fabric.js/src/util/misc.js
asturur dfbd1887bf Update misc.js
some more polishing
2014-07-17 16:24:46 +02:00

572 lines
16 KiB
JavaScript

(function(global) {
var sqrt = Math.sqrt,
atan2 = Math.atan2,
PiBy180 = Math.PI / 180;
/**
* @namespace fabric.util
*/
fabric.util = {
/**
* Removes value from an array.
* Presence of value (and its position in an array) is determined via `Array.prototype.indexOf`
* @static
* @memberOf fabric.util
* @param {Array} array
* @param {Any} value
* @return {Array} original array
*/
removeFromArray: function(array, value) {
var idx = array.indexOf(value);
if (idx !== -1) {
array.splice(idx, 1);
}
return array;
},
/**
* Returns random number between 2 specified ones.
* @static
* @memberOf fabric.util
* @param {Number} min lower limit
* @param {Number} max upper limit
* @return {Number} random value (between min and max)
*/
getRandomInt: function(min, max) {
return Math.floor(Math.random() * (max - min + 1)) + min;
},
/**
* Transforms degrees to radians.
* @static
* @memberOf fabric.util
* @param {Number} degrees value in degrees
* @return {Number} value in radians
*/
degreesToRadians: function(degrees) {
return degrees * PiBy180;
},
/**
* Transforms radians to degrees.
* @static
* @memberOf fabric.util
* @param {Number} radians value in radians
* @return {Number} value in degrees
*/
radiansToDegrees: function(radians) {
return radians / PiBy180;
},
/**
* Rotates `point` around `origin` with `radians`
* @static
* @memberOf fabric.util
* @param {fabric.Point} point The point to rotate
* @param {fabric.Point} origin The origin of the rotation
* @param {Number} radians The radians of the angle for the rotation
* @return {fabric.Point} The new rotated point
*/
rotatePoint: function(point, origin, radians) {
var sin = Math.sin(radians),
cos = Math.cos(radians);
point.subtractEquals(origin);
var rx = point.x * cos - point.y * sin,
ry = point.x * sin + point.y * cos;
return new fabric.Point(rx, ry).addEquals(origin);
},
/**
* Apply transform t to point p
* @static
* @memberOf fabric.util
* @param {fabric.Point} p The point to transform
* @param {Array} t The transform
* @param {Boolean} [ignoreOffset] Indicates that the offset should not be applied
* @return {fabric.Point} The transformed point
*/
transformPoint: function(p, t, ignoreOffset) {
if (ignoreOffset) {
return new fabric.Point(
t[0] * p.x + t[1] * p.y,
t[2] * p.x + t[3] * p.y
);
}
return new fabric.Point(
t[0] * p.x + t[1] * p.y + t[4],
t[2] * p.x + t[3] * p.y + t[5]
);
},
/**
* Invert transformation t
* @static
* @memberOf fabric.util
* @param {Array} t The transform
* @return {Array} The inverted transform
*/
invertTransform: function(t) {
var r = t.slice(),
a = 1 / (t[0] * t[3] - t[1] * t[2]);
r = [a * t[3], -a * t[1], -a * t[2], a * t[0], 0, 0];
var o = fabric.util.transformPoint({ x: t[4], y: t[5] }, r);
r[4] = -o.x;
r[5] = -o.y;
return r;
},
/**
* A wrapper around Number#toFixed, which contrary to native method returns number, not string.
* @static
* @memberOf fabric.util
* @param {Number | String} number number to operate on
* @param {Number} fractionDigits number of fraction digits to "leave"
* @return {Number}
*/
toFixed: function(number, fractionDigits) {
return parseFloat(Number(number).toFixed(fractionDigits));
},
/**
* Converts from attribute value to pixel value if applicable.
* Returns converted pixels or original value not converted.
* @param {Number | String} number to operate on
* @return {Number | String}
*/
parseUnit: function(value) {
var unit = /\D{0,2}$/.exec(value),
number = parseFloat(value);
switch (unit[0]) {
case 'mm':
return number * fabric.DPI / 25.4;
break;
case 'cm':
return number * fabric.DPI / 2.54;
break;
case 'in':
return number * fabric.DPI;
break;
case 'pt':
return number * fabric.DPI / 72; // or * 4 / 3
break;
case 'pc':
return number * fabric.DPI / 72 * 12; // or * 16
break;
default:
return number;
}
},
/**
* Function which always returns `false`.
* @static
* @memberOf fabric.util
* @return {Boolean}
*/
falseFunction: function() {
return false;
},
/**
* Returns klass "Class" object of given namespace
* @memberOf fabric.util
* @param {String} type Type of object (eg. 'circle')
* @param {String} namespace Namespace to get klass "Class" object from
* @return {Object} klass "Class"
*/
getKlass: function(type, namespace) {
// capitalize first letter only
type = fabric.util.string.camelize(type.charAt(0).toUpperCase() + type.slice(1));
return fabric.util.resolveNamespace(namespace)[type];
},
/**
* Returns object of given namespace
* @memberOf fabric.util
* @param {String} namespace Namespace string e.g. 'fabric.Image.filter' or 'fabric'
* @return {Object} Object for given namespace (default fabric)
*/
resolveNamespace: function(namespace) {
if (!namespace) {
return fabric;
}
var parts = namespace.split('.'),
len = parts.length,
obj = global || fabric.window;
for (var i = 0; i < len; ++i) {
obj = obj[parts[i]];
}
return obj;
},
/**
* Loads image element from given url and passes it to a callback
* @memberOf fabric.util
* @param {String} url URL representing an image
* @param {Function} callback Callback; invoked with loaded image
* @param {Any} [context] Context to invoke callback in
* @param {Object} [crossOrigin] crossOrigin value to set image element to
*/
loadImage: function(url, callback, context, crossOrigin) {
if (!url) {
callback && callback.call(context, url);
return;
}
var img = fabric.util.createImage();
/** @ignore */
img.onload = function () {
callback && callback.call(context, img);
img = img.onload = img.onerror = null;
};
/** @ignore */
img.onerror = function() {
fabric.log('Error loading ' + img.src);
callback && callback.call(context, null, true);
img = img.onload = img.onerror = null;
};
// data-urls appear to be buggy with crossOrigin
// https://github.com/kangax/fabric.js/commit/d0abb90f1cd5c5ef9d2a94d3fb21a22330da3e0a#commitcomment-4513767
// see https://code.google.com/p/chromium/issues/detail?id=315152
// https://bugzilla.mozilla.org/show_bug.cgi?id=935069
if (url.indexOf('data') !== 0 && typeof crossOrigin !== 'undefined') {
img.crossOrigin = crossOrigin;
}
img.src = url;
},
/**
* Creates corresponding fabric instances from their object representations
* @static
* @memberOf fabric.util
* @param {Array} objects Objects to enliven
* @param {Function} callback Callback to invoke when all objects are created
* @param {Function} Method for further parsing of object elements,
* called after each fabric object created.
*/
enlivenObjects: function(objects, callback, namespace, reviver) {
objects = objects || [ ];
function onLoaded() {
if (++numLoadedObjects === numTotalObjects) {
callback && callback(enlivenedObjects);
}
}
var enlivenedObjects = [ ],
numLoadedObjects = 0,
numTotalObjects = objects.length;
if (!numTotalObjects) {
callback && callback(enlivenedObjects);
return;
}
objects.forEach(function (o, index) {
// if sparse array
if (!o || !o.type) {
onLoaded();
return;
}
var klass = fabric.util.getKlass(o.type, namespace);
if (klass.async) {
klass.fromObject(o, function (obj, error) {
if (!error) {
enlivenedObjects[index] = obj;
reviver && reviver(o, enlivenedObjects[index]);
}
onLoaded();
});
}
else {
enlivenedObjects[index] = klass.fromObject(o);
reviver && reviver(o, enlivenedObjects[index]);
onLoaded();
}
});
},
/**
* Groups SVG elements (usually those retrieved from SVG document)
* @static
* @memberOf fabric.util
* @param {Array} elements SVG elements to group
* @param {Object} [options] Options object
* @return {fabric.Object|fabric.PathGroup}
*/
groupSVGElements: function(elements, options, path) {
var object;
if (elements.length > 1) {
object = new fabric.PathGroup(elements, options);
}
else {
object = elements[0];
}
if (typeof path !== 'undefined') {
object.setSourcePath(path);
}
return object;
},
/**
* Populates an object with properties of another object
* @static
* @memberOf fabric.util
* @param {Object} source Source object
* @param {Object} destination Destination object
* @return {Array} properties Propertie names to include
*/
populateWithProperties: function(source, destination, properties) {
if (properties && Object.prototype.toString.call(properties) === '[object Array]') {
for (var i = 0, len = properties.length; i < len; i++) {
if (properties[i] in source) {
destination[properties[i]] = source[properties[i]];
}
}
}
},
/**
* Draws a dashed line between two points
*
* This method is used to draw dashed line around selection area.
* See <a href="http://stackoverflow.com/questions/4576724/dotted-stroke-in-canvas">dotted stroke in canvas</a>
*
* @param {CanvasRenderingContext2D} ctx context
* @param {Number} x start x coordinate
* @param {Number} y start y coordinate
* @param {Number} x2 end x coordinate
* @param {Number} y2 end y coordinate
* @param {Array} da dash array pattern
*/
drawDashedLine: function(ctx, x, y, x2, y2, da) {
var dx = x2 - x,
dy = y2 - y,
len = sqrt(dx * dx + dy * dy),
rot = atan2(dy, dx),
dc = da.length,
di = 0,
draw = true;
ctx.save();
ctx.translate(x, y);
ctx.moveTo(0, 0);
ctx.rotate(rot);
x = 0;
while (len > x) {
x += da[di++ % dc];
if (x > len) {
x = len;
}
ctx[draw ? 'lineTo' : 'moveTo'](x, 0);
draw = !draw;
}
ctx.restore();
},
/**
* Creates canvas element and initializes it via excanvas if necessary
* @static
* @memberOf fabric.util
* @param {CanvasElement} [canvasEl] optional canvas element to initialize;
* when not given, element is created implicitly
* @return {CanvasElement} initialized canvas element
*/
createCanvasElement: function(canvasEl) {
canvasEl || (canvasEl = fabric.document.createElement('canvas'));
if (!canvasEl.getContext && typeof G_vmlCanvasManager !== 'undefined') {
G_vmlCanvasManager.initElement(canvasEl);
}
return canvasEl;
},
/**
* Creates image element (works on client and node)
* @static
* @memberOf fabric.util
* @return {HTMLImageElement} HTML image element
*/
createImage: function() {
return fabric.isLikelyNode
? new (require('canvas').Image)()
: fabric.document.createElement('img');
},
/**
* Creates accessors (getXXX, setXXX) for a "class", based on "stateProperties" array
* @static
* @memberOf fabric.util
* @param {Object} klass "Class" to create accessors for
*/
createAccessors: function(klass) {
var proto = klass.prototype;
for (var i = proto.stateProperties.length; i--; ) {
var propName = proto.stateProperties[i],
capitalizedPropName = propName.charAt(0).toUpperCase() + propName.slice(1),
setterName = 'set' + capitalizedPropName,
getterName = 'get' + capitalizedPropName;
// using `new Function` for better introspection
if (!proto[getterName]) {
proto[getterName] = (function(property) {
return new Function('return this.get("' + property + '")');
})(propName);
}
if (!proto[setterName]) {
proto[setterName] = (function(property) {
return new Function('value', 'return this.set("' + property + '", value)');
})(propName);
}
}
},
/**
* @static
* @memberOf fabric.util
* @param {fabric.Object} receiver Object implementing `clipTo` method
* @param {CanvasRenderingContext2D} ctx Context to clip
*/
clipContext: function(receiver, ctx) {
ctx.save();
ctx.beginPath();
receiver.clipTo(ctx);
ctx.clip();
},
/**
* Multiply matrix A by matrix B to nest transformations
* @static
* @memberOf fabric.util
* @param {Array} matrixA First transformMatrix
* @param {Array} matrixB Second transformMatrix
* @return {Array} The product of the two transform matrices
*/
multiplyTransformMatrices: function(matrixA, matrixB) {
// Matrix multiply matrixA * matrixB
var a = [
[matrixA[0], matrixA[2], matrixA[4]],
[matrixA[1], matrixA[3], matrixA[5]],
[0, 0, 1 ]
],
b = [
[matrixB[0], matrixB[2], matrixB[4]],
[matrixB[1], matrixB[3], matrixB[5]],
[0, 0, 1 ]
],
result = [];
for (var r = 0; r < 3; r++) {
result[r] = [];
for (var c = 0; c < 3; c++) {
var sum = 0;
for (var k = 0; k < 3; k++) {
sum += a[r][k] * b[k][c];
}
result[r][c] = sum;
}
}
return [
result[0][0],
result[1][0],
result[0][1],
result[1][1],
result[0][2],
result[1][2]
];
},
/**
* Returns string representation of function body
* @param {Function} fn Function to get body of
* @return {String} Function body
*/
getFunctionBody: function(fn) {
return (String(fn).match(/function[^{]*\{([\s\S]*)\}/) || {})[1];
},
/**
* Normalizes polygon/polyline points according to their dimensions
* @param {Array} points
* @param {Object} options
*/
normalizePoints: function(points, options) {
var minX = fabric.util.array.min(points, 'x'),
minY = fabric.util.array.min(points, 'y');
minX = minX < 0 ? minX : 0;
minY = minX < 0 ? minY : 0;
for (var i = 0, len = points.length; i < len; i++) {
// normalize coordinates, according to containing box
// (dimensions of which are passed via `options`)
points[i].x -= (options.width / 2 + minX) || 0;
points[i].y -= (options.height / 2 + minY) || 0;
}
},
/**
* Returns true if context has transparent pixel
* at specified location (taking tolerance into account)
* @param {CanvasRenderingContext2D} ctx context
* @param {Number} x x coordinate
* @param {Number} y y coordinate
* @param {Number} tolerance Tolerance
*/
isTransparent: function(ctx, x, y, tolerance) {
// If tolerance is > 0 adjust start coords to take into account.
// If moves off Canvas fix to 0
if (tolerance > 0) {
if (x > tolerance) {
x -= tolerance;
}
else {
x = 0;
}
if (y > tolerance) {
y -= tolerance;
}
else {
y = 0;
}
}
var _isTransparent = true,
imageData = ctx.getImageData(x, y, (tolerance * 2) || 1, (tolerance * 2) || 1);
// Split image data - for tolerance > 1, pixelDataSize = 4;
for (var i = 3, l = imageData.data.length; i < l; i += 4) {
var temp = imageData.data[i];
_isTransparent = temp <= 0;
if (_isTransparent === false) break; // Stop if colour found
}
imageData = null;
return _isTransparent;
}
};
})(typeof exports !== 'undefined' ? exports : this);