Source code
Revision control
Copy as Markdown
Other Tools
<!--
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">
<link rel="stylesheet" href="../../resources/js-test-style.css"/>
<script src="../../js/js-test-pre.js"></script>
<script src="../../js/webgl-test-utils.js"></script>
<script>
"use strict";
// These declarations need to be global for "shouldBe" to see them
var gl;
var pixel = [0, 0, 0, 1];
var canvas;
function init()
{
description('Verify that changing the size of an antialiased WebGL context does not cause it to stop working.');
runTest();
}
function getWebGL(canvasWidth, canvasHeight, contextAttribs)
{
canvas = document.createElement("canvas");
if (!canvas)
return null;
canvas.width = canvasWidth;
canvas.height = canvasHeight;
gl = WebGLTestUtils.create3DContext(canvas, contextAttribs);
if (!gl)
return null;
return gl;
}
function runTest()
{
shouldBeNonNull("gl = getWebGL(1, 1, { alpha: false, antialias: true })");
// Clear to black.
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT);
// Check that the pixel's R channel is 0.
var buf = new Uint8Array(1 * 1 * 4);
gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, buf);
pixel[0] = buf[0];
shouldBeTrue("pixel[0] == 0");
// Change the size of the canvas.
canvas.width = 3;
canvas.height = 3;
// Clear to black.
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT);
// Clear the top-left pixel to white.
gl.enable(gl.SCISSOR_TEST);
gl.scissor(0, 0, 1, 1);
gl.clearColor(1.0, 1.0, 1.0, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT);
// Check that the top-left pixel has R channel 255.
gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, buf);
pixel[0] = buf[0];
shouldBeTrue("pixel[0] == 255");
// Check that the bottom-right pixel has R channel 0.
gl.readPixels(2, 2, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, buf);
pixel[0] = buf[0];
shouldBeTrue("pixel[0] == 0");
finishTest();
}
</script>
</head>
<body onload="init()">
<div id="description"></div>
<div id="console"></div>
</body>
</html>