third_party/WebKit/PerformanceTests/Canvas/draw-dynamic-webgl-to-hw-accelerated-canvas-2d.html

   1 <!DOCTYPE html>
   2 <html>
   3 <body>
   4 <script src="../resources/runner.js"></script>
   5 <script src="resources/canvas_runner.js"></script>
   6 <script>
   7 var canvas2D = document.createElement("canvas");
   8 var ctx2D = canvas2D.getContext("2d");
   9 var canvas3D = document.createElement('canvas');
  10 var gl = canvas3D.getContext('webgl');
  11 if (!gl)
  12     CanvasRunner.logFatalError("\nWebGL is not supported or enabled on this platform!\n");
  13
  14 function setSize(canvas2DWidth, canvas2DHeight, webglWidth, webglHeight) {
  15     canvas2D.width = canvas2DWidth;
  16     canvas2D.height = canvas2DHeight;
  17     canvas3D.width = webglWidth;
  18     canvas3D.height = webglHeight;
  19 }
  20
  21 function rand(range) {
  22     return Math.floor(Math.random() * range);
  23 }
  24
  25 function renderWebGL(gl) {
  26     gl.disable(gl.SCISSOR_TEST);
  27     gl.clear(gl.COLOR_BUFER_BIT);
  28     gl.enable(gl.SCISSOR_TEST);
  29     gl.scissor(rand(1024), rand(1024), rand(1024), rand(1024));
  30     gl.clearColor(Math.random(), Math.random(), Math.random(), 1);
  31     gl.clear(gl.COLOR_BUFFER_BIT);
  32 }
  33
  34 function doRun() {
  35     renderWebGL(gl);
  36     // draw dynamic WebGL
  37     ctx2D.drawImage(canvas3D, 0, 0);
  38 }
  39
  40 function ensureComplete() {
  41     // Calling getImageData() is just to flush out the content when
  42     // accelerated 2D canvas is in use. The cost of reading 1x1 pixels is low.
  43     ctx2D.getImageData(0, 0, 1, 1);
  44 }
  45
  46 window.onload = function () {
  47     // It should use setMinimumAccelerated2dCanvasSize() to enable accelerated Canvas for a specified size
  48     // but this API is not available in JS or WebPage. Assume the threshold size is 256x257
  49     // and the dest canvas is HW accelerated Canvas when setting its size to 1024x1024.
  50     setSize(1024, 1024, 1024, 1024);
  51     renderWebGL(gl);
  52     CanvasRunner.start({
  53         description: "This bench test checks the speed on drawing dynamic WebGL(1024x1024) to HW accelerated Canvas2D(1024x1024).",
  54         doRun: doRun,
  55         ensureComplete: ensureComplete});
  56 }
  57
  58 </script>
  59 </body>
  60 </html>