glsl-function-texture2d-bias.html

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Copyright (c) 2019 The Khronos Group Inc.

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<html>

<head>

<meta charset="utf-8">

<title>WebGL texture2D GLSL conformance test.</title>

<link rel="stylesheet" href="../../../resources/js-test-style.css"/>

<link rel="stylesheet" href="../../../resources/glsl-feature-tests.css"/>

<script src="../../../js/js-test-pre.js"></script>

<script src="../../../js/webgl-test-utils.js"> </script>

</head>

<body>

<canvas id="example" width="256" height="256" style="width: 16px; height: 16px;"></canvas>

<div id="description"></div>

<div id="console"></div>

<script id="vshader2d" type="x-shader/x-vertex">

attribute vec4 vPosition;

attribute vec2 texCoord0;

varying vec2 texCoord;

void main() {

    gl_Position = vPosition;

    texCoord = texCoord0;

</script>

<script id="fshader2d" type="x-shader/x-fragment">

precision mediump float;

uniform sampler2D tex;

uniform float bias;

varying vec2 texCoord;

void main() {

    gl_FragData[0] = texture2D(tex, texCoord, bias);

</script>

<script>

"use strict";

description("tests GLSL texture2D function with bias");

var wtu = WebGLTestUtils;

var canvas = document.getElementById("example");

shouldBe("canvas.width", "256");

shouldBe("canvas.height", "256");

var gl = wtu.create3DContext(canvas);

var program = wtu.setupProgram(

    gl, ['vshader2d', 'fshader2d'], ['vPosition', 'texCoord0'], [0, 1]);

wtu.setupUnitQuad(gl, 0, 1);

var colors = [

  {name: 'red', color:[255, 0, 0, 255]},

  {name: 'green', color:[0, 255, 0, 255]},

  {name: 'blue', color:[0, 0, 255, 255]},

  {name: 'yellow', color:[255, 255, 0, 255]},

  {name: 'magenta', color:[255, 0, 255, 255]},

  {name: 'cyan', color:[0, 255, 255, 255]},

  {name: 'pink', color:[255, 128, 128, 255]},

  {name: 'gray', color:[128, 128, 128, 255]},

  {name: 'light green', color:[128, 255, 128, 255]},

];

shouldBe("colors.length", "9");

var tex = gl.createTexture();

gl.bindTexture(gl.TEXTURE_2D, tex);

gl.texParameteri(

    gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_NEAREST);

gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);

gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);

gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);

for (var ii = 0; ii < colors.length; ++ii) {

  var color = colors[ii];

  var size = Math.pow(2, colors.length - ii - 1);

  wtu.fillTexture(gl, tex, size, size, color.color, ii);

var loc = gl.getUniformLocation(program, "bias");

for (var ii = 0; ii < colors.length; ++ii) {

  gl.uniform1f(loc, ii);

  var color = colors[ii];

  wtu.clearAndDrawUnitQuad(gl);

  wtu.checkCanvas(

      gl, color.color,

      "256x256 texture drawn to 256x256 dest with bias = " + ii +

      " should be " + color.name);

wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Should be no errors.");

var successfullyParsed = true;

</script>

<script src="../../../js/js-test-post.js"></script>

</body>

</html>