content/canvas/test/test_2d.transformation.transform.skewed.html

   1 <!DOCTYPE HTML>
   2 <title>Canvas test: 2d.transformation.transform.skewed</title>
   3 <!-- Testing: transform() with skewy matrix transforms 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 // Create green with a red square ring inside it
  30 ctx.fillStyle = '#0f0';
  31 ctx.fillRect(0, 0, 100, 50);
  32 ctx.fillStyle = '#f00';
  33 ctx.fillRect(20, 10, 60, 30);
  34 ctx.fillStyle = '#0f0';
  35 ctx.fillRect(40, 20, 20, 10);
  36
  37 // Draw a skewed shape to fill that gap, to make sure it is aligned correctly
  38 ctx.transform(1,4, 2,3, 5,6);
  39 // Post-transform coordinates:
  40 //   [[20,10],[80,10],[80,40],[20,40],[20,10],[40,20],[40,30],[60,30],[60,20],[40,20],[20,10]];
  41 // Hence pre-transform coordinates:
  42 var pts=[[-7.4,11.2],[-43.4,59.2],[-31.4,53.2],[4.6,5.2],[-7.4,11.2],
  43          [-15.4,25.2],[-11.4,23.2],[-23.4,39.2],[-27.4,41.2],[-15.4,25.2],
  44          [-7.4,11.2]];
  45 ctx.beginPath();
  46 ctx.moveTo(pts[0][0], pts[0][1]);
  47 for (var i = 0; i < pts.length; ++i)
  48     ctx.lineTo(pts[i][0], pts[i][1]);
  49 ctx.fill();
  50 isPixel(ctx, 21,11, 0,255,0,255, "21,11", "0,255,0,255", 0);
  51 isPixel(ctx, 79,11, 0,255,0,255, "79,11", "0,255,0,255", 0);
  52 isPixel(ctx, 21,39, 0,255,0,255, "21,39", "0,255,0,255", 0);
  53 isPixel(ctx, 79,39, 0,255,0,255, "79,39", "0,255,0,255", 0);
  54 isPixel(ctx, 39,19, 0,255,0,255, "39,19", "0,255,0,255", 0);
  55 isPixel(ctx, 61,19, 0,255,0,255, "61,19", "0,255,0,255", 0);
  56 isPixel(ctx, 39,31, 0,255,0,255, "39,31", "0,255,0,255", 0);
  57 isPixel(ctx, 61,31, 0,255,0,255, "61,31", "0,255,0,255", 0);
  58
  59 SimpleTest.finish();
  60
  61 });
  62 </script>
  63