<!DOCTYPE HTML>
<html>
<head>
<title>WebGL in OffscreenCanvas</title>
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<link rel="stylesheet" href="/tests/SimpleTest/test.css">
</head>
<body>
<!--
  This test needs several workers run offscreen canvas simultaneously.
  So we choose 8 workers, 4 of them run basic webgl drawing test and
  others run size changing test.
-->
<script>

SimpleTest.waitForExplicitFinish();

function createCanvas() {
  var htmlCanvas = document.createElement('canvas');
  htmlCanvas.width = 64;
  htmlCanvas.height = 64;
  document.body.appendChild(htmlCanvas);
  return htmlCanvas;
}

function runTest() {
  var stillRunning = 0;

  var startWorker = function(canvas, test) {
    stillRunning++;
    var worker = new Worker("offscreencanvas.js");

    worker.onmessage = function(evt) {
      var msg = evt.data || {};
      if (msg.type == "test") {
        ok(msg.result, msg.name);
      }
      if (msg.type == "finish") {
        worker.terminate();
        if (--stillRunning == 0)
          SimpleTest.finish();
      }
    }

    var offscreenCanvas = canvas.transferControlToOffscreen();
    worker.postMessage({test, canvas: offscreenCanvas}, [offscreenCanvas]);
  }

  /* create 4 workers that do the regular drawing test and 4 workers
     that do the size change test */
  for (var i = 0; i < 4; i++) {
    startWorker(createCanvas(), 'webgl');
  }

  for (var i = 0; i < 4; i++) {
    startWorker(createCanvas(), 'webgl_changesize');
  }
}

SpecialPowers.pushPrefEnv({'set': [
  ['gfx.offscreencanvas.enabled', true],
  ['webgl.force-enabled', true]
]}, runTest);

</script>
</body>
</html>
