Add OGG_INCLUDE_DIR to SOUND_INCLUDE_DIRS

cmake/Modules/FindVorbis.cmake

@@ -2,6 +2,7 @@
 # Find the native vorbis includes and libraries
 #
 #  VORBIS_INCLUDE_DIR - where to find vorbis.h, etc.
+#  OGG_INCLUDE_DIR    - where to find ogg/ogg.h, etc.
 #  VORBIS_LIBRARIES   - List of libraries when using vorbis(file).
 #  VORBIS_FOUND       - True if vorbis found.
 

src/CMakeLists.txt

@@ -74,6 +74,7 @@ if(USE_SOUND)
 	set(SOUND_INCLUDE_DIRS
 		${OPENAL_INCLUDE_DIR}
 		${VORBIS_INCLUDE_DIR}
+		${OGG_INCLUDE_DIR}
 		)
 	set(SOUND_LIBRARIES
 		${OPENAL_LIBRARY}