/*
   * Pixastic Lib - Noise filter - v0.1.0
   * Copyright (c) 2008 Jacob Seidelin, jseidelin@nihilogic.dk, http://blog.nihilogic.dk/
   * MIT License [http://www.opensource.org/licenses/mit-license.php]
   */
  
  Pixastic.Actions.noise = {
  
          process : function(params) {
                  var amount = 0;
                  var strength = 0;
                  var mono = false;
  
                  if (typeof params.options.amount != "undefined")
                          amount = parseFloat(params.options.amount)||0;
                  if (typeof params.options.strength != "undefined")
                          strength = parseFloat(params.options.strength)||0;
                  if (typeof params.options.mono != "undefined")
                          mono = !!(params.options.mono);
  
                  amount = Math.max(0,Math.min(1,amount));
                  strength = Math.max(0,Math.min(1,strength));
  
                  var noise = 128 * strength;
                  var noise2 = noise / 2;
  
                  if (Pixastic.Client.hasCanvasImageData()) {
                          var data = Pixastic.prepareData(params);
                          var rect = params.options.rect;
                          var w = rect.width;
                          var h = rect.height;
                          var w4 = w*4;
                          var y = h;
                          var random = Math.random;
  
                          do {
                                  var offsetY = (y-1)*w4;
                                  var x = w;
                                  do {
                                          var offset = offsetY + (x-1)*4;
                                          if (random() < amount) {
                                                  if (mono) {
                                                          var pixelNoise = - noise2 + random() * noise;
                                                          var r = data[offset] + pixelNoise;
                                                          var g = data[offset+1] + pixelNoise;
                                                          var b = data[offset+2] + pixelNoise;
                                                  } else {
                                                          var r = data[offset] - noise2 + (random() * noise);
                                                          var g = data[offset+1] - noise2 + (random() * noise);
                                                          var b = data[offset+2] - noise2 + (random() * noise);
                                                  }
  
                                                  if (r < 0 ) r = 0;
                                                  if (g < 0 ) g = 0;
                                                  if (b < 0 ) b = 0;
                                                  if (r > 255 ) r = 255;
                                                  if (g > 255 ) g = 255;
                                                  if (b > 255 ) b = 255;
  
                                                  data[offset] = r;
                                                  data[offset+1] = g;
                                                  data[offset+2] = b;
                                          }
                                  } while (--x);
                          } while (--y);
                          return true;
                  }
          },
          checkSupport : function() {
                  return Pixastic.Client.hasCanvasImageData();
          }
  }