Merge r11677:11678 from trunk into the Qt branch: add a platform-abstraction header: `opengl.h`

Add a header to allow platform-indepent inclusion of the OpenGL API,
removing our dependency on SDL_opengl.h and consolidating
platform-specific code in that single header.

git-svn-id: https://warzone2100.svn.sourceforge.net/svnroot/warzone2100/branches/qt-trunk@11679 4a71c877-e1ca-e34f-864e-861f7616d084

lib/framework/opengl.h

@@ -0,0 +1,48 @@
+/*
+	This file is part of Warzone 2100.
+	Copyright (C) 2010  Giel van Schijndel
+	Copyright (C) 2010  Warzone 2100 Project
+
+	Warzone 2100 is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+
+	Warzone 2100 is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with Warzone 2100; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+*/
+/** @file
+ *  @brief Platform independent OpenGL inclusion.
+ */
+
+#ifndef __INCLUDED_LIB_FRAMEWORK_OPENGL_H__
+#define __INCLUDED_LIB_FRAMEWORK_OPENGL_H__
+
+#include "wzglobal.h"
+
+#if defined(__glext_h_)
+# define FRAMEWORK_GLEXT_INCLUDED
+#else
+// Prevent inclusion of glext.h by gl.h, requiring explicit inclusion by the user
+# define __glext_h_
+#endif
+
+#if   defined(WZ_OS_MAC)
+# include <OpenGL/gl.h>
+#else
+# include <GL/gl.h>
+#endif
+
+#if defined(FRAMEWORK_GLEXT_INCLUDED)
+# undef FRAMEWORK_GLEXT_INCLUDED
+#else
+# undef __glext_h_
+#endif
+
+#endif

lib/ivis_common/tex.h

@@ -20,12 +20,7 @@
 #ifndef _tex_
 #define _tex_
 
-//#include <GLee.h>
-#if defined __APPLE__ && defined __MACH__
-#include <OpenGL/gl.h>
-#else
-#include <GL/gl.h>
-#endif
+#include "lib/framework/opengl.h"
 #include "png_util.h"
 
 #ifdef __cplusplus

lib/ivis_opengl/piestate.c

@@ -30,6 +30,13 @@
 #include "lib/framework/frame.h"
 
 #include <physfs.h>
+#include "lib/framework/opengl.h"
+
+#if defined(WZ_OS_MAC)
+# include <OpenGL/glu.h>
+#else
+# include <GL/glu.h>
+#endif
 
 #include "lib/ivis_common/piestate.h"
 #include "lib/ivis_common/piedef.h"

lib/ivis_opengl/tex.c

@@ -22,9 +22,9 @@
 #include "lib/framework/frame.h"
 
 #if defined(WZ_OS_MAC)
-#include <OpenGL/glu.h>
+# include <OpenGL/glu.h>
 #else
-#include <GL/glu.h>
+# include <GL/glu.h>
 #endif
 
 #include "lib/ivis_common/ivisdef.h"