diff --git a/m4/sdl2.m4 b/m4/sdl2.m4
new file mode 100644
index 0000000..93bc4b0
--- /dev/null
+++ b/m4/sdl2.m4
@@ -0,0 +1,202 @@
+# Configure paths for SDL
+# Sam Lantinga 9/21/99
+# stolen from Manish Singh
+# stolen back from Frank Belew
+# stolen from Manish Singh
+# Shamelessly stolen from Owen Taylor
+
+# serial 1
+
+dnl AM_PATH_SDL2([MINIMUM-VERSION, [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]]])
+dnl Test for SDL, and define SDL_CFLAGS and SDL_LIBS
+dnl
+AC_DEFUN([AM_PATH_SDL2],
+[dnl 
+dnl Get the cflags and libraries from the sdl2-config script
+dnl
+AC_ARG_WITH(sdl-prefix,[  --with-sdl-prefix=PFX   Prefix where SDL is installed (optional)],
+            sdl_prefix="$withval", sdl_prefix="")
+AC_ARG_WITH(sdl-exec-prefix,[  --with-sdl-exec-prefix=PFX Exec prefix where SDL is installed (optional)],
+            sdl_exec_prefix="$withval", sdl_exec_prefix="")
+AC_ARG_ENABLE(sdltest, [  --disable-sdltest       Do not try to compile and run a test SDL program],
+		    , enable_sdltest=yes)
+
+  min_sdl_version=ifelse([$1], ,0.9.0,$1)
+
+  if test "x$sdl_prefix$sdl_exec_prefix" = x ; then
+    PKG_CHECK_MODULES([SDL], [sdl2 >= $min_sdl_version],
+           [sdl_pc=yes],
+           [sdl_pc=no])
+  else
+    sdl_pc=no
+    if test x$sdl_exec_prefix != x ; then
+      sdl_config_args="$sdl_config_args --exec-prefix=$sdl_exec_prefix"
+      if test x${SDL_CONFIG+set} != xset ; then
+        SDL_CONFIG=$sdl_exec_prefix/bin/sdl2-config
+      fi
+    fi
+    if test x$sdl_prefix != x ; then
+      sdl_config_args="$sdl_config_args --prefix=$sdl_prefix"
+      if test x${SDL_CONFIG+set} != xset ; then
+        SDL_CONFIG=$sdl_prefix/bin/sdl2-config
+      fi
+    fi
+  fi
+
+  if test "x$sdl_pc" = xyes ; then
+    no_sdl=""
+    SDL_CONFIG="pkg-config sdl2"
+  else
+    as_save_PATH="$PATH"
+    if test "x$prefix" != xNONE && test "$cross_compiling" != yes; then
+      PATH="$prefix/bin:$prefix/usr/bin:$PATH"
+    fi
+    AC_PATH_PROG(SDL_CONFIG, sdl2-config, no, [$PATH])
+    PATH="$as_save_PATH"
+    AC_MSG_CHECKING(for SDL - version >= $min_sdl_version)
+    no_sdl=""
+
+    if test "$SDL_CONFIG" = "no" ; then
+      no_sdl=yes
+    else
+      SDL_CFLAGS=`$SDL_CONFIG $sdl_config_args --cflags`
+      SDL_LIBS=`$SDL_CONFIG $sdl_config_args --libs`
+
+      sdl_major_version=`$SDL_CONFIG $sdl_config_args --version | \
+             sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\1/'`
+      sdl_minor_version=`$SDL_CONFIG $sdl_config_args --version | \
+             sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\2/'`
+      sdl_micro_version=`$SDL_CONFIG $sdl_config_args --version | \
+             sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\3/'`
+      if test "x$enable_sdltest" = "xyes" ; then
+        ac_save_CFLAGS="$CFLAGS"
+        ac_save_CXXFLAGS="$CXXFLAGS"
+        ac_save_LIBS="$LIBS"
+        CFLAGS="$CFLAGS $SDL_CFLAGS"
+        CXXFLAGS="$CXXFLAGS $SDL_CFLAGS"
+        LIBS="$LIBS $SDL_LIBS"
+dnl
+dnl Now check if the installed SDL is sufficiently new. (Also sanity
+dnl checks the results of sdl2-config to some extent
+dnl
+      rm -f conf.sdltest
+      AC_TRY_RUN([
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "SDL.h"
+
+char*
+my_strdup (char *str)
+{
+  char *new_str;
+  
+  if (str)
+    {
+      new_str = (char *)malloc ((strlen (str) + 1) * sizeof(char));
+      strcpy (new_str, str);
+    }
+  else
+    new_str = NULL;
+  
+  return new_str;
+}
+
+int main (int argc, char *argv[])
+{
+  int major, minor, micro;
+  char *tmp_version;
+
+  /* This hangs on some systems (?)
+  system ("touch conf.sdltest");
+  */
+  { FILE *fp = fopen("conf.sdltest", "a"); if ( fp ) fclose(fp); }
+
+  /* HP/UX 9 (%@#!) writes to sscanf strings */
+  tmp_version = my_strdup("$min_sdl_version");
+  if (sscanf(tmp_version, "%d.%d.%d", &major, &minor, &micro) != 3) {
+     printf("%s, bad version string\n", "$min_sdl_version");
+     exit(1);
+   }
+
+   if (($sdl_major_version > major) ||
+      (($sdl_major_version == major) && ($sdl_minor_version > minor)) ||
+      (($sdl_major_version == major) && ($sdl_minor_version == minor) && ($sdl_micro_version >= micro)))
+    {
+      return 0;
+    }
+  else
+    {
+      printf("\n*** 'sdl2-config --version' returned %d.%d.%d, but the minimum version\n", $sdl_major_version, $sdl_minor_version, $sdl_micro_version);
+      printf("*** of SDL required is %d.%d.%d. If sdl2-config is correct, then it is\n", major, minor, micro);
+      printf("*** best to upgrade to the required version.\n");
+      printf("*** If sdl2-config was wrong, set the environment variable SDL_CONFIG\n");
+      printf("*** to point to the correct copy of sdl2-config, and remove the file\n");
+      printf("*** config.cache before re-running configure\n");
+      return 1;
+    }
+}
+
+],, no_sdl=yes,[echo $ac_n "cross compiling; assumed OK... $ac_c"])
+        CFLAGS="$ac_save_CFLAGS"
+        CXXFLAGS="$ac_save_CXXFLAGS"
+        LIBS="$ac_save_LIBS"
+      fi
+    fi
+    if test "x$no_sdl" = x ; then
+      AC_MSG_RESULT(yes)
+    else
+      AC_MSG_RESULT(no)
+    fi
+  fi
+  if test "x$no_sdl" = x ; then
+     ifelse([$2], , :, [$2])
+  else
+     if test "$SDL_CONFIG" = "no" ; then
+       echo "*** The sdl2-config script installed by SDL could not be found"
+       echo "*** If SDL was installed in PREFIX, make sure PREFIX/bin is in"
+       echo "*** your path, or set the SDL_CONFIG environment variable to the"
+       echo "*** full path to sdl2-config."
+     else
+       if test -f conf.sdltest ; then
+        :
+       else
+          echo "*** Could not run SDL test program, checking why..."
+          CFLAGS="$CFLAGS $SDL_CFLAGS"
+          CXXFLAGS="$CXXFLAGS $SDL_CFLAGS"
+          LIBS="$LIBS $SDL_LIBS"
+          AC_TRY_LINK([
+#include <stdio.h>
+#include "SDL.h"
+
+int main(int argc, char *argv[])
+{ return 0; }
+#undef  main
+#define main K_and_R_C_main
+],      [ return 0; ],
+        [ echo "*** The test program compiled, but did not run. This usually means"
+          echo "*** that the run-time linker is not finding SDL or finding the wrong"
+          echo "*** version of SDL. If it is not finding SDL, you'll need to set your"
+          echo "*** LD_LIBRARY_PATH environment variable, or edit /etc/ld.so.conf to point"
+          echo "*** to the installed location  Also, make sure you have run ldconfig if that"
+          echo "*** is required on your system"
+	  echo "***"
+          echo "*** If you have an old version installed, it is best to remove it, although"
+          echo "*** you may also be able to get things to work by modifying LD_LIBRARY_PATH"],
+        [ echo "*** The test program failed to compile or link. See the file config.log for the"
+          echo "*** exact error that occured. This usually means SDL was incorrectly installed"
+          echo "*** or that you have moved SDL since it was installed. In the latter case, you"
+          echo "*** may want to edit the sdl2-config script: $SDL_CONFIG" ])
+          CFLAGS="$ac_save_CFLAGS"
+          CXXFLAGS="$ac_save_CXXFLAGS"
+          LIBS="$ac_save_LIBS"
+       fi
+     fi
+     SDL_CFLAGS=""
+     SDL_LIBS=""
+     ifelse([$3], , :, [$3])
+  fi
+  AC_SUBST(SDL_CFLAGS)
+  AC_SUBST(SDL_LIBS)
+  rm -f conf.sdltest
+])