84 lines
2.3 KiB
HTML
84 lines
2.3 KiB
HTML
<!-- Any copyright is dedicated to the Public Domain.
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http://creativecommons.org/publicdomain/zero/1.0/ -->
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<!doctype html>
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<html>
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<head>
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<meta charset="utf-8"/>
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<title>WebGL editor test page</title>
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<script id="shader-vs" type="x-shader/x-vertex">
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precision lowp float;
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void main(void) {
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gl_Position = vec4(0, 0, 0, 1); // I'm a vertex shader!
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}
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</script>
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<script id="shader-fs" type="x-shader/x-fragment">
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precision lowp float;
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varying vec3 vFragmentColor;
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void main(void) {
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gl_FragColor = vec4(1, 0, 0, 1); // I'm a fragment shader!
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}
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</script>
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</head>
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<body>
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<canvas width="512" height="512"></canvas>
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<script type="text/javascript;version=1.8">
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"use strict";
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let canvas, gl;
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window.onload = function() {
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canvas = document.querySelector("canvas");
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gl = canvas.getContext("webgl", { preserveDrawingBuffer: true });
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let shaderProgram = gl.createProgram();
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let vertexShader, fragmentShader;
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// Compile and attach the shaders in a random order. The test will
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// ensure that the correct vertex and fragment source is retrieved
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// regardless of this crazyness.
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if (Math.random() > 0.5) {
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vertexShader = getShader(gl, "shader-vs");
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fragmentShader = getShader(gl, "shader-fs");
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} else {
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fragmentShader = getShader(gl, "shader-fs");
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vertexShader = getShader(gl, "shader-vs");
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}
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if (Math.random() > 0.5) {
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gl.attachShader(shaderProgram, vertexShader);
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gl.attachShader(shaderProgram, fragmentShader);
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} else {
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gl.attachShader(shaderProgram, fragmentShader);
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gl.attachShader(shaderProgram, vertexShader);
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}
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gl.linkProgram(shaderProgram);
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}
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function getShader(gl, id) {
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let script = document.getElementById(id);
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let source = script.textContent;
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let shader;
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if (script.type == "x-shader/x-fragment") {
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shader = gl.createShader(gl.FRAGMENT_SHADER);
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} else if (script.type == "x-shader/x-vertex") {
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shader = gl.createShader(gl.VERTEX_SHADER);
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}
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gl.shaderSource(shader, source);
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gl.compileShader(shader);
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return shader;
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}
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</script>
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</body>
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</html>
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