<!DOCTYPE HTML>

<!-- READ BEFORE UPDATING:
If this test is updated make sure to increment the "revision" value of the
associated test in content/test/gpu/gpu_tests/pixel_test_pages.py. This will ensure
that the baseline images are regenerated on the next run.
-->

<html>
<head>
<title>OffscreenCanvas webgl commit flow on worker thread: Two Canvases</title>
<style type="text/css">
.nomargin {
  margin: 0px auto;
}
</style>
<script id="myWorker" type="text/worker">
/* This pixel test checks the following:
    1. Whether submission of frames for multiple canvases happen about the same
       time for OffscreenCanvas.commit() that are invoked in the same JS task.
    2. Whether overdraw frame in one animation loop is handled well.
    3. Whether the drawn webgl image is position upright in commit().
    4. Drawing to OffscreenCanvas without commit() has no rendering results.

    Correct end result of this test: The left canvas shows a upright white
    triangle on a green background and the right canvas shows dark-blue fill.
*/

var g_ctx1, g_ctx2;
var g_asyncCallbackNumber = 2;

self.onmessage = function(e) {
  g_ctx1 = e.data.offscreenCanvas1.getContext("webgl");
  g_ctx2 = e.data.offscreenCanvas2.getContext("webgl");

  startTest();
}  

function startTest() {
  g_ctx1.clearColor(0, 1, 0, 1);
  g_ctx1.clear(g_ctx1.COLOR_BUFFER_BIT);
  // The promise returned by this g_ctx1.commit() must be resolved at
  // about the same time as the other g_ctx2.commit() below as they are in the
  // same JS task.
  g_ctx1.commit().then(function() {
    g_ctx2.clearColor(0, 0, 1, 1);
    g_ctx2.clear(g_ctx2.COLOR_BUFFER_BIT);
    // This g_ctx2.commit() must happen after the other g_ctx2.commit() below.
    g_ctx2.commit();
    if (--g_asyncCallbackNumber == 0) self.postMessage("");
  });

  function drawTriangle(gl)
  {
    gl.clearColor(0, 1, 0, 1);
    gl.clear(gl.COLOR_BUFFER_BIT);

    var prog = gl.createProgram();
    var vs = gl.createShader(gl.VERTEX_SHADER);
    gl.shaderSource(vs, ['attribute vec2 pos;',
        'void main() {',
        '  gl_Position = vec4(pos, 0., 1.);',
        '}'].join('\n'));
    gl.compileShader(vs);
    if (!gl.getShaderParameter(vs, gl.COMPILE_STATUS)) {
        throw 'failed to compiled shader';
    }
    gl.attachShader(prog, vs);

    var fs = gl.createShader(gl.FRAGMENT_SHADER);
    gl.shaderSource(fs, ['void main() {',
        '  gl_FragColor = vec4(1.);',
        '}'].join('\n'));
    gl.compileShader(fs);
    if (!gl.getShaderParameter(fs, gl.COMPILE_STATUS)) {
        throw 'failed to compiled shader';
    }
    gl.attachShader(prog, fs);

    gl.linkProgram(prog);
    if (!gl.getProgramParameter(prog, gl.LINK_STATUS)) {
        throw "Could not link the shader program!";
    }
    gl.useProgram(prog);

    gl.bindBuffer(gl.ARRAY_BUFFER, gl.createBuffer());
    gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-.5,0, 0,.5, .5,0]), gl.STATIC_DRAW);
    var attr = gl.getAttribLocation(prog, 'pos');
    gl.enableVertexAttribArray(attr);
    gl.vertexAttribPointer(attr, 2, gl.FLOAT, false, 0, 0);

    gl.drawArrays(gl.TRIANGLE_STRIP, 0, 3);
  }

  // Do something complex to g_ctx2.
  drawTriangle(g_ctx2);
  // This g_ctx2.commit() must be resolved at about the same time as the first
  // g_ctx1.commit() above because they are in the same JS task, no matter how
  // complex the drawing operation is.
  g_ctx2.commit().then(function() {
    drawTriangle(g_ctx1);
    g_ctx1.commit();

    // The following clear is never committed
    g_ctx1.clearColor(1, 0, 0, 1);
    g_ctx1.clear(g_ctx1.COLOR_BUFFER_BIT);
    if (--g_asyncCallbackNumber == 0) self.postMessage("");
  });

}

</script>
<script>
var g_swapsBeforeAck = 15;

function makeWorker(script) {
   var blob = new Blob([script]);
   return new Worker(URL.createObjectURL(blob));
}

function waitForFinish()
{
  if (g_swapsBeforeAck == 0) {
    domAutomationController.send("SUCCESS");
  } else {
    g_swapsBeforeAck--;
    document.getElementById('container').style.zIndex = g_swapsBeforeAck + 1;
    window.requestAnimationFrame(waitForFinish);
  }
}

function main()
{
  var offscreenCanvas1 = document.getElementById("canvas1").transferControlToOffscreen();
  var offscreenCanvas2 = document.getElementById("canvas2").transferControlToOffscreen();
  
  var worker = makeWorker(document.getElementById("myWorker").textContent);
  worker.onmessage = function (e) {
      waitForFinish();
  };
  worker.postMessage(
      {offscreenCanvas1: offscreenCanvas1,
       offscreenCanvas2: offscreenCanvas2},
      [offscreenCanvas1, offscreenCanvas2]);
}
</script>
</head>
<body onload="main()">
<div style="position:relative; width:360px; height:200px; background-color:white">
</div>
<div id="container" style="position:absolute; top:0px; left:0px">
<canvas id="canvas1" width="180" height="200" class="nomargin"></canvas>
<canvas id="canvas2" width="180" height="200" class="nomargin"></canvas>
</div>
</body>
</html>