cssAudio - Activefile-genericCSS - ActiveGeneric - ActiveHTML - ActiveImage - ActiveJS - ActiveSVG - ActiveText - Activefile-genericVideo - ActiveLovehtmlicon-new-collectionicon-personicon-teamlog-outoctocatpop-outspinnerstartv

Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

Quick-add: + add another resource

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

Quick-add: + add another resource

Code Indentation


Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

<script id="vertex-shader" type="x-shader/x-vertex">
attribute vec4 vPosition;
void main() {
  gl_Position = vPosition;

<script id="fragment-shader" type="x-shader/x-fragment">
precision mediump float;
void main() {
  gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0);

<script type="text/javascript" src="../Common/webgl-utils.js"></script>

<script type="text/javascript" src="../Common/initShaders.js"></script>

<script type="text/javascript" src="myTriangle.js"></script>


<canvas id="gl-canvas" width="512" height="512">
Oops ... your browser doesn't support the HTML5 canvas element

              "use strict";

var gl;
var points;

window.onload = function init() {
	var canvas = document.getElementById("gl-canvas");
	gl = WebGLUtils.setupWebGL(canvas);
	if (!gl) {
		alert("WebGL isn't available");
	var vertices = new Float32Array([-1, -1, 0, 1, 1, -1]);
	// configure WebGL
	gl.viewport(0, 0, canvas.width, canvas.height);
	gl.clearColor(0.0, 1.0, 1.0, 1.0);
	// load shaders and initialize attribute buffers
	var program = initShaders(gl, "vertex-shader", "fragment-shader");
	// load the data into the GPU
	var bufferId = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, bufferId);
	gl.bufferData(gl.ARRAY_BUFFER, vertices, gl.STATIC_DRAW);
	// associate out shader variables with our data buffer
	var vPosition = gl.getAttribLocation(program, "vPosition");
	gl.vertexAttribPointer(vPosition, 2, gl.FLOAT, false, 0, 0);

function render() {
	gl.drawArrays(gl.TRIANGLES, 0, 3);

Loading ..................