# 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
  ~/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
  ~/Library/Frameworks
  /Library/Frameworks
  /opt
  [HKEY_LOCAL_MACHINE\\SOFTWARE\\Creative\ Labs\\OpenAL\ 1.1\ Software\ Development\ Kit\\1.00.0000;InstallDir]
)

unset(_OpenAL_ARCH_DIR)

include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(OpenAL  DEFAULT_MSG  OPENAL_LIBRARY OPENAL_INCLUDE_DIR)

mark_as_advanced(OPENAL_LIBRARY OPENAL_INCLUDE_DIR)