js2/mwEmbed/libClipEdit/pixastic-lib/actions/pointillize.js

   1 /*
   2  * Pixastic Lib - Pointillize filter - v0.1.0
   3  * Copyright (c) 2008 Jacob Seidelin, jseidelin@nihilogic.dk, http://blog.nihilogic.dk/
   4  * MIT License [http://www.opensource.org/licenses/mit-license.php]
   5  */
   6
   7 Pixastic.Actions.pointillize = {
   8
   9         process : function(params) {
  10                 var radius = Math.max(1,parseInt(params.options.radius,10));
  11                 var density = Math.min(5,Math.max(0,parseFloat(params.options.density)||0));
  12                 var noise = Math.max(0,parseFloat(params.options.noise)||0);
  13                 var transparent = !!params.options.transparent;
  14
  15                 if (Pixastic.Client.hasCanvasImageData()) {
  16                         var rect = params.options.rect;
  17                         var w = rect.width;
  18                         var h = rect.height;
  19                         var w4 = w*4;
  20                         var y = h;
  21
  22                         var ctx = params.canvas.getContext("2d");
  23
  24                         var pixel = document.createElement("canvas");
  25                         pixel.width = pixel.height = 1;
  26                         var pixelCtx = pixel.getContext("2d");
  27
  28                         var copy = document.createElement("canvas");
  29                         copy.width = w;
  30                         copy.height = h;
  31                         var copyCtx = copy.getContext("2d");
  32                         copyCtx.drawImage(params.canvas,rect.left,rect.top,w,h, 0,0,w,h);
  33
  34                         var diameter = radius * 2;
  35
  36                         if (transparent)
  37                                 ctx.clearRect(rect.left, rect.top, rect.width, rect.height);
  38
  39                         var noiseRadius = radius * noise;
  40
  41                         var dist = 1 / density;
  42
  43                         for (var y=0;y<h+radius;y+=diameter*dist) {
  44                                 for (var x=0;x<w+radius;x+=diameter*dist) {
  45                                         rndX = noise ? (x+((Math.random()*2-1) * noiseRadius))>>0 : x;
  46                                         rndY = noise ? (y+((Math.random()*2-1) * noiseRadius))>>0 : y;
  47
  48                                         var pixX = rndX - radius;
  49                                         var pixY = rndY - radius;
  50                                         if (pixX < 0) pixX = 0;
  51                                         if (pixY < 0) pixY = 0;
  52
  53                                         pixelCtx.drawImage(copy, pixX, pixY, diameter, diameter, 0, 0, 1, 1);
  54                                         var data = pixelCtx.getImageData(0,0,1,1).data;
  55                                         ctx.fillStyle = "rgb(" + data[0] + "," + data[1] + "," + data[2] + ")";
  56                                         ctx.beginPath();
  57                                         ctx.arc(rect.left + rndX,rect.top + rndY, radius, 0, Math.PI*2, true);
  58                                         ctx.closePath();
  59                                         ctx.fill();
  60                                 }
  61                         }
  62
  63                         params.useData = false;
  64
  65                         return true;
  66                 }
  67         },
  68         checkSupport : function() {
  69                 return (Pixastic.Client.hasCanvasImageData());
  70         }
  71 }