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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>ColorMask Must Be Preserved During Implicit Clears</title>
<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>
</head>
<body>
<div id="description"></div>
<div id="canvases"></div>
<div id="console"></div>
<script>
"use strict";
const wtu = WebGLTestUtils;
const sz = 128;
let frames;
let gl;
let tests = [
{ alpha: false, antialias: false, premultipliedAlpha: false },
{ alpha: false, antialias: false, premultipliedAlpha: true },
{ alpha: false, antialias: true, premultipliedAlpha: false },
{ alpha: false, antialias: true, premultipliedAlpha: true },
];
let currentTest;
let testIndex = 0;
function initTest() {
description();
debug('ColorMask must be preserved during implicit clears of textures.');
debug('Regression test for <a href="http://crbug.com/911918">http://crbug.com/911918</a>');
requestAnimationFrame(nextTest);
}
function nextTest() {
if (testIndex >= tests.length) {
finishTest();
return;
}
frames = 20;
let canvases = document.getElementById('canvases');
let canvas = document.createElement('canvas');
canvas.width = sz;
canvas.height = sz;
canvases.appendChild(canvas);
currentTest = tests[testIndex];
++testIndex;
gl = wtu.create3DContext(canvas, currentTest);
requestAnimationFrame(runTest);
}
function runTest() {
// Create a user-defined framebuffer which has an alpha channel.
let fb = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, fb);
// Set color mask to disable alpha writes. This is important; see below.
gl.colorMask(true, true, true, false);
let tex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, sz, sz, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
// Upload a sub-rectangle. In Chrome, this was lazily clearing level 0 of the
// texture using OpenGL, setting the driver's color mask to (true, true, true,
// true) in the process. Because the user's color mask was set to (true, true,
// true, false) above, incorrect caching code was failing to reset the
// driver's color mask later. On macOS, Chrome implements alpha:false WebGL
// contexts on top of RGBA textures whose alpha channel is cleared to 1.0 and
// where the color mask is set to (true, true, true, false) during all writes.
// This bug was allowing that texture's alpha channel to be destroyed.
gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, new Uint8Array(4));
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, tex, 0);
// We have to issue one clear to this framebuffer to get the color mask
// latched into the internal caching code.
gl.clear(gl.COLOR_BUFFER_BIT);
// Switch back to default framebuffer.
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
// Set clear color to transparent green.
gl.clearColor(0, 1, 0, 0);
// Clear. Result should be opaque green. Was transparent green when
// bug was encountered.
gl.clear(gl.COLOR_BUFFER_BIT);
wtu.checkCanvasRect(gl, 0, 0, sz, sz,
[ 0, 255, 0, 255 ],
"default framebuffer should be opaque green for " + JSON.stringify(currentTest));
gl.deleteFramebuffer(fb);
gl.deleteTexture(tex);
--frames;
if (frames == 0) {
requestAnimationFrame(nextTest);
} else {
requestAnimationFrame(runTest);
}
}
requestAnimationFrame(initTest);
</script>
</body>
</html>
|
