Better error message when WebGL not found.

samples/o3d-webgl/client.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.
@@ skipping 174 matching lines @@
  * The only reason to look at this flag is for things like video that are
  * updating the texture every frame. In that case, you might want to know
  * that you could run faster if you used a power of 2 texture instead of
  * a non power of 2 texture.
  *
  * @type {boolean}
  */
 o3d.ClientInfo.prototype.non_power_of_two_textures = true;
 
 
+
+/**
+ * True if shaders need to be GLSL instead of Cg/HLSL.
+ * In this implementation of o3d, that is true by default.
+ **/
+o3d.ClientInfo.prototype.glsl = true;
+
+
+
 /**
  * The Client class is the main point of entry to O3D.  It defines methods
  * for creating and deleting packs. Each new object created by the Client is
  * assigned a unique ID.
  *
  * The Client has a root transform for the transform graph and a root render
  * node for the render graph.
  * @constructor
  */
 o3d.Client = function() {
   o3d.NamedObject.call(this);
 
   var tempPack = this.createPack();
   this.root = tempPack.createObject('Transform');
   this.renderGraphRoot = tempPack.createObject('RenderNode');
   this.clientId = o3d.Client.nextId++;
   this.packs_ = [tempPack];
+  this.clientInfo = tempPack.createObject('ClientInfo');
 
   if (o3d.Renderer.clients_.length == 0)
     o3d.Renderer.installRenderInterval();
 
   o3d.Renderer.clients_.push(this);
 };
 o3d.inherit('Client', 'NamedObject');
 
 /**
  * @type {function(!o3d.RenderEvent): void}
@@ skipping 345 matching lines @@
 o3d.Client.prototype.__defineSetter__('height',
     function(x) {
       this.gl.hack_canvas.height = x;
     }
 );
 
 
 /**
  * Initializes this client using the canvas.
  * @param {Canvas}
+ * @return {boolean} Success.
  */
 o3d.Client.prototype.initWithCanvas = function(canvas) {
   var gl;
 
   var standard_attributes = {
     alpha : true,
     depth : true,
     stencil : true,
     antialias : true,
     premultipliedAlpha : true
   };
 
+  if (!canvas || !canvas.getContext) {
+    return false;
+  }
   try {gl = canvas.getContext("experimental-webgl", standard_attributes) } catch(e) { }
-  if (!gl)
-      try {gl = canvas.getContext("moz-webgl") } catch(e) { }
   if (!gl) {
-      alert("No WebGL context found");
-      return null;
+    try {
+      gl = canvas.getContext("moz-webgl")
+    } catch(e) { }
   }
 
-  // TODO(petersont): hack workaround for WebGLRenderingContext.canvas
-  // not being implemented in Firefox. Remove.
+  if (!gl) {
+    return false;
+  }
+
+  // TODO(petersont): Remove this workaround once WebGLRenderingContext.canvas
+  // is implemented in Firefox.
   gl.hack_canvas = canvas;
   this.gl = gl;
   this.root.gl = gl;
   this.renderGraphRoot.gl = gl;
 
   gl.client = this;
   gl.displayInfo = {width: canvas.width,
                     height: canvas.height};
+
+  return true;
 };
 
 
 /**
  * Sets the per frame render callback.
  *
  * Note: The callback will not be called recursively. When your callback is
  * called if you somehow manage to cause the client to render more frames
  * before you've returned from the callback you will not be called for those
  * frames.
@@ skipping 452 matching lines @@
 
 /**
  * A unique id for this client.
  * @type {number}
  */
 o3d.Client.prototype.clientId = 0;
 
 
 
 /**
+ * Gets info about the client.
+ */
+o3d.Client.prototype.clientInfo = null;
+
+
+/**
  * The canvas associated with this client.
  * @type {Element}
  */
 o3d.Client.prototype.canvas = null;