1// Copyright (c) 2013 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5// Global variable. 6var gl_context; 7 8initializeWebGL = function(canvas) { 9 gl_context = null; 10 // Try to grab the standard context. 11 gl_context = canvas.getContext("webgl") || 12 canvas.getContext("experimental-webgl"); 13 // If we don't have a GL context, give up now 14 if (!gl_context) { 15 alert("Unable to initialize WebGL. Your browser may not support it."); 16 } 17} 18 19startWebGLContext = function() { 20 var canvas = document.getElementById("glcanvas"); 21 // Initialize the GL context. 22 initializeWebGL(canvas); 23 24 // Only continue if WebGL is available and working. 25 if (gl_context) { 26 gl_context.clearColor(0.0, 0.0, 0.0, 1.0); 27 gl_context.enable(gl_context.DEPTH_TEST); 28 gl_context.depthFunc(gl_context.LEQUAL); 29 gl_context.clearDepth(1); 30 gl_context.clear(gl_context.COLOR_BUFFER_BIT | 31 gl_context.DEPTH_BUFFER_BIT); 32 } 33}