) {
						match = false;
						break;
					}
				}
				if (match == true)
					return true;
				if (mode == 0) { // check for a match in reverse vertices direction ie. a reflection
					for (var q = 1; q < p2.length; q++) {
						var r = p - q;
						if (r < 0)
							r = p2.length + r;
						if (Math.abs(lengths1[q] - lengths2[r]) > 0.001 || Math.abs(angles1[q] - angles2[r]) > 0.001) {
							match = false;
							break;
						}
					}
					if (match == true)
						return true;
				}
			}
		}
		return false;
	}
}
function polygonGetCenter(polygon) {
	var totals = [0,0];
	for (var p = 0; p < polygon.length; p++) {
		totals[0] += polygon[p][0];
		totals[1] += polygon[p][1];
		if (polygon[p].length == 3) { 
			if (un(totals[2])) totals[2] = 0;
			totals[2] += polygon[p][2];
		}
	}
	for (var t = 0; t < totals.length; t++) {
		totals[t] /= polygon.length;
	}
	return totals;
}

function lineSegmentsIntersectionTest(line1, line2) {
	return intersects(line1[0][0], line1[0][1], line1[1][0], line1[1][1], line2[0][0], line2[0][1], line2[1][0], line2[1][1]);
}
function linesIntersection(line1, line2) {
	return intersection(line1[0][0], line1[0][1], line1[1][0], line1[1][1], line2[0][0], line2[0][1], line2[1][0], line2[1][1]);
}
function intersects(a, b, c, d, p, q, r, s) {
	// returns true iff the line segemnt from (a,b)->(c,d) intersects with the line segment from (p,q)->(r,s)
	var det,
	gamma,
	lambda;
	det = (c - a) * (s - q) - (r - p) * (d - b);
	if (det === 0) {
		return false;
	} else {
		lambda = ((s - q) * (r - a) + (p - r) * (s - b)) / det;
		gamma = ((b - d) * (r - a) + (c - a) * (s - b)) / det;
		return (0 < lambda && lambda < 1) && (0 < gamma && gamma < 1);
	}
};
function intersects2(a, b, c, d, p, q, r, s) {
	// returns true iff the infinite line though (a,b) & (c,d) intersects with line segment (p,q)->(r,s)
	var int = intersection(a, b, c, d, p, q, r, s);
	return isPointOnLineSegment(int, [p, q], [r, s]);
};
function intersection(aX, aY, bX, bY, cX, cY, dX, dY) { // finds and returns the intersection point of the lines AB and CD
	if (aX instanceof Array) {
		var a = aX, b = aY, c = bX, d = bY;
		aX = a[0];
		aY = a[1];
		bX = b[0];
		bY = b[1];
		cX = c[0];
		cY = c[1];
		dX = d[0];
		dY = d[1];
	}
	if (aX !== bX && cX !== dX) {
		var m1 = (bY - aY) / (bX - aX); // gradient of AB;
		var m2 = (dY - cY) / (dX - cX); // gradient of CD;
		if (m1 == m2)
			return 'parallel';
		var xIntersection = ((aY - aX * m1) - (cY - cX * m2)) / (m2 - m1);
		var yIntersection = aY + m1 * (xIntersection - aX);
		return [xIntersection, yIntersection];
	} else if (aX == bX && cX == dX) {
		return 'parallel';
	} else if (aX == bX) {
		// if AB is vertical
		var m2 = (dY - cY) / (dX - cX); // gradient of CD;
		var xIntersection = aX;
		var yIntersection = cY + m2 * (xIntersection - cX);
		return [xIntersection, yIntersection];
	} else if (cX == dX) {
		// if CD is vertical
		var m1 = (bY - aY) / (bX - aX); // gradient of AB;
		var xIntersection = cX;
		var yIntersection = aY + m1 * (xIntersection - aX);
		return [xIntersection, yIntersection];
	}
}
function dist(x1, y1, x2, y2) {
	if (x1 instanceof Array && y1 instanceof Array) return (dist(x1[0],x1[1],y1[0],y1[1]));
	return Math.pow(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2), 0.5);
}
function midpoint(x1, y1, x2, y2) {
	return [0.5 * (x1 + x2), 0.5 * (y1 + y2)];
}
function collapsePath(path) {
	var path1 = path.slice(0);

	do {
		var joinFound = false;
		for (var i = path1.length - 1; i >= 0; i--) {
			if (joinFound == false) {
				for (var j = i - 1; j >= 0; j--) {
					if (path1[i].obj[0].type == path1[j].obj[0].type) {
						if (path1[i].type == 'pen') {}
						else if (path1[i].obj[0].type == 'line') {
							var x1 = path1[i].obj[0].startPos[0];
							var y1 = path1[i].obj[0].startPos[1];
							var x2 = path1[i].obj[0].finPos[0];
							var y2 = path1[i].obj[0].finPos[1];
							var x3 = path1[j].obj[0].startPos[0];
							var y3 = path1[j].obj[0].startPos[1];
							var x4 = path1[j].obj[0].finPos[0];
							var y4 = path1[j].obj[0].finPos[1];
							var m1 = (y2 - y1) / (x2 - x1);
							var m2 = (y4 - y3) / (x4 - x3);
							if (Math.abs(m1) > Math.abs(m2)) {
								var mMax = m1;
								var mMin = m2;
							} else {
								var mMax = m2;
								var mMin = m1;
							}
							// if gradients are equal and point from line 1 is on line 2
							//console.log('grad/grad: ',mMax/mMin);
							//console.log('pointOnLine: ',isPointOnLine([x1,y1],[x3,y3],[x4,y4],3.5));
							if (((mMin >= 0 && mMax >= 0) || (mMin < 0 && mMax < 0)) && Math.abs(mMax / mMin) < 1.1 && isPointOnLine([x1, y1], [x3, y3], [x4, y4], 3.5) == true) {
								// if one of the points is between the two points on the other line
								if ((x1 >= Math.min(x3, x4) && x1 <= Math.max(x3, x4) && y1 >= Math.min(y3, y4) && y1 <= Math.max(y3, y4)) || (x2 >= Math.min(x3, x4) && x2 <= Math.max(x3, x4) && y2 >= Math.min(y3, y4) && y2 <= Math.max(y3, y4)) || (x3 >= Math.min(x1, x2) && x3 <= Math.max(x1, x2) && y3 >= Math.min(y1, y2) && y3 <= Math.max(y1, y2)) || (x4 >= Math.min(x1, x2) && x4 <= Math.max(x1, x2) && y4 >= Math.min(y1, y2) && y4 <= Math.max(y1, y2))) {
									var xMin = Math.min(x1, x2, x3, x4);
									var xMax = Math.max(x1, x2, x3, x4);
									if (xMin == x1)
										var yMin = y1;
									if (xMin == x2)
										var yMin = y2;
									if (xMin == x3)
										var yMin = y3;
									if (xMin == x4)
										var yMin = y4;
									if (xMax == x1)
										var yMax = y1;
									if (xMax == x2)
										var yMax = y2;
									if (xMax == x3)
										var yMax = y3;
									if (xMax == x4)
										var yMax = y4;
									joinFound = true;
									path1[i].startPos = [xMin, yMin];
									path1[i].finPos = [xMax, yMax];
									path1.splice(j, 1);
									break;
								}
							}
						} else if (path1[i].obj[0].type == 'arc') {
							if (Math.abs(path1[i].obj[0].center[0] - path1[j].obj[0].center[0]) < 2 && Math.abs(path1[i].obj[0].center[1] - path1[j].obj[0].center[1]) < 2 && Math.abs(path1[i].obj[0].radius - path1[j].obj[0].radius) < 2) {
								if ((path1[i].obj[0].startAngle >= path1[j].obj[0].startAngle && path1[i].obj[0].startAngle <= path1[j].obj[0].finAngle) ||
									/* if min angle of first is between min & max angle of second*/
									(path1[i].obj[0].finAngle >= path1[j].obj[0].startAngle && path1[i].obj[0].finAngle <= path1[j].obj[0].finAngle) ||
									/* if max angle of first is between min & max angle of second*/
									(path1[j].obj[0].startAngle >= path1[i].obj[0].startAngle && path1[j].obj[0].startAngle <= path1[i].obj[0].finAngle) ||
									/* if min angle of second is between min & max angle of first*/
									(path1[j].obj[0].finAngle >= path1[i].obj[0].startAngle && path1[j].obj[0].finAngle <= path1[i].obj[0].finAngle) ||
									/* if max angle of second is between min & max angle of first*/
									(path1[i].obj[0].startAngle <= path1[j].obj[0].startAngle && path1[i].obj[0].finAngle >= path1[j].obj[0].finAngle) ||
									/* if second is contained within first*/
									(path1[j].obj[0].startAngle <= path1[i].obj[0].startAngle && path1[j].obj[0].finAngle >= path1[i].obj[0].finAngle))
									/* if first is contained within second*/
								{
									joinFound = true;
									path1[i].obj[0].startAngle = Math.min(path1[i].obj[0].startAngle, path1[j].obj[0].startAngle);
									path1[i].obj[0].finAngle = Math.max(path1[i].obj[0].finAngle, path1[j].obj[0].finAngle);
									path1.splice(j, 1);
									break;
								}
							}
						}
					}
				}
			}
		}
	} while (joinFound == true);

	return path1;
}
function getIntersectionPoints(path) {
	// currently only handles line/line, line/arc and arc/arc intersections
	var intPoints = [];
	for (var i = 0; i < path.length; i++) {
		if (typeof path[i].obj == 'undefined')
			continue;
		for (var j = 0; j < path[i].obj.length; j++) {
			var obj1 = path[i].obj[j];
			if (obj1.drawing == true)
				continue;
			for (var k = i; k < path.length; k++) {
				for (var l = 0; l < path[k].obj.length; l++) {
					if (i == k && j == l)
						continue;
					var obj2 = path[k].obj[l];
					if (obj2.drawing == true)
						continue;
					if (obj1.type == 'line' && obj2.type == 'line') {
						var int = intersection(obj1.startPos[0], obj1.startPos[1], obj1.finPos[0], obj1.finPos[1], obj2.startPos[0], obj2.startPos[1], obj2.finPos[0], obj2.finPos[1]);
						if (isPointOnLineSegment(int, obj1.startPos, obj1.finPos) == true)
							intPoints.push(int);
					} else if (obj1.type == 'line' && obj2.type == 'arc') {
						var int = lineCircleIntersections(obj1.startPos, obj1.finPos, obj2.center, obj2.radius);
						for (var m = 0; m < int.length; m++) {
							if (isPointOnLineSegment(int[m], obj1.startPos, obj1.finPos) == true && isAngleInPath(obj2, obj2.center, obj2.radius, int[m][2], 1) == true)
								intPoints.push(int[m]);
						}
					} else if (obj1.type == 'arc' && obj2.type == 'line') {
						var int = lineCircleIntersections(obj2.startPos, obj2.finPos, obj1.center, obj1.radius);
						for (var m = 0; m < int.length; m++) {
							if (isPointOnLineSegment(int[m], obj2.startPos, obj2.finPos) == true && isAngleInPath(obj1, obj1.center, obj1.radius, int[m][2], 1) == true)
								intPoints.push(int[m]);
						}
					} else if (obj1.type == 'arc' && obj2.type == 'arc') {
						var int = circleIntersections(obj1.center[0], obj1.center[1], obj1.radius, obj2.center[0], obj2.center[1], obj2.radius);
						for (var m = 0; m < int.length; m++) {
							var a = isPointOnArc(int[m], obj1);
							var b = isPointOnArc(int[m], obj2);
							if (a == true && b == true)
								intPoints.push(int[m]);
						}
					}
				}
			}
		}
	}
	return intPoints;
}
function getEndPoints(path) {
	// currently only handles pen, line and arc paths
	var endPoints = [];
	for (var i = 0; i < path.length; i++) {
		if (typeof path[i].obj == 'undefined')
			continue;
		for (var j = 0; j < path[i].obj.length; j++) {
			if (path[i].obj[j].drawing == true)
				continue;
			switch (path[i].obj[j].type) {
			case 'line':
				endPoints.push(path[i].obj[j].startPos, path[i].obj[j].finPos);
				break;
			case 'arc':
				var arcEnds = getEndPointsOfArc(path[i].obj[j]);
				for (var k = 0; k < arcEnds.length; k++) {
					endPoints.push(arcEnds[k]);
				}
				break;
			}
		}
	}
	return endPoints;
}
function isAngleInPath(arcPath, center, radius, angle, tolerance) {
	if (dist(arcPath.center[0], arcPath.center[1], center[0], center[1]) > tolerance)
		return false;
	if (Math.abs(arcPath.radius - radius) > tolerance)
		return false;
	var startAngle = arcPath.startAngle;
	var finAngle = arcPath.finAngle;
	if (arcPath.clockwise == true) {
		if (startAngle < angle && finAngle > angle)
			return true;
		if (startAngle + 2 * Math.PI < angle && finAngle + 2 * Math.PI > angle)
			return true;
		if (startAngle - 2 * Math.PI < angle && finAngle - 2 * Math.PI > angle)
			return true;
	} else {
		if (startAngle < finAngle)
			startAngle += 2 * Math.PI;
		if (startAngle > angle && finAngle < angle)
			return true;
		if (startAngle + 2 * Math.PI > angle && finAngle + 2 * Math.PI < angle)
			return true;
		if (startAngle - 2 * Math.PI > angle && finAngle - 2 * Math.PI < angle)
			return true;
	}
	return false;
}
function doesArcIncludeAngle(arc, angle) {
	while (angle < 0) {
		angle += 2 * Math.PI;
	}
	angle = angle % (2 * Math.PI);
	if (arc.clockwise == false) {
		if (arc.finAngle > arc.startAngle) {
			if (angle <= arc.startAngle || angle >= arc.finAngle)
				return true;
		} else {
			if (angle >= arc.finAngle && angle <= arc.startAngle)
				return true;
		}
	} else {
		if (arc.finAngle > arc.startAngle) {
			if (angle >= arc.startAngle || angle <= arc.finAngle)
				return true;
		} else {
			if (angle <= arc.finAngle && angle >= arc.startAngle)
				return true;
		}
	}
	return false;
}
function distancePointToPath(point, path) {
	if (path.length > 1) {
		var closestDist = distancePointToLineSegment(point, path[0], path[1]);
		for (var i = 1; i < path.length - 1; i++) {
			closestDist = Math.min(closestDist, distancePointToLineSegment(point, path[i], path[i + 1]));
		}
		return closestDist;
	} else if (path.length == 1) {
		return dist(point[0], point[1], path[0][0], path[0][1]);
	} else {
		return 100000000000;
	}

}
function isPointOnLine(point, linePos1, linePos2, tolerance) {
	if (un(tolerance))
		tolerance = 0.001;
	var closestPos = closestPointOnLine(point, linePos1, linePos2);
	var distance = dist(closestPos[0], closestPos[1], point[0], point[1]);
	if (distance <= tolerance)
		return true;
	return false;
}
function closestPointOnLine(point, linePos1, linePos2) {
	var dirVector = [linePos2[0] - linePos1[0], linePos2[1] - linePos1[1]];
	var lambda = ((point[0] - linePos1[0]) * dirVector[0] + (point[1] - linePos1[1]) * dirVector[1]) / (Math.pow(dirVector[0], 2) + Math.pow(dirVector[1], 2));
	return [linePos1[0] + lambda * dirVector[0], linePos1[1] + lambda * dirVector[1]];
}
function distancePointToLine(point, linePos1, linePos2) {
	var closest = closestPointOnLine(point, linePos1, linePos2);
	return dist(point[0], point[1], closest[0], closest[1]);
}
function closestPointOnLineSegment(point, linePos1, linePos2) {
	var dirVector = [linePos2[0] - linePos1[0], linePos2[1] - linePos1[1]];
	var lambda = ((point[0] - linePos1[0]) * dirVector[0] + (point[1] - linePos1[1]) * dirVector[1]) / (Math.pow(dirVector[0], 2) + Math.pow(dirVector[1], 2));
	if (lambda <= 0) {
		return linePos1;
	} else if (lambda >= 1) {
		return linePos2;
	} else {
		return [linePos1[0] + lambda * dirVector[0], linePos1[1] + lambda * dirVector[1]];
	}
}
function distancePointToLineSegment(point, linePos1, linePos2) {
	var closest = closestPointOnLineSegment(point, linePos1, linePos2);
	return dist(point[0], point[1], closest[0], closest[1]);
}
function checkPathForLine(path, x1, y1, isEnd1, x2, y2, isEnd2, tolerance) {
	for (var i = 0; i < path.length; i++) {
		for (var k = 0; k < path[i].obj.length; k++) {
			if (path[i].obj[k].type == 'line' && lineCheck(x1, y1, isEnd1, x2, y2, isEnd2, tolerance, path[i].obj[k].startPos[0], path[i].obj[k].startPos[1], path[i].obj[k].finPos[0], path[i].obj[k].finPos[1]) == true)
				return true;
		}
	}
	return false;
}
function isPointOnLineSegment(point, linePos1, linePos2, tolerance) {
	if (un(tolerance)) tolerance = 0.001;
	return distancePointToLineSegment(point, linePos1, linePos2) < tolerance;
}
/*function isPointOnLineSegment(point,linePos1,linePos2) {
var dirVector = [linePos2[0]-linePos1[0],linePos2[1]-linePos1[1]];
var lambda = ((point[0]-linePos1[0])*dirVector[0]+(point[1]-linePos1[1])*dirVector[1])/(Math.pow(dirVector[0],2)+Math.pow(dirVector[1],2));
if (lambda >= 0 && lambda <= 1) {
return true;
} else {
return false;
}
}*/
function isPointInSector(point, dims) {
	if (dist(point[0], point[1], dims[0], dims[1]) > dims[2])
		return false;
	var a1 = dims[3];
	var a2 = getAngleTwoPoints([dims[0], dims[1]], point);
	var a3 = dims[4];
	return anglesInOrder(a1, a2, a3);
}

function sameLine(line1, line2) {
	return (isPointOnLine(line1[0], line2[0], line2[1], 0) && isPointOnLine(line1[1], line2[0], line2[1], 0));
}

function lineCheck(x1, y1, isEnd1, x2, y2, isEnd2, tolerance, xTest1, yTest1, xTest2, yTest2) {
	//console.log(x1,y1,isEnd1,x2,y2,isEnd2,tolerance,xTest1,yTest1,xTest2,yTest2);
	// if points should be ends of the line, test if they are
	if (isEnd1 == true && dist(x1, y1, xTest1, yTest1) > tolerance && dist(x1, y1, xTest2, yTest2) > tolerance) {
		return false;
	}
	if (isEnd2 == true && dist(x2, y2, xTest1, yTest1) > tolerance && dist(x2, y2, xTest2, yTest2) > tolerance) {
		return false;
	}
	// test if the points are on the line, with the given tolerance
	if (isPointOnLine([x1, y1], [xTest1, yTest1], [xTest2, yTest2], tolerance) == false || isPointOnLine([x2, y2], [xTest1, yTest1], [xTest2, yTest2], tolerance) == false) {
		return false;
	}
	// test if the line has been drawn far enough
	var mag = dist(x1, y1, x2, y2);
	var minPos1 = [x1 + 2 * tolerance / mag * (x2 - x1), y1 + 2 * tolerance / mag * (y2 - y1)];
	var minPos2 = [x2 + 2 * tolerance / mag * (x1 - x2), y2 + 2 * tolerance / mag * (y1 - y2)];

	/*
	console.log('pos1:'+x1+','+y1);
	console.log('pos2:'+x2+','+y2);
	console.log('minPos1:'+minPos1[0]+','+minPos1[1]);
	console.log('minPos2:'+minPos2[0]+','+minPos2[1]);
	console.log('testPos1:'+xTest1+','+yTest1);
	console.log('testPos2:'+xTest2+','+yTest2);
	console.log('dist to min pos, dist to actual pos:');
	console.log('pos1,testPos1:',dist(minPos1[0],minPos1[1],xTest1,yTest1),dist(x1,y1,xTest1,yTest1),dist(minPos1[0],minPos1[1],xTest1,yTest1)>dist(x1,y1,xTest1,yTest1));
	console.log('pos2,testPos2:',dist(minPos2[0],minPos2[1],xTest2,yTest2),dist(x2,y2,xTest2,yTest2),dist(minPos2[0],minPos2[1],xTest2,yTest2)>dist(x2,y2,xTest2,yTest2));
	console.log('pos1,testPos2:',dist(minPos1[0],minPos1[1],xTest2,yTest2),dist(x1,y1,xTest2,yTest2),dist(minPos1[0],minPos1[1],xTest2,yTest2)>dist(x1,y1,xTest2,yTest2));
	console.log('pos2,testPos1:',dist(minPos2[0],minPos2[1],xTest1,yTest1),dist(x2,y2,xTest1,yTest1),dist(minPos2[0],minPos2[1],xTest1,yTest1)>dist(x2,y2,xTest1,yTest1));
	//*/

	// if both points are closer to minPos than to either of the actual points
	if ((dist(minPos1[0], minPos1[1], xTest1, yTest1) > dist(x1, y1, xTest1, yTest1)
			 && dist(minPos1[0], minPos1[1], xTest2, yTest2) > dist(x1, y1, xTest2, yTest2))

		 || (dist(minPos2[0], minPos2[1], xTest1, yTest1) > dist(x2, y2, xTest1, yTest1)
			 && dist(minPos2[0], minPos2[1], xTest2, yTest2) > dist(x2, y2, xTest2, yTest2))) {
		return false;
	}
	return true;
}
function getAngleTwoPoints(pos1, pos2) { // returns the angle in rad from pos1 to pos2
	var m = (pos2[1] - pos1[1]) / (pos2[0] - pos1[0]);
	var a = Math.atan(m);
	if (pos1[1] == pos2[1]) { // horizontal
		if (pos1[0] < pos2[0]) {
			return 0;
		} else {
			return Math.PI;
		}
	}
	if (pos1[0] == pos2[0]) { // vertical
		if (pos1[1] < pos2[1]) {
			return Math.PI / 2;
		} else {
			return 3 * Math.PI / 2;
		}
	}
	if (m > 0) {
		if (pos2[0] > pos1[0]) {
			return a;
		} else {
			return a + Math.PI;
		}
	} else {
		if (pos2[0] > pos1[0]) {
			return a;
		} else {
			return a + Math.PI;
		}
	}
}
function interpolateTwoPoints(pos1, pos2, proportion) {
	if (typeof proportion == 'undefined')
		proportion = 0.5;
	return [pos1[0] + proportion * (pos2[0] - pos1[0]), pos1[1] + proportion * (pos2[1] - pos1[1])];
}
function angleToPos(angle, centerX, centerY, radius, opt_angleType) {
	if (opt_angleType == 'degrees')
		angle = angle * Math.PI / 180;
	return [centerX + Math.cos(angle) * radius, centerY - Math.sin(angle) * radius];
}
function posToAngle(posX, posY, centerX, centerY, radius) {
	if (un(radius))
		radius = dist(posX, posY, centerX, centerY);
	var cosTheta = (posX - centerX) / radius;
	var sinTheta = (posY - centerY) / radius;
	if (sinTheta >= 0)
		return Math.acos(cosTheta);
	if (sinTheta < 0)
		return 2 * Math.PI - Math.acos(cosTheta);
}
function extendLine(pos1, pos2, extLength) {
	var m = (pos2[1] - pos1[1]) / (pos2[0] - pos1[0]);
	var angle = Math.atan(m);
	if (pos1[1] == pos2[1]) { // horizontal
		if (pos1[0] < pos2[0]) {
			return [pos2[0] + extLength, pos2[1]];
		} else {
			return [pos2[0] - extLength, pos2[1]];
		}
	}
	if (pos1[0] == pos2[0]) { // vertical
		if (pos1[1] < pos2[1]) {
			return [pos2[0], pos2[1] + extLength];
		} else {
			return [pos2[0], pos2[1] - extLength];
		}
	}
	if (m > 0) {
		if (pos2[0] >= pos1[0]) {
			return ([pos2[0] + extLength * Math.cos(angle), pos2[1] + extLength * Math.sin(angle)]);
		} else {
			return ([pos2[0] - extLength * Math.cos(angle), pos2[1] - extLength * Math.sin(angle)]);
		}
	} else {
		if (pos2[0] <= pos1[0]) {
			return ([pos2[0] - extLength * Math.cos(angle), pos2[1] - extLength * Math.sin(angle)]);
		} else {
			return ([pos2[0] + extLength * Math.cos(angle), pos2[1] + extLength * Math.sin(angle)]);
		}
	}
}

function isPointOnEllipse(point, center, radiusX, radiusY, tolerance) {
	if (typeof tolerance == 'undefined') {
		if (roundToNearest(Math.pow((point[0] - center[0]) / radiusX, 2) + Math.pow((point[1] - center[1]) / radiusY, 2), 0.0001) == 1) {
			return true;
		} else {
			return false;
		}
	} else {
		var max = Math.pow((point[0] - center[0]) / (radiusX + tolerance), 2) + Math.pow((point[1] - center[1]) / (radiusY + tolerance), 2);
		var min = Math.pow((point[0] - center[0]) / (radiusX - tolerance), 2) + Math.pow((point[1] - center[1]) / (radiusY - tolerance), 2);
		if (Math.max(min, max) >= 1 && Math.min(min, max) <= 1) {
			return true;
		} else {
			return false;
		}
	}
}
function isPointInEllipse(point, center, radiusX, radiusY) {
	if (roundToNearest(Math.pow((point[0] - center[0]) / radiusX, 2) + Math.pow((point[1] - center[1]) / radiusY, 2), 0.0001) <= 1) {
		return true;
	} else {
		return false;
	}
}
function isPointInRect(point, left, top, width, height) {
	if (point[0] >= left && point[0] <= left + width && point[1] >= top && point[1] <= top + height) {
		return true;
	} else {
		return false;
	}
}
function distPointToRect(point, left, top, width, height) {
	if (isPointInRect(point, left, top, width, height) == true)
		return 0;
	return Math.min(
		distancePointToLineSegment(point, [left, top], [left + width, top]),
		distancePointToLineSegment(point, [left + width, top], [left + width, top + height]),
		distancePointToLineSegment(point, [left + width, top + height], [left, top + height]),
		distancePointToLineSegment(point, [left, top + height], [left + width, top]))
}
function lineCircleIntersections(linePoint1, linePoint2, circleCenter, circleRadius) {
	var a = linePoint1[0];
	var b = linePoint1[1];
	var c = linePoint2[0];
	var d = linePoint2[1];
	var p = circleCenter[0];
	var q = circleCenter[1];
	var r = circleRadius;

	var m = (d - b) / (c - a);
	var s = m * m + 1;
	var t = -2 * p + 2 * m * (-m * a + b - q);
	var u = p * p + (-m * a + b - q) * (-m * a + b - q) - r * r;
	var discrim = t * t - 4 * s * u;
	if (discrim < 0) {
		return [];
	} else if (discrim == 0) {
		var x = (-t + Math.sqrt(discrim)) / (2 * s);
		var y = m * (x - a) + b;
		if (x >= p) {
			if (y >= q) {
				var angle = Math.atan((y - q) / (x - p));
			} else {
				var angle = 2 * Math.PI + Math.atan((y - q) / (x - p));
			}
		} else {
			var angle = Math.PI + Math.atan((y - q) / (x - p));
		}
		return [[x, y, angle]];
	} else {
		var x1 = (-t + Math.sqrt(discrim)) / (2 * s);
		var y1 = m * (x1 - a) + b;
		if (x1 >= p) {
			if (y1 >= q) {
				var angle1 = Math.atan((y1 - q) / (x1 - p));
			} else {
				var angle1 = 2 * Math.PI + Math.atan((y1 - q) / (x1 - p));
			}
		} else {
			var angle1 = Math.PI + Math.atan((y1 - q) / (x1 - p));
		}
		var x2 = (-t - Math.sqrt(discrim)) / (2 * s);
		var y2 = m * (x2 - a) + b;
		if (x2 >= p) {
			if (y2 >= q) {
				var angle2 = Math.atan((y2 - q) / (x2 - p));
			} else {
				var angle2 = 2 * Math.PI + Math.atan((y2 - q) / (x2 - p));
			}
		} else {
			var angle2 = Math.PI + Math.atan((y2 - q) / (x2 - p));
		}
		return [[x1, y1, angle1], [x2, y2, angle2]];
	}
}
function circleIntersections(x0, y0, r0, x1, y1, r1) {
	var a,
	dx,
	dy,
	d,
	h,
	rx,
	ry;
	var x2,
	y2;
	/* dx and dy are the vertical and horizontal distances between the circle centers. */
	dx = x1 - x0;
	dy = y1 - y0;
	/* Determine the straight-line distance between the centers. */
	d = Math.sqrt((dy * dy) + (dx * dx));
	/* Check for solvability. */
	if (d > (r0 + r1)) {
		/* no solution. circles do not intersect. */
		return [];
	}
	if (d < Math.abs(r0 - r1)) {
		/* no solution. one circle is contained in the other */
		return [];
	}
	/* 'point 2' is the point where the line through the circle intersection points crosses the line between the circle centers. */
	/* Determine the distance from point 0 to point 2. */
	a = ((r0 * r0) - (r1 * r1) + (d * d)) / (2 * d);
	/* Determine the coordinates of point 2. */
	x2 = x0 + (dx * a / d);
	y2 = y0 + (dy * a / d);
	/* Determine the distance from point 2 to either of the intersection points. */
	h = Math.sqrt((r0 * r0) - (a * a));
	/* Now determine the offsets of the intersection points from point 2. */
	rx = -dy * (h / d);
	ry = dx * (h / d);
	/* Determine the absolute intersection points. */
	var xi = x2 + rx;
	var xii = x2 - rx;
	var yi = y2 + ry;
	var yii = y2 - ry;
	return [[xi, yi], [xii, yii]];
}
function isPointOnArc(point, arcPath, tolerance) {
	if (!tolerance)
		tolerance = 0.00001;
	var rad = dist(point[0], point[1], arcPath.center[0], arcPath.center[1]);
	if (rad < arcPath.radius - tolerance || rad > arcPath.radius + tolerance)
		return false;
	if (Math.abs(arcPath.startAngle - arcPath.finAngle) + 0.00001 >= 2 * Math.PI)
		return true;
	var angle = getAngleFromAToB(arcPath.center, point);
	var angle1 = simplifyAngle(arcPath.startAngle);
	var angle2 = simplifyAngle(arcPath.finAngle);
	var a = arcPath.clockwise;
	var b = angle1 < angle2;
	var c = angle >= angle1 && angle <= angle2;
	/*
	if (a && b && c) return true;
	if (a && b && !c) return false;
	if (a && !b && c) return true;
	if (a && !b && !c) return false;
	if (!a && b && c) return false;
	if (!a && b && !c) return true;
	if (!a && !b && c) return false;
	if (!a && !b && !c) return true;
	/*/
	if (a == true) {
		if (b == true) {
			if (c == true) {
				return true;
			} else {
				return false;
			}
		} else {
			if (c == true) {
				return true;
			} else {
				return false;
			}
		}
	} else {
		if (b == true) {
			if (c == true) {
				return false;
			} else {
				return true;
			}
		} else {
			if (c == true) {
				return false;
			} else {
				return true;
			}
		}
	}
	//*/
}

function simplifyAngle(angle) {
	while (angle < 0) {
		angle += (2 * Math.PI)
	};
	angle = angle % (2 * Math.PI);
	return angle;
}
function getAngleFromAToB(a, b) {
	// angle as measured anticlockwise from positive x-direction (upside down on canvas) - A is in the centre
	var angle = Math.atan((b[1] - a[1]) / (b[0] - a[0]));
	if (b[0] >= a[0] && b[1] >= a[1])
		return angle;
	if (b[0] >= a[0] && b[1] < a[1])
		return angle + 2 * Math.PI;
	if (b[0] < a[0])
		return angle + Math.PI;
}
function getEndPointsOfArc(arcPath) {
	// if closed circle, return empty
	if (Math.abs(arcPath.startAngle - arcPath.finAngle) % (2 * Math.PI) == 0)
		return [];
	return [
		[arcPath.center[0] + arcPath.radius * Math.cos(arcPath.startAngle), arcPath.center[1] + arcPath.radius * Math.sin(arcPath.startAngle)],
		[arcPath.center[0] + arcPath.radius * Math.cos(arcPath.finAngle), arcPath.center[1] + arcPath.radius * Math.sin(arcPath.finAngle)]
	]
}
function vectorFromAToB(a, b) {
	return [b[0] - a[0], b[1] - a[1]];
}

function snapToPoints(point, snapPoints, tolerance) {
	var minDist = [];
	for (var i = 0; i < snapPoints.length; i++) {
		minDist.push(dist(point[0], point[1], snapPoints[i][0], snapPoints[i][1]));
	}
	if (arrayMin(minDist) < tolerance) {
		return snapPoints[minDist.indexOf(arrayMin(minDist))].slice(0);
	} else {
		return point.slice(0);
	}
}
function snapToGrid(point, snapGrid) {
	//snapGrid should contain: {left,top,width,height,dx,dy}
}

function getBezierPoints(p1, p2, p3, density) {
	if (!density)
		density = 10;
	var length = quadraticBezierLength(p1, p2, p3);
	var points = [p1];
	for (var i = density; i < length; i += density) {
		points.push(getQuadraticCurvePoint(p1[0], p1[1], p2[0], p2[1], p3[0], p3[1], i / length));
	}
	points.push(p3);
	return points;
}
function getQBezierValue(t, p1, p2, p3) { // called by getQuadraticCurvePoint, src: http://jsfiddle.net/QA6VG/
	var iT = 1 - t;
	return iT * iT * p1 + 2 * iT * t * p2 + t * t * p3;
}
function getQuadraticCurvePoint(startX, startY, cpX, cpY, endX, endY, position) { // called by getBezierPoints, src: http://jsfiddle.net/QA6VG/
	return [getQBezierValue(position, startX, cpX, endX), getQBezierValue(position, startY, cpY, endY)];
}
function quadraticBezierLength(p0, p1, p2) { // called by getBezierPoints, src: https://gist.github.com/tunght13488/6744e77c242cc7a94859
	function Point(x, y) {
		this.x = x;
		this.y = y;
	}
	var a = new Point(
			p0[0] - 2 * p1[0] + p2[0],
			p0[1] - 2 * p1[1] + p2[1]);
	var b = new Point(
			2 * p1[0] - 2 * p0[0],
			2 * p1[1] - 2 * p0[1]);
	var A = 4 * (a.x * a.x + a.y * a.y);
	var B = 4 * (a.x * b.x + a.y * b.y);
	var C = b.x * b.x + b.y * b.y;

	var Sabc = 2 * Math.sqrt(A + B + C);
	var A_2 = Math.sqrt(A);
	var A_32 = 2 * A * A_2;
	var C_2 = 2 * Math.sqrt(C);
	var BA = B / A_2;

	return (A_32 * Sabc + A_2 * B * (Sabc - C_2) + (4 * C * A - B * B) * Math.log((2 * A_2 + BA + Sabc) / (BA + C_2))) / (4 * A_32);
}

function drawTextBox(canvas, canvasctx, canvasData, backgroundColor, borderColor, borderWidth, font, textColor, textAlign, textLine1, textLine2) {
	var polygon = false;
	if (typeof canvasData[41] !== 'undefined')
		polygon = true;
	canvasctx.clearRect(0, 0, canvasData[2], canvasData[3]);
	canvasctx.fillStyle = backgroundColor;
	canvasctx.strokeStyle = borderColor;
	canvasctx.lineWidth = borderWidth;
	if (polygon == true) {
		canvasctx.beginPath();
		canvasctx.moveTo(canvasData[41][0][0], canvasData[41][0][1]);
		for (j = 0; j < canvasData[41].length; j++) {
			if (j > 0)
				canvasctx.lineTo(canvasData[41][j][0], canvasData[41][j][1]);
		}
		canvasctx.closePath();
		canvasctx.fill();
		canvasctx.stroke();
	} else {
		if (backgroundColor !== '')
			canvasctx.fillRect(0, 0, canvasData[2], canvasData[3]);
		if (borderColor !== '')
			canvasctx.strokeRect(0, 0, canvasData[2], canvasData[3]);
	}
	canvasctx.font = font;
	canvasctx.fillStyle = textColor;
	canvasctx.textAlign = textAlign;
	canvasctx.textBaseline = "middle";
	if (!textLine2) {
		canvasctx.fillText(textLine1, 0.5 * canvasData[2], 0.5 * canvasData[3]);
	} else {
		canvasctx.fillText(textLine1, 0.5 * canvasData[2], 0.3 * canvasData[3]);
		canvasctx.fillText(textLine2, 0.5 * canvasData[2], 0.7 * canvasData[3]);
	}
}
function drawMathsTextBox(canvasctx, canvasData, textArray, object) {
	// optional object can contain: backColor, algText, fontSize, borderColor, borderWidth, textColor, textAlign
	if (!object) {
		var fontSize = 0.45 * canvasData[3];
		var horizAlign = 'center';
		var algText = true;
		var textColor = '#000';
		var backgroundColor = '#6F9';
		var borderColor = '#000';
		var borderWidth = 4;
	} else {
		var fontSize = object.fontSize || 0.45 * canvasData[3];
		var horizAlign = object.textAlign || 'center';
		var algText = true;
		if (typeof object.algText == 'boolean')
			algText = object.algText;
		var textColor = object.textColor || '#000';
		var backgroundColor = object.backColor || '#6F9';
		var borderColor = object.borderColor || '#000';
		var borderWidth = object.borderWidth || 4;
	}
	var horizPos = 0.5 * canvasData[2];
	if (horizAlign == 'left')
		horizPos = 5;
	if (horizAlign == 'right')
		horizPos = canvasData[2] - 5;
	canvasctx.clearRect(0, 0, canvasData[2], canvasData[3]);
	canvasctx.fillStyle = backgroundColor;
	canvasctx.strokeStyle = borderColor;
	canvasctx.lineWidth = borderWidth;
	canvasctx.fillRect(0, 0, canvasData[2], canvasData[3]);
	canvasctx.strokeRect(borderWidth * 0.5, borderWidth * 0.5, canvasData[2] - borderWidth, canvasData[3] - borderWidth);
	drawMathsText(canvasctx, textArray, fontSize, horizPos, 0.47 * canvasData[3], algText, [], horizAlign, 'middle', textColor, 'draw');
}
function wrapText(context, text, x, y, maxWidth, lineHeight, font, fillStyle) {
	context.font = font;
	context.fillStyle = fillStyle;
	var words = text.split(' ');
	var line = '';
	for (var n = 0; n < words.length; n++) {
		var testLine = line + words[n] + ' ';
		var metrics = context.measureText(testLine);
		var testWidth = metrics.width;
		if (testWidth > maxWidth && n > 0) {
			context.fillText(line, x, y);
			line = words[n] + ' ';
			y += lineHeight;
		} else {
			line = testLine;
		}
	}
	context.fillText(line, x, y);
}
function drawFrac(context, font, x, y, horizAlign, numerator, denominator) {
	context.save();
	context.font = font;
	var fractionWidth = Math.max(context.measureText(numerator).width, context.measureText(denominator).width);
	context.textAlign = 'center';
	context.textBaseline = 'bottom';
	switch (horizAlign) {
	case 'right':
		context.fillText(numerator, x - 2 - 0.5 * fractionWidth, y - 5);
		context.textBaseline = 'top';
		context.fillText(denominator, x - 2 - 0.5 * fractionWidth, y + 5);
		context.strokeStyle = textColor;
		context.lineWidth = 3;
		context.moveTo(x - 4 - fractionWidth, y);
		context.lineTo(x, y);
		break;
	case 'center':
		context.fillText(numerator, x, y - 5);
		context.textBaseline = 'top';
		context.fillText(denominator, x, y + 5);
		context.strokeStyle = textColor;
		context.lineWidth = 3;
		context.moveTo(x - 2 - 0.5 * fractionWidth, y);
		context.lineTo(x + 2 + 0.5 * fractionWidth, y);
		break;
	default:
		context.fillText(numerator, x + 2 + 0.5 * fractionWidth, y - 5);
		context.textBaseline = 'top';
		context.fillText(denominator, x + 2 + 0.5 * fractionWidth, y + 5);
		context.strokeStyle = textColor;
		context.lineWidth = 3;
		context.moveTo(x, y);
		context.lineTo(x + 4 + fractionWidth, y);
		break;
	}
	context.stroke();
	context.restore();
}

function generateNormalData(mean, sd, n) {
	var normal = gaussian(mean, sd);
	var data = [];
	var groups = [];
	for (var i = 0; i < 8; i++)
		groups[i] = {
			min: roundToNearest(mean + (i - 4) * sd, 0.00001),
			max: roundToNearest(mean + (i - 3) * sd, 0.00001),
			frequency: 0
		};
	for (var i = 0; i < n; i++) {
		var value = normal()
			data.push(value);
		for (var g = 0; g < 8; g++) {
			if (value >= groups[g].min && value <= groups[g].max) {
				groups[g].frequency++;
				break;
			}
		}
	}
	return {
		data: data,
		grouped: groups
	};
}
// returns a gaussian random function with the given mean and stdev.
function gaussian(mean, stdev) {
	var y2;
	var use_last = false;
	return function () {
		var y1;
		if (use_last) {
			y1 = y2;
			use_last = false;
		} else {
			var x1,
			x2,
			w;
			do {
				x1 = 2.0 * Math.random() - 1.0;
				x2 = 2.0 * Math.random() - 1.0;
				w = x1 * x1 + x2 * x2;
			} while (w >= 1.0);
			w = Math.sqrt((-2.0 * Math.log(w)) / w);
			y1 = x1 * w;
			y2 = x2 * w;
			use_last = true;
		}

		var retval = mean + stdev * y1;
		if (retval > 0)
			return retval;
		return -retval;
	}
}
function phi(x) { // for normal distribution
	var a1 = 0.254829592;
	var a2 = -0.284496736;
	var a3 = 1.421413741;
	var a4 = -1.453152027;
	var a5 = 1.061405429;
	var p = 0.3275911;

	var sign = 1
		if (x < 0)
			sign = -1
				x = Math.abs(x) / Math.sqrt(2)

				// A&S formula 7.1.26
				var t = 1 / (1 + p * x)
				var y = 1 - (((((a5 * t + a4) * t) + a3) * t + a2) * t + a1) * t * Math.exp(-x * x)

				return 0.5 * (1 + sign * y)
}
function enlargeDash(dash, sf) {
	if (typeof sf == 'undefined')
		return dash;
	for (var i = 0; i < dash.length; i++) {
		dash[i] = dash[i] * sf;
	}
	return dash;
}

function numberToString(n, commaForThousand) {
	var decPart = roundToNearest(n - Math.floor(n), 0.00001);
	var str = Math.floor(n).toString();
	if (str.length < 4 || (str.length == 4 && boolean(commaForThousand, false) == false)) {}
	else {
		var count = 0;
		for (var i = str.length; i >= 1; i--) {
			if (count == 3) {
				str = str.slice(0, i) + ',' + str.slice(i);
				count = 0;
			}
			count++;
		}
	}
	if (decPart > 0) {
		var str2 = String(decPart);
		str = str + str2.slice(1);
	}
	return str;
}
function stringToNumber(str) {
	var str = replaceAll(str, ',', '');
	var str = replaceAll(str, ' ', '');
	return parseInt(str);
}
function numberToWords(n, capFirstLetter) {
	var string = n.toString(),
	units,
	tens,
	scales,
	start,
	end,
	chunks,
	chunksLen,
	chunk,
	ints,
	i,
	word,
	words,
	and = 'and';
	if (parseInt(string) === 0)
		return 'zero';

	units = ['', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten', 'eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen'];

	tens = ['', '', 'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety'];

	scales = ['', 'thousand', 'million', 'billion', 'trillion', 'quadrillion', 'quintillion', 'sextillion', 'septillion', 'octillion', 'nonillion', 'decillion', 'undecillion', 'duodecillion', 'tredecillion', 'quatttuor-decillion', 'quindecillion', 'sexdecillion', 'septen-decillion', 'octodecillion', 'novemdecillion', 'vigintillion', 'centillion'];

	start = string.length; /* Split user arguemnt into 3 digit chunks from right to left */
	chunks = [];
	while (start > 0) {
		end = start;
		chunks.push(string.slice((start = Math.max(0, start - 3)), end));
	}

	chunksLen = chunks.length; /* Check if function has enough scale words to be able to stringify the user argument */
	if (chunksLen > scales.length) {
		return '';
	}

	words = []; /* Stringify each integer in each chunk */
	for (i = 0; i < chunksLen; i++) {
		chunk = parseInt(chunks[i]);
		if (chunk) {

			/* Split chunk into array of individual integers */
			ints = chunks[i].split('').reverse().map(parseFloat);

			/* If tens integer is 1, i.e. 10, then add 10 to units integer */
			if (ints[1] === 1) {
				ints[0] += 10;
			}

			if (i > 0)
				words.push(',');

			/* Add scale word if chunk is not zero and array item exists */
			if ((word = scales[i])) {
				words.push(word);
			}

			/* Add unit word if array item exists */
			if ((word = units[ints[0]])) {
				words.push(word);
			}

			/* Add tens word if array item exists */
			if ((word = tens[ints[1]])) {
				words.push(word);
			}

			/* Add 'and' string after units or tens integer if: */
			if (ints[0] || ints[1]) {

				/* Chunk has a hundreds integer or chunk is the first of multiple chunks */
				if (ints[2] || !i && chunksLen) {
					words.push(and);
				}

			}

			/* Add hundreds word if array item exists */
			if ((word = units[ints[2]])) {
				words.push(word + ' hundred');
			}

		}

	}

	var str = words.reverse().join(' ');
	str = replaceAll(str, ' ,', ',');
	str = replaceAll(str, ', and', ' and');
	if (str.slice(0, 4) == 'and ')
		str = str.slice(4);
	if (str.slice(-1) == ',')
		str = str.slice(0, -1);
	if (boolean(capFirstLetter, true))
		str = str.charAt(0).toUpperCase() + str.slice(1);
	return str;
}