Refactored OpenGL embedder that works on Android, Mac or Linux.

runtime/embedders/openglui/common/opengl.h

Index: runtime/embedders/openglui/common/opengl.h
===================================================================
--- runtime/embedders/openglui/common/opengl.h	(revision 0)
+++ runtime/embedders/openglui/common/opengl.h	(revision 0)
@@ -0,0 +1,43 @@
+// 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.
+
+#ifndef EMBEDDERS_OPENGLUI_COMMON_OPENGL_H_
+#define EMBEDDERS_OPENGLUI_COMMON_OPENGL_H_
+
+#if defined(__APPLE__)
+#  ifdef GL_ES_VERSION_2_0
+#    include <OpenGLES/ES2/gl.h>
+#  else
+#    include <Glut/glut.h>
+#    include <OpenGL/gl.h>
+#  endif

[vsm, 2013/01/14 21:31:40]

Why the funny spacing with '#'?  It is inconsistent with the below.

Looks like either style is ok:
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Type_N...
but we should be consistent.

[gram, 2013/01/16 01:49:16]

Done.

+    #define GLSwapBuffers()    glutSwapBuffers()
+#elif defined(_WIN32) || defined(_WIN64)
+    #include <GL/glew.h>
+    #include <GL/wglew.h>
+    #include <GLUT/glut.h>  // changed according to your path of glut.h
+    #include <Windows.h>
+    #define GLSwapBuffers()    glutSwapBuffers()
+#elif defined(__ANDROID__)
+    #include <EGL/egl.h>
+    #include <GLES2/gl2.h>
+    #include <GLES2/gl2ext.h>
+
+    #define GLSwapBuffers() \
+        do {\
+            EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY); \
+            EGLSurface surface = eglGetCurrentSurface(EGL_DRAW); \
+            eglSwapBuffers(display, surface); \
+        } while (0);
+
+#else
+#define GL_GLEXT_PROTOTYPES 1
+    #include <GL/gl.h>
+    #include <GL/glext.h>
+    #include <GL/glut.h>
+    #define GLSwapBuffers()    glutSwapBuffers()
+#endif
+
+#endif  // EMBEDDERS_OPENGLUI_COMMON_OPENGL_H_
+