webgl-utils.js

/*
 * Copyright 2010, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


WebGLUtils = function() {

var makeFailHTML = function(msg) {
  return '' +
    '<table style="background-color: #8CE; width: 100%; height: 100%;"><tr>' +
    '<td align="center">' +
    '<div style="display: table-cell; vertical-align: middle;">' +
    '<div style="">' + msg + '</div>' +
    '</div>' +
    '</td></tr></table>';
};

var GET_A_WEBGL_BROWSER = '' +
  'This page requires a browser that supports WebGL.<br/>' +
  '<a href="http://get.webgl.org">Click here to upgrade your browser.</a>';

var OTHER_PROBLEM = '' +
  "It doesn't appear your computer can support WebGL.<br/>" +
  '<a href="http://get.webgl.org/troubleshooting/">Click here for more information.</a>';

var setupWebGL = function(canvas, opt_attribs, opt_onError) {
  function handleCreationError(msg) {
    var container = canvas.parentNode;
    if (container) {
      var str = window.WebGLRenderingContext ?
           OTHER_PROBLEM :
           GET_A_WEBGL_BROWSER;
      if (msg) {
        str += "<br/><br/>Status: " + msg;
      }
      container.innerHTML = makeFailHTML(str);
    }
  };

  opt_onError = opt_onError || handleCreationError;

  if (canvas.addEventListener) {
    canvas.addEventListener("webglcontextcreationerror", function(event) {
          opt_onError(event.statusMessage);
        }, false);
  }
  var context = create3DContext(canvas, opt_attribs);
  if (!context) {
    if (!window.WebGLRenderingContext) {
      opt_onError("");
    }
  }
  return context;
};

var create3DContext = function(canvas, opt_attribs) {
  var names = ["webgl", "experimental-webgl", "webkit-3d", "moz-webgl"];
  var context = null;
  for (var ii = 0; ii < names.length; ++ii) {
    try {
      context = canvas.getContext(names[ii], opt_attribs);
    } catch(e) {}
    if (context) {
      break;
    }
  }
  return context;
}

return {
  create3DContext: create3DContext,
  setupWebGL: setupWebGL
};
}();

window.requestAnimFrame = (function() {
  return window.requestAnimationFrame ||
         window.webkitRequestAnimationFrame ||
         window.mozRequestAnimationFrame ||
         window.oRequestAnimationFrame ||
         window.msRequestAnimationFrame ||
         function(/* function FrameRequestCallback */ callback, /* DOMElement Element */ element) {
           window.setTimeout(callback, 1000/60);
         };
})();