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

runtime/embedders/openglui/common/opengl.h

+// Copyright (c) 2013, 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 semi-generic header file that can be used to isolate platform differences
+// for OpenGL headers.
+#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
+#  define GLSwapBuffers()    glutSwapBuffers()
+#elif defined(_WIN32) || defined(_WIN64)
+#  include <GL/glew.h>
+#  include <GL/wglew.h>
+#  include <GLUT/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  // Linux.
+#  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_
+