# - Try to find GLEW
# Once done this will define
#  
#  GLEW_FOUND        - system has GLEW
#  GLEW_INCLUDE_DIR  - the GLEW include directory
#  GLEW_LIBRARY_DIR  - where the libraries are
#  GLEW_LIBRARY      - Link these to use GLEW
#   

IF (GLEW_INCLUDE_DIR)
  # Already in cache, be silent
  SET(GLEW_FIND_QUIETLY TRUE)
ENDIF (GLEW_INCLUDE_DIR)

if( WIN32 )

   # Check if the base path is set
   if ( NOT CMAKE_WINDOWS_LIBS_DIR )
     # This is the base directory for windows library search used in the finders we shipp.
     set(CMAKE_WINDOWS_LIBS_DIR "c:\libs" CACHE STRING "Default Library search dir on windows." )
   endif()

   if ( CMAKE_GENERATOR MATCHES "^Visual Studio 11.*Win64" )
     SET(VS_SEARCH_PATH "${CMAKE_WINDOWS_LIBS_DIR}/vs2012/x64/")
   elseif ( CMAKE_GENERATOR MATCHES "^Visual Studio 11.*" )
     SET(VS_SEARCH_PATH "${CMAKE_WINDOWS_LIBS_DIR}/vs2012/x32/")
   elseif ( CMAKE_GENERATOR MATCHES "^Visual Studio 12.*Win64" )
     SET(VS_SEARCH_PATH "${CMAKE_WINDOWS_LIBS_DIR}/vs2013/x64/")
   elseif ( CMAKE_GENERATOR MATCHES "^Visual Studio 12.*" )
     SET(VS_SEARCH_PATH "${CMAKE_WINDOWS_LIBS_DIR}/vs2013/x32/")
   elseif ( CMAKE_GENERATOR MATCHES "^Visual Studio 14.*Win64" )
     SET(VS_SEARCH_PATH "${CMAKE_WINDOWS_LIBS_DIR}/vs2015/x64/")
   elseif ( CMAKE_GENERATOR MATCHES "^Visual Studio 14.*" )
     SET(VS_SEARCH_PATH "${CMAKE_WINDOWS_LIBS_DIR}/vs2015/x32/")
   elseif ( CMAKE_GENERATOR MATCHES "^Visual Studio 15.*Win64" )
     SET(VS_SEARCH_PATH "${CMAKE_WINDOWS_LIBS_DIR}/vs2017/x64/")
   elseif ( CMAKE_GENERATOR MATCHES "^Visual Studio 15.*" )
     SET(VS_SEARCH_PATH "${CMAKE_WINDOWS_LIBS_DIR}/vs2017/x32/")
   endif()

   if( MSVC80 )
       set( COMPILER_PATH "C:/Program\ Files/Microsoft\ Visual\ Studio\ 8/VC" )
   endif( MSVC80 )
   if( MSVC71 )
       set( COMPILER_PATH "C:/Program\ Files/Microsoft\ Visual\ Studio\ .NET\ 2003/Vc7" )
   endif( MSVC71 )

   FIND_PATH( GLEW_INCLUDE_DIR gl/glew.h gl/wglew.h
              PATHS "${CMAKE_WINDOWS_LIBS_DIR}/glew/include" 
                    "${CMAKE_WINDOWS_LIBS_DIR}/glew-1.6.0/include" 
                    ${COMPILER_PATH}/PlatformSDK/Include 
  		    "${VS_SEARCH_PATH}glew-2.0.0/include"
                    "${VS_SEARCH_PATH}glew-1.10.0/include"
                    "${VS_SEARCH_PATH}glew-1.13.0/include")

   SET( GLEW_NAMES glew32 )
   FIND_LIBRARY( GLEW_LIBRARY
                 NAMES ${GLEW_NAMES}
                 PATHS "${CMAKE_WINDOWS_LIBS_DIR}/glew/lib" 
                       "${CMAKE_WINDOWS_LIBS_DIR}/glew-1.6.0/lib" 
                       ${COMPILER_PATH}/PlatformSDK/Lib 
  		       "${VS_SEARCH_PATH}glew-2.0.0/lib"
                       "${VS_SEARCH_PATH}glew-1.10.0/lib" 
                       "${VS_SEARCH_PATH}glew-1.13.0/lib" )

else( WIN32 )
   FIND_PATH( GLEW_INCLUDE_DIR GL/glew.h GL/wglew.h
              PATHS /usr/local/include /usr/include )
   SET( GLEW_NAMES glew GLEW )
   FIND_LIBRARY( GLEW_LIBRARY
                 NAMES ${GLEW_NAMES}
                 PATHS /usr/lib /usr/local/lib )
endif( WIN32 )

GET_FILENAME_COMPONENT( GLEW_LIBRARY_DIR ${GLEW_LIBRARY} PATH )

IF (GLEW_INCLUDE_DIR AND GLEW_LIBRARY)
   SET(GLEW_FOUND TRUE)
ELSE (GLEW_INCLUDE_DIR AND GLEW_LIBRARY)
   SET( GLEW_FOUND FALSE )
   SET( GLEW_LIBRARY_DIR )
ENDIF (GLEW_INCLUDE_DIR AND GLEW_LIBRARY)