Added raytracer to gl samples.

samples/simplegl/web/simplegl.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/**
- * A sample GL application.
- */
-library simplegl;
-
-import 'gl.dart';
-
-num r;
-num g;
-num b;
-
-/**
- * Invoked on initial startup.
- */
-void setup(GlContext gl) {
-  r = 0;
-  g = 0;
-  b = 0;
-}
-
-/**
- * Invoked on each frame render.
- */
-void draw(GlContext gl) {
-  gl.clearColor(r, g, b, 1.0);
-  gl.clear(gl.COLOR_BUFFER_BIT |
-      gl.DEPTH_BUFFER_BIT);
-  r = r + 0.1;
-  if (r > 1) {
-    r = 0;
-    g = g + 0.1;
-  }
-  if (g > 1) {
-    g = 0;
-    b = b + 0.1;
-  }
-  if (b > 1) {
-    b = 0;
-  }
-}