content/canvas/test/test_2d.transformation.rotate.wrap.html

   1 <!DOCTYPE HTML>
   2 <title>Canvas test: 2d.transformation.rotate.wrap</title>
   3 <!-- Testing: rotate() wraps large positive values correctly -->
   4 <script src="/MochiKit/MochiKit.js"></script>
   5 <script src="/tests/SimpleTest/SimpleTest.js"></script>
   6 <link rel="stylesheet" href="/tests/SimpleTest/test.css">
   7 <body>
   8 <canvas id="c" width="100" height="50"><p class="fallback">FAIL (fallback content)</p></canvas>
   9 <script>
  10 function isPixel(ctx, x,y, r,g,b,a, pos, colour, d) {
  11     var pixel = ctx.getImageData(x, y, 1, 1);
  12     var pr = pixel.data[0],
  13         pg = pixel.data[1],
  14         pb = pixel.data[2],
  15         pa = pixel.data[3];
  16     ok(r-d <= pr && pr <= r+d &&
  17        g-d <= pg && pg <= g+d &&
  18        b-d <= pb && pb <= b+d &&
  19        a-d <= pa && pa <= a+d,
  20        "pixel "+pos+" is "+pr+","+pg+","+pb+","+pa+"; expected "+colour+" +/- "+d);
  21 }
  22
  23 SimpleTest.waitForExplicitFinish();
  24 MochiKit.DOM.addLoadEvent(function () {
  25
  26 var canvas = document.getElementById('c');
  27 var ctx = canvas.getContext('2d');
  28
  29 ctx.fillStyle = '#f00';
  30 ctx.fillRect(0, 0, 100, 50);
  31
  32 ctx.rotate(Math.PI * (1 + 4096)); // == pi (mod 2*pi)
  33 // We need about pi +/- 0.001 in order to get correct-looking results
  34 // 32-bit floats can store pi*4097 with precision 2^-10, so that should
  35 // be safe enough on reasonable implementations
  36 ctx.fillStyle = '#0f0';
  37 ctx.fillRect(-100, -50, 100, 50);
  38 isPixel(ctx, 50,25, 0,255,0,255, "50,25", "0,255,0,255", 0);
  39 isPixel(ctx, 98,2, 0,255,0,255, "98,2", "0,255,0,255", 0);
  40 isPixel(ctx, 98,47, 0,255,0,255, "98,47", "0,255,0,255", 0);
  41
  42 SimpleTest.finish();
  43
  44 });
  45 </script>
  46