/* * DisplacementFilter * 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: /** * Distorts portions of the image, creates effects like computer glitches, bulge/pinch, and pond ripples. This filter * Uses a reference image/canvas and interprets its r/g channels as a displacement map. A displacement map species * how far from the original pixel the output pixel should be taken from. * * Painting a displacement map means understanding how the r/g channel are interpreted. The red channel changes * how far in the x to sample, and the green changes how far in the y to sample. The maximum range is -distance to * +distance ('distance' being the distance value on the filter instance). This maps to the 0-255 color space for * each channel. This means that for an image to experience no change it should be painted #808000 as that is in the * middle for both the x and the y displacements. * <ul> * <li>Red values smaller than 0x80 sample from further left, and larger than 0x80 sample form further right.</li> * <li>Green values smaller than 0x80 sample from higher up, and larger than 0x80 sample form lower down.</li> * </ul> * The output vs input can take some getting used to so experiment! As a tip: when painting to a canvas that * will act as displacement map, consider using the blend mode of "overlay" or "softlight". These blend modes * will preserve mid tones (no displacement) while still mixing the high and low values as you might need per channel. * * See {{#crossLink "Filter"}}{{/crossLink}} for an more information on applying filters. * @class DisplacementFilter * @extends Filter * @constructor * @param {HTMLImageElement|HTMLCanvasElement|WebGLTexture} dudvMap The horizontal blur radius in pixels. * @param {Number} [distance=0] The absolute value of the maximum possible displacement from the original pixel. **/ function DisplacementFilter(dudvMap, distance) { this.Filter_constructor(); if (!createjs.Filter.isValidImageSource(dudvMap)) { throw "Must provide valid image source for displacement map, see Filter.isValidImageSource"; } // public properties: /** * The visual source to fetch the displacement map from. * @property dudvMap * @type {Image|HTMLCanvasElement} **/ this.dudvMap = dudvMap; /** * The absolute value of the maximum shift in x/y possible. * @property distance * @default 128 * @type {Image|HTMLCanvasElement} **/ this.distance = Number(distance); if(isNaN(this.distance)) { this.distance = 128; } /** * This is a template to generate the shader for {{#crossLink FRAG_SHADER_BODY}}{{/crossLink}} */ this.FRAG_SHADER_BODY = ( "uniform sampler2D uDudvSampler;"+ "uniform float fPower;" + "uniform vec2 pixelAdjustment;" + "void main(void) {" + "vec4 dudvValue = texture2D(uDudvSampler, vTextureCoord);" + "vec2 sampleOffset = mix(vec2(0.0), dudvValue.rg-0.5, dudvValue.a) * (fPower*pixelAdjustment);" + "gl_FragColor = texture2D(uSampler, vTextureCoord + sampleOffset);" + "}" ); if(dudvMap instanceof WebGLTexture) { this._mapTexture = dudvMap; } else if (dudvMap instanceof HTMLCanvasElement) { this._dudvCanvas = dudvMap; this._dudvCtx = dudvMap.getContext("2d"); } else { var canvas = this._dudvCanvas = createjs.createCanvas ? createjs.createCanvas() : document.createElement("canvas"); canvas.width = dudvMap.width; canvas.height = dudvMap.height; (this._dudvCtx = canvas.getContext("2d")).drawImage(dudvMap, 0,0); } } var p = createjs.extend(DisplacementFilter, createjs.Filter); // public methods: /** docced in super class **/ p.shaderParamSetup = function(gl, stage, shaderProgram) { if (!this._mapTexture) { this._mapTexture = gl.createTexture(); } gl.activeTexture(gl.TEXTURE1); gl.bindTexture(gl.TEXTURE_2D, this._mapTexture); stage.setTextureParams(gl); if (this.dudvMap !== this._mapTexture) { gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, this.dudvMap); } gl.uniform1i( gl.getUniformLocation(shaderProgram, "uDudvSampler"), 1 ); gl.uniform1f( gl.getUniformLocation(shaderProgram, "fPower"), this.distance ); gl.uniform2f( //this is correct as the color maps to -0.5,0.5. This compounds the pixel delta, thus 2/size gl.getUniformLocation(shaderProgram, "pixelAdjustment"), 2/stage._viewportWidth, -2/stage._viewportHeight ); }; // private methods: /** docced in super class **/ p._applyFilter = function(imageData) { // as we're reaching across pixels we need an unmodified clone of the source // slice/from/map/filter don't work correctly in IE11 and subarray creates a ref var refArray, refArraySrc = imageData.data; if (refArraySrc.slice !== undefined) { refArray = refArraySrc.slice(); } else { refArray = new Uint8ClampedArray(refArraySrc.length); refArray.set(refArraySrc); } var outArray = imageData.data; var width = imageData.width; var height = imageData.height; var rowOffset, pixelStart; var sampleData = this._dudvCtx.getImageData(0,0, this.dudvMap.width,this.dudvMap.height); var sampleArray = sampleData.data; var sampleWidth = sampleData.width; var sampleHeight = sampleData.height; var sampleRowOffset, samplePixelStart; var widthRatio = sampleWidth/width; var heightRatio = sampleHeight/height; var pxRange = 1/255; // performance optimizing lookup var distance = this.distance*2; // the x and y need to stretch separately, nesting the for loops simplifies this logic even if the array is flat for (var i=0; i<height; i++) { rowOffset = i * width; sampleRowOffset = ((i*heightRatio) |0) * sampleWidth; // the arrays are int arrays, so a single pixel is [r,g,b,a, ...],so calculate the start of the pixel for (var j=0; j<width; j++) { pixelStart = (rowOffset + j) *4; samplePixelStart = (sampleRowOffset + ((j*widthRatio) |0)) *4; // modify the pixels var deltaPower = sampleArray[samplePixelStart+3] * pxRange * distance; var xDelta = ((sampleArray[samplePixelStart] * pxRange - 0.5) * deltaPower) |0; var yDelta = ((sampleArray[samplePixelStart+1] * pxRange - 0.5) * deltaPower) |0; if (j+xDelta < 0) { xDelta = -j; } if (j+xDelta > width) { xDelta = width-j; } if (i+yDelta < 0) { yDelta = -i; } if (i+yDelta > height) { yDelta = height-i; } var targetPixelStart = (pixelStart + xDelta*4) + yDelta*4*width; outArray[pixelStart] = refArray[targetPixelStart]; outArray[pixelStart+1] = refArray[targetPixelStart+1]; outArray[pixelStart+2] = refArray[targetPixelStart+2]; outArray[pixelStart+3] = refArray[targetPixelStart+3]; } } return true; }; createjs.DisplacementFilter = createjs.promote(DisplacementFilter, "Filter"); }());