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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">
<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 id="vshader" type="x-shader/x-vertex">
attribute vec3 pos;
attribute vec4 colorIn;
varying vec4 color;
void main()
{
color = colorIn;
gl_Position = vec4(pos.xyz, 1.0);
}
</script>
<script id="fshader" type="x-shader/x-fragment">
precision mediump float;
varying vec4 color;
void main()
{
gl_FragColor = color;
}
</script>
</head>
<body>
<canvas id="example" width="32" height="32"></canvas>
<canvas id="example2" width="32" height="32"></canvas>
<div id="description"></div>
<div id="console"></div>
<script>
"use strict";
// The below declarations need to be global for "shouldBe" to see them
var wtu = WebGLTestUtils;
var gl = null;
var array = null;
var pixel = [ 0, 0, 0, 0 ];
var expectedColor = [ 0, 0, 0, 0 ];
function calculatePixelBytes(format, type)
{
var size = 0;
switch (format) {
case gl.ALPHA:
size = 1;
break;
case gl.RGB:
size = 3;
break;
case gl.RGBA:
size = 4;
break;
default:
return -1;
}
switch (type) {
case gl.UNSIGNED_BYTE:
break;
case gl.UNSIGNED_SHORT_5_6_5:
if (format != gl.RGB)
return -1;
size = 2;
break;
case gl.UNSIGNED_SHORT_4_4_4_4:
case gl.UNSIGNED_SHORT_5_5_5_1:
if (format != gl.RGBA)
return -1;
size = 2;
break;
default:
return -1;
}
return size;
}
function calculatePaddingBytes(bytesPerPixel, packAlignment, width)
{
var padding = 0;
switch (packAlignment) {
case 1:
case 2:
case 4:
case 8:
padding = (bytesPerPixel * width) % packAlignment;
if (padding > 0)
padding = packAlignment - padding;
break;
default:
return -1;
}
return padding;
}
function packColor(format, type, r, g, b, a)
{
// FIXME: not sure if the color packing is correct for UNSIGNED_SHORT_*.
var color = [ 0, 0, 0, 0 ];
switch (type) {
case gl.UNSIGNED_BYTE:
switch (format) {
case gl.ALPHA:
color[0] = a;
break;
case gl.RGB:
color[0] = r;
color[1] = g;
color[2] = b;
break;
case gl.RGBA:
color[0] = r;
color[1] = g;
color[2] = b;
color[3] = a;
break;
default:
return null;
}
break;
case gl.UNSIGNED_SHORT_5_6_5:
if (format != gl.RGB)
return null;
r >>= 3;
g >>= 2;
b >>= 3;
color[0] = (r << 11) + (g << 5) + b;
break;
case gl.UNSIGNED_SHORT_4_4_4_4:
if (format != gl.RGBA)
return null;
r >>= 4;
g >>= 4;
b >>= 4;
a >>= 4;
color[0] = (r << 12) + (g << 8) + (b << 4) + a;
break;
case gl.UNSIGNED_SHORT_5_5_5_1:
if (format != gl.RGBA)
return null;
r >>= 3;
g >>= 3;
b >>= 3;
a >>= 7;
color[0] = (r << 11) + (g << 6) + (b << 1) + a;
break;
Default:
return null;
}
return color;
}
function runTestIteration(format, type, packAlignment, width, height)
{
debug("Testing PACK_ALIGNMENT = " + packAlignment + ", width = " + width + ", height = " + height);
gl.clearColor(1, 0.4, 0, 1);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.pixelStorei(gl.PACK_ALIGNMENT, packAlignment);
wtu.glErrorShouldBe(gl, gl.NO_ERROR);
var bytesPerPixel = calculatePixelBytes(format, type);
var padding = calculatePaddingBytes(bytesPerPixel, packAlignment, width);
var size = bytesPerPixel * width * height + padding * (height - 1);
if (type != gl.UNSIGNED_BYTE) {
throw "test error: only UNSIGNED_BYTE is valid to ReadPixels";
}
if (size < 0)
size = 0;
array = new Uint8Array(size);
gl.readPixels(0, 0, width, height, format, type, array);
if (width < 0 || height < 0) {
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE);
return;
}
wtu.glErrorShouldBe(gl, gl.NO_ERROR);
if (!array.length)
return;
// Check the last pixel of the last row.
var bytesPerRow = width * bytesPerPixel + padding;
var pos = bytesPerRow * (height - 1) + (width - 1) * bytesPerPixel;
var numComponents = bytesPerPixel;
for (var i = 0; i < numComponents; ++i)
pixel[i] = array[pos + i];
for (var i = numComponents; i < 4; ++i)
pixel[i] = 0;
expectedColor = packColor(format, type, 255, 102, 0, 255);
shouldBeNonNull("expectedColor");
shouldBe("pixel", "expectedColor");
}
description('Verify readPixels() works fine with various PACK_ALIGNMENT values.');
debug("<h1>antialias = false</h1>");
shouldBeNonNull("gl = wtu.create3DContext('example', {antialias: false})")
var formats = [ gl.RGBA ];
var formatNames = [ "RGBA" ];
runAllIterations();
debug("<h1>antialias = true</h1>");
shouldBeNonNull("gl = wtu.create3DContext('example2', {antialias: true})")
runAllIterations();
function runAllIterations() {
shouldBeNonNull("program = wtu.setupProgram(gl, ['vshader', 'fshader'], ['pos', 'colorIn'])");
for (var i = 0; i < formats.length; ++i) {
var format = formats[i];
debug("Testing format = " + formatNames[i] + " and type = UNSIGNED_BYTE");
runTestIteration(format, gl.UNSIGNED_BYTE, 1, 1, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 2, 1, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 4, 1, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 1, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 4, 2, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 2, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 4, 3, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 3, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 4, 4, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 4, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 5, 1);
runTestIteration(format, gl.UNSIGNED_BYTE, 4, 5, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 5, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 6, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 7, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 8, 2);
runTestIteration(format, gl.UNSIGNED_BYTE, 1, 0, 0);
runTestIteration(format, gl.UNSIGNED_BYTE, 2, 0, 0);
runTestIteration(format, gl.UNSIGNED_BYTE, 4, 0, 0);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, 0, 0);
runTestIteration(format, gl.UNSIGNED_BYTE, 1, -1, 1);
runTestIteration(format, gl.UNSIGNED_BYTE, 2, 1, -1);
runTestIteration(format, gl.UNSIGNED_BYTE, 4, 0, -1);
runTestIteration(format, gl.UNSIGNED_BYTE, 8, -1, -1);
}
}
var successfullyParsed = true;
</script>
<script src="../../js/js-test-post.js"></script>
</body>
</html>