JSFiddle - React, Tailwind, and code Playground
HTML
<main>
<canvas id="glcanvas" width="480" height="360">
WebGL not supported!
</canvas>
</main>
JavaScript
(function() {
var gl;
var gProgram;
var gVertexAttribLocation;
var gColorAttribLocation;
var gTriangleVertexBuffer;
var gTriangleColorBuffer;
var gQuadVertexBuffer;
var gQuadColorBuffer;
function initGL() {
var glcanvas = document.getElementById("glcanvas");
gl = glcanvas.getContext("webgl");
}
function createAndCompileShader(type, source) {
var shader = gl.createShader(type);
gl.shaderSource(shader, source);
gl.compileShader(shader);
if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
throw new Error(gl.getShaderInfoLog(shader));
}
return shader;
}
function createAndLinkProgram(glVertexShader, glFragmentShader) {
var glProgram = gl.createProgram();
gl.attachShader(glProgram, glVertexShader);
gl.attachShader(glProgram, glFragmentShader);
gl.linkProgram(glProgram);
if (!gl.getProgramParameter(glProgram, gl.LINK_STATUS)) {
throw new Error("Could not initialise shaders");
}
return glProgram;
}
function initShaderPrograms() {
var gVertexShader = createAndCompileShader(gl.VERTEX_SHADER, [
"attribute vec3 a_vertex;",
"attribute vec4 a_color;",
"varying vec4 v_color;",
"void main(void) {",
"v_color = a_color;",
"gl_Position = vec4(a_vertex, 1.0);",
"}"
].join("\n"));
var gFragmentShader = createAndCompileShader(gl.FRAGMENT_SHADER, [
"precision mediump float;",
"varying vec4 v_color;",
"void main(void) {",
"gl_FragColor = v_color;",
"}"
].join("\n"));
gProgram = createAndLinkProgram(gVertexShader, gFragmentShader);
}
function initGLAttribLocations() {
gVertexAttribLocation = gl.getAttribLocation(gProgram, "a_vertex");
gColorAttribLocation = gl.getAttribLocation(gProgram, "a_color");
}
function initBuffers() {
gTriangleVertexBuffer = gl.createBuffer();
gTriangleColorBuffer = gl.createBuffer();
gQuadVertexBuffer = gl.createBuffer();
gQuadColorBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, gTriangleVertexBuffer);
var vertices = new Float32Array([
0.0, 1.0, 0.0,
...