/*!!
* SVGCanvas v2.0.3
* Draw on SVG using Canvas's 2D Context API.
*
* Licensed under the MIT license:
* http://www.opensource.org/licenses/mit-license.php
*
* Author:
* Kerry Liu
* Zeno Zeng
*
* Copyright (c) 2014 Gliffy Inc.
* Copyright (c) 2021 Zeno Zeng
*/
import * as utils from './utils';
import imageUtils from './image';
export default (function () {
"use strict";
var STYLES, Context, 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 (utils.toString(color).indexOf("rgba") !== -1) {
//separate alpha value, since webkit can't handle it
regex = /rgba\(\s*(\d*\.?\d+)\s*,\s*(\d*\.?\d+)\s*,\s*(\d*\.?\d+)\s*,\s*(\d?\.?\d*)\s*\)/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", utils.toString(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)
*/
Context = function (o) {
var defaultOptions = { width:500, height:500, enableMirroring : false}, options;
// keep support for this way of calling Context: new Context(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 Context)) {
//did someone call this without new?
return new Context(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.__styleStack = [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);
// init transformation matrix
this.resetTransform();
this.__options = options;
this.__id = Math.random().toString(16).substring(2, 8);
this.__debug(`new`, o);
};
/**
* Log
*
* @private
*/
Context.prototype.__debug = function(...data) {
if (!this.__options.debug) {
return
}
console.debug(`svgcanvas#${this.__id}:`, ...data)
}
/**
* Creates the specified svg element
* @private
*/
Context.prototype.__createElement = function (elementName, properties, resetFill) {
if (typeof properties === "undefined") {
properties = {};
}
var element = this.__document.createElementNS("http://www.w3.org/2000/svg", elementName),
keys = Object.keys(properties), i, key;
if (resetFill) {
//if fill or stroke is not specified, the svg element should not display. By default SVG's fill is black.
element.setAttribute("fill", "none");
element.setAttribute("stroke", "none");
}
for (i=0; i<keys.length; i++) {
key = keys[i];
element.setAttribute(key, properties[key]);
}
return element;
};
/**
* Applies default canvas styles to the context
* @private
*/
Context.prototype.__setDefaultStyles = function () {
//default 2d canvas context properties see:http://www.w3.org/TR/2dcontext/
var keys = Object.keys(STYLES), i, key;
for (i=0; i<keys.length; i++) {
key = keys[i];
this[key] = STYLES[key].canvas;
}
};
/**
* Applies styles on restore
* @param styleState
* @private
*/
Context.prototype.__applyStyleState = function (styleState) {
var keys = Object.keys(styleState), i, key;
for (i=0; i<keys.length; i++) {
key = keys[i];
this[key] = styleState[key];
}
};
/**
* Gets the current style state
* @return {Object}
* @private
*/
Context.prototype.__getStyleState = function () {
var i, styleState = {}, keys = Object.keys(STYLES), key;
for (i=0; i<keys.length; i++) {
key = keys[i];
styleState[key] = this[key];
}
return styleState;
};
/**
* @see https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/transform
*/
Context.prototype.__applyTransformation = function (element, matrix) {
const {a, b, c, d, e, f} = matrix || this.getTransform();
element.setAttribute('transform', `matrix(${a} ${b} ${c} ${d} ${e} ${f})`)
}
/**
* Apples the current styles to the current SVG element. On "ctx.fill" or "ctx.stroke"
* @param type
* @private
*/
Context.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, regex, matches, id, nodeIndex, node;
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
for(nodeIndex = 0; nodeIndex < value.__ctx.__defs.childNodes.length; nodeIndex++){
node = value.__ctx.__defs.childNodes[nodeIndex];
id = node.getAttribute("id");
this.__ids[id] = id;
this.__defs.appendChild(node);
}
}
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\(\s*(\d*\.?\d+)\s*,\s*(\d*\.?\d+)\s*,\s*(\d*\.?\d+)\s*,\s*(\d?\.?\d*)\s*\)/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
*/
Context.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
*/
Context.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
*/
Context.prototype.getSvg = function () {
return this.__root;
};
/**
* Will generate a group tag.
*/
Context.prototype.save = function () {
var group = this.__createElement("g");
var parent = this.__closestGroupOrSvg();
this.__groupStack.push(parent);
parent.appendChild(group);
this.__currentElement = group;
const style = this.__getStyleState();
this.__debug('save style', style)
this.__styleStack.push(style);
if (!this.__transformMatrixStack) {
this.__transformMatrixStack = [];
}
this.__transformMatrixStack.push(this.getTransform());
};
/**
* Sets current element to parent, or just root if already root
*/
Context.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.__styleStack.pop();
this.__debug('restore style', state);
this.__applyStyleState(state);
if (this.__transformMatrixStack && this.__transformMatrixStack.length > 0) {
this.setTransform(this.__transformMatrixStack.pop())
}
};
/**
* Create a new Path Element
*/
Context.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
*/
Context.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
*/
Context.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
*/
Context.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: this.__matrixTransform(x, y).x,
y: this.__matrixTransform(x, y).y
}));
};
/**
* Closes the current path
*/
Context.prototype.closePath = function () {
if (this.__currentDefaultPath) {
this.__addPathCommand("Z");
}
};
/**
* Adds a line to command
*/
Context.prototype.lineTo = function (x, y) {
this.__currentPosition = {x: x, y: y};
if (this.__currentDefaultPath.indexOf('M') > -1) {
this.__addPathCommand(format("L {x} {y}", {
x: this.__matrixTransform(x, y).x,
y: this.__matrixTransform(x, y).y
}));
} else {
this.__addPathCommand(format("M {x} {y}", {
x: this.__matrixTransform(x, y).x,
y: this.__matrixTransform(x, y).y
}));
}
};
/**
* Add a bezier command
*/
Context.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: this.__matrixTransform(cp1x, cp1y).x,
cp1y: this.__matrixTransform(cp1x, cp1y).y,
cp2x: this.__matrixTransform(cp2x, cp2y).x,
cp2y: this.__matrixTransform(cp2x, cp2y).y,
x: this.__matrixTransform(x, y).x,
y: this.__matrixTransform(x, y).y
}));
};
/**
* Adds a quadratic curve to command
*/
Context.prototype.quadraticCurveTo = function (cpx, cpy, x, y) {
this.__currentPosition = {x: x, y: y};
this.__addPathCommand(format("Q {cpx} {cpy} {x} {y}", {
cpx: this.__matrixTransform(cpx, cpy).x,
cpy: this.__matrixTransform(cpx, cpy).y,
x: this.__matrixTransform(x, y).x,
y: this.__matrixTransform(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
*/
Context.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
*/
Context.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
*/
Context.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.
*/
Context.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
*/
Context.prototype.fillRect = function (x, y, width, height) {
let {a, b, c, d, e, f} = this.getTransform();
if (JSON.stringify([a, b, c, d, e, f]) === JSON.stringify([1, 0, 0, 1, 0, 0])) {
//clear entire canvas
if (x === 0 && y === 0 && width === this.width && height === this.height) {
this.__clearCanvas();
}
}
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.__applyTransformation(rect);
this.__applyStyleToCurrentElement("fill");
};
/**
* Draws a rectangle with no fill
* @param x
* @param y
* @param width
* @param height
*/
Context.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.__applyTransformation(rect);
this.__applyStyleToCurrentElement("stroke");
};
/**
* Clear entire canvas:
* 1. save current transforms
* 2. remove all the childNodes of the root g element
*/
Context.prototype.__clearCanvas = function () {
var rootGroup = this.__root.childNodes[1];
this.__root.removeChild(rootGroup);
this.__currentElement = this.__document.createElementNS("http://www.w3.org/2000/svg", "g");
this.__root.appendChild(this.__currentElement);
//reset __groupStack as all the child group nodes are all removed.
this.__groupStack = [];
};
/**
* "Clears" a canvas by just drawing a white rectangle in the current group.
*/
Context.prototype.clearRect = function (x, y, width, height) {
let {a, b, c, d, e, f} = this.getTransform();
if (JSON.stringify([a, b, c, d, e, f]) === JSON.stringify([1, 0, 0, 1, 0, 0])) {
//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);
this.__applyTransformation(rect)
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
*/
Context.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",
y2 : y2+"px",
"gradientUnits" : "userSpaceOnUse"
}, false);
this.__defs.appendChild(grad);
return new CanvasGradient(grad, this);
};
/**
* Adds a radial gradient to a defs tag.
* Returns a canvas gradient object that has a reference to it's parent def
*/
Context.prototype.createRadialGradient = function (x0, y0, r0, x1, y1, r1) {
var grad = this.__createElement("radialGradient", {
id : randomString(this.__ids),
cx : x1+"px",
cy : y1+"px",
r : r1+"px",
fx : x0+"px",
fy : y0+"px",
"gradientUnits" : "userSpaceOnUse"
}, false);
this.__defs.appendChild(grad);
return new CanvasGradient(grad, this);
};
/**
* Fills or strokes text
* @param text
* @param x
* @param y
* @param action - stroke or fill
* @private
*/
Context.prototype.__applyText = function (text, x, y, action) {
var el = document.createElement("span");
el.setAttribute("style", 'font:' + this.font);
var style = el.style, // CSSStyleDeclaration object
parent = this.__closestGroupOrSvg(),
textElement = this.__createElement("text", {
"font-family": style.fontFamily,
"font-size": style.fontSize,
"font-style": style.fontStyle,
"font-weight": style.fontWeight,
// canvas doesn't support underline natively, but we do :)
"text-decoration": this.__fontUnderline,
"x": x,
"y": y,
"text-anchor": getTextAnchor(this.textAlign),
"dominant-baseline": getDominantBaseline(this.textBaseline)
}, true);
textElement.appendChild(this.__document.createTextNode(text));
this.__currentElement = textElement;
this.__applyTransformation(textElement);
this.__applyStyleToCurrentElement(action);
if (this.__fontHref) {
var a = this.__createElement("a");
// canvas doesn't natively support linking, but we do :)
a.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href", this.__fontHref);
a.appendChild(textElement);
textElement = a;
}
parent.appendChild(textElement);
};
/**
* Creates a text element
* @param text
* @param x
* @param y
*/
Context.prototype.fillText = function (text, x, y) {
this.__applyText(text, x, y, "fill");
};
/**
* Strokes text
* @param text
* @param x
* @param y
*/
Context.prototype.strokeText = function (text, x, y) {
this.__applyText(text, x, y, "stroke");
};
/**
* No need to implement this for svg.
* @param text
* @return {TextMetrics}
*/
Context.prototype.measureText = function (text) {
this.__ctx.font = this.font;
return this.__ctx.measureText(text);
};
/**
* Arc command!
*/
Context.prototype.arc = function (x, y, radius, startAngle, endAngle, counterClockwise) {
// in canvas no circle is drawn if no angle is provided.
if (startAngle === endAngle) {
return;
}
startAngle = startAngle % (2*Math.PI);
endAngle = endAngle % (2*Math.PI);
if (startAngle === endAngle) {
//circle time! subtract some of the angle so svg is happy (svg elliptical arc can't draw a full circle)
endAngle = ((endAngle + (2*Math.PI)) - 0.001 * (counterClockwise ? -1 : 1)) % (2*Math.PI);
}
var endX = x+radius*Math.cos(endAngle),
endY = y+radius*Math.sin(endAngle),
startX = x+radius*Math.cos(startAngle),
startY = y+radius*Math.sin(startAngle),
sweepFlag = counterClockwise ? 0 : 1,
largeArcFlag = 0,
diff = endAngle - startAngle;
// https://github.com/gliffy/canvas2svg/issues/4
if (diff < 0) {
diff += 2*Math.PI;
}
if (counterClockwise) {
largeArcFlag = diff > Math.PI ? 0 : 1;
} else {
largeArcFlag = diff > Math.PI ? 1 : 0;
}
var scaleX = Math.hypot(this.__transformMatrix.a, this.__transformMatrix.b);
var scaleY = Math.hypot(this.__transformMatrix.c, this.__transformMatrix.d);
this.lineTo(startX, startY);
this.__addPathCommand(format("A {rx} {ry} {xAxisRotation} {largeArcFlag} {sweepFlag} {endX} {endY}",
{
rx:radius * scaleX,
ry:radius * scaleY,
xAxisRotation:0,
largeArcFlag:largeArcFlag,
sweepFlag:sweepFlag,
endX: this.__matrixTransform(endX, endY).x,
endY: this.__matrixTransform(endX, endY).y
}));
this.__currentPosition = {x: endX, y: endY};
};
/**
* Ellipse command!
*/
Context.prototype.ellipse = function(x, y, radiusX, radiusY, rotation, startAngle, endAngle, counterClockwise) {
if (startAngle === endAngle) {
return;
}
x = this.__matrixTransform(x, y).x;
y = this.__matrixTransform(x, y).y;
var scaleX = Math.hypot(this.__transformMatrix.a, this.__transformMatrix.b);
var scaleY = Math.hypot(this.__transformMatrix.c, this.__transformMatrix.d);
radiusX = radiusX * scaleX;
radiusY = radiusY * scaleY;
startAngle = startAngle % (2*Math.PI);
endAngle = endAngle % (2*Math.PI);
if(startAngle === endAngle) {
endAngle = ((endAngle + (2*Math.PI)) - 0.001 * (counterClockwise ? -1 : 1)) % (2*Math.PI);
}
var endX = x + Math.cos(-rotation) * radiusX * Math.cos(endAngle)
+ Math.sin(-rotation) * radiusY * Math.sin(endAngle),
endY = y - Math.sin(-rotation) * radiusX * Math.cos(endAngle)
+ Math.cos(-rotation) * radiusY * Math.sin(endAngle),
startX = x + Math.cos(-rotation) * radiusX * Math.cos(startAngle)
+ Math.sin(-rotation) * radiusY * Math.sin(startAngle),
startY = y - Math.sin(-rotation) * radiusX * Math.cos(startAngle)
+ Math.cos(-rotation) * radiusY * Math.sin(startAngle),
sweepFlag = counterClockwise ? 0 : 1,
largeArcFlag = 0,
diff = endAngle - startAngle;
if(diff < 0) {
diff += 2*Math.PI;
}
if(counterClockwise) {
largeArcFlag = diff > Math.PI ? 0 : 1;
} else {
largeArcFlag = diff > Math.PI ? 1 : 0;
}
this.lineTo(startX / scaleX, startY / scaleY);
this.__addPathCommand(format("A {rx} {ry} {xAxisRotation} {largeArcFlag} {sweepFlag} {endX} {endY}",
{
rx:radiusX,
ry:radiusY,
xAxisRotation:rotation*(180/Math.PI),
largeArcFlag:largeArcFlag,
sweepFlag:sweepFlag,
endX:endX,
endY:endY
}));
this.__currentPosition = {x: endX, y: endY};
};
/**
* Generates a ClipPath from the clip command.
*/
Context.prototype.clip = function () {
var group = this.__closestGroupOrSvg(),
clipPath = this.__createElement("clipPath"),
id = randomString(this.__ids),
newGroup = this.__createElement("g");
this.__applyCurrentDefaultPath();
group.removeChild(this.__currentElement);
clipPath.setAttribute("id", id);
clipPath.appendChild(this.__currentElement);
this.__defs.appendChild(clipPath);
//set the clip path to this group
group.setAttribute("clip-path", format("url(#{id})", {id:id}));
//clip paths can be scaled and transformed, we need to add another wrapper group to avoid later transformations
// to this path
group.appendChild(newGroup);
this.__currentElement = newGroup;
};
/**
* Draws a canvas, image or mock context to this canvas.
* Note that all svg dom manipulation uses node.childNodes rather than node.children for IE support.
* http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-context-2d-drawimage
*/
Context.prototype.drawImage = function () {
//convert arguments to a real array
var args = Array.prototype.slice.call(arguments),
image=args[0],
dx, dy, dw, dh, sx=0, sy=0, sw, sh, parent, svg, defs, group,
currentElement, svgImage, canvas, context, id;
if (args.length === 3) {
dx = args[1];
dy = args[2];
sw = image.width;
sh = image.height;
dw = sw;
dh = sh;
} else if (args.length === 5) {
dx = args[1];
dy = args[2];
dw = args[3];
dh = args[4];
sw = image.width;
sh = image.height;
} else if (args.length === 9) {
sx = args[1];
sy = args[2];
sw = args[3];
sh = args[4];
dx = args[5];
dy = args[6];
dw = args[7];
dh = args[8];
} else {
throw new Error("Invalid number of arguments passed to drawImage: " + arguments.length);
}
parent = this.__closestGroupOrSvg();
currentElement = this.__currentElement;
const matrix = this.getTransform().translate(dx, dy);
if (image instanceof Context) {
//canvas2svg mock canvas context. In the future we may want to clone nodes instead.
//also I'm currently ignoring dw, dh, sw, sh, sx, sy for a mock context.
svg = image.getSvg().cloneNode(true);
if (svg.childNodes && svg.childNodes.length > 1) {
defs = svg.childNodes[0];
while(defs.childNodes.length) {
id = defs.childNodes[0].getAttribute("id");
this.__ids[id] = id;
this.__defs.appendChild(defs.childNodes[0]);
}
group = svg.childNodes[1];
if (group) {
this.__applyTransformation(group, matrix);
parent.appendChild(group);
}
}
} else if (image.nodeName === "CANVAS" || image.nodeName === "IMG") {
//canvas or image
svgImage = this.__createElement("image");
svgImage.setAttribute("width", dw);
svgImage.setAttribute("height", dh);
svgImage.setAttribute("preserveAspectRatio", "none");
if (sx || sy || sw !== image.width || sh !== image.height) {
//crop the image using a temporary canvas
canvas = this.__document.createElement("canvas");
canvas.width = dw;
canvas.height = dh;
context = canvas.getContext("2d");
context.drawImage(image, sx, sy, sw, sh, 0, 0, dw, dh);
image = canvas;
}
this.__applyTransformation(svgImage, matrix);
svgImage.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href",
image.nodeName === "CANVAS" ? image.toDataURL() : image.getAttribute("src"));
parent.appendChild(svgImage);
}
};
/**
* Generates a pattern tag
*/
Context.prototype.createPattern = function (image, repetition) {
var pattern = this.__document.createElementNS("http://www.w3.org/2000/svg", "pattern"), id = randomString(this.__ids),
img;
pattern.setAttribute("id", id);
pattern.setAttribute("width", image.width);
pattern.setAttribute("height", image.height);
// We want the pattern sizing to be absolute, and not relative
// https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Patterns
// https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/patternUnits
pattern.setAttribute("patternUnits", "userSpaceOnUse");
if (image.nodeName === "CANVAS" || image.nodeName === "IMG") {
img = this.__document.createElementNS("http://www.w3.org/2000/svg", "image");
img.setAttribute("width", image.width);
img.setAttribute("height", image.height);
img.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href",
image.nodeName === "CANVAS" ? image.toDataURL() : image.getAttribute("src"));
pattern.appendChild(img);
this.__defs.appendChild(pattern);
} else if (image instanceof Context) {
pattern.appendChild(image.__root.childNodes[1]);
this.__defs.appendChild(pattern);
}
return new CanvasPattern(pattern, this);
};
Context.prototype.setLineDash = function (dashArray) {
if (dashArray && dashArray.length > 0) {
this.lineDash = dashArray.join(",");
} else {
this.lineDash = null;
}
};
/**
* SetTransform changes the current transformation matrix to
* the matrix given by the arguments as described below.
*
* @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/setTransform
*/
Context.prototype.setTransform = function (a, b, c, d, e, f) {
if (a instanceof DOMMatrix) {
this.__transformMatrix = new DOMMatrix([a.a, a.b, a.c, a.d, a.e, a.f]);
} else {
this.__transformMatrix = new DOMMatrix([a, b, c, d, e, f]);
}
};
/**
* GetTransform Returns a copy of the current transformation matrix,
* as a newly created DOMMAtrix Object
*
* @returns A DOMMatrix Object
*/
Context.prototype.getTransform = function () {
let {a, b, c, d, e, f} = this.__transformMatrix;
return new DOMMatrix([a, b, c, d, e, f]);
};
/**
* ResetTransform resets the current transformation matrix to the identity matrix
*
* @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/resetTransform
*/
Context.prototype.resetTransform = function () {
this.setTransform(1, 0, 0, 1, 0, 0);
};
/**
* Add the scaling transformation described by the arguments to the current transformation matrix.
*
* @param x The x argument represents the scale factor in the horizontal direction
* @param y The y argument represents the scale factor in the vertical direction.
* @see https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-scale
*/
Context.prototype.scale = function (x, y) {
if (y === undefined) {
y = x;
}
// If either of the arguments are infinite or NaN, then return.
if (isNaN(x) || isNaN(y) || !isFinite(x) || !isFinite(y)) {
return
}
let matrix = this.getTransform().scale(x, y);
this.setTransform(matrix);
};
/**
* Rotate adds a rotation to the transformation matrix.
*
* @param angle The rotation angle, clockwise in radians. You can use degree * Math.PI / 180 to calculate a radian from a degree.
* @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/rotate
* @see https://www.w3.org/TR/css-transforms-1
*/
Context.prototype.rotate = function (angle) {
let matrix = this.getTransform().multiply(new DOMMatrix([
Math.cos(angle),
Math.sin(angle),
-Math.sin(angle),
Math.cos(angle),
0,
0
]))
this.setTransform(matrix);
};
/**
* Translate adds a translation transformation to the current matrix.
*
* @param x Distance to move in the horizontal direction. Positive values are to the right, and negative to the left.
* @param y Distance to move in the vertical direction. Positive values are down, and negative are up.
* @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/translate
*/
Context.prototype.translate = function (x, y) {
const matrix = this.getTransform().translate(x, y);
this.setTransform(matrix);
};
/**
* Transform multiplies the current transformation with the matrix described by the arguments of this method.
* This lets you scale, rotate, translate (move), and skew the context.
*
* @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/transform
*/
Context.prototype.transform = function (a, b, c, d, e, f) {
const matrix = this.getTransform().multiply(new DOMMatrix([a, b, c, d, e, f]));
this.setTransform(matrix);
};
Context.prototype.__matrixTransform = function(x, y) {
return new DOMPoint(x, y).matrixTransform(this.__transformMatrix)
}
/**
*
* @param {*} sx The x-axis coordinate of the top-left corner of the rectangle from which the ImageData will be extracted.
* @param {*} sy The y-axis coordinate of the top-left corner of the rectangle from which the ImageData will be extracted.
* @param {*} sw The width of the rectangle from which the ImageData will be extracted. Positive values are to the right, and negative to the left.
* @param {*} sh The height of the rectangle from which the ImageData will be extracted. Positive values are down, and negative are up.
* @param {Boolean} options.async Will return a Promise<ImageData> if true, must be set to true
* @returns An ImageData object containing the image data for the rectangle of the canvas specified. The coordinates of the rectangle's top-left corner are (sx, sy), while the coordinates of the bottom corner are (sx + sw, sy + sh).
*/
Context.prototype.getImageData = function(sx, sy, sw, sh, options) {
return imageUtils.getImageData(this.getSvg(), this.width, this.height, sx, sy, sw, sh, options);
};
/**
* Not yet implemented
*/
Context.prototype.drawFocusRing = function () {};
Context.prototype.createImageData = function () {};
Context.prototype.putImageData = function () {};
Context.prototype.globalCompositeOperation = function () {};
return Context;
}());