if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_BINARY_DIR})

  message(FATAL_ERROR "Prevented in-tree built. Please create a build directory outside of the SDL source code and call cmake from there")

endif()

cmake_minimum_required(VERSION 2.8)

project(SDL2 C)

include(CheckFunctionExists)

include(CheckLibraryExists)

include(CheckIncludeFiles)

include(CheckIncludeFile)

include(CheckSymbolExists)

include(CheckCSourceRuns)

include(CheckCCompilerFlag)

include(CheckTypeSize)

include(CheckStructHasMember)

include(CMakeDependentOption)

include(FindPkgConfig)

set(CMAKE_MODULE_PATH "${SDL2_SOURCE_DIR}/cmake")

include(${SDL2_SOURCE_DIR}/cmake/macros.cmake)

include(${SDL2_SOURCE_DIR}/cmake/sdlchecks.cmake)

# General settings

# Edit include/SDL_version.h and change the version, then:

#   SDL_MICRO_VERSION += 1;

#   SDL_INTERFACE_AGE += 1;

#   SDL_BINARY_AGE += 1;

# if any functions have been added, set SDL_INTERFACE_AGE to 0.

# if backwards compatibility has been broken,

# set SDL_BINARY_AGE and SDL_INTERFACE_AGE to 0.

set(SDL_MAJOR_VERSION 2)

set(SDL_MINOR_VERSION 0)

set(SDL_MICRO_VERSION 4)

set(SDL_INTERFACE_AGE 0)

set(SDL_BINARY_AGE 4)

set(SDL_VERSION "${SDL_MAJOR_VERSION}.${SDL_MINOR_VERSION}.${SDL_MICRO_VERSION}")

# Calculate a libtool-like version number

math(EXPR LT_CURRENT "${SDL_MICRO_VERSION} - ${SDL_INTERFACE_AGE}")

math(EXPR LT_AGE "${SDL_BINARY_AGE} - ${SDL_INTERFACE_AGE}")

math(EXPR LT_MAJOR "${LT_CURRENT}- ${LT_AGE}")

set(LT_REVISION "${SDL_INTERFACE_AGE}")

set(LT_RELEASE "${SDL_MAJOR_VERSION}.${SDL_MINOR_VERSION}")

set(LT_VERSION "${LT_MAJOR}.${LT_AGE}.${LT_REVISION}")

message(STATUS "${LT_VERSION} :: ${LT_AGE} :: ${LT_REVISION} :: ${LT_CURRENT} :: ${LT_RELEASE}")

# General settings & flags

set(LIBRARY_OUTPUT_DIRECTORY "build")

# Check for 64 or 32 bit

set(SIZEOF_VOIDP ${CMAKE_SIZEOF_VOID_P})

if(CMAKE_SIZEOF_VOID_P EQUAL 8)

  set(ARCH_64 TRUE)

  set(PROCESSOR_ARCH "x64")

else()

  set(ARCH_64 FALSE)

  set(PROCESSOR_ARCH "x86")

endif()

set(LIBNAME SDL2)

if(NOT LIBTYPE)

  set(LIBTYPE SHARED)

endif()

# Get the platform

if(WIN32)

  if(NOT WINDOWS)

    set(WINDOWS TRUE)

  endif()

elseif(UNIX AND NOT APPLE)

  if(CMAKE_SYSTEM_NAME MATCHES ".*Linux")

    set(LINUX TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "kFreeBSD.*")

    set(FREEBSD TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "kNetBSD.*|NetBSD.*")

    set(NETBSD TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "kOpenBSD.*|OpenBSD.*")

    set(OPENBSD TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES ".*GNU.*")

    set(GNU TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES ".*BSDI.*")

    set(BSDI TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "DragonFly.*|FreeBSD")

    set(FREEBSD TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "SYSV5.*")

    set(SYSV5 TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "Solaris.*")

    set(SOLARIS TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "HP-UX.*")

    set(HPUX TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "AIX.*")

    set(AIX TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES "Minix.*")

    set(MINIX TRUE)

  endif()

elseif(APPLE)

  if(CMAKE_SYSTEM_NAME MATCHES ".*Darwin.*")

    set(DARWIN TRUE)

  elseif(CMAKE_SYSTEM_NAME MATCHES ".*MacOS.*")

    set(MACOSX TRUE)

  endif()

  # TODO: iOS?

elseif(CMAKE_SYSTEM_NAME MATCHES "BeOS.*")

  message_error("BeOS support has been removed as of SDL 2.0.2.")

elseif(CMAKE_SYSTEM_NAME MATCHES "Haiku.*")

  set(HAIKU TRUE)

endif()

# Don't mistake osx for unix

if(UNIX AND NOT APPLE)

  set(UNIX_SYS ON)

else()

  set(UNIX_SYS OFF)

endif()

if(UNIX OR APPLE)

  set(UNIX_OR_MAC_SYS ON)

else()

  set(UNIX_OR_MAC_SYS OFF)

endif()

if (UNIX_OR_MAC_SYS AND NOT EMSCRIPTEN) # JavaScript does not yet have threading support, so disable pthreads when building for Emscripten.

  set(SDL_PTHREADS_ENABLED_BY_DEFAULT ON)

else()

  set(SDL_PTHREADS_ENABLED_BY_DEFAULT OFF)

endif()

# Default option knobs

if(APPLE OR ARCH_64)

  set(OPT_DEF_SSEMATH ON)

endif()

if(UNIX OR MINGW OR MSYS)

  set(OPT_DEF_LIBC ON)

endif()

# Compiler info

if(CMAKE_COMPILER_IS_GNUCC)

  set(USE_GCC TRUE)

  set(OPT_DEF_ASM TRUE)

elseif(CMAKE_C_COMPILER_ID MATCHES "Clang")

  set(USE_CLANG TRUE)

  set(OPT_DEF_ASM TRUE)

elseif(MSVC_VERSION GREATER 1400) # VisualStudio 8.0+

  set(OPT_DEF_ASM TRUE)

  #set(CMAKE_C_FLAGS "/ZI /WX- /

else()

  set(OPT_DEF_ASM FALSE)

endif()

# Default flags, if not set otherwise

if("$ENV{CFLAGS}" STREQUAL "")

  if(USE_GCC OR USE_CLANG)

    set(CMAKE_C_FLAGS "-g -O3")

  endif()

else()

  set(CMAKE_C_FLAGS "$ENV{CFLAGS}")

  list(APPEND EXTRA_CFLAGS "$ENV{CFLAGS}")

endif()

if(NOT ("$ENV{CFLAGS}" STREQUAL "")) # Hackish, but does the trick on Win32

  list(APPEND EXTRA_LDFLAGS "$ENV{LDFLAGS}")

endif()

if(MSVC)

  option(FORCE_STATIC_VCRT "Force /MT for static VC runtimes" OFF)

  if(FORCE_STATIC_VCRT)

    foreach(flag_var

        CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE

        CMAKE_C_FLAGS_MINSIZEREL CMAKE_C_FLAGS_RELWITHDEBINFO)

      if(${flag_var} MATCHES "/MD")

        string(REGEX REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")

      endif()

    endforeach()

  endif()

endif()

# Those are used for pkg-config and friends, so that the SDL2.pc, sdl2-config,

# etc. are created correctly.

set(SDL_LIBS "-lSDL2")

set(SDL_CFLAGS "")

# Emscripten toolchain has a nonempty default value for this, and the checks 

# in this file need to change that, so remember the original value, and 

# restore back to that afterwards. For check_function_exists() to work in

# Emscripten, this value must be at its default value.

set(ORIG_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})

if(CYGWIN)

  # We build SDL on cygwin without the UNIX emulation layer

  include_directories("-I/usr/include/mingw")

  set(CMAKE_REQUIRED_FLAGS "-mno-cygwin")

  check_c_source_compiles("int main(int argc, char **argv) {}"

    HAVE_GCC_NO_CYGWIN)

  set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

  if(HAVE_GCC_NO_CYGWIN)

    list(APPEND EXTRA_LDFLAGS "-mno-cygwin")

    list(APPEND SDL_LIBS "-mno-cygwin")

  endif()

  set(SDL_CFLAGS "${SDL_CFLAGS} -I/usr/include/mingw")

endif()

add_definitions(-DUSING_GENERATED_CONFIG_H)

# General includes

include_directories(${SDL2_BINARY_DIR}/include ${SDL2_SOURCE_DIR}/include)

# All these ENABLED_BY_DEFAULT vars will default to ON if not specified, so

#  you only need to have a platform override them if they are disabling.

set(OPT_DEF_ASM TRUE)

if(EMSCRIPTEN)

  # Set up default values for the currently supported set of subsystems:

  # Emscripten/Javascript does not have assembly support, a dynamic library 

  # loading architecture, low-level CPU inspection or multithreading.

  set(OPT_DEF_ASM FALSE)

  set(SDL_SHARED_ENABLED_BY_DEFAULT OFF)

  set(SDL_ATOMIC_ENABLED_BY_DEFAULT OFF)

  set(SDL_THREADS_ENABLED_BY_DEFAULT OFF)

  set(SDL_LOADSO_ENABLED_BY_DEFAULT OFF)

  set(SDL_CPUINFO_ENABLED_BY_DEFAULT OFF)

  set(SDL_DLOPEN_ENABLED_BY_DEFAULT OFF)

endif()

set(SDL_SUBSYSTEMS

    Atomic Audio Video Render Events Joystick Haptic Power Threads Timers

    File Loadso CPUinfo Filesystem Dlopen)

foreach(_SUB ${SDL_SUBSYSTEMS})

  string(TOUPPER ${_SUB} _OPT)

  if (NOT DEFINED SDL_${_OPT}_ENABLED_BY_DEFAULT)

    set(SDL_${_OPT}_ENABLED_BY_DEFAULT ON)

  endif()

  option(SDL_${_OPT} "Enable the ${_SUB} subsystem" ${SDL_${_OPT}_ENABLED_BY_DEFAULT})

endforeach()

option_string(ASSERTIONS "Enable internal sanity checks (auto/disabled/release/enabled/paranoid)" "auto")

#set_option(DEPENDENCY_TRACKING "Use gcc -MMD -MT dependency tracking" ON)

set_option(LIBC                "Use the system C library" ${OPT_DEF_LIBC})

set_option(GCC_ATOMICS         "Use gcc builtin atomics" ${USE_GCC})

set_option(ASSEMBLY            "Enable assembly routines" ${OPT_DEF_ASM})

set_option(SSEMATH             "Allow GCC to use SSE floating point math" ${OPT_DEF_SSEMATH})

set_option(MMX                 "Use MMX assembly routines" ${OPT_DEF_ASM})

set_option(3DNOW               "Use 3Dnow! MMX assembly routines" ${OPT_DEF_ASM})

set_option(SSE                 "Use SSE assembly routines" ${OPT_DEF_ASM})

set_option(SSE2                "Use SSE2 assembly routines" ${OPT_DEF_SSEMATH})

set_option(ALTIVEC             "Use Altivec assembly routines" ${OPT_DEF_ASM})

set_option(DISKAUDIO           "Support the disk writer audio driver" ON)

set_option(DUMMYAUDIO          "Support the dummy audio driver" ON)

set_option(VIDEO_DIRECTFB      "Use DirectFB video driver" OFF)

dep_option(DIRECTFB_SHARED     "Dynamically load directfb support" ON "VIDEO_DIRECTFB" OFF)

set_option(FUSIONSOUND         "Use FusionSound audio driver" OFF)

dep_option(FUSIONSOUND_SHARED  "Dynamically load fusionsound audio support" ON "FUSIONSOUND" OFF)

set_option(VIDEO_DUMMY         "Use dummy video driver" ON)

set_option(VIDEO_OPENGL        "Include OpenGL support" ON)

set_option(VIDEO_OPENGLES      "Include OpenGL ES support" ON)

set_option(PTHREADS            "Use POSIX threads for multi-threading" ${SDL_PTHREADS_ENABLED_BY_DEFAULT})

dep_option(PTHREADS_SEM        "Use pthread semaphores" ON "PTHREADS" OFF)

set_option(SDL_DLOPEN          "Use dlopen for shared object loading" ${SDL_DLOPEN_ENABLED_BY_DEFAULT})

set_option(OSS                 "Support the OSS audio API" ${UNIX_SYS})

set_option(ALSA                "Support the ALSA audio API" ${UNIX_SYS})

dep_option(ALSA_SHARED         "Dynamically load ALSA audio support" ON "ALSA" OFF)

set_option(ESD                 "Support the Enlightened Sound Daemon" ${UNIX_SYS})

dep_option(ESD_SHARED          "Dynamically load ESD audio support" ON "ESD" OFF)

set_option(PULSEAUDIO          "Use PulseAudio" ${UNIX_SYS})

dep_option(PULSEAUDIO_SHARED   "Dynamically load PulseAudio support" ON "PULSEAUDIO" OFF)

set_option(ARTS                "Support the Analog Real Time Synthesizer" ${UNIX_SYS})

dep_option(ARTS_SHARED         "Dynamically load aRts audio support" ON "ARTS" OFF)

set_option(NAS                 "Support the NAS audio API" ${UNIX_SYS})

set_option(NAS_SHARED          "Dynamically load NAS audio API" ${UNIX_SYS})

set_option(SNDIO               "Support the sndio audio API" ${UNIX_SYS})

set_option(RPATH               "Use an rpath when linking SDL" ${UNIX_SYS})

set_option(CLOCK_GETTIME       "Use clock_gettime() instead of gettimeofday()" OFF)

set_option(INPUT_TSLIB         "Use the Touchscreen library for input" ${UNIX_SYS})

set_option(VIDEO_X11           "Use X11 video driver" ${UNIX_SYS})

set_option(VIDEO_WAYLAND       "Use Wayland video driver" ${UNIX_SYS})

dep_option(WAYLAND_SHARED      "Dynamically load Wayland support" ON "VIDEO_WAYLAND" OFF)

dep_option(VIDEO_WAYLAND_QT_TOUCH  "QtWayland server support for Wayland video driver" ON "VIDEO_WAYLAND" OFF)

set_option(VIDEO_MIR           "Use Mir video driver" ${UNIX_SYS})

dep_option(MIR_SHARED          "Dynamically load Mir support" ON "VIDEO_MIR" OFF)

set_option(VIDEO_RPI           "Use Raspberry Pi video driver" ${UNIX_SYS})

dep_option(X11_SHARED          "Dynamically load X11 support" ON "VIDEO_X11" OFF)

set(SDL_X11_OPTIONS Xcursor Xinerama XInput Xrandr Xscrnsaver XShape Xvm)

foreach(_SUB ${SDL_X11_OPTIONS})

  string(TOUPPER "VIDEO_X11_${_SUB}" _OPT)

  dep_option(${_OPT}           "Enable ${_SUB} support" ON "VIDEO_X11" OFF)

endforeach()

set_option(VIDEO_COCOA         "Use Cocoa video driver" ${APPLE})

set_option(DIRECTX             "Use DirectX for Windows audio/video" ${WINDOWS})

set_option(RENDER_D3D          "Enable the Direct3D render driver" ${WINDOWS})

set_option(VIDEO_VIVANTE       "Use Vivante EGL video driver" ${UNIX_SYS})

# TODO: We should (should we?) respect cmake's ${BUILD_SHARED_LIBS} flag here

# The options below are for compatibility to configure's default behaviour.

set(SDL_SHARED ${SDL_SHARED_ENABLED_BY_DEFAULT} CACHE BOOL "Build a shared version of the library")

set(SDL_STATIC ON CACHE BOOL "Build a static version of the library")

# General source files

file(GLOB SOURCE_FILES

  ${SDL2_SOURCE_DIR}/src/*.c

  ${SDL2_SOURCE_DIR}/src/atomic/*.c

  ${SDL2_SOURCE_DIR}/src/audio/*.c

  ${SDL2_SOURCE_DIR}/src/cpuinfo/*.c

  ${SDL2_SOURCE_DIR}/src/dynapi/*.c

  ${SDL2_SOURCE_DIR}/src/events/*.c

  ${SDL2_SOURCE_DIR}/src/file/*.c

  ${SDL2_SOURCE_DIR}/src/libm/*.c

  ${SDL2_SOURCE_DIR}/src/render/*.c

  ${SDL2_SOURCE_DIR}/src/render/*/*.c

  ${SDL2_SOURCE_DIR}/src/stdlib/*.c

  ${SDL2_SOURCE_DIR}/src/thread/*.c

  ${SDL2_SOURCE_DIR}/src/timer/*.c

  ${SDL2_SOURCE_DIR}/src/video/*.c)

if(ASSERTIONS STREQUAL "auto")

  # Do nada - use optimization settings to determine the assertion level

elseif(ASSERTIONS STREQUAL "disabled")

  set(SDL_DEFAULT_ASSERT_LEVEL 0)

elseif(ASSERTIONS STREQUAL "release")

  set(SDL_DEFAULT_ASSERT_LEVEL 1)

elseif(ASSERTIONS STREQUAL "enabled")

  set(SDL_DEFAULT_ASSERT_LEVEL 2)

elseif(ASSERTIONS STREQUAL "paranoid")

  set(SDL_DEFAULT_ASSERT_LEVEL 3)

else()

  message_error("unknown assertion level")

endif()

set(HAVE_ASSERTIONS ${ASSERTIONS})

# Compiler option evaluation

if(USE_GCC OR USE_CLANG)

  if(DEPENDENCY_TRACKING)

    check_c_source_compiles("

        #if !defined(__GNUC__) || __GNUC__ < 3

        #error Dependency tracking requires GCC 3.0 or newer

        #endif

        int main(int argc, char **argv) { }" HAVE_DEPENDENCY_TRACKING)

  endif()

  if(GCC_ATOMICS)

    check_c_source_compiles("int main(int argc, char **argv) {

        int a;

        void *x, *y, *z;

        __sync_lock_test_and_set(&a, 4);

        __sync_lock_test_and_set(&x, y);

        __sync_fetch_and_add(&a, 1);

        __sync_bool_compare_and_swap(&a, 5, 10);

        __sync_bool_compare_and_swap(&x, y, z); }" HAVE_GCC_ATOMICS)

    if(NOT HAVE_GCC_ATOMICS)

      check_c_source_compiles("int main(int argc, char **argv) {

          int a;

          __sync_lock_test_and_set(&a, 1);

          __sync_lock_release(&a); }" HAVE_GCC_SYNC_LOCK_TEST_AND_SET)

    endif()

  endif()

  set(CMAKE_REQUIRED_FLAGS "-mpreferred-stack-boundary=2")

  check_c_source_compiles("int x = 0; int main(int argc, char **argv) {}"

    HAVE_GCC_PREFERRED_STACK_BOUNDARY)

  set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

  set(CMAKE_REQUIRED_FLAGS "-fvisibility=hidden -Werror")

  check_c_source_compiles("

      #if !defined(__GNUC__) || __GNUC__ < 4

      #error SDL only uses visibility attributes in GCC 4 or newer

      #endif

      int main(int argc, char **argv) {}" HAVE_GCC_FVISIBILITY)

  if(HAVE_GCC_FVISIBILITY)

    list(APPEND EXTRA_CFLAGS "-fvisibility=hidden")

  endif()

  set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

  check_c_compiler_flag(-Wall HAVE_GCC_WALL)

  if(HAVE_GCC_WALL)

    list(APPEND EXTRA_CFLAGS "-Wall")

    if(HAIKU)

      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-multichar")

    endif()

  endif()

  check_c_compiler_flag(-Wshadow HAVE_GCC_WSHADOW)

  if(HAVE_GCC_WSHADOW)

    list(APPEND EXTRA_CFLAGS "-Wshadow")

  endif()

  set(CMAKE_REQUIRED_FLAGS "-Wl,--no-undefined")

  check_c_compiler_flag("" HAVE_NO_UNDEFINED)

  set(CMAKE_REQUIRED_FLAGS)

  if(HAVE_NO_UNDEFINED)

    list(APPEND EXTRA_LDFLAGS "-Wl,--no-undefined")

  endif()

endif()

if(ASSEMBLY)

  if(USE_GCC OR USE_CLANG)

    set(SDL_ASSEMBLY_ROUTINES 1)

    # TODO: Those all seem to be quite GCC specific - needs to be

    # reworked for better compiler support

    set(HAVE_ASSEMBLY TRUE)

    if(MMX)

      set(CMAKE_REQUIRED_FLAGS "-mmmx")

      check_c_source_compiles("

          #ifdef __MINGW32__

          #include <_mingw.h>

          #ifdef __MINGW64_VERSION_MAJOR

          #include <intrin.h>

          #else

          #include <mmintrin.h>

          #endif

          #else

          #include <mmintrin.h>

          #endif

          #ifndef __MMX__

          #error Assembler CPP flag not enabled

          #endif

          int main(int argc, char **argv) { }" HAVE_MMX)

      if(HAVE_MMX)

        list(APPEND EXTRA_CFLAGS "-mmmx")

      endif()

      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

    endif()

    if(3DNOW)

      set(CMAKE_REQUIRED_FLAGS "-m3dnow")

      check_c_source_compiles("

          #include <mm3dnow.h>

          #ifndef __3dNOW__

          #error Assembler CPP flag not enabled

          #endif

          int main(int argc, char **argv) {

            void *p = 0;

            _m_prefetch(p);

          }" HAVE_3DNOW)

      if(HAVE_3DNOW)

        list(APPEND EXTRA_CFLAGS "-m3dnow")

      endif()

      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

    endif()

    if(SSE)

      set(CMAKE_REQUIRED_FLAGS "-msse")

      check_c_source_compiles("

          #ifdef __MINGW32__

          #include <_mingw.h>

          #ifdef __MINGW64_VERSION_MAJOR

          #include <intrin.h>

          #else

          #include <xmmintrin.h>

          #endif

          #else

          #include <xmmintrin.h>

          #endif

          #ifndef __SSE__

          #error Assembler CPP flag not enabled

          #endif

          int main(int argc, char **argv) { }" HAVE_SSE)

      if(HAVE_SSE)

        list(APPEND EXTRA_CFLAGS "-msse")

      endif()

      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

    endif()

    if(SSE2)

      set(CMAKE_REQUIRED_FLAGS "-msse2")

      check_c_source_compiles("

          #ifdef __MINGW32__

          #include <_mingw.h>

          #ifdef __MINGW64_VERSION_MAJOR

          #include <intrin.h>

          #else

          #include <emmintrin.h>

          #endif

          #else

          #include <emmintrin.h>

          #endif

          #ifndef __SSE2__

          #error Assembler CPP flag not enabled

          #endif

          int main(int argc, char **argv) { }" HAVE_SSE2)

      if(HAVE_SSE2)

        list(APPEND EXTRA_CFLAGS "-msse2")

      endif()

      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

    endif()

    if(SSEMATH)

      if(SSE OR SSE2)

        if(USE_GCC)

          list(APPEND EXTRA_CFLAGS "-mfpmath=387")

        endif()

        set(HAVE_SSEMATH TRUE)

      endif()

    endif()

    if(ALTIVEC)

      set(CMAKE_REQUIRED_FLAGS "-maltivec")

      check_c_source_compiles("

          #include <altivec.h>

          vector unsigned int vzero() {

              return vec_splat_u32(0);

          }

          int main(int argc, char **argv) { }" HAVE_ALTIVEC_H_HDR)

      check_c_source_compiles("

          vector unsigned int vzero() {

              return vec_splat_u32(0);

          }

          int main(int argc, char **argv) { }" HAVE_ALTIVEC)

      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

      if(HAVE_ALTIVEC OR HAVE_ALTIVEC_H_HDR)

        set(HAVE_ALTIVEC TRUE) # if only HAVE_ALTIVEC_H_HDR is set

        list(APPEND EXTRA_CFLAGS "-maltivec")

        set(SDL_ALTIVEC_BLITTERS 1)

        if(HAVE_ALTIVEC_H_HDR)

          set(HAVE_ALTIVEC_H 1)

        endif()

      endif()

    endif()

  elseif(MSVC_VERSION GREATER 1500)