avoid duplicate pkg-config calls and make sure to use the pkg-config paths when found
# - Try to find the OggVorbis libraries# Once done this will define## OGGVORBIS_FOUND - system has both Ogg and Vorbis# OGGVORBIS_VERSION - set either to 1 or 2# OGGVORBIS_INCLUDE_DIR - the OggVorbis include directory# OGGVORBIS_LIBRARIES - the libraries needed to use OggVorbis## OGG_LIBRARY - the Ogg library# OGG_INCLUDE_DIR - the Ogg include directory# VORBIS_LIBRARY - the Vorbis library# VORBIS_INCLUDE_DIR - the Vorbis include directory# VORBISFILE_LIBRARY - the VorbisFile library## Copyright (c) 2006, Richard Laerkaeng <richard@goteborg.utfors.se># Copyright (c) 2013, Vittorio Giovara <vittorio.giovara@gmail.com>## Redistribution and use is allowed according to the terms of the BSD license.# For details see the accompanying COPYING-CMAKE-SCRIPTS file.### sommer [SuperTux]## - Removed unused vorbisenc library## - reversed order of libraries, so that cmake 2.4.5 for Windows generates an MSYS Makefile that will link correctly### koda [Hedgewars]## - split ogg and vorbis lookup## - special case for framework handling## - standard variables handlinginclude (CheckLibraryExists)include (FindPackageHandleStandardArgs)find_path(OGG_INCLUDE_DIR ogg.h PATH_SUFFIXES ogg)find_path(VORBIS_INCLUDE_DIR vorbisfile.h PATH_SUFFIXES vorbis)find_library(OGG_LIBRARY NAMES Ogg ogg)find_library(VORBIS_LIBRARY NAMES Vorbis vorbis)find_library(VORBISFILE_LIBRARY NAMES vorbisfile)set(_CMAKE_REQUIRED_LIBRARIES_TMP ${CMAKE_REQUIRED_LIBRARIES})set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} ${OGGVORBIS_LIBRARIES})check_library_exists(${VORBIS_LIBRARY} vorbis_bitrate_addblock "" HAVE_LIBVORBISENC2)set(CMAKE_REQUIRED_LIBRARIES ${_CMAKE_REQUIRED_LIBRARIES_TMP})if(HAVE_LIBVORBISENC2) set(OGGVORBIS_VERSION 2)else(HAVE_LIBVORBISENC2) set(OGGVORBIS_VERSION 1)endif(HAVE_LIBVORBISENC2)if(${OGG_LIBRARY} MATCHES ".framework" AND ${VORBIS_LIBRARY} MATCHES ".framework") set(VORBISFILE_LIBRARY "") #vorbisfile will appear as NOTFOUND and discarded set(fphsa_vorbis_list VORBIS_LIBRARY)else() set(fphsa_vorbis_list VORBISFILE_LIBRARY VORBIS_LIBRARY)endif()find_package_handle_standard_args(OggVorbis DEFAULT_MSG ${fphsa_vorbis_list} OGG_LIBRARY OGG_INCLUDE_DIR VORBIS_INCLUDE_DIR)unset(fphsa_vorbis_list)set(OGGVORBIS_LIBRARIES ${VORBISFILE_LIBRARY} ${VORBIS_LIBRARY} ${OGG_LIBRARY})set(OGGVORBIS_INCLUDE_DIR ${VORBIS_INCLUDE_DIR} ${OGG_INCLUDE_DIR})mark_as_advanced(OGGVORBIS_VERSION OGGVORBIS_INCLUDE_DIR OGGVORBIS_LIBRARIES OGG_LIBRARY OGG_INCLUDE_DIR VORBIS_LIBRARY VORBIS_INCLUDE_DIR VORBISFILE_LIBRARY)