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<!--
Copyright (c) 2022 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>GLSL texture bias test</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>
<script src="../../js/glsl-conformance-test.js"></script>
</head>
<body>
<div id="description"></div>
<div id="console"></div>
<script>
"use strict";
description("Texture bias should both function and respect limits.");
function runTest(gl) {
// no if idea any drivers have a giant limit like 2^32 so just in case.
const kMaxMaxTextureSize = 256 * 1024 * 1024;
const maxTextureSize = Math.min(kMaxMaxTextureSize, gl.getParameter(gl.MAX_TEXTURE_SIZE));
const maxLODs = (Math.log2(maxTextureSize) | 0) + 1;
const maxTextureLODBias = gl.getParameter(gl.MAX_TEXTURE_LOD_BIAS);
debug(`maxTextureSize: ${maxTextureSize}`);
debug(`maxLODs: ${maxLODs}`);
debug(`maxTextureLODBias: ${maxTextureLODBias}`);
const vs = `#version 300 es
uniform float uvMult;
out vec2 v_uv;
void main() {
vec2 xy = vec2(
gl_VertexID % 2,
(gl_VertexID / 2 + gl_VertexID / 3) % 2);
gl_Position = vec4(xy * 2. - 1.0, 0, 1);
v_uv = xy * uvMult;
}
`;
const fs = `#version 300 es
precision highp float;
uniform sampler2D tex;
uniform float biasMult;
in vec2 v_uv;
out vec4 fragColor;
void main() {
vec4 texColor = texture(tex, v_uv, (gl_FragCoord.x - 0.5) * biasMult); // the color we care about
vec4 texelColor = texelFetch(tex, ivec2(0), int(gl_FragCoord)); // just a sanity check
vec4 coordColor = vec4((100.0 + gl_FragCoord.x - 0.5) / 255.0); // another sanity check
fragColor = mix(texColor, coordColor, step(1.0, gl_FragCoord.y)); // line < 1 = texColor, line >= 1 = coordColor
fragColor = mix(fragColor, texelColor, step(2.0, gl_FragCoord.y)); // line < 2 = fragColor, line >= 2 = texelColor
}
`;
const program = wtu.setupProgram(gl, [vs, fs]);
const uvMultLoc = gl.getUniformLocation(program, 'uvMult');
const biasLoc = gl.getUniformLocation(program, 'biasMult');
gl.canvas.width = maxLODs;
gl.canvas.height = 3;
gl.viewport(0, 0, maxLODs, 3);
// create a texture where each mip is a different color (1, 2, 3, ...)
const tex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST_MIPMAP_NEAREST);
gl.texStorage2D(gl.TEXTURE_2D, maxLODs, gl.RGBA8, maxTextureSize, 1);
{
let level = 0;
for (let width = maxTextureSize; width > 0; width = width / 2 | 0) {
const pixels = new Uint8Array(width * 1 * 4);
pixels.fill(level + 1);
debug(`fill mip level: ${level}, width: ${width}`);
gl.texSubImage2D(gl.TEXTURE_2D, level, 0, 0, width, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
wtu.glErrorShouldBe(gl, gl.NO_ERROR);
++level;
}
}
// Draw each mip. Result should be [mip0, mip1, mip2, ...]
debug("");
debug("check positive bias");
// set the UVs so we'd get mip level 0 for every pixel
gl.uniform1f(uvMultLoc, maxLODs / maxTextureSize);
gl.uniform1f(biasLoc, 1);
gl.drawArrays(gl.TRIANGLES, 0, 6);
wtu.glErrorShouldBe(gl, gl.NO_ERROR);
const clampPlusMinus = (v, limit) => Math.min(limit, Math.max(-limit, v));
const checkResults = (gl, biasMult) => {
const base = biasMult > 0 ? 1 : maxLODs;
for (let i = 0; i < maxLODs; ++i) {
{
const expected = new Array(4).fill(clampPlusMinus(i * biasMult, maxTextureLODBias) + base);
wtu.checkCanvasRect(gl, i, 0, 1, 1, expected, `should be: ${expected}`);
}
{
const expected = new Array(4).fill(100 + i);
wtu.checkCanvasRect(gl, i, 1, 1, 1, expected, `should be: ${expected}`);
}
{
const expected = new Array(4).fill(i + 1);
wtu.checkCanvasRect(gl, i, 2, 1, 1, expected, `should be: ${expected}`);
}
}
}
checkResults(gl, 1);
// Draw each mip. Result should be [mipMax, mipMax - 1, mipMax - 2, ...]
debug("");
debug("check negative bias");
// set the UVs so we'd get highest mip level (the 1x1 level mip) for every pixel
gl.uniform1f(uvMultLoc, maxLODs);
gl.uniform1f(biasLoc, -1);
gl.drawArrays(gl.TRIANGLES, 0, 6);
checkResults(gl, -1);
finishTest();
}
const wtu = WebGLTestUtils;
const gl = wtu.create3DContext(undefined, undefined, 2);
var successfullyParsed = true;
if (!gl) {
testFailed("Unable to initialize WebGL 2.0 context.");
} else {
runTest(gl);
}
</script>
</body>
</html>
|
