readpixels-after-alert.html

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<!--

Copyright (c) 2019 The Khronos Group Inc.

Use of this source code is governed by an MIT-style license that can be

found in the LICENSE.txt file.

-->

<!DOCTYPE html>

<html>

<head>

<meta charset="utf-8">

<title>WebGL Behavior After Alert and Read Pixels Test</title>

<link rel="stylesheet" href="../resources/js-test-style.css"/>

<script src="../../devtools/src/debug/webgl-debug.js"></script>

<script src="../js/js-test-pre.js"></script>

<script src="../js/webgl-test-utils.js"></script>

</head>

<body>

<canvas id="canvas" width="100" height="100"> </canvas>

<div id="description">Verify WebGL behavior after an alert and then a readPixels()</div>

<div id="console"></div>

<script>

"use strict";

function checkPixels(buf, width, height, thresh) {

  for (var yy = 0; yy < height; ++yy) {

    for (var xx = 0; xx < width; ++xx) {

      var offset = (yy * width + xx) * 4;

      if (Math.abs(buf[offset] - 255) > thresh ||

          Math.abs(buf[offset + 1] - 0) > thresh ||

          Math.abs(buf[offset + 2] - 0) > thresh) {

        testFailed("Checking pixels");

        return false;

  testPassed("Checking pixels");

  return true;

var wtu = WebGLTestUtils;

var gl = wtu.create3DContext("canvas");

gl.clearColor(1, 0, 0, 1);

gl.clear(gl.COLOR_BUFFER_BIT);

wtu.glErrorShouldBe(gl, gl.NO_ERROR, "setup should succeed");

wtu.checkCanvas(gl, [255, 0, 0, 255], undefined, 3);

alert("Click me to continue");

wtu.glErrorShouldBe(gl, gl.NO_ERROR, "setup should succeed");

wtu.checkCanvas(gl, [255, 0, 0, 255], undefined, 3);

alert("Click me to continue");

gl.clearColor(1, 0, 0, 1);

gl.clear(gl.COLOR_BUFFER_BIT);

wtu.checkCanvas(gl, [255, 0, 0, 255], undefined, 3);

debug("");

var successfullyParsed = true;

</script>

<script src="../js/js-test-post.js"></script>

</body>

</html>