/*!!
* Canvas 2 Svg v1.0.19
* A low level canvas to SVG converter. Uses a mock canvas context to build an SVG document.
*
* Licensed under the MIT license:
* http://www.opensource.org/licenses/mit-license.php
*
* Author:
* Kerry Liu
*
* Copyright (c) 2014 Gliffy Inc.
*/
;(function () {
"use strict";
var STYLES, ctx, CanvasGradient, CanvasPattern, namedEntities;
//helper function to format a string
function format(str, args) {
var keys = Object.keys(args), i;
for (i=0; i<keys.length; i++) {
str = str.replace(new RegExp("\\{" + keys[i] + "\\}", "gi"), args[keys[i]]);
}
return str;
}
//helper function that generates a random string
function randomString(holder) {
var chars, randomstring, i;
if (!holder) {
throw new Error("cannot create a random attribute name for an undefined object");
}
chars = "ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
randomstring = "";
do {
randomstring = "";
for (i = 0; i < 12; i++) {
randomstring += chars[Math.floor(Math.random() * chars.length)];
}
} while (holder[randomstring]);
return randomstring;
}
//helper function to map named to numbered entities
function createNamedToNumberedLookup(items, radix) {
var i, entity, lookup = {}, base10, base16;
items = items.split(',');
radix = radix || 10;
// Map from named to numbered entities.
for (i = 0; i < items.length; i += 2) {
entity = '&' + items[i + 1] + ';';
base10 = parseInt(items[i], radix);
lookup[entity] = '&#'+base10+';';
}
//FF and IE need to create a regex from hex values ie == \xa0
lookup["\\xa0"] = ' ';
return lookup;
}
//helper function to map canvas-textAlign to svg-textAnchor
function getTextAnchor(textAlign) {
//TODO: support rtl languages
var mapping = {"left":"start", "right":"end", "center":"middle", "start":"start", "end":"end"};
return mapping[textAlign] || mapping.start;
}
//helper function to map canvas-textBaseline to svg-dominantBaseline
function getDominantBaseline(textBaseline) {
//INFO: not supported in all browsers
var mapping = {"alphabetic": "alphabetic", "hanging": "hanging", "top":"text-before-edge", "bottom":"text-after-edge", "middle":"central"};
return mapping[textBaseline] || mapping.alphabetic;
}
// Unpack entities lookup where the numbers are in radix 32 to reduce the size
// entity mapping courtesy of tinymce
namedEntities = createNamedToNumberedLookup(
'50,nbsp,51,iexcl,52,cent,53,pound,54,curren,55,yen,56,brvbar,57,sect,58,uml,59,copy,' +
'5a,ordf,5b,laquo,5c,not,5d,shy,5e,reg,5f,macr,5g,deg,5h,plusmn,5i,sup2,5j,sup3,5k,acute,' +
'5l,micro,5m,para,5n,middot,5o,cedil,5p,sup1,5q,ordm,5r,raquo,5s,frac14,5t,frac12,5u,frac34,' +
'5v,iquest,60,Agrave,61,Aacute,62,Acirc,63,Atilde,64,Auml,65,Aring,66,AElig,67,Ccedil,' +
'68,Egrave,69,Eacute,6a,Ecirc,6b,Euml,6c,Igrave,6d,Iacute,6e,Icirc,6f,Iuml,6g,ETH,6h,Ntilde,' +
'6i,Ograve,6j,Oacute,6k,Ocirc,6l,Otilde,6m,Ouml,6n,times,6o,Oslash,6p,Ugrave,6q,Uacute,' +
'6r,Ucirc,6s,Uuml,6t,Yacute,6u,THORN,6v,szlig,70,agrave,71,aacute,72,acirc,73,atilde,74,auml,' +
'75,aring,76,aelig,77,ccedil,78,egrave,79,eacute,7a,ecirc,7b,euml,7c,igrave,7d,iacute,7e,icirc,' +
'7f,iuml,7g,eth,7h,ntilde,7i,ograve,7j,oacute,7k,ocirc,7l,otilde,7m,ouml,7n,divide,7o,oslash,' +
'7p,ugrave,7q,uacute,7r,ucirc,7s,uuml,7t,yacute,7u,thorn,7v,yuml,ci,fnof,sh,Alpha,si,Beta,' +
'sj,Gamma,sk,Delta,sl,Epsilon,sm,Zeta,sn,Eta,so,Theta,sp,Iota,sq,Kappa,sr,Lambda,ss,Mu,' +
'st,Nu,su,Xi,sv,Omicron,t0,Pi,t1,Rho,t3,Sigma,t4,Tau,t5,Upsilon,t6,Phi,t7,Chi,t8,Psi,' +
't9,Omega,th,alpha,ti,beta,tj,gamma,tk,delta,tl,epsilon,tm,zeta,tn,eta,to,theta,tp,iota,' +
'tq,kappa,tr,lambda,ts,mu,tt,nu,tu,xi,tv,omicron,u0,pi,u1,rho,u2,sigmaf,u3,sigma,u4,tau,' +
'u5,upsilon,u6,phi,u7,chi,u8,psi,u9,omega,uh,thetasym,ui,upsih,um,piv,812,bull,816,hellip,' +
'81i,prime,81j,Prime,81u,oline,824,frasl,88o,weierp,88h,image,88s,real,892,trade,89l,alefsym,' +
'8cg,larr,8ch,uarr,8ci,rarr,8cj,darr,8ck,harr,8dl,crarr,8eg,lArr,8eh,uArr,8ei,rArr,8ej,dArr,' +
'8ek,hArr,8g0,forall,8g2,part,8g3,exist,8g5,empty,8g7,nabla,8g8,isin,8g9,notin,8gb,ni,8gf,prod,' +
'8gh,sum,8gi,minus,8gn,lowast,8gq,radic,8gt,prop,8gu,infin,8h0,ang,8h7,and,8h8,or,8h9,cap,8ha,cup,' +
'8hb,int,8hk,there4,8hs,sim,8i5,cong,8i8,asymp,8j0,ne,8j1,equiv,8j4,le,8j5,ge,8k2,sub,8k3,sup,8k4,' +
'nsub,8k6,sube,8k7,supe,8kl,oplus,8kn,otimes,8l5,perp,8m5,sdot,8o8,lceil,8o9,rceil,8oa,lfloor,8ob,' +
'rfloor,8p9,lang,8pa,rang,9ea,loz,9j0,spades,9j3,clubs,9j5,hearts,9j6,diams,ai,OElig,aj,oelig,b0,' +
'Scaron,b1,scaron,bo,Yuml,m6,circ,ms,tilde,802,ensp,803,emsp,809,thinsp,80c,zwnj,80d,zwj,80e,lrm,' +
'80f,rlm,80j,ndash,80k,mdash,80o,lsquo,80p,rsquo,80q,sbquo,80s,ldquo,80t,rdquo,80u,bdquo,810,dagger,' +
'811,Dagger,81g,permil,81p,lsaquo,81q,rsaquo,85c,euro', 32);
//Some basic mappings for attributes and default values.
STYLES = {
"strokeStyle":{
svgAttr : "stroke", //corresponding svg attribute
canvas : "#000000", //canvas default
svg : "none", //svg default
apply : "stroke" //apply on stroke() or fill()
},
"fillStyle":{
svgAttr : "fill",
canvas : "#000000",
svg : null, //svg default is black, but we need to special case this to handle canvas stroke without fill
apply : "fill"
},
"lineCap":{
svgAttr : "stroke-linecap",
canvas : "butt",
svg : "butt",
apply : "stroke"
},
"lineJoin":{
svgAttr : "stroke-linejoin",
canvas : "miter",
svg : "miter",
apply : "stroke"
},
"miterLimit":{
svgAttr : "stroke-miterlimit",
canvas : 10,
svg : 4,
apply : "stroke"
},
"lineWidth":{
svgAttr : "stroke-width",
canvas : 1,
svg : 1,
apply : "stroke"
},
"globalAlpha": {
svgAttr : "opacity",
canvas : 1,
svg : 1,
apply : "fill stroke"
},
"font":{
//font converts to multiple svg attributes, there is custom logic for this
canvas : "10px sans-serif"
},
"shadowColor":{
canvas : "#000000"
},
"shadowOffsetX":{
canvas : 0
},
"shadowOffsetY":{
canvas : 0
},
"shadowBlur":{
canvas : 0
},
"textAlign":{
canvas : "start"
},
"textBaseline":{
canvas : "alphabetic"
},
"lineDash" : {
svgAttr : "stroke-dasharray",
canvas : [],
svg : null,
apply : "stroke"
}
};
/**
*
* @param gradientNode - reference to the gradient
* @constructor
*/
CanvasGradient = function (gradientNode, ctx) {
this.__root = gradientNode;
this.__ctx = ctx;
};
/**
* Adds a color stop to the gradient root
*/
CanvasGradient.prototype.addColorStop = function (offset, color) {
var stop = this.__ctx.__createElement("stop"), regex, matches;
stop.setAttribute("offset", offset);
if (color.indexOf("rgba") !== -1) {
//separate alpha value, since webkit can't handle it
regex = /rgba\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d?\.?\d*)\s*\)/gi;
matches = regex.exec(color);
stop.setAttribute("stop-color", format("rgb({r},{g},{b})", {r:matches[1], g:matches[2], b:matches[3]}));
stop.setAttribute("stop-opacity", matches[4]);
} else {
stop.setAttribute("stop-color", color);
}
this.__root.appendChild(stop);
};
CanvasPattern = function (pattern, ctx) {
this.__root = pattern;
this.__ctx = ctx;
};
/**
* The mock canvas context
* @param o - options include:
* ctx - existing Context2D to wrap around
* width - width of your canvas (defaults to 500)
* height - height of your canvas (defaults to 500)
* enableMirroring - enables canvas mirroring (get image data) (defaults to false)
* document - the document object (defaults to the current document)
*/
ctx = function (o) {
var defaultOptions = { width:500, height:500, enableMirroring : false}, options;
//keep support for this way of calling C2S: new C2S(width,height)
if (arguments.length > 1) {
options = defaultOptions;
options.width = arguments[0];
options.height = arguments[1];
} else if ( !o ) {
options = defaultOptions;
} else {
options = o;
}
if (!(this instanceof ctx)) {
//did someone call this without new?
return new ctx(options);
}
//setup options
this.width = options.width || defaultOptions.width;
this.height = options.height || defaultOptions.height;
this.enableMirroring = options.enableMirroring !== undefined ? options.enableMirroring : defaultOptions.enableMirroring;
this.canvas = this; ///point back to this instance!
this.__document = options.document || document;
// allow passing in an existing context to wrap around
// if a context is passed in, we know a canvas already exist
if (options.ctx) {
this.__ctx = options.ctx;
} else {
this.__canvas = this.__document.createElement("canvas");
this.__ctx = this.__canvas.getContext("2d");
}
this.__setDefaultStyles();
this.__stack = [this.__getStyleState()];
this.__groupStack = [];
//the root svg element
this.__root = this.__document.createElementNS("http://www.w3.org/2000/svg", "svg");
this.__root.setAttribute("version", 1.1);
this.__root.setAttribute("xmlns", "http://www.w3.org/2000/svg");
this.__root.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:xlink", "http://www.w3.org/1999/xlink");
this.__root.setAttribute("width", this.width);
this.__root.setAttribute("height", this.height);
//make sure we don't generate the same ids in defs
this.__ids = {};
//defs tag
this.__defs = this.__document.createElementNS("http://www.w3.org/2000/svg", "defs");
this.__root.appendChild(this.__defs);
//also add a group child. the svg element can't use the transform attribute
this.__currentElement = this.__document.createElementNS("http://www.w3.org/2000/svg", "g");
this.__root.appendChild(this.__currentElement);
};
/**
* Creates the specified svg element
* @private
*/
ctx.prototype.__createElement = function (elementName, properties, resetFill) {
if (typeof properties === "undefined") {
properties = {};
}
var element = this.__document.createElementNS("http://www.w3.org/2000/svg", elementName),
keys = Object.keys(properties), i, key;
if (resetFill) {
//if fill or stroke is not specified, the svg element should not display. By default SVG's fill is black.
element.setAttribute("fill", "none");
element.setAttribute("stroke", "none");
}
for (i=0; i<keys.length; i++) {
key = keys[i];
element.setAttribute(key, properties[key]);
}
return element;
};
/**
* Applies default canvas styles to the context
* @private
*/
ctx.prototype.__setDefaultStyles = function () {
//default 2d canvas context properties see:http://www.w3.org/TR/2dcontext/
var keys = Object.keys(STYLES), i, key;
for (i=0; i<keys.length; i++) {
key = keys[i];
this[key] = STYLES[key].canvas;
}
};
/**
* Applies styles on restore
* @param styleState
* @private
*/
ctx.prototype.__applyStyleState = function (styleState) {
var keys = Object.keys(styleState), i, key;
for (i=0; i<keys.length; i++) {
key = keys[i];
this[key] = styleState[key];
}
};
/**
* Gets the current style state
* @return {Object}
* @private
*/
ctx.prototype.__getStyleState = function () {
var i, styleState = {}, keys = Object.keys(STYLES), key;
for (i=0; i<keys.length; i++) {
key = keys[i];
styleState[key] = this[key];
}
return styleState;
};
/**
* Apples the current styles to the current SVG element. On "ctx.fill" or "ctx.stroke"
* @param type
* @private
*/
ctx.prototype.__applyStyleToCurrentElement = function (type) {
var currentElement = this.__currentElement;
var currentStyleGroup = this.__currentElementsToStyle;
if (currentStyleGroup) {
currentElement.setAttribute(type, "");
currentElement = currentStyleGroup.element;
currentStyleGroup.children.forEach(function (node) {
node.setAttribute(type, "");
})
}
var keys = Object.keys(STYLES), i, style, value, id, regex, matches;
for (i = 0; i < keys.length; i++) {
style = STYLES[keys[i]];
value = this[keys[i]];
if (style.apply) {
//is this a gradient or pattern?
if (value instanceof CanvasPattern) {
//pattern
if (value.__ctx) {
//copy over defs
while(value.__ctx.__defs.childNodes.length) {
id = value.__ctx.__defs.childNodes[0].getAttribute("id");
this.__ids[id] = id;
this.__defs.appendChild(value.__ctx.__defs.childNodes[0]);
}
}
currentElement.setAttribute(style.apply, format("url(#{id})", {id:value.__root.getAttribute("id")}));
}
else if (value instanceof CanvasGradient) {
//gradient
currentElement.setAttribute(style.apply, format("url(#{id})", {id:value.__root.getAttribute("id")}));
} else if (style.apply.indexOf(type)!==-1 && style.svg !== value) {
if ((style.svgAttr === "stroke" || style.svgAttr === "fill") && value.indexOf("rgba") !== -1) {
//separate alpha value, since illustrator can't handle it
regex = /rgba\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d?\.?\d*)\s*\)/gi;
matches = regex.exec(value);
currentElement.setAttribute(style.svgAttr, format("rgb({r},{g},{b})", {r:matches[1], g:matches[2], b:matches[3]}));
//should take globalAlpha here
var opacity = matches[4];
var globalAlpha = this.globalAlpha;
if (globalAlpha != null) {
opacity *= globalAlpha;
}
currentElement.setAttribute(style.svgAttr+"-opacity", opacity);
} else {
var attr = style.svgAttr;
if (keys[i] === 'globalAlpha') {
attr = type+'-'+style.svgAttr;
if (currentElement.getAttribute(attr)) {
//fill-opacity or stroke-opacity has already been set by stroke or fill.
continue;
}
}
//otherwise only update attribute if right type, and not svg default
currentElement.setAttribute(attr, value);
}
}
}
}
};
/**
* Will return the closest group or svg node. May return the current element.
* @private
*/
ctx.prototype.__closestGroupOrSvg = function (node) {
node = node || this.__currentElement;
if (node.nodeName === "g" || node.nodeName === "svg") {
return node;
} else {
return this.__closestGroupOrSvg(node.parentNode);
}
};
/**
* Returns the serialized value of the svg so far
* @param fixNamedEntities - Standalone SVG doesn't support named entities, which document.createTextNode encodes.
* If true, we attempt to find all named entities and encode it as a numeric entity.
* @return serialized svg
*/
ctx.prototype.getSerializedSvg = function (fixNamedEntities) {
var serialized = new XMLSerializer().serializeToString(this.__root),
keys, i, key, value, regexp, xmlns;
//IE search for a duplicate xmnls because they didn't implement setAttributeNS correctly
xmlns = /xmlns="http:\/\/www\.w3\.org\/2000\/svg".+xmlns="http:\/\/www\.w3\.org\/2000\/svg/gi;
if (xmlns.test(serialized)) {
serialized = serialized.replace('xmlns="http://www.w3.org/2000/svg','xmlns:xlink="http://www.w3.org/1999/xlink');
}
if (fixNamedEntities) {
keys = Object.keys(namedEntities);
//loop over each named entity and replace with the proper equivalent.
for (i=0; i<keys.length; i++) {
key = keys[i];
value = namedEntities[key];
regexp = new RegExp(key, "gi");
if (regexp.test(serialized)) {
serialized = serialized.replace(regexp, value);
}
}
}
return serialized;
};
/**
* Returns the root svg
* @return
*/
ctx.prototype.getSvg = function () {
return this.__root;
};
/**
* Will generate a group tag.
*/
ctx.prototype.save = function () {
var group = this.__createElement("g");
var parent = this.__closestGroupOrSvg();
this.__groupStack.push(parent);
parent.appendChild(group);
this.__currentElement = group;
this.__stack.push(this.__getStyleState());
};
/**
* Sets current element to parent, or just root if already root
*/
ctx.prototype.restore = function () {
this.__currentElement = this.__groupStack.pop();
this.__currentElementsToStyle = null;
//Clearing canvas will make the poped group invalid, currentElement is set to the root group node.
if (!this.__currentElement) {
this.__currentElement = this.__root.childNodes[1];
}
var state = this.__stack.pop();
this.__applyStyleState(state);
};
/**
* Helper method to add transform
* @private
*/
ctx.prototype.__addTransform = function (t) {
//if the current element has siblings, add another group
var parent = this.__closestGroupOrSvg();
if (parent.childNodes.length > 0) {
if (this.__currentElement.nodeName === "path") {
if (!this.__currentElementsToStyle) this.__currentElementsToStyle = {element: parent, children: []};
this.__currentElementsToStyle.children.push(this.__currentElement)
this.__applyCurrentDefaultPath();
}
var group = this.__createElement("g");
parent.appendChild(group);
this.__currentElement = group;
}
var transform = this.__currentElement.getAttribute("transform");
if (transform) {
transform += " ";
} else {
transform = "";
}
transform += t;
this.__currentElement.setAttribute("transform", transform);
};
/**
* scales the current element
*/
ctx.prototype.scale = function (x, y) {
if (y === undefined) {
y = x;
}
this.__addTransform(format("scale({x},{y})", {x:x, y:y}));
};
/**
* rotates the current element
*/
ctx.prototype.rotate = function (angle) {
var degrees = (angle * 180 / Math.PI);
this.__addTransform(format("rotate({angle},{cx},{cy})", {angle:degrees, cx:0, cy:0}));
};
/**
* translates the current element
*/
ctx.prototype.translate = function (x, y) {
this.__addTransform(format("translate({x},{y})", {x:x,y:y}));
};
/**
* applies a transform to the current element
*/
ctx.prototype.transform = function (a, b, c, d, e, f) {
this.__addTransform(format("matrix({a},{b},{c},{d},{e},{f})", {a:a, b:b, c:c, d:d, e:e, f:f}));
};
/**
* Create a new Path Element
*/
ctx.prototype.beginPath = function () {
var path, parent;
// Note that there is only one current default path, it is not part of the drawing state.
// See also: https://html.spec.whatwg.org/multipage/scripting.html#current-default-path
this.__currentDefaultPath = "";
this.__currentPosition = {};
path = this.__createElement("path", {}, true);
parent = this.__closestGroupOrSvg();
parent.appendChild(path);
this.__currentElement = path;
};
/**
* Helper function to apply currentDefaultPath to current path element
* @private
*/
ctx.prototype.__applyCurrentDefaultPath = function () {
var currentElement = this.__currentElement;
if (currentElement.nodeName === "path") {
currentElement.setAttribute("d", this.__currentDefaultPath);
} else {
console.error("Attempted to apply path command to node", currentElement.nodeName);
}
};
/**
* Helper function to add path command
* @private
*/
ctx.prototype.__addPathCommand = function (command) {
this.__currentDefaultPath += " ";
this.__currentDefaultPath += command;
};
/**
* Adds the move command to the current path element,
* if the currentPathElement is not empty create a new path element
*/
ctx.prototype.moveTo = function (x,y) {
if (this.__currentElement.nodeName !== "path") {
this.beginPath();
}
// creates a new subpath with the given point
this.__currentPosition = {x: x, y: y};
this.__addPathCommand(format("M {x} {y}", {x:x, y:y}));
};
/**
* Closes the current path
*/
ctx.prototype.closePath = function () {
if (this.__currentDefaultPath) {
this.__addPathCommand("Z");
}
};
/**
* Adds a line to command
*/
ctx.prototype.lineTo = function (x, y) {
this.__currentPosition = {x: x, y: y};
if (this.__currentDefaultPath.indexOf('M') > -1) {
this.__addPathCommand(format("L {x} {y}", {x:x, y:y}));
} else {
this.__addPathCommand(format("M {x} {y}", {x:x, y:y}));
}
};
/**
* Add a bezier command
*/
ctx.prototype.bezierCurveTo = function (cp1x, cp1y, cp2x, cp2y, x, y) {
this.__currentPosition = {x: x, y: y};
this.__addPathCommand(format("C {cp1x} {cp1y} {cp2x} {cp2y} {x} {y}",
{cp1x:cp1x, cp1y:cp1y, cp2x:cp2x, cp2y:cp2y, x:x, y:y}));
};
/**
* Adds a quadratic curve to command
*/
ctx.prototype.quadraticCurveTo = function (cpx, cpy, x, y) {
this.__currentPosition = {x: x, y: y};
this.__addPathCommand(format("Q {cpx} {cpy} {x} {y}", {cpx:cpx, cpy:cpy, x:x, y:y}));
};
/**
* Return a new normalized vector of given vector
*/
var normalize = function (vector) {
var len = Math.sqrt(vector[0] * vector[0] + vector[1] * vector[1]);
return [vector[0] / len, vector[1] / len];
};
/**
* Adds the arcTo to the current path
*
* @see http://www.w3.org/TR/2015/WD-2dcontext-20150514/#dom-context-2d-arcto
*/
ctx.prototype.arcTo = function (x1, y1, x2, y2, radius) {
// Let the point (x0, y0) be the last point in the subpath.
var x0 = this.__currentPosition && this.__currentPosition.x;
var y0 = this.__currentPosition && this.__currentPosition.y;
// First ensure there is a subpath for (x1, y1).
if (typeof x0 == "undefined" || typeof y0 == "undefined") {
return;
}
// Negative values for radius must cause the implementation to throw an IndexSizeError exception.
if (radius < 0) {
throw new Error("IndexSizeError: The radius provided (" + radius + ") is negative.");
}
// If the point (x0, y0) is equal to the point (x1, y1),
// or if the point (x1, y1) is equal to the point (x2, y2),
// or if the radius radius is zero,
// then the method must add the point (x1, y1) to the subpath,
// and connect that point to the previous point (x0, y0) by a straight line.
if (((x0 === x1) && (y0 === y1))
|| ((x1 === x2) && (y1 === y2))
|| (radius === 0)) {
this.lineTo(x1, y1);
return;
}
// Otherwise, if the points (x0, y0), (x1, y1), and (x2, y2) all lie on a single straight line,
// then the method must add the point (x1, y1) to the subpath,
// and connect that point to the previous point (x0, y0) by a straight line.
var unit_vec_p1_p0 = normalize([x0 - x1, y0 - y1]);
var unit_vec_p1_p2 = normalize([x2 - x1, y2 - y1]);
if (unit_vec_p1_p0[0] * unit_vec_p1_p2[1] === unit_vec_p1_p0[1] * unit_vec_p1_p2[0]) {
this.lineTo(x1, y1);
return;
}
// Otherwise, let The Arc be the shortest arc given by circumference of the circle that has radius radius,
// and that has one point tangent to the half-infinite line that crosses the point (x0, y0) and ends at the point (x1, y1),
// and that has a different point tangent to the half-infinite line that ends at the point (x1, y1), and crosses the point (x2, y2).
// The points at which this circle touches these two lines are called the start and end tangent points respectively.
// note that both vectors are unit vectors, so the length is 1
var cos = (unit_vec_p1_p0[0] * unit_vec_p1_p2[0] + unit_vec_p1_p0[1] * unit_vec_p1_p2[1]);
var theta = Math.acos(Math.abs(cos));
// Calculate origin
var unit_vec_p1_origin = normalize([
unit_vec_p1_p0[0] + unit_vec_p1_p2[0],
unit_vec_p1_p0[1] + unit_vec_p1_p2[1]
]);
var len_p1_origin = radius / Math.sin(theta / 2);
var x = x1 + len_p1_origin * unit_vec_p1_origin[0];
var y = y1 + len_p1_origin * unit_vec_p1_origin[1];
// Calculate start angle and end angle
// rotate 90deg clockwise (note that y axis points to its down)
var unit_vec_origin_start_tangent = [
-unit_vec_p1_p0[1],
unit_vec_p1_p0[0]
];
// rotate 90deg counter clockwise (note that y axis points to its down)
var unit_vec_origin_end_tangent = [
unit_vec_p1_p2[1],
-unit_vec_p1_p2[0]
];
var getAngle = function (vector) {
// get angle (clockwise) between vector and (1, 0)
var x = vector[0];
var y = vector[1];
if (y >= 0) { // note that y axis points to its down
return Math.acos(x);
} else {
return -Math.acos(x);
}
};
var startAngle = getAngle(unit_vec_origin_start_tangent);
var endAngle = getAngle(unit_vec_origin_end_tangent);
// Connect the point (x0, y0) to the start tangent point by a straight line
this.lineTo(x + unit_vec_origin_start_tangent[0] * radius,
y + unit_vec_origin_start_tangent[1] * radius);
// Connect the start tangent point to the end tangent point by arc
// and adding the end tangent point to the subpath.
this.arc(x, y, radius, startAngle, endAngle);
};
/**
* Sets the stroke property on the current element
*/
ctx.prototype.stroke = function () {
if (this.__currentElement.nodeName === "path") {
this.__currentElement.setAttribute("paint-order", "fill stroke markers");
}
this.__applyCurrentDefaultPath();
this.__applyStyleToCurrentElement("stroke");
};
/**
* Sets fill properties on the current element
*/
ctx.prototype.fill = function () {
if (this.__currentElement.nodeName === "path") {
this.__currentElement.setAttribute("paint-order", "stroke fill markers");
}
this.__applyCurrentDefaultPath();
this.__applyStyleToCurrentElement("fill");
};
/**
* Adds a rectangle to the path.
*/
ctx.prototype.rect = function (x, y, width, height) {
if (this.__currentElement.nodeName !== "path") {
this.beginPath();
}
this.moveTo(x, y);
this.lineTo(x+width, y);
this.lineTo(x+width, y+height);
this.lineTo(x, y+height);
this.lineTo(x, y);
this.closePath();
};
/**
* adds a rectangle element
*/
ctx.prototype.fillRect = function (x, y, width, height) {
var rect, parent;
rect = this.__createElement("rect", {
x : x,
y : y,
width : width,
height : height
}, true);
parent = this.__closestGroupOrSvg();
parent.appendChild(rect);
this.__currentElement = rect;
this.__applyStyleToCurrentElement("fill");
};
/**
* Draws a rectangle with no fill
* @param x
* @param y
* @param width
* @param height
*/
ctx.prototype.strokeRect = function (x, y, width, height) {
var rect, parent;
rect = this.__createElement("rect", {
x : x,
y : y,
width : width,
height : height
}, true);
parent = this.__closestGroupOrSvg();
parent.appendChild(rect);
this.__currentElement = rect;
this.__applyStyleToCurrentElement("stroke");
};
/**
* Clear entire canvas:
* 1. save current transforms
* 2. remove all the childNodes of the root g element
*/
ctx.prototype.__clearCanvas = function () {
var current = this.__closestGroupOrSvg(),
transform = current.getAttribute("transform");
var rootGroup = this.__root.childNodes[1];
var childNodes = rootGroup.childNodes;
for (var i = childNodes.length - 1; i >= 0; i--) {
if (childNodes[i]) {
rootGroup.removeChild(childNodes[i]);
}
}
this.__currentElement = rootGroup;
//reset __groupStack as all the child group nodes are all removed.
this.__groupStack = [];
if (transform) {
this.__addTransform(transform);
}
};
/**
* "Clears" a canvas by just drawing a white rectangle in the current group.
*/
ctx.prototype.clearRect = function (x, y, width, height) {
//clear entire canvas
if (x === 0 && y === 0 && width === this.width && height === this.height) {
this.__clearCanvas();
return;
}
var rect, parent = this.__closestGroupOrSvg();
rect = this.__createElement("rect", {
x : x,
y : y,
width : width,
height : height,
fill : "#FFFFFF"
}, true);
parent.appendChild(rect);
};
/**
* Adds a linear gradient to a defs tag.
* Returns a canvas gradient object that has a reference to it's parent def
*/
ctx.prototype.createLinearGradient = function (x1, y1, x2, y2) {
var grad = this.__createElement("linearGradient", {
id : randomString(this.__ids),
x1 : x1+"px",
x2 : x2+"px",
y1 : y1+"px",
!
