# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.

#[=======================================================================[.rst:
FindOpenAL
----------


Finds Open Audio Library (OpenAL).
This module defines ``OPENAL_LIBRARY OPENAL_FOUND``, if
false, do not try to link to OpenAL ``OPENAL_INCLUDE_DIR``, where to find
the headers.

``$OPENALDIR`` is an environment variable that would correspond to the
``./configure --prefix=$OPENALDIR`` used in building OpenAL.

Created by Eric Wing.  This was influenced by the ``FindSDL.cmake``
module.
#]=======================================================================]

# This makes the presumption that you are include al.h like
# #include "al.h"
# and not
# #include <AL/al.h>
# The reason for this is that the latter is not entirely portable.
# Windows/Creative Labs does not by default put their headers in AL/ and
# OS X uses the convention <OpenAL/al.h>.
#
# For Windows, Creative Labs seems to have added a registry key for their
# OpenAL 1.1 installer. I have added that key to the list of search paths,
# however, the key looks like it could be a little fragile depending on
# if they decide to change the 1.00.0000 number for bug fix releases.
# Also, they seem to have laid down groundwork for multiple library platforms
# which puts the library in an extra subdirectory. Currently there is only
# Win32 and I have hardcoded that here. This may need to be adjusted as
# platforms are introduced.
# The OpenAL 1.0 installer doesn't seem to have a useful key I can use.
# I do not know if the Nvidia OpenAL SDK has a registry key.
#
# For OS X, remember that OpenAL was added by Apple in 10.4 (Tiger).
# To support the framework, I originally wrote special framework detection
# code in this module which I have now removed with CMake's introduction
# of native support for frameworks.
# In addition, OpenAL is open source, and it is possible to compile on Panther.
# Furthermore, due to bugs in the initial OpenAL release, and the
# transition to OpenAL 1.1, it is common to need to override the built-in
# framework.
# Per my request, CMake should search for frameworks first in
# the following order:
# ~/Library/Frameworks/OpenAL.framework/Headers
# /Library/Frameworks/OpenAL.framework/Headers
# /System/Library/Frameworks/OpenAL.framework/Headers
#
# On OS X, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of
# OPENAL_LIBRARY to override this selection or set the CMake environment
# CMAKE_INCLUDE_PATH to modify the search paths.

find_path(OPENAL_INCLUDE_DIR al.h
  HINTS
    ENV OPENALDIR
  PATH_SUFFIXES include/AL include/OpenAL include AL OpenAL
  PATHS
  /
  ${OPENAL_ROOT}
  ~/Library/Frameworks
  /Library/Frameworks
  /opt
  [HKEY_LOCAL_MACHINE\\SOFTWARE\\Creative\ Labs\\OpenAL\ 1.1\ Software\ Development\ Kit\\1.00.0000;InstallDir]
)

if(CMAKE_SIZEOF_VOID_P EQUAL 8)
  set(_OpenAL_ARCH_DIR libs/Win64)
else()
  set(_OpenAL_ARCH_DIR libs/Win32)
endif()

find_library(OPENAL_LIBRARY
  NAMES OpenAL al openal OpenAL32
  HINTS
  ENV OPENALDIR
  PATH_SUFFIXES libx32 lib64 lib libs64 libs ${_OpenAL_ARCH_DIR}
  PATHS
  /
  ${OPENAL_ROOT}
  ~/Library/Frameworks
  /Library/Frameworks
  /opt
  [HKEY_LOCAL_MACHINE\\SOFTWARE\\Creative\ Labs\\OpenAL\ 1.1\ Software\ Development\ Kit\\1.00.0000;InstallDir]
)

set(_openal_framework FALSE)
# Some special-casing if we've found/been given a framework.
# Handles whether we're given the library inside the framework or the framework itself.
if(APPLE AND "${OPENAL_LIBRARY}" MATCHES "(/[^/]+)*.framework(/.*)?$")
    set(_openal_framework TRUE)
    set(OPENAL_FRAMEWORK "${OPENAL_LIBRARY}")
    # Move up in the directory tree as required to get the framework directory.
    while("${OPENAL_FRAMEWORK}" MATCHES "(/[^/]+)*.framework(/.*)$" AND NOT "${OPENAL_FRAMEWORK}" MATCHES "(/[^/]+)*.framework$")
        get_filename_component(OPENAL_FRAMEWORK "${OPENAL_FRAMEWORK}" DIRECTORY)
    endwhile()
    if("${OPENAL_FRAMEWORK}" MATCHES "(/[^/]+)*.framework$")
        set(OPENAL_FRAMEWORK_NAME ${CMAKE_MATCH_1})
        if(EXISTS "${OPENAL_FRAMEWORK}${OPENAL_FRAMEWORK_NAME}.tbd")
            set(OPENAL_FRAMEWORK_NAME "${OPENAL_FRAMEWORK_NAME}.tbd")
        endif()
    else()
        # For some reason we couldn't get the framework directory itself.
        # Shouldn't happen, but might if something is weird.
        unset(OPENAL_FRAMEWORK)
    endif()
endif()

if(CMAKE_SIZEOF_VOID_P EQUAL 8)
  set(_OpenAL_ARCH_DIR bin/Win64)
else()
  set(_OpenAL_ARCH_DIR bin/Win32)
endif()

if(WIN32 AND OPENAL_LIBRARY)
    find_file(OPENAL_RUNTIME_LIBRARY
        NAMES
        OpenAL32.dll
        libOpenAL32.dll
        HINTS
        ENV OPENALDIR
        PATHS
        ${OPENAL_ROOT}
        ~/Library/Frameworks
        /Library/Frameworks
        /opt
        [HKEY_LOCAL_MACHINE\\SOFTWARE\\Creative\ Labs\\OpenAL\ 1.1\ Software\ Development\ Kit\\1.00.0000;InstallDir]
        PATH_SUFFIXES bin lib ${_OpenAL_ARCH_DIR})
endif()

unset(_OpenAL_ARCH_DIR)

include(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(OpenAL  DEFAULT_MSG  OPENAL_LIBRARY OPENAL_INCLUDE_DIR)

if(OPENAL_FOUND)
    if(NOT TARGET OpenAL::OpenAL)
        add_library(OpenAL::OpenAL UNKNOWN IMPORTED)
        if(OPENAL_FRAMEWORK AND OPENAL_FRAMEWORK_NAME)
                # Handle the case that OPENAL is a framework and we were able to decompose it above.
                set_target_properties(OpenAL::OpenAL PROPERTIES
                    IMPORTED_LOCATION "${OPENAL_FRAMEWORK}/${OPENAL_FRAMEWORK_NAME}"
                )
        else()
            set_target_properties(OpenAL::OpenAL PROPERTIES 
                IMPORTED_LOCATION ${OPENAL_LIBRARY}
            )
        endif()
        set_target_properties(OpenAL::OpenAL PROPERTIES 
            INTERFACE_INCLUDE_DIRECTORIES ${OPENAL_INCLUDE_DIR}
        )
    endif()
endif()

mark_as_advanced(OPENAL_LIBRARY OPENAL_INCLUDE_DIR OPENAL_RUNTIME_LIBRARY)