superbuild/modules/openal-soft/cmake/FindSDL_sound.cmake

# - Locates the SDL_sound library
#
# This module depends on SDL being found and
# must be called AFTER FindSDL.cmake or FindSDL2.cmake is called.
#
# This module defines
#  SDL_SOUND_INCLUDE_DIR, where to find SDL_sound.h
#  SDL_SOUND_FOUND, if false, do not try to link to SDL_sound
#  SDL_SOUND_LIBRARIES, this contains the list of libraries that you need
#    to link against. This is a read-only variable and is marked INTERNAL.
#  SDL_SOUND_EXTRAS, this is an optional variable for you to add your own
#    flags to SDL_SOUND_LIBRARIES. This is prepended to SDL_SOUND_LIBRARIES.
#    This is available mostly for cases this module failed to anticipate for
#    and you must add additional flags. This is marked as ADVANCED.
#  SDL_SOUND_VERSION_STRING, human-readable string containing the version of SDL_sound
#
# This module also defines (but you shouldn't need to use directly)
#   SDL_SOUND_LIBRARY, the name of just the SDL_sound library you would link
#   against. Use SDL_SOUND_LIBRARIES for you link instructions and not this one.
# And might define the following as needed
#   MIKMOD_LIBRARY
#   MODPLUG_LIBRARY
#   OGG_LIBRARY
#   VORBIS_LIBRARY
#   SMPEG_LIBRARY
#   FLAC_LIBRARY
#   SPEEX_LIBRARY
#
# Typically, you should not use these variables directly, and you should use
# SDL_SOUND_LIBRARIES which contains SDL_SOUND_LIBRARY and the other audio libraries
# (if needed) to successfully compile on your system.
#
# Created by Eric Wing.
# This module is a bit more complicated than the other FindSDL* family modules.
# The reason is that SDL_sound can be compiled in a large variety of different ways
# which are independent of platform. SDL_sound may dynamically link against other 3rd
# party libraries to get additional codec support, such as Ogg Vorbis, SMPEG, ModPlug,
# MikMod, FLAC, Speex, and potentially others.
# Under some circumstances which I don't fully understand,
# there seems to be a requirement
# that dependent libraries of libraries you use must also be explicitly
# linked against in order to successfully compile. SDL_sound does not currently
# have any system in place to know how it was compiled.
# So this CMake module does the hard work in trying to discover which 3rd party
# libraries are required for building (if any).
# This module uses a brute force approach to create a test program that uses SDL_sound,
# and then tries to build it. If the build fails, it parses the error output for
# known symbol names to figure out which libraries are needed.
#
# Responds to the $SDLDIR and $SDLSOUNDDIR environmental variable that would
# correspond to the ./configure --prefix=$SDLDIR used in building SDL.
#
# On OSX, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of
# SDL_LIBRARY or SDL2_LIBRARY to override this selection or set the CMake
# environment CMAKE_INCLUDE_PATH to modify the search paths.

#=============================================================================
# Copyright 2005-2009 Kitware, Inc.
# Copyright 2012 Benjamin Eikel
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
#  License text for the above reference.)

set(SDL_SOUND_EXTRAS "" CACHE STRING "SDL_sound extra flags")
mark_as_advanced(SDL_SOUND_EXTRAS)

# Find SDL_sound.h
find_path(SDL_SOUND_INCLUDE_DIR SDL_sound.h
    HINTS
        ENV SDLSOUNDDIR
        ENV SDLDIR
    PATH_SUFFIXES SDL SDL12 SDL11
)

find_library(SDL_SOUND_LIBRARY
    NAMES SDL_sound
    HINTS
        ENV SDLSOUNDDIR
        ENV SDLDIR
)

if(SDL2_FOUND OR SDL_FOUND)
    if(SDL_SOUND_INCLUDE_DIR AND SDL_SOUND_LIBRARY)
        # CMake is giving me problems using TRY_COMPILE with the CMAKE_FLAGS
        # for the :STRING syntax if I have multiple values contained in a
        # single variable. This is a problem for the SDL2_LIBRARY variable
        # because it does just that. When I feed this variable to the command,
        # only the first value gets the appropriate modifier (e.g. -I) and
        # the rest get dropped.
        # To get multiple single variables to work, I must separate them with a "\;"
        # I could go back and modify the FindSDL2.cmake module, but that's kind of painful.
        # The solution would be to try something like:
        # set(SDL2_TRY_COMPILE_LIBRARY_LIST "${SDL2_TRY_COMPILE_LIBRARY_LIST}\;${CMAKE_THREAD_LIBS_INIT}")
        # Instead, it was suggested on the mailing list to write a temporary CMakeLists.txt
        # with a temporary test project and invoke that with TRY_COMPILE.
        # See message thread "Figuring out dependencies for a library in order to build"
        # 2005-07-16
        #     try_compile(
        #             MY_RESULT
        #             ${CMAKE_BINARY_DIR}
        #             ${PROJECT_SOURCE_DIR}/DetermineSoundLibs.c
        #             CMAKE_FLAGS
        #                     -DINCLUDE_DIRECTORIES:STRING=${SDL2_INCLUDE_DIR}\;${SDL_SOUND_INCLUDE_DIR}
        #                     -DLINK_LIBRARIES:STRING=${SDL_SOUND_LIBRARY}\;${SDL2_LIBRARY}
        #             OUTPUT_VARIABLE MY_OUTPUT
        #     )

        # To minimize external dependencies, create a sdlsound test program
        # which will be used to figure out if additional link dependencies are
        # required for the link phase.
        file(WRITE ${PROJECT_BINARY_DIR}/CMakeTmp/DetermineSoundLibs.c
            "#include \"SDL_sound.h\"
            #include \"SDL.h\"
            int main(int argc, char* argv[])
            {
                Sound_AudioInfo desired;
                Sound_Sample* sample;

                SDL_Init(0);
                Sound_Init();

                /* This doesn't actually have to work, but Init() is a no-op
                 * for some of the decoders, so this should force more symbols
                 * to be pulled in.
                 */
                sample = Sound_NewSampleFromFile(argv[1], &desired, 4096);

                Sound_Quit();
                SDL_Quit();
                return 0;
            }"
        )

        # Calling
        # target_link_libraries(DetermineSoundLibs "${SDL_SOUND_LIBRARY} ${SDL2_LIBRARY})
        # causes problems when SDL2_LIBRARY looks like
        # /Library/Frameworks/SDL2.framework;-framework Cocoa
        # The ;-framework Cocoa seems to be confusing CMake once the OS X
        # framework support was added. I was told that breaking up the list
        # would fix the problem.
        set(TMP_LIBS "")
        if(SDL2_FOUND)
            set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARY} ${SDL2_LIBRARY})
            foreach(lib ${SDL_SOUND_LIBRARY} ${SDL2_LIBRARY})
                set(TMP_LIBS "${TMP_LIBS} \"${lib}\"")
            endforeach()
            set(TMP_INCLUDE_DIRS ${SDL2_INCLUDE_DIR} ${SDL_SOUND_INCLUDE_DIR})
        else()
            set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARY} ${SDL_LIBRARY})
            foreach(lib ${SDL_SOUND_LIBRARY} ${SDL_LIBRARY})
                set(TMP_LIBS "${TMP_LIBS} \"${lib}\"")
            endforeach()
            set(TMP_INCLUDE_DIRS ${SDL_INCLUDE_DIR} ${SDL_SOUND_INCLUDE_DIR})
        endif()

        # Keep trying to build a temp project until we find all missing libs.
        set(TRY_AGAIN TRUE)
        WHILE(TRY_AGAIN)
            set(TRY_AGAIN FALSE)
            # message("TMP_TRY_LIBS ${TMP_TRY_LIBS}")

            # Write the CMakeLists.txt and test project
            # Weird, this is still sketchy. If I don't quote the variables
            # in the TARGET_LINK_LIBRARIES, I seem to loose everything
            # in the SDL2_LIBRARY string after the "-framework".
            # But if I quote the stuff in INCLUDE_DIRECTORIES, it doesn't work.
            file(WRITE ${PROJECT_BINARY_DIR}/CMakeTmp/CMakeLists.txt
                "cmake_minimum_required(VERSION 2.8)
                project(DetermineSoundLibs C)
                include_directories(${TMP_INCLUDE_DIRS})
                add_executable(DetermineSoundLibs DetermineSoundLibs.c)
                target_link_libraries(DetermineSoundLibs ${TMP_LIBS})"
            )

            try_compile(
                MY_RESULT
                ${PROJECT_BINARY_DIR}/CMakeTmp
                ${PROJECT_BINARY_DIR}/CMakeTmp
                DetermineSoundLibs
                OUTPUT_VARIABLE MY_OUTPUT
            )
            # message("${MY_RESULT}")
            # message(${MY_OUTPUT})

            if(NOT MY_RESULT)
                # I expect that MPGLIB, VOC, WAV, AIFF, and SHN are compiled in statically.
                # I think Timidity is also compiled in statically.
                # I've never had to explcitly link against Quicktime, so I'll skip that for now.

                # Find libmath
                if("${MY_OUTPUT}" MATCHES "cos@@GLIBC")
                    find_library(MATH_LIBRARY NAMES m)
                    if(MATH_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${MATH_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${MATH_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif(MATH_LIBRARY)
                endif("${MY_OUTPUT}" MATCHES "cos@@GLIBC")

                # Find MikMod
                if("${MY_OUTPUT}" MATCHES "MikMod_")
                    find_library(MIKMOD_LIBRARY
                        NAMES libmikmod-coreaudio mikmod
                        PATHS
                            ENV MIKMODDIR
                            ENV SDLSOUNDDIR
                            ENV SDLDIR
                            /sw
                            /opt/local
                            /opt/csw
                            /opt
                        PATH_SUFFIXES lib
                    )
                    if(MIKMOD_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${MIKMOD_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${MIKMOD_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif(MIKMOD_LIBRARY)
                endif("${MY_OUTPUT}" MATCHES "MikMod_")

                # Find ModPlug
                if("${MY_OUTPUT}" MATCHES "MODPLUG_")
                    find_library(MODPLUG_LIBRARY
                        NAMES modplug
                        PATHS
                            ENV MODPLUGDIR
                            ENV SDLSOUNDDIR
                            ENV SDLDIR
                            /sw
                            /opt/local
                            /opt/csw
                            /opt
                        PATH_SUFFIXES lib
                    )
                    if(MODPLUG_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${MODPLUG_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${MODPLUG_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif()
                endif()

                # Find Ogg and Vorbis
                if("${MY_OUTPUT}" MATCHES "ov_")
                    find_library(VORBISFILE_LIBRARY
                        NAMES vorbisfile VorbisFile VORBISFILE
                        PATHS
                            ENV VORBISDIR
                            ENV OGGDIR
                            ENV SDLSOUNDDIR
                            ENV SDLDIR
                            /sw
                            /opt/local
                            /opt/csw
                            /opt
                        PATH_SUFFIXES lib
                    )
                    if(VORBISFILE_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${VORBISFILE_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${VORBISFILE_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif()

                    find_library(VORBIS_LIBRARY
                        NAMES vorbis Vorbis VORBIS
                        PATHS
                            ENV OGGDIR
                            ENV VORBISDIR
                            ENV SDLSOUNDDIR
                            ENV SDLDIR
                            /sw
                            /opt/local
                            /opt/csw
                            /opt
                        PATH_SUFFIXES lib
                    )
                    if(VORBIS_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${VORBIS_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${VORBIS_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif()

                    find_library(OGG_LIBRARY
                        NAMES ogg Ogg OGG
                        PATHS
                            ENV OGGDIR
                            ENV VORBISDIR
                            ENV SDLSOUNDDIR
                            ENV SDLDIR
                            /sw
                            /opt/local
                            /opt/csw
                            /opt
                        PATH_SUFFIXES lib
                    )
                    if(OGG_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${OGG_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${OGG_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif()
                endif()

                # Find SMPEG
                if("${MY_OUTPUT}" MATCHES "SMPEG_")
                    find_library(SMPEG_LIBRARY
                        NAMES smpeg SMPEG Smpeg SMpeg
                        PATHS
                            ENV SMPEGDIR
                            ENV SDLSOUNDDIR
                            ENV SDLDIR
                            /sw
                            /opt/local
                            /opt/csw
                            /opt
                        PATH_SUFFIXES lib
                    )
                    if(SMPEG_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${SMPEG_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${SMPEG_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif()
                endif()


                # Find FLAC
                if("${MY_OUTPUT}" MATCHES "FLAC_")
                    find_library(FLAC_LIBRARY
                        NAMES flac FLAC
                        PATHS
                            ENV FLACDIR
                            ENV SDLSOUNDDIR
                            ENV SDLDIR
                            /sw
                            /opt/local
                            /opt/csw
                            /opt
                        PATH_SUFFIXES lib
                    )
                    if(FLAC_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${FLAC_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${FLAC_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif()
                endif()


                # Hmmm...Speex seems to depend on Ogg. This might be a problem if
                # the TRY_COMPILE attempt gets blocked at SPEEX before it can pull
                # in the Ogg symbols. I'm not sure if I should duplicate the ogg stuff
                # above for here or if two ogg entries will screw up things.
                if("${MY_OUTPUT}" MATCHES "speex_")
                    find_library(SPEEX_LIBRARY
                        NAMES speex SPEEX
                        PATHS
                            ENV SPEEXDIR
                            ENV SDLSOUNDDIR
                            ENV SDLDIR
                            /sw
                            /opt/local
                            /opt/csw
                            /opt
                        PATH_SUFFIXES lib
                    )
                    if(SPEEX_LIBRARY)
                        set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${SPEEX_LIBRARY})
                        set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${SPEEX_LIBRARY}\"")
                        set(TRY_AGAIN TRUE)
                    endif()

                    # Find OGG (needed for Speex)
                    # We might have already found Ogg for Vorbis, so skip it if so.
                    if(NOT OGG_LIBRARY)
                        find_library(OGG_LIBRARY
                            NAMES ogg Ogg OGG
                            PATHS
                                ENV OGGDIR
                                ENV VORBISDIR
                                ENV SPEEXDIR
                                ENV SDLSOUNDDIR
                                ENV SDLDIR
                                /sw
                                /opt/local
                                /opt/csw
                                /opt
                            PATH_SUFFIXES lib
                        )
                        if(OGG_LIBRARY)
                            set(SDL_SOUND_LIBRARIES_TMP ${SDL_SOUND_LIBRARIES_TMP} ${OGG_LIBRARY})
                            set(TMP_LIBS "${SDL_SOUND_LIBRARIES_TMP} \"${OGG_LIBRARY}\"")
                            set(TRY_AGAIN TRUE)
                        endif()
                    endif()
                endif()
            endif()
        ENDWHILE()
        unset(TMP_INCLUDE_DIRS)
        unset(TMP_LIBS)

        set(SDL_SOUND_LIBRARIES ${SDL_SOUND_EXTRAS} ${SDL_SOUND_LIBRARIES_TMP} CACHE INTERNAL "SDL_sound and dependent libraries")
    endif()
endif()

if(SDL_SOUND_INCLUDE_DIR AND EXISTS "${SDL_SOUND_INCLUDE_DIR}/SDL_sound.h")
  file(STRINGS "${SDL_SOUND_INCLUDE_DIR}/SDL_sound.h" SDL_SOUND_VERSION_MAJOR_LINE REGEX "^#define[ \t]+SOUND_VER_MAJOR[ \t]+[0-9]+$")
  file(STRINGS "${SDL_SOUND_INCLUDE_DIR}/SDL_sound.h" SDL_SOUND_VERSION_MINOR_LINE REGEX "^#define[ \t]+SOUND_VER_MINOR[ \t]+[0-9]+$")
  file(STRINGS "${SDL_SOUND_INCLUDE_DIR}/SDL_sound.h" SDL_SOUND_VERSION_PATCH_LINE REGEX "^#define[ \t]+SOUND_VER_PATCH[ \t]+[0-9]+$")
  string(REGEX REPLACE "^#define[ \t]+SOUND_VER_MAJOR[ \t]+([0-9]+)$" "\\1" SDL_SOUND_VERSION_MAJOR "${SDL_SOUND_VERSION_MAJOR_LINE}")
  string(REGEX REPLACE "^#define[ \t]+SOUND_VER_MINOR[ \t]+([0-9]+)$" "\\1" SDL_SOUND_VERSION_MINOR "${SDL_SOUND_VERSION_MINOR_LINE}")
  string(REGEX REPLACE "^#define[ \t]+SOUND_VER_PATCH[ \t]+([0-9]+)$" "\\1" SDL_SOUND_VERSION_PATCH "${SDL_SOUND_VERSION_PATCH_LINE}")
  set(SDL_SOUND_VERSION_STRING ${SDL_SOUND_VERSION_MAJOR}.${SDL_SOUND_VERSION_MINOR}.${SDL_SOUND_VERSION_PATCH})
  unset(SDL_SOUND_VERSION_MAJOR_LINE)
  unset(SDL_SOUND_VERSION_MINOR_LINE)
  unset(SDL_SOUND_VERSION_PATCH_LINE)
  unset(SDL_SOUND_VERSION_MAJOR)
  unset(SDL_SOUND_VERSION_MINOR)
  unset(SDL_SOUND_VERSION_PATCH)
endif()

include(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL_sound
                                  REQUIRED_VARS SDL_SOUND_LIBRARIES SDL_SOUND_INCLUDE_DIR
                                  VERSION_VAR SDL_SOUND_VERSION_STRING)