cmake/Modules/FindSDL.cmake

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

#.rst:
# FindSDL
# -------
#
# Locate SDL library
#
# This module defines
#
# ::
#
#   SDL_LIBRARY, the name of the library to link against
#   SDL_FOUND, if false, do not try to link to SDL
#   SDL_INCLUDE_DIR, where to find SDL.h
#   SDL_VERSION_STRING, human-readable string containing the version of SDL
#
#
#
# This module responds to the flag:
#
# ::
#
#   SDL_BUILDING_LIBRARY
#     If this is defined, then no SDL_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 SDL_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 -lSDLmain 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 SDL_LIBRARY_TEMP in your
# configuration and no SDL_LIBRARY, it means CMake did not find your SDL
# library (SDL.dll, libsdl.so, SDL.framework, etc).  Set
# SDL_LIBRARY_TEMP to point to your SDL library, and configure again.
# Similarly, if you see an empty SDLMAIN_LIBRARY, you should set this
# value as appropriate.  These values are used to generate the final
# SDL_LIBRARY variable, but when these values are unset, SDL_LIBRARY
# does not get created.
#
#
#
# $SDLDIR is an environment variable that would correspond to the
# ./configure --prefix=$SDLDIR 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 SDL_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 SDL/SDL.h to just SDL.h
# This needed to change because "proper" SDL convention is #include
# "SDL.h", not <SDL/SDL.h>.  This is done for portability reasons
# because not all systems place things in SDL/ (see FreeBSD).

find_path(SDL_INCLUDE_DIR SDL.h
  HINTS
    ENV SDLDIR
  PATH_SUFFIXES SDL SDL12 SDL11
                # path suffixes to search inside ENV{SDLDIR}
                include/SDL include/SDL12 include/SDL11 include
)

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

# SDL-1.1 is the name used by FreeBSD ports...
# don't confuse it for the version number.
find_library(SDL_LIBRARY_TEMP
  NAMES SDL SDL-1.1
  HINTS
    ENV SDLDIR
  PATH_SUFFIXES lib ${VC_LIB_PATH_SUFFIX}
)

# Hide this cache variable from the user, it's an internal implementation
# detail. The documented library variable for the user is SDL_LIBRARY
# which is derived from SDL_LIBRARY_TEMP further below.
set_property(CACHE SDL_LIBRARY_TEMP PROPERTY TYPE INTERNAL)

if(NOT SDL_BUILDING_LIBRARY)
  if(NOT SDL_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(SDLMAIN_LIBRARY
      NAMES SDLmain SDLmain-1.1
      HINTS
        ENV SDLDIR
      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 link flag, -mwindows
# It's total link flags should look like -lmingw32 -lSDLmain -lSDL -mwindows
if(MINGW)
  set(MINGW32_LIBRARY mingw32 "-mwindows" CACHE STRING "link flags for MinGW")
endif()

if(SDL_LIBRARY_TEMP)
  # For SDLmain
  if(SDLMAIN_LIBRARY AND NOT SDL_BUILDING_LIBRARY)
    list(FIND SDL_LIBRARY_TEMP "${SDLMAIN_LIBRARY}" _SDL_MAIN_INDEX)
    if(_SDL_MAIN_INDEX EQUAL -1)
      set(SDL_LIBRARY_TEMP "${SDLMAIN_LIBRARY}" ${SDL_LIBRARY_TEMP})
    endif()
    unset(_SDL_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(SDL_LIBRARY_TEMP ${SDL_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(SDL_LIBRARY_TEMP ${SDL_LIBRARY_TEMP} ${CMAKE_THREAD_LIBS_INIT})
  endif()

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

  # Set the final string here so the GUI reflects the final state.
  set(SDL_LIBRARY ${SDL_LIBRARY_TEMP} CACHE STRING "Where the SDL Library can be found")
endif()

if(SDL_INCLUDE_DIR AND EXISTS "${SDL_INCLUDE_DIR}/SDL_version.h")
  file(STRINGS "${SDL_INCLUDE_DIR}/SDL_version.h" SDL_VERSION_MAJOR_LINE REGEX "^#define[ \t]+SDL_MAJOR_VERSION[ \t]+[0-9]+$")
  file(STRINGS "${SDL_INCLUDE_DIR}/SDL_version.h" SDL_VERSION_MINOR_LINE REGEX "^#define[ \t]+SDL_MINOR_VERSION[ \t]+[0-9]+$")
  file(STRINGS "${SDL_INCLUDE_DIR}/SDL_version.h" SDL_VERSION_PATCH_LINE REGEX "^#define[ \t]+SDL_PATCHLEVEL[ \t]+[0-9]+$")
  string(REGEX REPLACE "^#define[ \t]+SDL_MAJOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL_VERSION_MAJOR "${SDL_VERSION_MAJOR_LINE}")
  string(REGEX REPLACE "^#define[ \t]+SDL_MINOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL_VERSION_MINOR "${SDL_VERSION_MINOR_LINE}")
  string(REGEX REPLACE "^#define[ \t]+SDL_PATCHLEVEL[ \t]+([0-9]+)$" "\\1" SDL_VERSION_PATCH "${SDL_VERSION_PATCH_LINE}")
  set(SDL_VERSION_STRING ${SDL_VERSION_MAJOR}.${SDL_VERSION_MINOR}.${SDL_VERSION_PATCH})
  unset(SDL_VERSION_MAJOR_LINE)
  unset(SDL_VERSION_MINOR_LINE)
  unset(SDL_VERSION_PATCH_LINE)
  unset(SDL_VERSION_MAJOR)
  unset(SDL_VERSION_MINOR)
  unset(SDL_VERSION_PATCH)
endif()

include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)

FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL
                                  REQUIRED_VARS SDL_LIBRARY SDL_INCLUDE_DIR
                                  VERSION_VAR SDL_VERSION_STRING)