fabric.js/src/canvas_path.class.js

468 lines
No EOL
12 KiB
JavaScript

(function(){
var Canvas = this.Canvas || (this.Canvas = { });
if (Canvas.Path) {
console.warn('Canvas.Path is already defined');
return;
}
if (!Canvas.Object) {
console.warn('Canvas.Path requires Canvas.Object');
return;
}
// Instance methods
Canvas.Path = Class.create(Canvas.Object, Canvas.IStub, {
type: 'path',
/**
* @constructor
* @param path {Array | String} path data
* (i.e. sequence of coordinates and corresponding "command" tokens)
* @param options {Object} options object
*/
initialize: function(path, options) {
options = options || { };
this.setOptions(options);
this._importProperties();
this.originalState = { };
if (!path) {
throw Error('`path` argument is required');
}
var fromArray = Object.isArray(path);
this.path = fromArray
? path
: path.match && path.match(/[a-zA-Z][^a-zA-Z]*/g);
if (!this.path) return;
// TODO (kangax): rewrite this idiocracy
if (!fromArray) {
this._initializeFromArray(options);
};
this.setCoords();
if (options.sourcePath) {
this.setSourcePath(options.sourcePath);
}
},
_initializeFromArray: function(options) {
var isWidthSet = 'width' in options,
isHeightSet = 'height' in options;
this.path = this._parsePath();
if (!isWidthSet || !isHeightSet) {
Object.extend(this, this._parseDimensions());
if (isWidthSet) {
this.width = this.options.width;
}
if (isHeightSet) {
this.height = this.options.height;
}
}
},
_render: function(ctx) {
var current, // current instruction
x = 0, // current x
y = 0, // current y
controlX = 0, // current control point x
controlY = 0, // current control point y
tempX,
tempY,
l = -(this.width / 2),
t = -(this.height / 2);
for (var i=0, len=this.path.length; i<len; ++i) {
current = this.path[i];
switch (current[0]) { // first letter
case 'l': // lineto, relative
x += current[1];
y += current[2];
ctx.lineTo(x + l, y + t);
break;
case 'L': // lineto, absolute
x = current[1];
y = current[2];
ctx.lineTo(x + l, y + t);
break;
case 'h': // horizontal lineto, relative
x += current[1];
ctx.lineTo(x + l, y + t);
break;
case 'H': // horizontal lineto, absolute
x = current[1];
ctx.lineTo(x + l, y + t);
break;
case 'v': // vertical lineto, relative
y += current[1];
ctx.lineTo(x + l, y + t);
break;
case 'V': // verical lineto, absolute
y = current[1];
ctx.lineTo(x + l, y + t);
break;
case 'm': // moveTo, relative
x += current[1];
y += current[2];
ctx.moveTo(x + l, y + t);
break;
case 'M': // moveTo, absolute
x = current[1];
y = current[2];
ctx.moveTo(x + l, y + t);
break;
case 'c': // bezierCurveTo, relative
tempX = x + current[5];
tempY = y + current[6];
controlX = x + current[3];
controlY = y + current[4];
ctx.bezierCurveTo(
x + current[1] + l, // x1
y + current[2] + t, // y1
controlX + l, // x2
controlY + t, // y2
tempX + l,
tempY + t
);
x = tempX;
y = tempY;
break;
case 'C': // bezierCurveTo, absolute
x = current[5];
y = current[6];
controlX = current[3];
controlY = current[4];
ctx.bezierCurveTo(
current[1] + l,
current[2] + t,
controlX + l,
controlY + t,
x + l,
y + t
);
break;
case 's': // shorthand cubic bezierCurveTo, relative
// transform to absolute x,y
tempX = x + current[3];
tempY = y + current[4];
// calculate reflection of previous control points
controlX = 2 * x - controlX;
controlY = 2 * y - controlY;
ctx.bezierCurveTo(
controlX + l,
controlY + t,
x + current[1] + l,
y + current[2] + t,
tempX + l,
tempY + t
);
x = tempX;
y = tempY;
break;
case 'S': // shorthand cubic bezierCurveTo, absolute
tempX = current[3];
tempY = current[4];
// calculate reflection of previous control points
controlX = 2*x - controlX;
controlY = 2*y - controlY;
ctx.bezierCurveTo(
controlX + l,
controlY + t,
current[1] + l,
current[2] + t,
tempX + l,
tempY + t
);
x = tempX;
y = tempY;
break;
case 'q': // quadraticCurveTo, relative
x += current[3];
y += current[4];
ctx.quadraticCurveTo(
current[1] + l,
current[2] + t,
x + l,
y + t
);
break;
case 'Q': // quadraticCurveTo, absolute
x = current[3];
y = current[4];
controlX = current[1];
controlY = current[2];
ctx.quadraticCurveTo(
controlX + l,
controlY + t,
x + l,
y + t
);
break;
case 'T':
tempX = x;
tempY = y;
x = current[1];
y = current[2];
// calculate reflection of previous control points
controlX = -controlX + 2 * tempX;
controlY = -controlY + 2 * tempY;
ctx.quadraticCurveTo(
controlX + l,
controlY + t,
x + l,
y + t
);
break;
case 'a':
// TODO (kangax): implement arc (relative)
break;
case 'A':
// TODO (kangax): implement arc (absolute)
break;
case 'z':
case 'Z':
ctx.closePath();
break;
}
}
},
render: function(ctx, noTransform) {
ctx.save();
var m = this.transformMatrix;
if (m) {
ctx.transform(m[0], m[1], m[2], m[3], m[4], m[5]);
}
if (!noTransform) {
this.transform(ctx);
}
// ctx.globalCompositeOperation = this.fillRule;
if (this.overlayFill) {
ctx.fillStyle = this.overlayFill;
}
else if (this.fill) {
ctx.fillStyle = this.fill;
}
if (this.stroke) {
ctx.strokeStyle = this.stroke;
}
ctx.beginPath();
// stubbb !!!
if (this.stub) {
this.stub._render(ctx);
}
else {
this._render(ctx);
}
if (this.fill) {
ctx.fill();
}
if (this.options.stroke) {
ctx.strokeStyle = this.options.stroke;
ctx.lineWidth = this.options.strokeWidth;
ctx.stroke();
}
if (!noTransform && this.active) {
this.drawBorders(ctx);
this.hideCorners || this.drawCorners(ctx);
}
ctx.restore();
},
/**
* Returns string representation of an instance
* @method toString
* @return {String} string representation of an instance
*/
toString: function() {
return '#<Canvas.Path ('+ this.complexity() +'): ' +
Object.toJSON({ top: this.top, left: this.left }) +'>';
},
/**
* @method toObject
* @return {Object}
*/
toObject: function() {
var o = Object.extend(this.callSuper('toObject'), {
path: this.path,
sourcePath: this.sourcePath
});
if (this.transformMatrix) {
o.transformMatrix = this.transformMatrix;
}
return o;
},
/**
* @method toDatalessObject
* @return {Object}
*/
toDatalessObject: function() {
var o = this.toObject();
if (this.sourcePath) {
o.path = this.sourcePath;
}
delete o.sourcePath;
return o;
},
complexity: function() {
return this.path.length;
},
set: function(prop, value) {
if (this.stub) {
this.stub.set(prop, value)
}
return this.callSuper('set', prop, value);
},
_parsePath: function() {
var result = [],
currentPath,
chunks;
// use plain loop for perf.
for (var i = 0, len = this.path.length; i < len; i++) {
currentPath = this.path[i];
chunks = currentPath.slice(1).strip().replace(/(\d)-/g, '$1###-').split(/\s|,|###/);
result.push([currentPath.charAt(0)].concat(chunks.map(parseFloat)));
}
return result;
},
_parseDimensions: function() {
var aX = [],
aY = [],
previousX,
previousY,
isLowerCase = false,
x,
y;
function getX(item) {
if (item[0] === 'H') {
return item[1];
}
return item[item.length - 2];
}
function getY(item) {
if (item[0] === 'V') {
return item[1];
}
return item[item.length - 1];
}
this.path.each(function(item, i) {
if (item[0] !== 'H') {
previousX = (i === 0) ? getX(item) : getX(this.path[i-1]);
}
if (item[0] !== 'V') {
previousY = (i === 0) ? getY(item) : getY(this.path[i-1]);
}
// lowercased letter denotes relative position;
// transform to absolute
if (item[0] === item[0].toLowerCase()) {
isLowerCase = true;
}
// last 2 items in an array of coordinates are the actualy x/y (except H/V);
// collect them
// TODO (kangax): support relative h/v commands
x = isLowerCase
? previousX + getX(item)
: item[0] === 'V'
? previousX
: getX(item);
y = isLowerCase
? previousY + getY(item)
: item[0] === 'H'
? previousY
: getY(item);
aX.push(x);
aY.push(y);
}, this);
var minX = aX.min(),
minY = aY.min(),
deltaX = deltaY = 0;
var o = {
top: minY - deltaY,
left: minX - deltaX,
bottom: aY.max() - deltaY,
right: aX.max() - deltaX
}
o.width = o.right - o.left;
o.height = o.bottom - o.top;
return o;
}
});
/**
* Creates an instance of Canvas.Path from an object
* @static
* @method Canvas.Path.fromObject
* @return {Canvas.Path} Instance of Canvas.Path
*/
Canvas.Path.fromObject = function(object) {
return new Canvas.Path(object.path, object);
};
var ATTRIBUTE_NAMES = Canvas.Path.ATTRIBUTE_NAMES = 'd fill fill-opacity fill-rule stroke stroke-width transform'.split(' ');
/**
* Creates an instance of Canvas.Path from an SVG <PATH> element
* @static
* @method Canvas.Path.fromElement
* @param {SVGElement} element to parse
* @param {Object} options object
* @return {Canvas.Path} Instance of Canvas.Path
*/
Canvas.Path.fromElement = function(element, options) {
var parsedAttributes = Canvas.parseAttributes(element, ATTRIBUTE_NAMES),
path = parsedAttributes.d;
delete parsedAttributes.d;
return new Canvas.Path(path, Object.extend(parsedAttributes, options));
}
})();