+
+if test "$enable_x11" != "no"; then
+ AC_CHECK_LIB(X11, XOpenDisplay, x11lib=yes, x11lib=no)
+ AC_CHECK_HEADERS(X11/Xlib.h, x11header=yes, x11header=no)
+
+ if test "$x11lib" = "yes"; then
+ if test "$x11header" = "yes"; then
+ AC_DEFINE_UNQUOTED([USE_X11], 1, [ Define to enable X11 specific code (e.g. fullscreen mode ).])
+ LIBS="$LIBS -lX11"
+ using_x11=yes
+ OPTION_X11=yes
+ else
+ if test "$enable_x11" = "yes"; then
+ AC_MSG_ERROR([** X11 headers not installed or broken **])
+ fi
+ fi
+ else
+ if test "$enable_x11" = "yes"; then
+ AC_MSG_ERROR([** X11 libs not installed or broken **])
+ fi
+ fi
+fi