# - Find OPENAL
# Find the native OPENAL headers
#
#  OPENAL_INCLUDE_DIR  - where to find OPENAL.h, etc.
#  OPENAL_LIBRARIES    - OPENAL library
#  OPENAL_FOUND        - True if OPENAL found.

IF(OPENAL_FOUND)
    # Already in cache, be silent
    SET(OPENAL_FIND_QUIETLY TRUE)
ENDIF()

IF(BUILD_OPENAL OR ACGL_GLOBAL_EXTERN_DIR_FOUND_FIRST_TIME OR BUILD_TYPE_CHANGED)
    UNSET(OPENAL_INCLUDE_DIR CACHE)
    UNSET(OPENAL_LIBRARIES CACHE)
ENDIF()

IF(BUILD_OPENAL)
    SET(OPENAL_INCLUDE_DIR "${ACGL_LOCAL_EXTERN_DIR}/openal/include")
    SET(OPENAL_LIBRARIES openal${COMPILE_POSTFIX})
ELSE()
    # Look for the header file.
    IF(ACGL_GLOBAL_EXTERN_DIR)
        FIND_PATH(OPENAL_INCLUDE_DIR NAMES AL/al.h PATHS "${ACGL_GLOBAL_EXTERN_DIR}/openal/include" NO_DEFAULT_PATH)
    ENDIF()
    IF(NOT OPENAL_INCLUDE_DIR)
        FIND_PATH(OPENAL_INCLUDE_DIR NAMES AL/al.h)
    ENDIF()

    # Look for the library file.
    IF(ACGL_GLOBAL_EXTERN_DIR)
        FIND_LIBRARY(OPENAL_LIBRARIES NAMES openal${COMPILE_POSTFIX} PATHS "${ACGL_GLOBAL_EXTERN_DIR}/openal/lib" NO_DEFAULT_PATH)
    ENDIF()
    IF(NOT OPENAL_LIBRARIES)
        FIND_LIBRARY(OPENAL_LIBRARIES NAMES openal${COMPILE_POSTFIX})
    ENDIF()
ENDIF()

# Copy the results to the output variables.
IF(OPENAL_INCLUDE_DIR AND OPENAL_LIBRARIES)
    SET(OPENAL_FOUND TRUE CACHE INTERNAL "")
ELSE()
    SET(OPENAL_FOUND FALSE CACHE INTERNAL "")
ENDIF()

# Report the results.
IF(NOT OPENAL_FOUND)
    SET(OPENAL_MESSAGE "OPENAL was not found. Make sure OPENAL_INCLUDE_DIR AND OPENAL_LIBRARIES are set correctly.")
    IF(OPENAL_FIND_REQUIRED)
        MESSAGE(FATAL_ERROR "${OPENAL_MESSAGE}")
    ELSEIF(NOT OPENAL_FIND_QUIETLY)
        MESSAGE(STATUS "${OPENAL_MESSAGE}")
    ENDIF()
ELSEIF(NOT OPENAL_FIND_QUIETLY)
    MESSAGE(STATUS "Looking for OPENAL - found")
ENDIF()

MESSAGE(STATUS "OPENAL_INCLUDE_DIR:${OPENAL_INCLUDE_DIR}")
MESSAGE(STATUS "OPENAL_LIBRARIES:${OPENAL_LIBRARIES}")