Fixes for non-native SDL builds on OS X [Paulo Cabral]

src/osd/sdl/osd_opengl.h

@@ -32,6 +32,17 @@
 #endif
 	#ifdef USE_DISPATCH_GL
 
+#ifdef MACOSX_USE_LIBSDL
+	#ifndef APIENTRY
+	#define APIENTRY
+	#endif
+	
+	#include "GL/gl.h"
+	#include "GL/glext.h"
+
+	typedef void (APIENTRY * PFNGLACTIVETEXTUREARBPROC) (GLenum target);
+#endif
+
 	#define OSD_GL(ret,func,params) ret (APIENTRY *func) params;
 	#define OSD_GL_UNUSED(ret,func,params)
 

src/osd/sdl/sdl.mak

@@ -420,6 +420,7 @@ INCPATH += `sdl-config --cflags | sed 's:/SDL::'`
 CCOMFLAGS += -DNO_SDL_GLEXT
 # Remove libSDLmain, as its symbols conflict with SDLMain_tmpl.m
 LIBS += `sdl-config --libs | sed 's/-lSDLmain//'` -lpthread
+DEFS += -DMACOSX_USE_LIBSDL
 endif
 
 endif	# Mac OS X