sawine@6: /*
sawine@6:  * Copyright 2010, Google Inc.
sawine@6:  * All rights reserved.
sawine@6:  *
sawine@6:  * Redistribution and use in source and binary forms, with or without
sawine@6:  * modification, are permitted provided that the following conditions are
sawine@6:  * met:
sawine@6:  *
sawine@6:  *     * Redistributions of source code must retain the above copyright
sawine@6:  * notice, this list of conditions and the following disclaimer.
sawine@6:  *     * Redistributions in binary form must reproduce the above
sawine@6:  * copyright notice, this list of conditions and the following disclaimer
sawine@6:  * in the documentation and/or other materials provided with the
sawine@6:  * distribution.
sawine@6:  *     * Neither the name of Google Inc. nor the names of its
sawine@6:  * contributors may be used to endorse or promote products derived from
sawine@6:  * this software without specific prior written permission.
sawine@6:  *
sawine@6:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
sawine@6:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
sawine@6:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
sawine@6:  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
sawine@6:  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
sawine@6:  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
sawine@6:  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
sawine@6:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
sawine@6:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
sawine@6:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
sawine@6:  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
sawine@6:  */
sawine@6: 
sawine@6: 
sawine@6: /**
sawine@6:  * @fileoverview This file contains functions every webgl program will need
sawine@6:  * a version of one way or another.
sawine@6:  *
sawine@6:  * Instead of setting up a context manually it is recommended to
sawine@6:  * use. This will check for success or failure. On failure it
sawine@6:  * will attempt to present an approriate message to the user.
sawine@6:  *
sawine@6:  *       gl = WebGLUtils.setupWebGL(canvas);
sawine@6:  *
sawine@6:  * For animated WebGL apps use of setTimeout or setInterval are
sawine@6:  * discouraged. It is recommended you structure your rendering
sawine@6:  * loop like this.
sawine@6:  *
sawine@6:  *       function render() {
sawine@6:  *         window.requestAnimFrame(render, canvas);
sawine@6:  *
sawine@6:  *         // do rendering
sawine@6:  *         ...
sawine@6:  *       }
sawine@6:  *       render();
sawine@6:  *
sawine@6:  * This will call your rendering function up to the refresh rate
sawine@6:  * of your display but will stop rendering if your app is not
sawine@6:  * visible.
sawine@6:  */
sawine@6: 
sawine@6: WebGLUtils = function() {
sawine@6: 
sawine@6: /**
sawine@6:  * Creates the HTLM for a failure message
sawine@6:  * @param {string} canvasContainerId id of container of th
sawine@6:  *        canvas.
sawine@6:  * @return {string} The html.
sawine@6:  */
sawine@6: var makeFailHTML = function(msg) {
sawine@6:   return '' +
sawine@6:     '<table style="background-color: #8CE; width: 100%; height: 100%;"><tr>' +
sawine@6:     '<td align="center">' +
sawine@6:     '<div style="display: table-cell; vertical-align: middle;">' +
sawine@6:     '<div style="">' + msg + '</div>' +
sawine@6:     '</div>' +
sawine@6:     '</td></tr></table>';
sawine@6: };
sawine@6: 
sawine@6: /**
sawine@6:  * Mesasge for getting a webgl browser
sawine@6:  * @type {string}
sawine@6:  */
sawine@6: var GET_A_WEBGL_BROWSER = '' +
sawine@6:   'This page requires a browser that supports WebGL.<br/>' +
sawine@6:   '<a href="http://get.webgl.org">Click here to upgrade your browser.</a>';
sawine@6: 
sawine@6: /**
sawine@6:  * Mesasge for need better hardware
sawine@6:  * @type {string}
sawine@6:  */
sawine@6: var OTHER_PROBLEM = '' +
sawine@6:   "It doesn't appear your computer can support WebGL.<br/>" +
sawine@6:   '<a href="http://get.webgl.org/troubleshooting/">Click here for more information.</a>';
sawine@6: 
sawine@6: /**
sawine@6:  * Creates a webgl context. If creation fails it will
sawine@6:  * change the contents of the container of the <canvas>
sawine@6:  * tag to an error message with the correct links for WebGL.
sawine@6:  * @param {Element} canvas. The canvas element to create a
sawine@6:  *     context from.
sawine@6:  * @param {WebGLContextCreationAttirbutes} opt_attribs Any
sawine@6:  *     creation attributes you want to pass in.
sawine@6:  * @return {WebGLRenderingContext} The created context.
sawine@6:  */
sawine@6: var setupWebGL = function(canvas, opt_attribs) {
sawine@6:   function showLink(str) {
sawine@6:     var container = canvas.parentNode;
sawine@6:     if (container) {
sawine@6:       container.innerHTML = makeFailHTML(str);
sawine@6:     }
sawine@6:   };
sawine@6: 
sawine@6:   if (!window.WebGLRenderingContext) {
sawine@6:     showLink(GET_A_WEBGL_BROWSER);
sawine@6:     return null;
sawine@6:   }
sawine@6: 
sawine@6:   var context = create3DContext(canvas, opt_attribs);
sawine@6:   if (!context) {
sawine@6:     showLink(OTHER_PROBLEM);
sawine@6:   }
sawine@6:   return context;
sawine@6: };
sawine@6: 
sawine@6: /**
sawine@6:  * Creates a webgl context.
sawine@6:  * @param {!Canvas} canvas The canvas tag to get context
sawine@6:  *     from. If one is not passed in one will be created.
sawine@6:  * @return {!WebGLContext} The created context.
sawine@6:  */
sawine@6: var create3DContext = function(canvas, opt_attribs) {
sawine@6:   var names = ["webgl", "experimental-webgl", "webkit-3d", "moz-webgl"];
sawine@6:   var context = null;
sawine@6:   for (var ii = 0; ii < names.length; ++ii) {
sawine@6:     try {
sawine@6:       context = canvas.getContext(names[ii], opt_attribs);
sawine@6:     } catch(e) {}
sawine@6:     if (context) {
sawine@6:       break;
sawine@6:     }
sawine@6:   }
sawine@6:   return context;
sawine@6: }
sawine@6: 
sawine@6: return {
sawine@6:   create3DContext: create3DContext,
sawine@6:   setupWebGL: setupWebGL
sawine@6: };
sawine@6: }();
sawine@6: 
sawine@6: /**
sawine@6:  * Provides requestAnimationFrame in a cross browser way.
sawine@6:  */
sawine@6: window.requestAnimFrame = (function() {
sawine@6:   return window.requestAnimationFrame ||
sawine@6:          window.webkitRequestAnimationFrame ||
sawine@6:          window.mozRequestAnimationFrame ||
sawine@6:          window.oRequestAnimationFrame ||
sawine@6:          window.msRequestAnimationFrame ||
sawine@6:          function(/* function FrameRequestCallback */ callback, /* DOMElement Element */ element) {
sawine@6:            window.setTimeout(callback, 1000/60);
sawine@6:          };
sawine@6: })();
sawine@6: 
sawine@6: