chrome/test/data/third_party/spaceport/js/sprites/renderers/canvasDrawImageFullClearAlign.js

   1 define([ 'util/ensureCallback', 'sprites/canvas' ], function (ensureCallback, canvas) {
   2     function RenderContext(sourceData, frameData) {
   3         this.sourceData = sourceData;
   4         this.frameData = frameData;
   5
   6         this.canvas = canvas();
   7
   8         this.context = this.canvas.getContext('2d');
   9         this.context.globalCompositeOperation = 'source-over';
  10     }
  11
  12     RenderContext.prototype.load = function load(callback) {
  13         callback = ensureCallback(callback);
  14
  15         // Anything not simply translated is disallowed
  16         var isValid = this.frameData.every(function (frame) {
  17             return frame.every(function (transform) {
  18                 return transform.matrix[0] === 1
  19                     && transform.matrix[1] === 0
  20                     && transform.matrix[3] === 0
  21                     && transform.matrix[4] === 1;
  22             });
  23         });
  24
  25         if (!isValid) {
  26             callback(new Error("Not supported"));
  27             return;
  28         }
  29
  30         document.body.appendChild(this.canvas);
  31
  32         callback(null);
  33     };
  34
  35     RenderContext.prototype.unload = function unload() {
  36         if (this.canvas.parentNode) {
  37             this.canvas.parentNode.removeChild(this.canvas);
  38         }
  39     };
  40
  41     RenderContext.prototype.clear = function clear() {
  42         this.canvas.width = this.canvas.width;
  43     };
  44
  45     RenderContext.prototype.renderFrame = function renderFrame(frameIndex) {
  46         var context = this.context;
  47         var sourceData = this.sourceData;
  48
  49         var transforms = this.frameData[frameIndex];
  50         var count = transforms.length;
  51         var i;
  52
  53         // Reset view and transforms
  54         context.canvas.width = context.canvas.width;
  55
  56         for (i = 0; i < count; ++i) {
  57             var transform = transforms[i];
  58             context.setTransform(1, 0, 0, 1, Math.floor(transform.x), Math.floor(transform.y));
  59             sourceData.drawToCanvas(context, 0, 0, frameIndex);
  60         }
  61     };
  62
  63     return function (element, frameData) {
  64         return new RenderContext(element, frameData);
  65     };
  66 });