/*
* Filter
* Visit http://createjs.com/ for documentation, updates and examples.
*
* Copyright (c) 2010 gskinner.com, inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* @module EaselJS
*/
// namespace:
this.createjs = this.createjs||{};
(function() {
"use strict";
// constructor:
/**
* Base class that all filters should inherit from. Filters need to be applied to objects that have been cached using
* the {{#crossLink "DisplayObject/cache"}}{{/crossLink}} method. If an object changes, please cache it again, or use
* {{#crossLink "DisplayObject/updateCache"}}{{/crossLink}}. Note that the filters must be applied before caching.
*
* <h4>Example</h4>
*
* myInstance.filters = [
* new createjs.ColorFilter(0, 0, 0, 1, 255, 0, 0),
* new createjs.BlurFilter(5, 5, 10)
* ];
* myInstance.cache(0,0, 100, 100);
*
* Note that each filter can implement a {{#crossLink "Filter/getBounds"}}{{/crossLink}} method, which returns the
* margins that need to be applied in order to fully display the filter. For example, the {{#crossLink "BlurFilter"}}{{/crossLink}}
* will cause an object to feather outwards, resulting in a margin around the shape.
*
* <h4>EaselJS Filters</h4>
* EaselJS comes with a number of pre-built filters. Note that individual filters are not compiled into the minified
* version of EaselJS. To use them, you must include them manually in the HTML.
* <ul><li>{{#crossLink "AlphaMapFilter"}}{{/crossLink}} : Map a greyscale image to the alpha channel of a display object</li>
* <li>{{#crossLink "AlphaMaskFilter"}}{{/crossLink}}: Map an image's alpha channel to the alpha channel of a display object</li>
* <li>{{#crossLink "BlurFilter"}}{{/crossLink}}: Apply vertical and horizontal blur to a display object</li>
* <li>{{#crossLink "ColorFilter"}}{{/crossLink}}: Color transform a display object</li>
* <li>{{#crossLink "ColorMatrixFilter"}}{{/crossLink}}: Transform an image using a {{#crossLink "ColorMatrix"}}{{/crossLink}}</li>
* </ul>
*
* @class Filter
* @constructor
**/
function Filter() {}
var p = Filter.prototype;
// public methods:
/**
* Provides padding values for this filter. That is, how much the filter will extend the visual bounds of an object it is applied to.
* @method getBounds
* @param {Rectangle} [rect] If specified, the provided Rectangle instance will be expanded by the padding amounts and returned.
* @return {Rectangle} If a `rect` param was provided, it is returned. If not, either a new rectangle with the padding values, or null if no padding is required for this filter.
**/
p.getBounds = function(rect) {
return rect;
};
/**
* Applies the filter to the specified context.
* @method applyFilter
* @param {CanvasRenderingContext2D} ctx The 2D context to use as the source.
* @param {Number} x The x position to use for the source rect.
* @param {Number} y The y position to use for the source rect.
* @param {Number} width The width to use for the source rect.
* @param {Number} height The height to use for the source rect.
* @param {CanvasRenderingContext2D} [targetCtx] The 2D context to draw the result to. Defaults to the context passed to ctx.
* @param {Number} [targetX] The x position to draw the result to. Defaults to the value passed to x.
* @param {Number} [targetY] The y position to draw the result to. Defaults to the value passed to y.
* @return {Boolean} If the filter was applied successfully.
**/
p.applyFilter = function(ctx, x, y, width, height, targetCtx, targetX, targetY) {
// this is the default behaviour because most filters access pixel data. It is overridden when not needed.
targetCtx = targetCtx || ctx;
if (targetX == null) { targetX = x; }
if (targetY == null) { targetY = y; }
try {
var imageData = ctx.getImageData(x, y, width, height);
} catch (e) {
return false;
}
if (this._applyFilter(imageData)) {
targetCtx.putImageData(imageData, targetX, targetY);
return true;
}
return false;
};
/**
* Returns a string representation of this object.
* @method toString
* @return {String} a string representation of the instance.
**/
p.toString = function() {
return "[Filter]";
};
/**
* Returns a clone of this Filter instance.
* @method clone
* @return {Filter} A clone of the current Filter instance.
**/
p.clone = function() {
return new Filter();
};
// private methods:
/**
* @method _applyFilter
* @param {ImageData} imageData Target ImageData instance.
* @return {Boolean}
**/
p._applyFilter = function(imageData) { return true; };
createjs.Filter = Filter;
}());