dom/canvas/test/reftest/webgl-disable-test.html

   1 <!DOCTYPE html>
   2 <html class="reftest-wait">
   3 <head>
   4 <meta charset="UTF-8">
   5
   6 <script type="text/javascript" src="webgl-utils.js"></script>
   7 <script type="text/javascript">
   8 /* Disable Test
   9  *
  10  * If we succeed in getting a WebGL context, we will fill
  11  * the canvas with red. If we fail to acquire a WebGL context,
  12  * we will use Canvas2D to instead fill it with green.
  13  *
  14  * Note that this test differs from the others in that
  15  * it will draw differently if it receives a WebGL context.
  16  * Other tests are designed to fallback silently to Canvas2D.
  17  *
  18  * We use this test to assure that when we disable WebGL,
  19  * WebGL does not function. This is trivially true for systems
  20  * that don't support WebGL. This test is not viable for testing
  21  * that WebGL works, as blocklisted systems will always draw green.
  22  */
  23
  24 "use strict";
  25
  26 function renderGL(gl) {
  27   gl.clearColor(1.0, 0.0, 0.0, 1.0);
  28   gl.clear(gl.COLOR_BUFFER_BIT);
  29   gl.finish();
  30 }
  31
  32 function renderBackup(canvas) {
  33   var context = canvas.getContext("2d");
  34   context.fillStyle = "rgba(0, 255, 0, 1.0)";
  35   context.fillRect(0, 0, 256, 256);
  36 }
  37
  38 function runTest() {
  39   var canvas = document.getElementById("canvas");
  40   var gl = initGL(canvas);
  41
  42   if (gl)
  43     renderGL(gl);
  44   else
  45     renderBackup(canvas);
  46
  47   waitForComposite(testComplete);
  48 }
  49
  50 function testComplete() {
  51   document.documentElement.removeAttribute("class");
  52 }
  53 </script>
  54 </head>
  55
  56 <body onload="rAF(runTest);">
  57   <canvas id="canvas" width="256" height="256"></canvas>
  58 </body>
  59
  60 </html>