better to find mac opengl

Modules/FindOpenGL.cmake

@@ -13,20 +13,23 @@ IF (WIN32)
     SET (OPENGL_LIBRARY opengl32 CACHE STRING "OpenGL library for win32")
   ENDIF(BORLAND)
 ELSE (WIN32)
-  FIND_PATH(OPENGL_INCLUDE_PATH GL/gl.h 
-  /usr/include 
-  /usr/local/include 
-  /usr/openwin/share/include 
-  /opt/graphics/OpenGL/include 
-  /usr/X11R6/include 
-  )
-
-  FIND_LIBRARY(OPENGL_LIBRARY GL
-  /usr/lib 
-  /usr/local/lib 
-  /opt/graphics/OpenGL/lib 
-  /usr/openwin/lib 
-  /usr/X11R6/lib
-  )
-
+  IF (APPLE)
+    SET(OPENGL_LIBRARY "-framework AppKit -framework OpenGL" CACHE STRING "OpenGL library for OSX")
+  ELSE (APPLE)
+     FIND_PATH(OPENGL_INCLUDE_PATH GL/gl.h 
+     /usr/include 
+     /usr/local/include 
+     /usr/openwin/share/include 
+     /opt/graphics/OpenGL/include 
+     /usr/X11R6/include 
+     )
+   
+     FIND_LIBRARY(OPENGL_LIBRARY GL
+     /usr/lib 
+     /usr/local/lib 
+     /opt/graphics/OpenGL/lib 
+     /usr/openwin/lib 
+     /usr/X11R6/lib
+     )
+   ENDIF (APPLE)
 ENDIF (WIN32)