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 the SDL library


Imported targets
^^^^^^^^^^^^^^^^

.. versionadded:: 3.19

This module defines the following :prop_tgt:`IMPORTED` target:

``SDL::SDL``
  The SDL library, if found

Result variables
^^^^^^^^^^^^^^^^

This module will set the following variables in your project:

``SDL_INCLUDE_DIRS``
  where to find SDL.h
``SDL_LIBRARIES``
  the name of the library to link against
``SDL_FOUND``
  if false, do not try to link to SDL
``SDL_VERSION``
  the human-readable string containing the version of SDL if found
``SDL_VERSION_MAJOR``
  SDL major version
``SDL_VERSION_MINOR``
  SDL minor version
``SDL_VERSION_PATCH``
  SDL patch version

.. versionadded:: 3.19
  Added the ``SDL_INCLUDE_DIRS``, ``SDL_LIBRARIES`` and ``SDL_VERSION[_<PART>]``
  variables.

Cache variables
^^^^^^^^^^^^^^^

These variables may optionally be set to help this module find the correct files:

``SDL_INCLUDE_DIR``
  where to find SDL.h
``SDL_LIBRARY``
  the name of the library to link against


Variables for locating 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.


Obsolete variables
^^^^^^^^^^^^^^^^^^

.. deprecated:: 3.19

These variables are obsolete and provided for backwards compatibility:

``SDL_VERSION_STRING``
  the human-readable string containing the version of SDL if found.
  Identical to SDL_VERSION


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

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).
#]=======================================================================]

cmake_policy(PUSH)
cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>

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
      /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 preused 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}")
  unset(SDL_VERSION_MAJOR_LINE)
  unset(SDL_VERSION_MINOR_LINE)
  unset(SDL_VERSION_PATCH_LINE)
  set(SDL_VERSION ${SDL_VERSION_MAJOR}.${SDL_VERSION_MINOR}.${SDL_VERSION_PATCH})
  set(SDL_VERSION_STRING ${SDL_VERSION})
endif()

include(FindPackageHandleStandardArgs)

find_package_handle_standard_args(SDL
                                  REQUIRED_VARS SDL_LIBRARY SDL_INCLUDE_DIR
                                  VERSION_VAR SDL_VERSION_STRING)

if(SDL_FOUND)
  set(SDL_LIBRARIES ${SDL_LIBRARY})
  set(SDL_INCLUDE_DIRS ${SDL_INCLUDE_DIR})
  if(NOT TARGET SDL::SDL)
    add_library(SDL::SDL INTERFACE IMPORTED)
    set_target_properties(SDL::SDL PROPERTIES
      INTERFACE_INCLUDE_DIRECTORIES "${SDL_INCLUDE_DIR}"
      INTERFACE_LINK_LIBRARIES "${SDL_LIBRARY}")
  endif()
endif()

cmake_policy(POP)