easyqrcodejs-nodejs
Version:
NodeJS QRCode generator. Can save image or svg to file, get standard base64 image data url text or get SVG serialized text. Cross-browser QRCode generator for pure javascript. Support Dot style, Logo, Background image, Colorful, Title etc. settings. suppo
1,451 lines (1,344 loc) • 43.3 kB
JavaScript
/*!!
* Canvas 2 Svg for EasyQRCodeJS-NodeJS
* A low level canvas to SVG converter. Uses a mock canvas context to build an SVG document.
*
*/
;(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,
veiwBoxWidth: 500,
veiwBoxHeight: 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];
options.veiwBoxWidth = arguments[2];
options.veiwBoxHeight = arguments[3];
} 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.veiwBoxWidth = options.veiwBoxWidth || this.width;
this.veiwBoxHeight = options.veiwBoxHeight || this.height;
this.enableMirroring =
options.enableMirroring !== undefined
? options.enableMirroring
: defaultOptions.enableMirroring;
this.canvas = this; ///point back to this instance!
this.__document = options.document || document;
this.XMLSerializer = options.XMLSerializer || XMLSerializer;
// console.log(document.createElement);
// 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);
this.__root.setAttribute(
"viewBox",
"0 0 " + this.veiwBoxWidth + " " + this.veiwBoxHeight
);
//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 this.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",
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
*/
ctx.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);
};
/**
* Parses the font string and returns svg mapping
* @private
*/
ctx.prototype.__parseFont = function () {
var regex =
/^\s*(?=(?:(?:[-a-z]+\s*){0,2}(italic|oblique))?)(?=(?:(?:[-a-z]+\s*){0,2}(small-caps))?)(?=(?:(?:[-a-z]+\s*){0,2}(bold(?:er)?|lighter|[1-9]00))?)(?:(?:normal|\1|\2|\3)\s*){0,3}((?:xx?-)?(?:small|large)|medium|smaller|larger|[.\d]+(?:\%|in|[cem]m|ex|p[ctx]))(?:\s*\/\s*(normal|[.\d]+(?:\%|in|[cem]m|ex|p[ctx])))?\s*([-,\'\"\sa-z0-9]+?)\s*$/i;
var fontPart = regex.exec(this.font);
var data = {
style: fontPart[1] || "normal",
size: fontPart[4] || "10px",
family: fontPart[6] || "sans-serif",
weight: fontPart[3] || "normal",
decoration: fontPart[2] || "normal",
href: null,
};
//canvas doesn't support underline natively, but we can pass this attribute
if (this.__fontUnderline === "underline") {
data.decoration = "underline";
}
//canvas also doesn't support linking, but we can pass this as well
if (this.__fontHref) {
data.href = this.__fontHref;
}
return data;
};
/**
* Helper to link text fragments
* @param font
* @param element
* @return {*}
* @private
*/
ctx.prototype.__wrapTextLink = function (font, element) {
if (font.href) {
var a = this.__createElement("a");
a.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href", font.href);
a.appendChild(element);
return a;
}
return element;
};
/**
* Fills or strokes text
* @param text
* @param x
* @param y
* @param action - stroke or fill
* @private
*/
ctx.prototype.__applyText = function (text, x, y, action) {
var font = this.__parseFont(),
parent = this.__closestGroupOrSvg(),
textElement = this.__createElement(
"text",
{
"font-family": font.family,
"font-size": font.size,
"font-style": font.style,
"font-weight": font.weight,
"text-decoration": font.decoration,
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.__applyStyleToCurrentElement(action);
parent.appendChild(this.__wrapTextLink(font, textElement));
};
/**
* Creates a text element
* @param text
* @param x
* @param y
*/
ctx.prototype.fillText = function (text, x, y) {
this.__applyText(text, x, y, "fill");
};
/**
* Strokes text
* @param text
* @param x
* @param y
*/
ctx.prototype.strokeText = function (text, x, y) {
this.__applyText(text, x, y, "stroke");
};
/**
* No need to implement this for svg.
* @param text
* @return {TextMetrics}
*/
ctx.prototype.measureText = function (text) {
this.__ctx.font = this.font;
return this.__ctx.measureText(text);
};
/**
* Arc command!
*/
ctx.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;
}
this.lineTo(startX, startY);
this.__addPathCommand(
format(
"A {rx} {ry} {xAxisRotation} {largeArcFlag} {sweepFlag} {endX} {endY}",
{
rx: radius,
ry: radius,
xAxisRotation: 0,
largeArcFlag: largeArcFlag,
sweepFlag: sweepFlag,
endX: endX,
endY: endY,
}
)
);
this.__currentPosition = {
x: endX,
y: endY,
};
};
/**
* Generates a ClipPath from the clip command.
*/
ctx.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
*/
ctx.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;
var translateDirective = "translate(" + dx + ", " + dy + ")";
//canvas image
svgImage = this.__createElement("image");
svgImage.setAttribute("width", dw);
svgImage.setAttribute("height", dh);
svgImage.setAttribute("preserveAspectRatio", "none");
svgImage.setAttribute("opacity", this.globalAlpha);
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;
}
svgImage.setAttribute("transform", translateDirective);
svgImage.setAttributeNS(
"http://www.w3.org/1999/xlink",
"xlink:href",
image.nodeName === "CANVAS" ? image.toDataURL() : image.originalSrc
);
parent.appendChild(svgImage);
};
/**
* Generates a pattern tag
*/
ctx.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);
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 ctx) {
pattern.appendChild(image.__root.childNodes[1]);
this.__defs.appendChild(pattern);
}
return new CanvasPattern(pattern, this);
};
ctx.prototype.setLineDash = function (dashArray) {
if (dashArray && dashArray.length > 0) {
this.lineDash = dashArray.join(",");
} else {
this.lineDash = null;
}
};
/**
* Not yet implemented
*/
ctx.prototype.drawFocusRing = function () {};
ctx.prototype.createImageData = function () {};
ctx.prototype.getImageData = function () {};
ctx.prototype.putImageData = function () {};
ctx.prototype.globalCompositeOperation = function () {};
ctx.prototype.setTransform = function () {};
//add options for alternative namespace
if (typeof window === "object") {
window.C2S = ctx;
}
// CommonJS/Browserify
if (typeof module === "object" && typeof module.exports === "object") {
module.exports = ctx;
}
})();