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

   1 /*
   2  * Pixastic Lib - Blur Fast - 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.blurfast = {
   8         process : function(params) {
   9
  10                 var amount = parseFloat(params.options.amount)||0;
  11
  12                 amount = Math.max(0,Math.min(5,amount));
  13
  14                 if (Pixastic.Client.hasCanvas()) {
  15                         var rect = params.options.rect;
  16
  17                         var ctx = params.canvas.getContext("2d");
  18                         ctx.save();
  19                         ctx.beginPath();
  20                         ctx.moveTo(rect.left,rect.top);
  21                         ctx.lineTo(rect.left+rect.width,rect.top);
  22                         ctx.lineTo(rect.left+rect.width,rect.top+rect.height);
  23                         ctx.lineTo(rect.left,rect.top+rect.height);
  24                         ctx.lineTo(rect.left,rect.top);
  25                         ctx.closePath();
  26                         ctx.clip();
  27
  28                         var scale = 2;
  29                         var smallWidth = Math.round(params.width / scale);
  30                         var smallHeight = Math.round(params.height / scale);
  31
  32                         var copy = document.createElement("canvas");
  33                         copy.width = smallWidth;
  34                         copy.height = smallHeight;
  35
  36                         var clear = true;
  37                         var steps = Math.round(amount * 20);
  38
  39                         var copyCtx = copy.getContext("2d");
  40                         for (var i=0;i<steps;i++) {
  41                                 var scaledWidth = Math.max(1,Math.round(smallWidth - i));
  42                                 var scaledHeight = Math.max(1,Math.round(smallHeight - i));
  43
  44                                 copyCtx.clearRect(0,0,smallWidth,smallHeight);
  45
  46                                 copyCtx.drawImage(
  47                                         params.canvas,
  48                                         0,0,params.width,params.height,
  49                                         0,0,scaledWidth,scaledHeight
  50                                 );
  51
  52                                 if (clear)
  53                                         ctx.clearRect(rect.left,rect.top,rect.width,rect.height);
  54
  55                                 ctx.drawImage(
  56                                         copy,
  57                                         0,0,scaledWidth,scaledHeight,
  58                                         0,0,params.width,params.height
  59                                 );
  60                         }
  61
  62                         ctx.restore();
  63
  64                         params.useData = false;
  65                         return true;
  66                 } else if (Pixastic.Client.isIE()) {
  67                         var radius = 10 * amount;
  68                         params.image.style.filter += " progid:DXImageTransform.Microsoft.Blur(pixelradius=" + radius + ")";
  69
  70                         if (params.options.fixMargin || 1) {
  71                                 params.image.style.marginLeft = (parseInt(params.image.style.marginLeft,10)||0) - Math.round(radius) + "px";
  72                                 params.image.style.marginTop = (parseInt(params.image.style.marginTop,10)||0) - Math.round(radius) + "px";
  73                         }
  74
  75                         return true;
  76                 }
  77         },
  78         checkSupport : function() {
  79                 return (Pixastic.Client.hasCanvas() || Pixastic.Client.isIE());
  80         }
  81 }