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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>Bug - calculating powers of constants smaller than 1.0e-5 in user-defined functions should work</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>
<canvas id="canvas" width="256" height="256"> </canvas>
<div id="description"></div>
<div id="console"></div>
<script id="vshader" type="x-shader/x-vertex">
attribute vec3 aPosition;
void main() {
gl_Position = vec4(aPosition, 1);
}
</script>
<script id="fshader" type="x-shader/x-fragment">
precision highp float;
float fun(float arg) {
// These values are still easily within the highp range.
// The minimum range in terms of 10's exponent is around -19 to 19, and IEEE-754 single precision range is higher than that.
return 1.0e12 * pow(arg, 2.0);
}
void main() {
// Note that the bug did not reproduce if an uniform was passed to the function instead of a constant,
// or if the expression was moved outside the user-defined function.
const float a = 1.0e-6;
float b = fun(a);
if (abs(b - 1.0) < 0.01) {
gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0); // green
} else {
gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0); // red
}
}
</script>
<script type="application/javascript">
"use strict";
description();
debug("");
var wtu = WebGLTestUtils;
function test() {
var gl = wtu.create3DContext("canvas");
if (!gl) {
testFailed("context does not exist");
return;
}
if (gl.getShaderPrecisionFormat(gl.FRAGMENT_SHADER, gl.HIGH_FLOAT).precision == 0) {
testPassed("highp precision not supported");
} else {
wtu.setupUnitQuad(gl);
var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["aPosition"], undefined, true);
wtu.drawUnitQuad(gl);
wtu.checkCanvasRect(gl, 0, 0, 256, 256, [0, 255, 0, 255]);
}
};
test();
finishTest();
</script>
</body>
</html>