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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 out of bounds uniform array access.</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>
<canvas id="example" width="128" height="128" style="background: black;">
</canvas>
<div id="console"></div>
<script id="vshader" type="x-shader/x-vertex">
attribute vec4 vPosition;
varying vec4 v_color;
uniform float lineWidth;
uniform int elemMult;
uniform vec4 colorArray[6];
void main()
{
vec2 texcoord = vec2(vPosition.xy * 0.5 + vec2(0.5, 0.5));
int index = int(texcoord.x + texcoord.y * lineWidth) * elemMult;
v_color = colorArray[index];
gl_Position = vPosition;
gl_PointSize = 1.0;
}
</script>
<script id="fshader" type="x-shader/x-fragment">
precision mediump float;
varying vec4 v_color;
void main()
{
gl_FragColor = v_color;
}
</script>
<script>
"use strict";
debug("Tests a WebGL program that accesses out of bounds uniform array elements");
var gl;
var gridRes = 127;
var lineWidthLoc;
var elemMultLoc;
var width = 128;
var height = 128;
var pixels = new Uint8Array(width * height * 4);
var lineWidth = 0;
var elemMult = 0;
var knownColors = [
1.0, 0.0, 0.0, 1.0, // Red
0.0, 1.0, 0.0, 1.0, // Green
0.0, 0.0, 1.0, 1.0, // Blue
0.0, 1.0, 1.0, 1.0, // Cyan
1.0, 0.0, 1.0, 1.0, // Magenta
1.0, 1.0, 0.0, 1.0 // Yellow
];
function main() {
var wtu = WebGLTestUtils;
gl = wtu.create3DContext("example");
var program = wtu.setupProgram(
gl,
['vshader', 'fshader'],
['vPosition'], [0]);
// setupQuad produces the geometry we want for a gridRes x gridRes grid
// of points. No interpolation will be performed across the points, so
// according to the WebGL specification for out-of-bounds array accesses,
// we will get exactly the input colors from the uniform colorArray, or
// zero, for each pixel on the canvas.
wtu.setupIndexedQuad(gl, gridRes, 0);
var colorArrayLoc = gl.getUniformLocation(program, "colorArray[0]");
assertMsg(colorArrayLoc != null, "color array uniform should be found");
var colors = new Float32Array(knownColors);
gl.uniform4fv(colorArrayLoc, colors);
lineWidthLoc = gl.getUniformLocation(program, "lineWidth");
elemMultLoc = gl.getUniformLocation(program, "elemMult");
assertMsg(gl.getError() == gl.NO_ERROR, "Should be no errors from setup.");
runOneIteration();
}
function withinEpsilon(val1, val2) {
return Math.abs(val1 - val2) < 0.0001;
}
function isKnownColor(r, g, b) {
if (r == 0 && g == 0 && b == 0)
return true;
for (var ii = 0; ii < knownColors.length; ii += 4) {
if (withinEpsilon(r / 255.0, knownColors[ii + 0]) &&
withinEpsilon(g / 255.0, knownColors[ii + 1]) &&
withinEpsilon(b / 255.0, knownColors[ii + 2]))
return true;
}
return false;
}
function runOneIteration() {
if (elemMult < 2048) {
var ok = true;
var startingLineWidth = lineWidth;
var firstFailingPixel = null;
var firstFailingValue = null;
for (; lineWidth < 2540; lineWidth += 31) {
// Draw
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
gl.uniform1f(lineWidthLoc, lineWidth);
gl.uniform1i(elemMultLoc, elemMult);
gl.drawArrays(gl.POINTS, 0, gridRes * gridRes);
// Read back
gl.readPixels(0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
// Verify
for (var y = 0; y < height; ++y) {
for (var x = 0; x < width; ++x) {
if (!isKnownColor(pixels[4 * (width * y + x) + 0],
pixels[4 * (width * y + x) + 1],
pixels[4 * (width * y + x) + 2])) {
ok = false;
if (firstFailingPixel == null) {
firstFailingPixel = [x, y];
firstFailingValue = [pixels[4 * (width * y + x) + 0],
pixels[4 * (width * y + x) + 1],
pixels[4 * (width * y + x) + 2]];
}
}
}
}
}
var endingLineWidth = lineWidth - 31;
lineWidth -= 2540;
if (ok) {
testPassed("Good rendering results for lineWidths " +
startingLineWidth + "..." + endingLineWidth +
" at elemMult=" + elemMult);
} else {
testFailed("for lineWidth=" + lineWidth + ", elemMult=" + elemMult +
": first failing pixel (" + firstFailingPixel[0] + ", " + firstFailingPixel[1] + ") was (" +
firstFailingValue[0] + ", " +
firstFailingValue[1] + ", " +
firstFailingValue[2] + "), should be (0, 0, 0) or one of known colors");
}
elemMult += 73;
setTimeout(runOneIteration, 0);
} else {
finishTest();
}
}
main();
var successfullyParsed = true;
</script>
</body>
</html>
|
