macro(FindLibraryAndSONAME _LIB)
  string(TOUPPER ${_LIB} _UPPERLNAME)
  string(REGEX REPLACE "\\-" "_" _LNAME "${_UPPERLNAME}")

  find_library(${_LNAME}_LIB ${_LIB})
  if(${_LNAME}_LIB)
    # reduce the library name for shared linking

    get_filename_component(_LIB_REALPATH ${${_LNAME}_LIB} REALPATH)  # resolves symlinks
    get_filename_component(_LIB_JUSTNAME ${_LIB_REALPATH} NAME)

    if(APPLE)
      string(REGEX REPLACE "(\\.[0-9]*)\\.[0-9\\.]*dylib$" "\\1.dylib" _LIB_REGEXD "${_LIB_JUSTNAME}")
    else()
      string(REGEX REPLACE "(\\.[0-9]*)\\.[0-9\\.]*$" "\\1" _LIB_REGEXD "${_LIB_JUSTNAME}")
    endif()

    SET(_DEBUG_FindSONAME FALSE)
    if(_DEBUG_FindSONAME)
      message_warn("DYNLIB OUTPUTVAR: ${_LIB} ... ${_LNAME}_LIB")
      message_warn("DYNLIB ORIGINAL LIB: ${_LIB} ... ${${_LNAME}_LIB}")
      message_warn("DYNLIB REALPATH LIB: ${_LIB} ... ${_LIB_REALPATH}")
      message_warn("DYNLIB JUSTNAME LIB: ${_LIB} ... ${_LIB_JUSTNAME}")
      message_warn("DYNLIB REGEX'd LIB: ${_LIB} ... ${_LIB_REGEXD}")
    endif()

    message(STATUS "dynamic lib${_LIB} -> ${_LIB_REGEXD}")
    set(${_LNAME}_LIB_SONAME ${_LIB_REGEXD})
  endif()
endmacro()

macro(CheckDLOPEN)
  check_symbol_exists(dlopen "dlfcn.h" HAVE_DLOPEN)
  if(NOT HAVE_DLOPEN)
    check_library_exists(dl dlopen "" DLOPEN_LIB)
    if(DLOPEN_LIB)
      list(APPEND EXTRA_LIBS dl)
      set(_DLLIB dl)
      set(HAVE_DLOPEN TRUE)
    endif()
  endif()

  if(HAVE_DLOPEN)
    if(_DLLIB)
      set(CMAKE_REQUIRED_LIBRARIES ${_DLLIB})
    endif()
    check_c_source_compiles("
       #include <dlfcn.h>
       int main(int argc, char **argv) {
         void *handle = dlopen(\"\", RTLD_NOW);
         const char *loaderror = (char *) dlerror();
       }" HAVE_DLOPEN)
    set(CMAKE_REQUIRED_LIBRARIES)
  endif()
endmacro()

# Requires:
# - n/a
macro(CheckOSS)
  if(SDL_OSS)
    set(OSS_HEADER_FILE "sys/soundcard.h")
    check_c_source_compiles("
        #include <sys/soundcard.h>
        int main() { int arg = SNDCTL_DSP_SETFRAGMENT; }" OSS_FOUND)
    if(NOT OSS_FOUND)
      set(OSS_HEADER_FILE "soundcard.h")
      check_c_source_compiles("
          #include <soundcard.h>
          int main() { int arg = SNDCTL_DSP_SETFRAGMENT; }" OSS_FOUND)
    endif()

    if(OSS_FOUND)
      set(HAVE_OSS TRUE)
      file(GLOB OSS_SOURCES ${SDL2_SOURCE_DIR}/src/audio/dsp/*.c)
      if(OSS_HEADER_FILE STREQUAL "soundcard.h")
        set(SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H 1)
      endif()
      set(SDL_AUDIO_DRIVER_OSS 1)
      set(SOURCE_FILES ${SOURCE_FILES} ${OSS_SOURCES})
      if(NETBSD OR OPENBSD)
        list(APPEND EXTRA_LIBS ossaudio)
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - n/a
# Optional:
# - SDL_ALSA_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckALSA)
  if(SDL_ALSA)
    CHECK_INCLUDE_FILE(alsa/asoundlib.h HAVE_ASOUNDLIB_H)
    if(HAVE_ASOUNDLIB_H)
      CHECK_LIBRARY_EXISTS(asound snd_pcm_recover "" HAVE_LIBASOUND)
    endif()
    if(HAVE_LIBASOUND)
      set(HAVE_ALSA TRUE)
      file(GLOB ALSA_SOURCES ${SDL2_SOURCE_DIR}/src/audio/alsa/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${ALSA_SOURCES})
      set(SDL_AUDIO_DRIVER_ALSA 1)
      if(SDL_ALSA_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic ALSA loading")
      endif()
      if(SDL_ALSA_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME("asound")
        set(SDL_AUDIO_DRIVER_ALSA_DYNAMIC "\"${ASOUND_LIB_SONAME}\"")
        set(HAVE_ALSA_SHARED TRUE)
      else()
        list(APPEND EXTRA_LIBS asound)
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - PkgCheckModules
# Optional:
# - SDL_PIPEWIRE_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckPipewire)
    if(SDL_PIPEWIRE)
        pkg_check_modules(PKG_PIPEWIRE libpipewire-0.3>=0.3.20)
        if(PKG_PIPEWIRE_FOUND)
            set(HAVE_PIPEWIRE TRUE)
            file(GLOB PIPEWIRE_SOURCES ${SDL2_SOURCE_DIR}/src/audio/pipewire/*.c)
            set(SOURCE_FILES ${SOURCE_FILES} ${PIPEWIRE_SOURCES})
            set(SDL_AUDIO_DRIVER_PIPEWIRE 1)
            list(APPEND EXTRA_CFLAGS ${PKG_PIPEWIRE_CFLAGS})
            if(SDL_PIPEWIRE_SHARED AND NOT HAVE_SDL_LOADSO)
                message_warn("You must have SDL_LoadObject() support for dynamic Pipewire loading")
            endif()
            if(SDL_PIPEWIRE_SHARED AND HAVE_SDL_LOADSO)
                FindLibraryAndSONAME("pipewire-0.3")
                set(SDL_AUDIO_DRIVER_PIPEWIRE_DYNAMIC "\"${PIPEWIRE_0.3_LIB_SONAME}\"")
                set(HAVE_PIPEWIRE_SHARED TRUE)
            else()
                list(APPEND EXTRA_LDFLAGS ${PKG_PIPEWIRE_LDFLAGS})
            endif()
            set(HAVE_SDL_AUDIO TRUE)
        endif()
    endif()
endmacro()


# Requires:
# - PkgCheckModules
# Optional:
# - SDL_PULSEAUDIO_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckPulseAudio)
  if(SDL_PULSEAUDIO)
    pkg_check_modules(PKG_PULSEAUDIO libpulse-simple)
    if(PKG_PULSEAUDIO_FOUND)
      set(HAVE_PULSEAUDIO TRUE)
      file(GLOB PULSEAUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/pulseaudio/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${PULSEAUDIO_SOURCES})
      set(SDL_AUDIO_DRIVER_PULSEAUDIO 1)
      list(APPEND EXTRA_CFLAGS ${PKG_PULSEAUDIO_CFLAGS})
      if(SDL_PULSEAUDIO_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic PulseAudio loading")
      endif()
      if(SDL_PULSEAUDIO_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME("pulse-simple")
        set(SDL_AUDIO_DRIVER_PULSEAUDIO_DYNAMIC "\"${PULSE_SIMPLE_LIB_SONAME}\"")
        set(HAVE_PULSEAUDIO_SHARED TRUE)
      else()
        list(APPEND EXTRA_LDFLAGS ${PKG_sPULSEAUDIO_LDFLAGS})
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - PkgCheckModules
# Optional:
# - SDL_JACK_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckJACK)
  if(SDL_JACK)
    pkg_check_modules(PKG_JACK jack)
    if(PKG_JACK_FOUND)
      set(HAVE_JACK TRUE)
      file(GLOB JACK_SOURCES ${SDL2_SOURCE_DIR}/src/audio/jack/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${JACK_SOURCES})
      set(SDL_AUDIO_DRIVER_JACK 1)
      list(APPEND EXTRA_CFLAGS ${PKG_JACK_CFLAGS})
      if(SDL_JACK_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic JACK audio loading")
      endif()
      if(SDL_JACK_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME("jack")
        set(SDL_AUDIO_DRIVER_JACK_DYNAMIC "\"${JACK_LIB_SONAME}\"")
        set(HAVE_JACK_SHARED TRUE)
      else()
        list(APPEND EXTRA_LDFLAGS ${PKG_JACK_LDFLAGS})
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - PkgCheckModules
# Optional:
# - SDL_ESD_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckESD)
  if(SDL_ESD)
    pkg_check_modules(PKG_ESD esound)
    if(PKG_ESD_FOUND)
      set(HAVE_ESD TRUE)
      file(GLOB ESD_SOURCES ${SDL2_SOURCE_DIR}/src/audio/esd/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${ESD_SOURCES})
      set(SDL_AUDIO_DRIVER_ESD 1)
      list(APPEND EXTRA_CFLAGS ${PKG_ESD_CFLAGS})
      if(SDL_ESD_SHARED AND NOT HAVE_SDL_LOADSO)
          message_warn("You must have SDL_LoadObject() support for dynamic ESD loading")
      endif()
      if(SDL_ESD_SHARED AND HAVE_SDL_LOADSO)
          FindLibraryAndSONAME(esd)
          set(SDL_AUDIO_DRIVER_ESD_DYNAMIC "\"${ESD_LIB_SONAME}\"")
          set(HAVE_ESD_SHARED TRUE)
      else()
          list(APPEND EXTRA_LDFLAGS ${PKG_ESD_LDFLAGS})
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - n/a
# Optional:
# - SDL_ARTS_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckARTS)
  if(SDL_ARTS)
    find_program(ARTS_CONFIG arts-config)
    if(ARTS_CONFIG)
      execute_process(CMD_ARTSCFLAGS ${ARTS_CONFIG} --cflags
        OUTPUT_VARIABLE ARTS_CFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
      list(APPEND EXTRA_CFLAGS ${ARTS_CFLAGS})
      execute_process(CMD_ARTSLIBS ${ARTS_CONFIG} --libs
        OUTPUT_VARIABLE ARTS_LIBS OUTPUT_STRIP_TRAILING_WHITESPACE)
      file(GLOB ARTS_SOURCES ${SDL2_SOURCE_DIR}/src/audio/arts/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${ARTS_SOURCES})
      set(SDL_AUDIO_DRIVER_ARTS 1)
      set(HAVE_ARTS TRUE)
      if(SDL_ARTS_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic ARTS loading")
      endif()
      if(SDL_ARTS_SHARED AND HAVE_SDL_LOADSO)
        # TODO
        FindLibraryAndSONAME(artsc)
        set(SDL_AUDIO_DRIVER_ARTS_DYNAMIC "\"${ARTSC_LIB_SONAME}\"")
        set(HAVE_ARTS_SHARED TRUE)
      else()
        list(APPEND EXTRA_LDFLAGS ${ARTS_LIBS})
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - n/a
# Optional:
# - SDL_NAS_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckNAS)
  if(SDL_NAS)
    # TODO: set include paths properly, so the NAS headers are found
    check_include_file(audio/audiolib.h HAVE_NAS_H)
    find_library(D_NAS_LIB audio)
    if(HAVE_NAS_H AND D_NAS_LIB)
      set(HAVE_NAS TRUE)
      file(GLOB NAS_SOURCES ${SDL2_SOURCE_DIR}/src/audio/nas/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${NAS_SOURCES})
      set(SDL_AUDIO_DRIVER_NAS 1)
      if(SDL_NAS_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic NAS loading")
      endif()
      if(SDL_NAS_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME("audio")
        set(SDL_AUDIO_DRIVER_NAS_DYNAMIC "\"${AUDIO_LIB_SONAME}\"")
        set(HAVE_NAS_SHARED TRUE)
      else()
        list(APPEND EXTRA_LIBS ${D_NAS_LIB})
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - n/a
# Optional:
# - SDL_SNDIO_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckSNDIO)
  if(SDL_SNDIO)
    # TODO: set include paths properly, so the sndio headers are found
    check_include_file(sndio.h HAVE_SNDIO_H)
    find_library(D_SNDIO_LIB sndio)
    if(HAVE_SNDIO_H AND D_SNDIO_LIB)
      set(HAVE_SNDIO TRUE)
      file(GLOB SNDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/sndio/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${SNDIO_SOURCES})
      set(SDL_AUDIO_DRIVER_SNDIO 1)
      if(SDL_SNDIO_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic sndio loading")
      endif()
      if(SDL_SNDIO_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME("sndio")
        set(SDL_AUDIO_DRIVER_SNDIO_DYNAMIC "\"${SNDIO_LIB_SONAME}\"")
        set(HAVE_SNDIO_SHARED TRUE)
      else()
        list(APPEND EXTRA_LIBS ${D_SNDIO_LIB})
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - PkgCheckModules
# Optional:
# - FUSIONSOUND_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckFusionSound)
  if(FUSIONSOUND)
    pkg_check_modules(PKG_FUSIONSOUND fusionsound>=1.0.0)
    if(PKG_FUSIONSOUND_FOUND)
      set(HAVE_FUSIONSOUND TRUE)
      file(GLOB FUSIONSOUND_SOURCES ${SDL2_SOURCE_DIR}/src/audio/fusionsound/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${FUSIONSOUND_SOURCES})
      set(SDL_AUDIO_DRIVER_FUSIONSOUND 1)
      list(APPEND EXTRA_CFLAGS ${PKG_FUSIONSOUND_CFLAGS})
      if(FUSIONSOUND_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic FusionSound loading")
      endif()
      if(FUSIONSOUND_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME("fusionsound")
        set(SDL_AUDIO_DRIVER_FUSIONSOUND_DYNAMIC "\"${FUSIONSOUND_LIB_SONAME}\"")
        set(HAVE_FUSIONSOUND_SHARED TRUE)
      else()
        list(APPEND EXTRA_LDFLAGS ${PKG_FUSIONSOUND_LDFLAGS})
      endif()
      set(HAVE_SDL_AUDIO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - SDL_LIBSAMPLERATE
# Optional:
# - SDL_LIBSAMPLERATE_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckLibSampleRate)
  if(SDL_LIBSAMPLERATE)
    check_include_file(samplerate.h HAVE_LIBSAMPLERATE_H)
    if(HAVE_LIBSAMPLERATE_H)
      set(HAVE_LIBSAMPLERATE TRUE)
      if(SDL_LIBSAMPLERATE_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic libsamplerate loading")
      endif()
      if(SDL_LIBSAMPLERATE_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME("samplerate")
        set(SDL_LIBSAMPLERATE_DYNAMIC "\"${SAMPLERATE_LIB_SONAME}\"")
        set(HAVE_LIBSAMPLERATE_SHARED TRUE)
      else()
        list(APPEND EXTRA_LDFLAGS -lsamplerate)
      endif()
    endif()
  endif()
endmacro()

# Requires:
# - n/a
# Optional:
# - SDL_X11_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckX11)
  if(SDL_X11)
    foreach(_LIB X11 Xext Xcursor Xinerama Xi Xrandr Xrender Xss Xxf86vm)
        FindLibraryAndSONAME("${_LIB}")
    endforeach()

    find_path(X_INCLUDEDIR X11/Xlib.h
        /usr/pkg/xorg/include
        /usr/X11R6/include
        /usr/X11R7/include
        /usr/local/include/X11
        /usr/include/X11
        /usr/openwin/include
        /usr/openwin/share/include
        /opt/graphics/OpenGL/include
        /opt/X11/include
    )

    if(X_INCLUDEDIR)
      list(APPEND EXTRA_CFLAGS "-I${X_INCLUDEDIR}")
      list(APPEND CMAKE_REQUIRED_INCLUDES "${X_INCLUDEDIR}")
    endif()

    check_include_file(X11/Xcursor/Xcursor.h HAVE_XCURSOR_H)
    check_include_file(X11/extensions/Xinerama.h HAVE_XINERAMA_H)
    check_include_file(X11/extensions/XInput2.h HAVE_XINPUT2_H)
    check_include_file(X11/extensions/Xrandr.h HAVE_XRANDR_H)
    check_include_file(X11/extensions/Xrender.h HAVE_XRENDER_H)
    check_include_file(X11/extensions/scrnsaver.h HAVE_XSS_H)
    check_include_file(X11/extensions/shape.h HAVE_XSHAPE_H)
    check_include_files("X11/Xlib.h;X11/extensions/xf86vmode.h" HAVE_XF86VM_H)
    check_include_files("X11/Xlib.h;X11/Xproto.h;X11/extensions/Xext.h" HAVE_XEXT_H)

    if(X11_LIB)
      if(NOT HAVE_XEXT_H)
        message_error("Missing Xext.h, maybe you need to install the libxext-dev package?")
      endif()

      set(HAVE_X11 TRUE)
      set(HAVE_SDL_VIDEO TRUE)

      file(GLOB X11_SOURCES ${SDL2_SOURCE_DIR}/src/video/x11/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${X11_SOURCES})
      set(SDL_VIDEO_DRIVER_X11 1)

      # !!! FIXME: why is this disabled for Apple?
      if(APPLE)
        set(SDL_X11_SHARED OFF)
      endif()

      check_symbol_exists(shmat "sys/shm.h" HAVE_SHMAT)
      if(NOT HAVE_SHMAT)
        check_library_exists(ipc shmat "" HAVE_SHMAT)
        if(HAVE_SHMAT)
          list(APPEND EXTRA_LIBS ipc)
        endif()
        if(NOT HAVE_SHMAT)
          list(APPEND EXTRA_CFLAGS "-DNO_SHARED_MEMORY")
        endif()
      endif()

      if(SDL_X11_SHARED)
        if(NOT HAVE_SDL_LOADSO)
          message_warn("You must have SDL_LoadObject() support for dynamic X11 loading")
          set(HAVE_X11_SHARED FALSE)
        else()
          set(HAVE_X11_SHARED TRUE)
        endif()
        if(HAVE_X11_SHARED)
          set(SDL_VIDEO_DRIVER_X11_DYNAMIC "\"${X11_LIB_SONAME}\"")
          set(SDL_VIDEO_DRIVER_X11_DYNAMIC_XEXT "\"${XEXT_LIB_SONAME}\"")
        else()
          list(APPEND EXTRA_LIBS ${X11_LIB} ${XEXT_LIB})
        endif()
      endif()

      set(CMAKE_REQUIRED_LIBRARIES ${X11_LIB} ${X11_LIB})

      check_c_source_compiles("
          #include <X11/Xlib.h>
          int main(int argc, char **argv) {
            Display *display;
            XEvent event;
            XGenericEventCookie *cookie = &event.xcookie;
            XNextEvent(display, &event);
            XGetEventData(display, cookie);
            XFreeEventData(display, cookie); }" HAVE_XGENERICEVENT)
      if(HAVE_XGENERICEVENT)
        set(SDL_VIDEO_DRIVER_X11_SUPPORTS_GENERIC_EVENTS 1)
      endif()

      check_symbol_exists(XkbKeycodeToKeysym "X11/Xlib.h;X11/XKBlib.h" SDL_VIDEO_DRIVER_X11_HAS_XKBKEYCODETOKEYSYM)

      if(SDL_X11_XCURSOR AND HAVE_XCURSOR_H)
        set(HAVE_X11_XCURSOR TRUE)
        if(HAVE_X11_SHARED AND XCURSOR_LIB)
          set(SDL_VIDEO_DRIVER_X11_DYNAMIC_XCURSOR "\"${XCURSOR_LIB_SONAME}\"")
        else()
          list(APPEND EXTRA_LIBS ${XCURSOR_LIB})
        endif()
        set(SDL_VIDEO_DRIVER_X11_XCURSOR 1)
      endif()

      if(SDL_X11_XINERAMA AND HAVE_XINERAMA_H)
        set(HAVE_X11_XINERAMA TRUE)
        if(HAVE_X11_SHARED AND XINERAMA_LIB)
          set(SDL_VIDEO_DRIVER_X11_DYNAMIC_XINERAMA "\"${XINERAMA_LIB_SONAME}\"")
        else()
          list(APPEND EXTRA_LIBS ${XINERAMA_LIB})
        endif()
        set(SDL_VIDEO_DRIVER_X11_XINERAMA 1)
      endif()

      if(SDL_X11_XINPUT AND HAVE_XINPUT2_H)
        set(HAVE_X11_XINPUT TRUE)
        if(HAVE_X11_SHARED AND XI_LIB)
          set(SDL_VIDEO_DRIVER_X11_DYNAMIC_XINPUT2 "\"${XI_LIB_SONAME}\"")
        else()
          list(APPEND EXTRA_LIBS ${XI_LIB})
        endif()
        set(SDL_VIDEO_DRIVER_X11_XINPUT2 1)

        # Check for multitouch
        check_c_source_compiles("
            #include <X11/Xlib.h>
            #include <X11/Xproto.h>
            #include <X11/extensions/XInput2.h>
            int event_type = XI_TouchBegin;
            XITouchClassInfo *t;
            Status XIAllowTouchEvents(Display *a,int b,unsigned int c,Window d,int f)
            {
              return (Status)0;
            }
            int main(int argc, char **argv) {}" HAVE_XINPUT2_MULTITOUCH)
        if(HAVE_XINPUT2_MULTITOUCH)
          set(SDL_VIDEO_DRIVER_X11_XINPUT2_SUPPORTS_MULTITOUCH 1)
        endif()
      endif()

      if(SDL_X11_XRANDR AND HAVE_XRANDR_H)
        if(HAVE_X11_SHARED AND XRANDR_LIB)
          set(SDL_VIDEO_DRIVER_X11_DYNAMIC_XRANDR "\"${XRANDR_LIB_SONAME}\"")
        else()
          list(APPEND EXTRA_LIBS ${XRANDR_LIB})
        endif()
        set(SDL_VIDEO_DRIVER_X11_XRANDR 1)
        set(HAVE_X11_XRANDR TRUE)
      endif()

      if(SDL_X11_XSCRNSAVER AND HAVE_XSS_H)
        if(HAVE_X11_SHARED AND XSS_LIB)
          set(SDL_VIDEO_DRIVER_X11_DYNAMIC_XSS "\"${XSS_LIB_SONAME}\"")
        else()
          list(APPEND EXTRA_LIBS ${XSS_LIB})
        endif()
        set(SDL_VIDEO_DRIVER_X11_XSCRNSAVER 1)
        set(HAVE_X11_XSCRNSAVER TRUE)
      endif()

      if(SDL_X11_XSHAPE AND HAVE_XSHAPE_H)
        set(SDL_VIDEO_DRIVER_X11_XSHAPE 1)
        set(HAVE_X11_XSHAPE TRUE)
      endif()

      if(SDL_X11_XVM AND HAVE_XF86VM_H)
        if(HAVE_X11_SHARED AND XXF86VM_LIB)
          set(SDL_VIDEO_DRIVER_X11_DYNAMIC_XVIDMODE "\"${XXF86VM_LIB_SONAME}\"")
        else()
          list(APPEND EXTRA_LIBS ${XXF86VM_LIB})
        endif()
        set(SDL_VIDEO_DRIVER_X11_XVIDMODE 1)
        set(HAVE_X11_XVM TRUE)
      endif()

      set(CMAKE_REQUIRED_LIBRARIES)
    endif()
  endif()
  if(NOT HAVE_X11)
    # Prevent Mesa from including X11 headers
    list(APPEND EXTRA_CFLAGS "-DMESA_EGL_NO_X11_HEADERS -DEGL_NO_X11")
  endif()
endmacro()

macro(WaylandProtocolGen _SCANNER _CODE_MODE _XML _PROTL)
    set(_WAYLAND_PROT_C_CODE "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols/${_PROTL}-protocol.c")
    set(_WAYLAND_PROT_H_CODE "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols/${_PROTL}-client-protocol.h")

    add_custom_command(
        OUTPUT "${_WAYLAND_PROT_H_CODE}"
        DEPENDS "${_XML}"
        COMMAND "${_SCANNER}"
        ARGS client-header "${_XML}" "${_WAYLAND_PROT_H_CODE}"
    )

    add_custom_command(
        OUTPUT "${_WAYLAND_PROT_C_CODE}"
        DEPENDS "${_WAYLAND_PROT_H_CODE}"
        COMMAND "${_SCANNER}"
        ARGS "${_CODE_MODE}" "${_XML}" "${_WAYLAND_PROT_C_CODE}"
    )

    set(SOURCE_FILES ${SOURCE_FILES} "${_WAYLAND_PROT_C_CODE}")
endmacro()

# Requires:
# - EGL
# - PkgCheckModules
# Optional:
# - SDL_WAYLAND_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckWayland)
  if(SDL_WAYLAND)
    pkg_check_modules(WAYLAND wayland-client wayland-scanner wayland-egl wayland-cursor egl "xkbcommon>=0.5.0")
    pkg_check_modules(WAYLAND_SCANNER_1_15 "wayland-scanner>=1.15")

    if(WAYLAND_FOUND AND HAVE_OPENGL_EGL)
      execute_process(
        COMMAND ${PKG_CONFIG_EXECUTABLE} --variable=wayland_scanner wayland-scanner
        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
        RESULT_VARIABLE WAYLAND_SCANNER_RC
        OUTPUT_VARIABLE WAYLAND_SCANNER
        ERROR_QUIET
        OUTPUT_STRIP_TRAILING_WHITESPACE
      )
      if(NOT WAYLAND_SCANNER_RC EQUAL 0)
        set(WAYLAND_FOUND FALSE)
      endif()
    endif()

    if(WAYLAND_FOUND)
      if(WAYLAND_SCANNER_1_15_FOUND)
        set(WAYLAND_SCANNER_CODE_MODE "private-code")
      else()
        set(WAYLAND_SCANNER_CODE_MODE "code")
      endif()

      target_link_directories(sdl-build-options INTERFACE "${WAYLAND_LIBRARY_DIRS}")
      target_include_directories(sdl-build-options INTERFACE "${WAYLAND_INCLUDE_DIRS}")

      set(HAVE_WAYLAND TRUE)
      set(HAVE_SDL_VIDEO TRUE)

      file(GLOB WAYLAND_SOURCES ${SDL2_SOURCE_DIR}/src/video/wayland/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${WAYLAND_SOURCES})

      # We have to generate some protocol interface code for some unstable Wayland features.
      file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols")
      target_include_directories(sdl-build-options INTERFACE "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols")

      file(GLOB WAYLAND_PROTOCOLS_XML RELATIVE "${SDL2_SOURCE_DIR}/wayland-protocols/" "${SDL2_SOURCE_DIR}/wayland-protocols/*.xml")
      foreach(_XML ${WAYLAND_PROTOCOLS_XML})
        string(REGEX REPLACE "\\.xml$" "" _PROTL "${_XML}")
        WaylandProtocolGen("${WAYLAND_SCANNER}" "${WAYLAND_SCANNER_CODE_MODE}" "${SDL2_SOURCE_DIR}/wayland-protocols/${_XML}" "${_PROTL}")
      endforeach()

      if(SDL_WAYLAND_QT_TOUCH)
          set(HAVE_WAYLAND_QT_TOUCH TRUE)
          set(SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH 1)
      endif()

      if(SDL_WAYLAND_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic Wayland loading")
      endif()
      if(SDL_WAYLAND_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME(wayland-client)
        FindLibraryAndSONAME(wayland-egl)
        FindLibraryAndSONAME(wayland-cursor)
        FindLibraryAndSONAME(xkbcommon)
        set(SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC "\"${WAYLAND_CLIENT_LIB_SONAME}\"")
        set(SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC_EGL "\"${WAYLAND_EGL_LIB_SONAME}\"")
        set(SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC_CURSOR "\"${WAYLAND_CURSOR_LIB_SONAME}\"")
        set(SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC_XKBCOMMON "\"${XKBCOMMON_LIB_SONAME}\"")
        set(HAVE_WAYLAND_SHARED TRUE)
      else()
        set(EXTRA_LIBS ${WAYLAND_LIBRARIES} ${EXTRA_LIBS})
      endif()

      if(SDL_WAYLAND_LIBDECOR)
        pkg_check_modules(LIBDECOR libdecor-0)
        if(LIBDECOR_FOUND)
            set(HAVE_WAYLAND_LIBDECOR TRUE)
            set(HAVE_LIBDECOR_H 1)
            target_link_directories(sdl-build-options INTERFACE "${LIBDECOR_LIBRARY_DIRS}")
            target_include_directories(sdl-build-options INTERFACE "${LIBDECOR_INCLUDE_DIRS}")
            if(SDL_WAYLAND_LIBDECOR_SHARED AND NOT HAVE_SDL_LOADSO)
                message_warn("You must have SDL_LoadObject() support for dynamic libdecor loading")
            endif()
            if(SDL_WAYLAND_LIBDECOR_SHARED AND HAVE_SDL_LOADSO)
                set(HAVE_LIBDECOR_SHARED TRUE)
                FindLibraryAndSONAME(decor-0)
                set(SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC_LIBDECOR "\"${DECOR_0_LIB_SONAME}\"")
            else()
              set(EXTRA_LIBS ${LIBDECOR_LIBRARIES} ${EXTRA_LIBS})
            endif()
        endif()
      endif()

      set(SDL_VIDEO_DRIVER_WAYLAND 1)
    endif()
  endif()
endmacro()

# Requires:
# - n/a
#
macro(CheckCOCOA)
  if(SDL_COCOA)
    if(APPLE) # Apple always has Cocoa.
      set(HAVE_COCOA TRUE)
    endif()
    if(HAVE_COCOA)
      file(GLOB COCOA_SOURCES ${SDL2_SOURCE_DIR}/src/video/cocoa/*.m)
      set_source_files_properties(${COCOA_SOURCES} PROPERTIES LANGUAGE C)
      set(SOURCE_FILES ${SOURCE_FILES} ${COCOA_SOURCES})
      set(SDL_VIDEO_DRIVER_COCOA 1)
      set(HAVE_SDL_VIDEO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - PkgCheckModules
# Optional:
# - DIRECTFB_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckDirectFB)
  if(SDL_DIRECTFB)
    pkg_check_modules(PKG_DIRECTFB directfb>=1.0.0)
    if(PKG_DIRECTFB_FOUND)
      set(HAVE_DIRECTFB TRUE)
      file(GLOB DIRECTFB_SOURCES ${SDL2_SOURCE_DIR}/src/video/directfb/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${DIRECTFB_SOURCES})
      set(SDL_VIDEO_DRIVER_DIRECTFB 1)
      set(SDL_VIDEO_RENDER_DIRECTFB 1)
      list(APPEND EXTRA_CFLAGS ${PKG_DIRECTFB_CFLAGS})
      if(SDL_DIRECTFB_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic DirectFB loading")
      endif()
      if(SDL_DIRECTFB_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME("directfb")
        set(SDL_VIDEO_DRIVER_DIRECTFB_DYNAMIC "\"${DIRECTFB_LIB_SONAME}\"")
        set(HAVE_DIRECTFB_SHARED TRUE)
      else()
        list(APPEND EXTRA_LDFLAGS ${PKG_DIRECTFB_LDFLAGS})
      endif()
      set(HAVE_SDL_VIDEO TRUE)
    endif()
  endif()
endmacro()

# Requires:
# - n/a
macro(CheckVivante)
  if(SDL_VIVANTE)
    check_c_source_compiles("
        #include <gc_vdk.h>
        int main(int argc, char** argv) {}" HAVE_VIVANTE_VDK)
    check_c_source_compiles("
        #define LINUX
        #define EGL_API_FB
        #include <EGL/eglvivante.h>
        int main(int argc, char** argv) {}" HAVE_VIVANTE_EGL_FB)
    if(HAVE_VIVANTE_VDK OR HAVE_VIVANTE_EGL_FB)
      set(HAVE_VIVANTE TRUE)
      set(HAVE_SDL_VIDEO TRUE)

      file(GLOB VIVANTE_SOURCES ${SDL2_SOURCE_DIR}/src/video/vivante/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${VIVANTE_SOURCES})
      set(SDL_VIDEO_DRIVER_VIVANTE 1)
      if(HAVE_VIVANTE_VDK)
        set(SDL_VIDEO_DRIVER_VIVANTE_VDK 1)
        list(APPEND EXTRA_LIBS VDK VIVANTE)
      else()
        set(SDL_CFLAGS "${SDL_CFLAGS} -DLINUX -DEGL_API_FB")
        list(APPEND EXTRA_LIBS EGL)
      endif(HAVE_VIVANTE_VDK)
    endif()
  endif()
endmacro()

# Requires:
# - nada
macro(CheckGLX)
  if(SDL_OPENGL)
    check_c_source_compiles("
        #include <GL/glx.h>
        int main(int argc, char** argv) {}" HAVE_OPENGL_GLX)
    if(HAVE_OPENGL_GLX)
      set(SDL_VIDEO_OPENGL_GLX 1)
    endif()
  endif()
endmacro()

# Requires:
# - PkgCheckModules
macro(CheckEGL)
  if (SDL_OPENGL OR SDL_OPENGLES)
    pkg_check_modules(EGL egl)
    string(REPLACE "-D_THREAD_SAFE;" "-D_THREAD_SAFE=1;" EGL_CFLAGS "${EGL_CFLAGS}")
    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${EGL_CFLAGS}")
    check_c_source_compiles("
        #define EGL_API_FB
        #define MESA_EGL_NO_X11_HEADERS
        #define EGL_NO_X11
        #include <EGL/egl.h>
        #include <EGL/eglext.h>
        int main (int argc, char** argv) {}" HAVE_OPENGL_EGL)
    if(HAVE_OPENGL_EGL)
      set(SDL_VIDEO_OPENGL_EGL 1)
    endif()
  endif()
endmacro()

# Requires:
# - nada
macro(CheckOpenGL)
  if(SDL_OPENGL)
    check_c_source_compiles("
        #include <GL/gl.h>
        #include <GL/glext.h>
        int main(int argc, char** argv) {}" HAVE_OPENGL)
    if(HAVE_OPENGL)
      set(SDL_VIDEO_OPENGL 1)
      set(SDL_VIDEO_RENDER_OGL 1)
    endif()
  endif()
endmacro()

# Requires:
# - nada
macro(CheckOpenGLES)
  if(SDL_OPENGLES)
    check_c_source_compiles("
        #include <GLES/gl.h>
        #include <GLES/glext.h>
        int main (int argc, char** argv) {}" HAVE_OPENGLES_V1)
    if(HAVE_OPENGLES_V1)
        set(HAVE_OPENGLES TRUE)
        set(SDL_VIDEO_OPENGL_ES 1)
        set(SDL_VIDEO_RENDER_OGL_ES 1)
    endif()
    check_c_source_compiles("
        #include <GLES2/gl2.h>
        #include <GLES2/gl2ext.h>
        int main (int argc, char** argv) {}" HAVE_OPENGLES_V2)
    if(HAVE_OPENGLES_V2)
        set(HAVE_OPENGLES TRUE)
        set(SDL_VIDEO_OPENGL_ES2 1)
        set(SDL_VIDEO_RENDER_OGL_ES2 1)
    endif()
  endif()
endmacro()

# Requires:
# - nada
# Optional:
# - THREADS opt
# Sets:
# PTHREAD_CFLAGS
# PTHREAD_LIBS
macro(CheckPTHREAD)
  if(SDL_PTHREADS)
    if(ANDROID)
      # the android libc provides built-in support for pthreads, so no
      # additional linking or compile flags are necessary
    elseif(LINUX)
      set(PTHREAD_CFLAGS "-D_REENTRANT")
      set(PTHREAD_LDFLAGS "-pthread")
    elseif(BSDI)
      set(PTHREAD_CFLAGS "-D_REENTRANT -D_THREAD_SAFE")
      set(PTHREAD_LDFLAGS "")
    elseif(DARWIN)
      set(PTHREAD_CFLAGS "-D_THREAD_SAFE")
      # causes Carbon.p complaints?
      # set(PTHREAD_CFLAGS "-D_REENTRANT -D_THREAD_SAFE")
      set(PTHREAD_LDFLAGS "")
    elseif(FREEBSD)
      set(PTHREAD_CFLAGS "-D_REENTRANT -D_THREAD_SAFE")
      set(PTHREAD_LDFLAGS "-pthread")
    elseif(NETBSD)
      set(PTHREAD_CFLAGS "-D_REENTRANT -D_THREAD_SAFE")
      set(PTHREAD_LDFLAGS "-lpthread")
    elseif(OPENBSD)
      set(PTHREAD_CFLAGS "-D_REENTRANT")
      set(PTHREAD_LDFLAGS "-pthread")
    elseif(SOLARIS)
      set(PTHREAD_CFLAGS "-D_REENTRANT")
      set(PTHREAD_LDFLAGS "-pthread -lposix4")
    elseif(SYSV5)
      set(PTHREAD_CFLAGS "-D_REENTRANT -Kthread")
      set(PTHREAD_LDFLAGS "")
    elseif(AIX)
      set(PTHREAD_CFLAGS "-D_REENTRANT -mthreads")
      set(PTHREAD_LDFLAGS "-pthread")
    elseif(HPUX)
      set(PTHREAD_CFLAGS "-D_REENTRANT")
      set(PTHREAD_LDFLAGS "-L/usr/lib -pthread")
    elseif(HAIKU)
      set(PTHREAD_CFLAGS "-D_REENTRANT")
      set(PTHREAD_LDFLAGS "")
    elseif(EMSCRIPTEN)
      set(PTHREAD_CFLAGS "-D_REENTRANT -pthread")
      set(PTHREAD_LDFLAGS "-pthread")
    else()
      set(PTHREAD_CFLAGS "-D_REENTRANT")
      set(PTHREAD_LDFLAGS "-lpthread")
    endif()

    # Run some tests
    set(ORIG_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${PTHREAD_CFLAGS} ${PTHREAD_LDFLAGS}")
    check_c_source_compiles("
      #include <pthread.h>
      int main(int argc, char** argv) {
        pthread_attr_t type;
        pthread_attr_init(&type);
        return 0;
      }" HAVE_PTHREADS)
    if(HAVE_PTHREADS)
      set(SDL_THREAD_PTHREAD 1)
      list(APPEND EXTRA_CFLAGS ${PTHREAD_CFLAGS})
      list(APPEND EXTRA_LDFLAGS ${PTHREAD_LDFLAGS})
      set(SDL_CFLAGS "${SDL_CFLAGS} ${PTHREAD_CFLAGS}")
      list(APPEND SDL_LIBS ${PTHREAD_LDFLAGS})

      check_c_source_compiles("
        #define _GNU_SOURCE 1
        #include <pthread.h>
        int main(int argc, char **argv) {
          pthread_mutexattr_t attr;
          pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
          return 0;
        }" HAVE_RECURSIVE_MUTEXES)
      if(HAVE_RECURSIVE_MUTEXES)
        set(SDL_THREAD_PTHREAD_RECURSIVE_MUTEX 1)
      else()
        check_c_source_compiles("
            #define _GNU_SOURCE 1
            #include <pthread.h>
            int main(int argc, char **argv) {
              pthread_mutexattr_t attr;
              pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE_NP);
              return 0;
            }" HAVE_RECURSIVE_MUTEXES_NP)
        if(HAVE_RECURSIVE_MUTEXES_NP)
          set(SDL_THREAD_PTHREAD_RECURSIVE_MUTEX_NP 1)
        endif()
      endif()

      if(SDL_PTHREADS_SEM)
        check_c_source_compiles("#include <pthread.h>
                                 #include <semaphore.h>
                                 int main(int argc, char **argv) { return 0; }" HAVE_PTHREADS_SEM)
        if(HAVE_PTHREADS_SEM)
          check_c_source_compiles("
              #include <pthread.h>
              #include <semaphore.h>
              int main(int argc, char **argv) {
                  sem_timedwait(NULL, NULL);
                  return 0;
              }" HAVE_SEM_TIMEDWAIT)
        endif()
      endif()

      check_include_files("pthread.h" HAVE_PTHREAD_H)
      check_include_files("pthread_np.h" HAVE_PTHREAD_NP_H)
      if (HAVE_PTHREAD_H)
        check_symbol_exists(pthread_setname_np "pthread.h" HAVE_PTHREAD_SETNAME_NP)
        if (HAVE_PTHREAD_NP_H)
          check_symbol_exists(pthread_set_name_np "pthread.h;pthread_np.h" HAVE_PTHREAD_SET_NAME_NP)
        endif()
      endif()

      set(SOURCE_FILES ${SOURCE_FILES}
          ${SDL2_SOURCE_DIR}/src/thread/pthread/SDL_systhread.c
          ${SDL2_SOURCE_DIR}/src/thread/pthread/SDL_sysmutex.c   # Can be faked, if necessary
          ${SDL2_SOURCE_DIR}/src/thread/pthread/SDL_syscond.c    # Can be faked, if necessary
          ${SDL2_SOURCE_DIR}/src/thread/pthread/SDL_systls.c
          )
      if(HAVE_PTHREADS_SEM)
        set(SOURCE_FILES ${SOURCE_FILES}
            ${SDL2_SOURCE_DIR}/src/thread/pthread/SDL_syssem.c)
      else()
        set(SOURCE_FILES ${SOURCE_FILES}
            ${SDL2_SOURCE_DIR}/src/thread/generic/SDL_syssem.c)
      endif()
      set(HAVE_SDL_THREADS TRUE)
    endif()
    set(CMAKE_REQUIRED_FLAGS "${ORIG_CMAKE_REQUIRED_FLAGS}")
  endif()
endmacro()

# Requires
# - nada
# Optional:
# Sets:
# USB_LIBS
# USB_CFLAGS
macro(CheckUSBHID)
  check_library_exists(usbhid hid_init "" LIBUSBHID)
  if(LIBUSBHID)
    check_include_file(usbhid.h HAVE_USBHID_H)
    if(HAVE_USBHID_H)
      set(USB_CFLAGS "-DHAVE_USBHID_H")
    endif()

    check_include_file(libusbhid.h HAVE_LIBUSBHID_H)
    if(HAVE_LIBUSBHID_H)
      set(USB_CFLAGS "${USB_CFLAGS} -DHAVE_LIBUSBHID_H")
    endif()
    set(USB_LIBS ${USB_LIBS} usbhid)
  else()
    check_include_file(usb.h HAVE_USB_H)
    if(HAVE_USB_H)
      set(USB_CFLAGS "-DHAVE_USB_H")
    endif()
    check_include_file(libusb.h HAVE_LIBUSB_H)
    if(HAVE_LIBUSB_H)
      set(USB_CFLAGS "${USB_CFLAGS} -DHAVE_LIBUSB_H")
    endif()
    check_library_exists(usb hid_init "" LIBUSB)
    if(LIBUSB)
      set(USB_LIBS ${USB_LIBS} usb)
    endif()
  endif()

  set(ORIG_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${USB_CFLAGS}")
  set(CMAKE_REQUIRED_LIBRARIES "${USB_LIBS}")
  check_c_source_compiles("
       #include <sys/types.h>
        #if defined(HAVE_USB_H)
        #include <usb.h>
        #endif
        #ifdef __DragonFly__
        # include <bus/u4b/usb.h>
        # include <bus/u4b/usbhid.h>
        #else
        # include <dev/usb/usb.h>
        # include <dev/usb/usbhid.h>
        #endif
        #if defined(HAVE_USBHID_H)
        #include <usbhid.h>
        #elif defined(HAVE_LIBUSB_H)
        #include <libusb.h>
        #elif defined(HAVE_LIBUSBHID_H)
        #include <libusbhid.h>
        #endif
        int main(int argc, char **argv) {
          struct report_desc *repdesc;
          struct usb_ctl_report *repbuf;
          hid_kind_t hidkind;
          return 0;
        }" HAVE_USBHID)
  if(HAVE_USBHID)
    check_c_source_compiles("
          #include <sys/types.h>
          #if defined(HAVE_USB_H)
          #include <usb.h>
          #endif
          #ifdef __DragonFly__
          # include <bus/u4b/usb.h>
          # include <bus/u4b/usbhid.h>
          #else
          # include <dev/usb/usb.h>
          # include <dev/usb/usbhid.h>
          #endif
          #if defined(HAVE_USBHID_H)
          #include <usbhid.h>
          #elif defined(HAVE_LIBUSB_H)
          #include <libusb.h>
          #elif defined(HAVE_LIBUSBHID_H)
          #include <libusbhid.h>
          #endif
          int main(int argc, char** argv) {
            struct usb_ctl_report buf;
            if (buf.ucr_data) { }
            return 0;
          }" HAVE_USBHID_UCR_DATA)
    if(HAVE_USBHID_UCR_DATA)
      set(USB_CFLAGS "${USB_CFLAGS} -DUSBHID_UCR_DATA")
    endif()

    check_c_source_compiles("
          #include <sys/types.h>
          #if defined(HAVE_USB_H)
          #include <usb.h>
          #endif
          #ifdef __DragonFly__
          #include <bus/u4b/usb.h>
          #include <bus/u4b/usbhid.h>
          #else
          #include <dev/usb/usb.h>
          #include <dev/usb/usbhid.h>
          #endif
          #if defined(HAVE_USBHID_H)
          #include <usbhid.h>
          #elif defined(HAVE_LIBUSB_H)
          #include <libusb.h>
          #elif defined(HAVE_LIBUSBHID_H)
          #include <libusbhid.h>
          #endif
          int main(int argc, char **argv) {
            report_desc_t d;
            hid_start_parse(d, 1, 1);
            return 0;
          }" HAVE_USBHID_NEW)
    if(HAVE_USBHID_NEW)
      set(USB_CFLAGS "${USB_CFLAGS} -DUSBHID_NEW")
    endif()

    check_c_source_compiles("
        #include <machine/joystick.h>
        int main(int argc, char** argv) {
            struct joystick t;
            return 0;
        }" HAVE_MACHINE_JOYSTICK)
    if(HAVE_MACHINE_JOYSTICK)
      set(SDL_HAVE_MACHINE_JOYSTICK_H 1)
    endif()
    set(SDL_JOYSTICK_USBHID 1)
    file(GLOB BSD_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/bsd/*.c)
    set(SOURCE_FILES ${SOURCE_FILES} ${BSD_JOYSTICK_SOURCES})
    list(APPEND EXTRA_CFLAGS ${USB_CFLAGS})
    list(APPEND EXTRA_LIBS ${USB_LIBS})
    set(HAVE_SDL_JOYSTICK TRUE)

    set(CMAKE_REQUIRED_LIBRARIES)
    set(CMAKE_REQUIRED_FLAGS "${ORIG_CMAKE_REQUIRED_FLAGS}")
  endif()
endmacro()

# Check for HIDAPI joystick drivers. This is currently a Unix thing, not Windows or macOS!
macro(CheckHIDAPI)
  if(SDL_HIDAPI)
    if(HIDAPI_SKIP_LIBUSB)
      set(HAVE_HIDAPI TRUE)
    else()
      set(HAVE_HIDAPI FALSE)
      pkg_check_modules(LIBUSB libusb-1.0)
      if (LIBUSB_FOUND)
        check_include_file(libusb.h HAVE_LIBUSB_H ${LIBUSB_CFLAGS})
        if (HAVE_LIBUSB_H)
          set(HAVE_HIDAPI TRUE)
        endif()
      endif()
    endif()

    if(HAVE_HIDAPI)
      set(SDL_JOYSTICK_HIDAPI 1)
      set(HAVE_SDL_JOYSTICK TRUE)
      file(GLOB HIDAPI_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/hidapi/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${HIDAPI_SOURCES})
      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${LIBUSB_CFLAGS} \"-I${SDL2_SOURCE_DIR}/src/hidapi/hidapi\"")
      if(NOT HIDAPI_SKIP_LIBUSB)
        if(HIDAPI_ONLY_LIBUSB)
          set(SOURCE_FILES ${SOURCE_FILES} ${SDL2_SOURCE_DIR}/src/hidapi/libusb/hid.c)
          list(APPEND EXTRA_LIBS ${LIBUSB_LIBS})
        else()
          set(SOURCE_FILES ${SOURCE_FILES} ${SDL2_SOURCE_DIR}/src/hidapi/SDL_hidapi.c)
          # libusb is loaded dynamically, so don't add it to EXTRA_LIBS
          FindLibraryAndSONAME("usb-1.0")
          set(SDL_LIBUSB_DYNAMIC "\"${USB_LIB_SONAME}\"")
        endif()
      endif()
    endif()
  endif()
endmacro()


# Requires:
# - n/a
macro(CheckRPI)
  if(SDL_RPI)
    pkg_check_modules(VIDEO_RPI bcm_host brcmegl)
    if (NOT VIDEO_RPI_FOUND)
      set(VIDEO_RPI_INCLUDE_DIRS "/opt/vc/include" "/opt/vc/include/interface/vcos/pthreads" "/opt/vc/include/interface/vmcs_host/linux/" )
      set(VIDEO_RPI_LIBRARY_DIRS "/opt/vc/lib" )
      set(VIDEO_RPI_LIBRARIES bcm_host )
      set(VIDEO_RPI_LDFLAGS "-Wl,-rpath,/opt/vc/lib")
    endif()
    listtostr(VIDEO_RPI_INCLUDE_DIRS VIDEO_RPI_INCLUDE_FLAGS "-I")
    listtostr(VIDEO_RPI_LIBRARY_DIRS VIDEO_RPI_LIBRARY_FLAGS "-L")

    set(ORIG_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${VIDEO_RPI_INCLUDE_FLAGS} ${VIDEO_RPI_LIBRARY_FLAGS}")
    set(CMAKE_REQUIRED_LIBRARIES "${VIDEO_RPI_LIBRARIES}")
    check_c_source_compiles("
        #include <bcm_host.h>
        int main(int argc, char **argv) {}" HAVE_RPI)
    set(CMAKE_REQUIRED_FLAGS "${ORIG_CMAKE_REQUIRED_FLAGS}")
    set(CMAKE_REQUIRED_LIBRARIES)

    if(SDL_VIDEO AND HAVE_RPI)
      set(HAVE_SDL_VIDEO TRUE)
      set(SDL_VIDEO_DRIVER_RPI 1)
      file(GLOB VIDEO_RPI_SOURCES ${SDL2_SOURCE_DIR}/src/video/raspberry/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${VIDEO_RPI_SOURCES})
      list(APPEND EXTRA_LIBS ${VIDEO_RPI_LIBRARIES})
      # !!! FIXME: shouldn't be using CMAKE_C_FLAGS, right?
      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${VIDEO_RPI_INCLUDE_FLAGS} ${VIDEO_RPI_LIBRARY_FLAGS}")
      list(APPEND EXTRA_LDFLAGS ${VIDEO_RPI_LDFLAGS})
    endif()
  endif()
endmacro()

# Requires:
# - EGL
# - PkgCheckModules
# Optional:
# - SDL_KMSDRM_SHARED opt
# - HAVE_SDL_LOADSO opt
macro(CheckKMSDRM)
  if(SDL_KMSDRM)
    pkg_check_modules(KMSDRM libdrm gbm egl)
    if(KMSDRM_FOUND AND HAVE_OPENGL_EGL)
      link_directories(
        ${KMSDRM_LIBRARY_DIRS}
      )
      target_include_directories(sdl-build-options INTERFACE "${KMSDRM_INCLUDE_DIRS}")
      set(HAVE_KMSDRM TRUE)
      set(HAVE_SDL_VIDEO TRUE)

      file(GLOB KMSDRM_SOURCES ${SDL2_SOURCE_DIR}/src/video/kmsdrm/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${KMSDRM_SOURCES})

      list(APPEND EXTRA_CFLAGS ${KMSDRM_CFLAGS})

      set(SDL_VIDEO_DRIVER_KMSDRM 1)

      if(SDL_KMSDRM_SHARED AND NOT HAVE_SDL_LOADSO)
        message_warn("You must have SDL_LoadObject() support for dynamic KMS/DRM loading")
      endif()
      if(SDL_KMSDRM_SHARED AND HAVE_SDL_LOADSO)
        FindLibraryAndSONAME(drm)
        FindLibraryAndSONAME(gbm)
        set(SDL_VIDEO_DRIVER_KMSDRM_DYNAMIC "\"${DRM_LIB_SONAME}\"")
        set(SDL_VIDEO_DRIVER_KMSDRM_DYNAMIC_GBM "\"${GBM_LIB_SONAME}\"")
        set(HAVE_KMSDRM_SHARED TRUE)
      else()
        set(EXTRA_LIBS ${KMSDRM_LIBRARIES} ${EXTRA_LIBS})
      endif()
    endif()
  endif()
endmacro()