superbuild/modules/openal-soft/cmake/FindSDL2.cmake

# Locate SDL2 library
# This module defines
# SDL2_LIBRARY, the name of the library to link against
# SDL2_FOUND, if false, do not try to link to SDL2
# SDL2_INCLUDE_DIR, where to find SDL.h
#
# This module responds to the the flag:
# SDL2_BUILDING_LIBRARY
# If this is defined, then no SDL2_main will be linked in because
# only applications need main().
# Otherwise, it is assumed you are building an application and this
# module will attempt to locate and set the the proper link flags
# as part of the returned SDL2_LIBRARY variable.
#
# Don't forget to include SDL2main.h and SDL2main.m your project for the
# OS X framework based version. (Other versions link to -lSDL2main which
# this module will try to find on your behalf.) Also for OS X, this
# module will automatically add the -framework Cocoa on your behalf.
#
#
# Additional Note: If you see an empty SDL2_CORE_LIBRARY in your configuration
# and no SDL2_LIBRARY, it means CMake did not find your SDL2 library
# (SDL2.dll, libsdl2.so, SDL2.framework, etc).
# Set SDL2_CORE_LIBRARY to point to your SDL2 library, and configure again.
# Similarly, if you see an empty SDL2MAIN_LIBRARY, you should set this value
# as appropriate. These values are used to generate the final SDL2_LIBRARY
# variable, but when these values are unset, SDL2_LIBRARY does not get created.
#
#
# $SDL2DIR is an environment variable that would
# correspond to the ./configure --prefix=$SDL2DIR
# used in building SDL2.
# l.e.galup  9-20-02
#
# Modified by Eric Wing.
# Added code to assist with automated building by using environmental variables
# and providing a more controlled/consistent search behavior.
# Added new modifications to recognize OS X frameworks and
# additional Unix paths (FreeBSD, etc).
# Also corrected the header search path to follow "proper" SDL2 guidelines.
# Added a search for SDL2main which is needed by some platforms.
# Added a search for threads which is needed by some platforms.
# Added needed compile switches for MinGW.
#
# On OSX, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of
# SDL2_LIBRARY to override this selection or set the CMake environment
# CMAKE_INCLUDE_PATH to modify the search paths.
#
# Note that the header path has changed from SDL2/SDL.h to just SDL.h
# This needed to change because "proper" SDL2 convention
# is #include "SDL.h", not <SDL2/SDL.h>. This is done for portability
# reasons because not all systems place things in SDL2/ (see FreeBSD).
#
# Ported by Johnny Patterson. This is a literal port for SDL2 of the FindSDL.cmake
# module with the minor edit of changing "SDL" to "SDL2" where necessary. This
# was not created for redistribution, and exists temporarily pending official
# SDL2 CMake modules.

#=============================================================================
# Copyright 2003-2009 Kitware, Inc.
#
# 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.)


FIND_PATH(SDL2_INCLUDE_DIR SDL.h
  HINTS
  $ENV{SDL2DIR}
  PATH_SUFFIXES include/SDL2 include
  PATHS
  ~/Library/Frameworks
  /Library/Frameworks
  /usr/local/include/SDL2
  /usr/include/SDL2
  /sw # Fink
  /opt/local # DarwinPorts
  /opt/csw # Blastwave
  /opt
)
#MESSAGE("SDL2_INCLUDE_DIR is ${SDL2_INCLUDE_DIR}")

FIND_LIBRARY(SDL2_CORE_LIBRARY
  NAMES SDL2
  HINTS
  $ENV{SDL2DIR}
  PATH_SUFFIXES lib64 lib
  PATHS
  /sw
  /opt/local
  /opt/csw
  /opt
)
#MESSAGE("SDL2_CORE_LIBRARY is ${SDL2_CORE_LIBRARY}")

IF(NOT SDL2_BUILDING_LIBRARY)
  IF(NOT ${SDL2_INCLUDE_DIR} MATCHES ".framework")
    # Non-OS X framework versions expect you to also dynamically link to
    # SDL2main. This is mainly for Windows and OS X. Other (Unix) platforms
    # seem to provide SDL2main for compatibility even though they don't
    # necessarily need it.
    FIND_LIBRARY(SDL2MAIN_LIBRARY
      NAMES SDL2main
      HINTS
      $ENV{SDL2DIR}
      PATH_SUFFIXES lib64 lib
      PATHS
      /sw
      /opt/local
      /opt/csw
      /opt
    )
  ENDIF(NOT ${SDL2_INCLUDE_DIR} MATCHES ".framework")
ENDIF(NOT SDL2_BUILDING_LIBRARY)

# SDL2 may require threads on your system.
# The Apple build may not need an explicit flag because one of the
# frameworks may already provide it.
# But for non-OSX systems, I will use the CMake Threads package.
IF(NOT APPLE)
  FIND_PACKAGE(Threads)
ENDIF(NOT APPLE)

# MinGW needs an additional library, mwindows
# It's total link flags should look like -lmingw32 -lSDL2main -lSDL2 -lmwindows
# (Actually on second look, I think it only needs one of the m* libraries.)
IF(MINGW)
  SET(MINGW32_LIBRARY mingw32 CACHE STRING "mwindows for MinGW")
ENDIF(MINGW)

SET(SDL2_FOUND "NO")
IF(SDL2_CORE_LIBRARY)
  SET(SDL2_LIBRARY_TEMP ${SDL2_CORE_LIBRARY})

  # For SDL2main
  IF(NOT SDL2_BUILDING_LIBRARY)
    IF(SDL2MAIN_LIBRARY)
      SET(SDL2_LIBRARY_TEMP ${SDL2MAIN_LIBRARY} ${SDL2_LIBRARY_TEMP})
    ENDIF(SDL2MAIN_LIBRARY)
  ENDIF(NOT SDL2_BUILDING_LIBRARY)

  # For OS X, SDL2 uses Cocoa as a backend so it must link to Cocoa.
  # CMake doesn't display the -framework Cocoa string in the UI even
  # though it actually is there if I modify a pre-used variable.
  # I think it has something to do with the CACHE STRING.
  # So I use a temporary variable until the end so I can set the
  # "real" variable in one-shot.
  IF(APPLE)
    SET(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} "-framework Cocoa")
  ENDIF(APPLE)

  # For threads, as mentioned Apple doesn't need this.
  # In fact, there seems to be a problem if I used the Threads package
  # and try using this line, so I'm just skipping it entirely for OS X.
  IF(NOT APPLE)
    SET(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} ${CMAKE_THREAD_LIBS_INIT})
  ENDIF(NOT APPLE)

  # For MinGW library
  IF(MINGW)
    SET(SDL2_LIBRARY_TEMP ${MINGW32_LIBRARY} ${SDL2_LIBRARY_TEMP})
  ENDIF(MINGW)
  
  IF(WIN32)
    SET(SDL2_LIBRARY_TEMP winmm imm32 version msimg32 ${SDL2_LIBRARY_TEMP})
  ENDIF(WIN32)

  # Set the final string here so the GUI reflects the final state.
  SET(SDL2_LIBRARY ${SDL2_LIBRARY_TEMP})

  SET(SDL2_FOUND "YES")
ENDIF(SDL2_CORE_LIBRARY)

INCLUDE(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2
                                  REQUIRED_VARS SDL2_LIBRARY SDL2_INCLUDE_DIR)

IF(SDL2_STATIC)
  if (UNIX AND NOT APPLE)
    EXECUTE_PROCESS(COMMAND sdl2-config --static-libs OUTPUT_VARIABLE SDL2_LINK_FLAGS)
    STRING(REGEX REPLACE "(\r?\n)+$" "" SDL2_LINK_FLAGS "${SDL2_LINK_FLAGS}")
    SET(SDL2_LIBRARY ${SDL2_LINK_FLAGS})
  ENDIF()
ENDIF(SDL2_STATIC)