third_party/WebKit/LayoutTests/fast/canvas/2d.composite.globalAlpha.fillPath.html

   1  <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
   2 <!-- Test based on that found at
   3      http://http://philip.html5.org/tests/canvas/suite/tests/index.2d.composite.globalAlpha.html
   4   -->
   5 <html>
   6 <head>
   7 <script src="../../resources/js-test.js"></script>
   8 </head>
   9 <body>
  10 <canvas id="canvas" width="100" height="100"></canvas>
  11 <script>
  12
  13 function assertPixelApprox(ctx, x,y, r,g,b,a, pos, colour, tolerance)
  14 {
  15     var imgdata = ctx.getImageData(x, y, 1, 1);
  16     var diff = Math.max(Math.abs(r-imgdata.data[0]), Math.abs(g-imgdata.data[1]), Math.abs(b-imgdata.data[2]), Math.abs(a-imgdata.data[3]));
  17     shouldBeFalse((diff > tolerance).toString());
  18 }
  19
  20 description("The test to ensure correct sync behaviour with globalAlpha and fillPath() in accelerated-2d-canvas mode.");
  21 var ctx = document.getElementById('canvas').getContext('2d');
  22
  23 ctx.fillStyle = '#0f0';
  24 ctx.fillRect(0, 0, 100, 100);
  25 ctx.globalAlpha = 0.01; // avoid any potential alpha=0 optimisations
  26 ctx.beginPath();
  27 ctx.fillStyle = '#f00';
  28 ctx.rect(0, 0, 100, 100);
  29 ctx.fill();
  30 assertPixelApprox(ctx, 50,25, 2,253,0,255, "50,25", "2,253,0,255", 2);
  31
  32 </script>
  33 </body>
  34 </html>
  35