Home | History | Annotate | Download | only in functional_files 
      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.
      6 var gl_context;
      7 
      8 initializeWebGL = 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 
     19 startWebGLContext = 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 }