topical media & game development
mobile-graphic-easel-src-easeljs-filters-BoxBlurFilter.js / js
/*
* BoxBlurFilter
* 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.
*/
// namespace:
this.createjs = this.createjs||{};
(function() {
BoxBlurFilter applies a box blur to DisplayObjects
See {{#crossLink "Filter"}}{{/crossLink}} for an example of how to apply filters.
@class BoxBlurFilter
@extends Filter
@constructor
parameter: {Number} blurX
parameter: {Number} blurY
parameter: {Number} quality
var BoxBlurFilter = function( blurX, blurY, quality ) {
this.initialize( blurX, blurY, quality );
}
var p = BoxBlurFilter.prototype = new createjs.Filter();
// constructor:
@ignore
p.initialize = function( blurX, blurY, quality ) {
if ( isNaN(blurX) || blurX < 0 ) blurX = 0;
this.blurX = blurX | 0;
if ( isNaN(blurY) || blurY < 0 ) blurY = 0;
this.blurY = blurY | 0;
if ( isNaN(quality) || quality < 1 ) quality = 1;
this.quality = quality | 0;
}
// public properties:
Horizontal blur radius
@property blurX
@type Number
p.blurX = 0;
Vertical blur radius
@property blurY
@type Number
p.blurY = 0;
Number of blur iterations. For example, a value of 1 will produce a rough blur.
A value of 2 will produce a smoother blur, but take twice as long to run.
@property quality
@type Number
p.quality = 1;
// public methods:
Returns a rectangle with values indicating the margins required to draw the filter.
For example, a filter that will extend the drawing area 4 pixels to the left, and 7 pixels to the right
(but no pixels up or down) would return a rectangle with (x=-4, y=0, width=11, height=0).
@method getBounds
returns: {Rectangle} a rectangle object indicating the margins required to draw the filter.
p.getBounds = function() {
// TODO: this doesn't properly account for blur quality.
return new createjs.Rectangle(-this.blurX,-this.blurY,2*this.blurX,2*this.blurY);
}
Applies the filter to the specified context.
@method applyFilter
parameter: {CanvasRenderingContext2D} ctx The 2D context to use as the source.
parameter: {Number} x The x position to use for the source rect.
parameter: {Number} y The y position to use for the source rect.
parameter: {Number} width The width to use for the source rect.
parameter: {Number} height The height to use for the source rect.
parameter: {CanvasRenderingContext2D} targetCtx Optional. The 2D context to draw the result to. Defaults to the context passed to ctx.
parameter: {Number} targetX Optional. The x position to draw the result to. Defaults to the value passed to x.
parameter: {Number} targetY Optional. The y position to draw the result to. Defaults to the value passed to y.
returns: {Boolean}
p.applyFilter = function(ctx, x, y, width, height, targetCtx, targetX, targetY) {
targetCtx = targetCtx || ctx;
if (targetX == null) { targetX = x; }
if (targetY == null) { targetY = y; }
try {
var imageData = ctx.getImageData(x, y, width, height);
} catch(e) {
//if (!this.suppressCrossDomainErrors) throw new Error("unable to access local image data: " + e);
return false;
}
var radiusX = this.blurX;
if ( isNaN(radiusX) || radiusX < 0 ) return false;
radiusX |= 0;
var radiusY = this.blurY;
if ( isNaN(radiusY) || radiusY < 0 ) return false;
radiusY |= 0;
if ( radiusX == 0 && radiusY == 0 ) return false;
var iterations = this.quality;
if ( isNaN(iterations) || iterations < 1 ) iterations = 1;
iterations |= 0;
if ( iterations > 3 ) iterations = 3;
if ( iterations < 1 ) iterations = 1;
var pixels = imageData.data;
var rsum,gsum,bsum,asum,x,y,i,p,p1,p2,yp,yi,yw;
var wm = width - 1;
var hm = height - 1;
var rad1x = radiusX + 1;
var divx = radiusX + rad1x;
var rad1y = radiusY + 1;
var divy = radiusY + rad1y;
var div2 = 1 / (divx * divy);
var r = [];
var g = [];
var b = [];
var a = [];
var vmin = [];
var vmax = [];
while ( iterations-- > 0 ) {
yw = yi = 0;
for ( y=0; y < height; y++ ){
rsum = pixels[yw] * rad1x;
gsum = pixels[yw+1] * rad1x;
bsum = pixels[yw+2] * rad1x;
asum = pixels[yw+3] * rad1x;
for( i = 1; i <= radiusX; i++ ) {
p = yw + (((i > wm ? wm : i )) << 2 );
rsum += pixels[p++];
gsum += pixels[p++];
bsum += pixels[p++];
asum += pixels[p]
}
for ( x = 0; x < width; x++ ) {
r[yi] = rsum;
g[yi] = gsum;
b[yi] = bsum;
a[yi] = asum;
if(y==0){
vmin[x] = Math.min( x + rad1x, wm ) << 2;
vmax[x] = Math.max( x - radiusX, 0 ) << 2;
}
p1 = yw + vmin[x];
p2 = yw + vmax[x];
rsum += pixels[p1++] - pixels[p2++];
gsum += pixels[p1++] - pixels[p2++];
bsum += pixels[p1++] - pixels[p2++];
asum += pixels[p1] - pixels[p2];
yi++;
}
yw += ( width << 2 );
}
for ( x = 0; x < width; x++ ) {
yp = x;
rsum = r[yp] * rad1y;
gsum = g[yp] * rad1y;
bsum = b[yp] * rad1y;
asum = a[yp] * rad1y;
for( i = 1; i <= radiusY; i++ ) {
yp += ( i > hm ? 0 : width );
rsum += r[yp];
gsum += g[yp];
bsum += b[yp];
asum += a[yp];
}
yi = x << 2;
for ( y = 0; y < height; y++) {
pixels[yi] = (rsum * div2 + 0.5) | 0;
pixels[yi+1] = (gsum * div2 + 0.5) | 0;
pixels[yi+2] = (bsum * div2 + 0.5) | 0;
pixels[yi+3] = (asum * div2 + 0.5) | 0;
if( x == 0 ){
vmin[y] = Math.min( y + rad1y, hm ) * width;
vmax[y] = Math.max( y - radiusY,0 ) * width;
}
p1 = x + vmin[y];
p2 = x + vmax[y];
rsum += r[p1] - r[p2];
gsum += g[p1] - g[p2];
bsum += b[p1] - b[p2];
asum += a[p1] - a[p2];
yi += width << 2;
}
}
}
targetCtx.putImageData(imageData, targetX, targetY);
return true;
}
Returns a clone of this object.
returns: {BoxBlurFilter}
p.clone = function() {
return new BoxBlurFilter(this.blurX, this.blurY, this.quality);
}
Returns a string representation of this object.
returns: {String}
p.toString = function() {
return "[BoxBlurFilter]";
}
// private methods:
createjs.BoxBlurFilter = BoxBlurFilter;
}());
(C) Æliens
04/09/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
