layout/reftests/canvas/ctm-singular-sanity.html

   1 <html>
   2 <head>
   3   <script type="text/javascript">
   4 function assert(cond, msg) {
   5   if (!cond) {
   6     throw msg;
   7   }
   8 }
   9
  10 assert.equal = function(m1, m2, msg) {
  11   assert(
  12     m1.is2D &&
  13       m2.is2D &&
  14       m1.a === m2.a &&
  15       m1.b === m2.b &&
  16       m1.c === m2.c &&
  17       m1.d === m2.d &&
  18       m1.e === m2.e &&
  19       m1.f === m2.f,
  20     msg
  21   );
  22 };
  23
  24 window.onload = function() {
  25   try {
  26     var ctx = document.getElementById("c1").getContext("2d");
  27
  28     var singular = new DOMMatrix([0, 0, 0, 0, 0, 0]);
  29     ctx.setTransform(singular);
  30     assert.equal(
  31       ctx.getTransform(),
  32       singular,
  33       "Expected setting transform to a singular matrix to work"
  34     );
  35     var inv = ctx.getTransform().invertSelf();
  36     assert(
  37       isNaN(inv.a) && isNaN(inv.b) && isNaN(inv.c) && isNaN(inv.d),
  38       "Expected to get back matrix of NaN's from inverse transform"
  39     );
  40
  41     var m = new DOMMatrix([1, 2, 3, 4, 5, 6]);
  42     ctx.setTransform(m);
  43     ctx.setTransform(singular.invertSelf());
  44     assert.equal(
  45       ctx.getTransform(),
  46       m,
  47       "Setting transform to an inverse singular matrix is a no-op"
  48     );
  49   } catch (e) {
  50     document.body.innerHTML = "FAIL: " + e.toString();
  51     return;
  52   }
  53   document.body.innerHTML = "Pass";
  54 };
  55   </script>
  56 </head>
  57 <body>
  58   <div><canvas id="c1" width="300" height="300"></canvas></div>
  59 </body>
  60 </html>