vcmi/cmake_modules/FindSDL2.cmake

#.rst:
# FindSDL2
# --------
#
# 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 SDL
#   SDL2_INCLUDE_DIR, where to find SDL.h
#   SDL2_VERSION_STRING, human-readable string containing the version of SDL
#
#
#
# This module responds to 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 proper link flags
#     as part of the returned SDL2_LIBRARY variable.
#
#
#
# Don't forget to include SDLmain.h and SDLmain.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_LIBRARY_TEMP in your
# configuration and no SDL2_LIBRARY, it means CMake did not find your SDL
# library (SDL2.dll, libSDL2.so, SDL.framework, etc).  Set
# SDL2_LIBRARY_TEMP to point to your SDL 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 SDL.  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" SDL
# guidelines.  Added a search for SDLmain 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.
#

#=============================================================================
# Copyright 2003-2009 Kitware, Inc.
# Copyright 2012 Benjamin Eikel
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file kitware license.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.)

if (NOT WIN32)
    find_package(PkgConfig)
    if (PKG_CONFIG_FOUND)
        pkg_check_modules(_SDL2 sdl2)
        set(SDL2_VERSION_STRING ${_SDL2_VERSION})
    endif ()
endif ()

find_path(SDL2_INCLUDE_DIR 
    SDL.h
  HINTS
    ${_SDL2_INCLUDEDIR}
    ENV SDL2DIR
  PATH_SUFFIXES 
    SDL2
    include/SDL2 
    include
)

if(CMAKE_SIZEOF_VOID_P EQUAL 8)
  set(VC_LIB_PATH_SUFFIX lib/x64)
else()
  set(VC_LIB_PATH_SUFFIX lib/x86)
endif()

find_library(SDL2_LIBRARY_TEMP
  NAMES 
    SDL2
  HINTS
    ${_SDL2_LIBDIR}
    ENV SDL2DIR
  PATH_SUFFIXES 
    lib 
    ${VC_LIB_PATH_SUFFIX}
)

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

# SDL 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()

# MinGW needs an additional library, mwindows
# It's total link flags should look like -lmingw32 -lSDLmain -lSDL -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()

if(SDL2_LIBRARY_TEMP)
  # For SDLmain
  if(SDL2MAIN_LIBRARY AND NOT SDL2_BUILDING_LIBRARY)
    list(FIND SDL2_LIBRARY_TEMP "${SDL2MAIN_LIBRARY}" _SDL2_MAIN_INDEX)
    if(_SDL2_MAIN_INDEX EQUAL -1)
      set(SDL2_LIBRARY_TEMP "${SDL2MAIN_LIBRARY}" ${SDL2_LIBRARY_TEMP})
    endif()
    unset(_SDL2_MAIN_INDEX)
  endif()

  # For OS X, SDL 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()

  # 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()

  # For MinGW library
  if(MINGW)
    set(SDL2_LIBRARY_TEMP ${MINGW32_LIBRARY} ${SDL2_LIBRARY_TEMP})
  endif()

  # Set the final string here so the GUI reflects the final state.
  set(SDL2_LIBRARY ${SDL2_LIBRARY_TEMP} CACHE STRING "Where the SDL Library can be found")
  # Set the temp variable to INTERNAL so it is not seen in the CMake GUI
  set(SDL2_LIBRARY_TEMP "${SDL2_LIBRARY_TEMP}" CACHE INTERNAL "")
endif()

if(SDL2_INCLUDE_DIR AND EXISTS "${SDL2_INCLUDE_DIR}/SDL_version.h" AND NOT SDL2_VERSION_STRING)
  file(STRINGS "${SDL2_INCLUDE_DIR}/SDL_version.h" SDL2_VERSION_MAJOR_LINE REGEX "^#define[ \t]+SDL_MAJOR_VERSION[ \t]+[0-9]+$")
  file(STRINGS "${SDL2_INCLUDE_DIR}/SDL_version.h" SDL2_VERSION_MINOR_LINE REGEX "^#define[ \t]+SDL_MINOR_VERSION[ \t]+[0-9]+$")
  file(STRINGS "${SDL2_INCLUDE_DIR}/SDL_version.h" SDL2_VERSION_PATCH_LINE REGEX "^#define[ \t]+SDL_PATCHLEVEL[ \t]+[0-9]+$")
  string(REGEX REPLACE "^#define[ \t]+SDL_MAJOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_MAJOR "${SDL2_VERSION_MAJOR_LINE}")
  string(REGEX REPLACE "^#define[ \t]+SDL_MINOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_MINOR "${SDL2_VERSION_MINOR_LINE}")
  string(REGEX REPLACE "^#define[ \t]+SDL_PATCHLEVEL[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_PATCH "${SDL2_VERSION_PATCH_LINE}")
  set(SDL2_VERSION_STRING ${SDL2_VERSION_MAJOR}.${SDL2_VERSION_MINOR}.${SDL2_VERSION_PATCH})
  unset(SDL2_VERSION_MAJOR_LINE)
  unset(SDL2_VERSION_MINOR_LINE)
  unset(SDL2_VERSION_PATCH_LINE)
  unset(SDL2_VERSION_MAJOR)
  unset(SDL2_VERSION_MINOR)
  unset(SDL2_VERSION_PATCH)
endif()

set(SDL2_LIBRARIES ${SDL2_LIBRARY})
set(SDL2_INCLUDE_DIRS ${SDL2_INCLUDE_DIR})

include(FindPackageHandleStandardArgs)

FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2
                                  REQUIRED_VARS SDL2_LIBRARY SDL2_INCLUDE_DIR
                                  VERSION_VAR SDL2_VERSION_STRING)