--- BasiliskII/src/Unix/configure.in	1999/11/03 10:56:28	1.16
+++ BasiliskII/src/Unix/configure.in	1999/11/03 21:04:22	1.17
@@ -6,11 +6,12 @@ AC_PREREQ(2.12)
 AC_CONFIG_HEADER(config.h)
 
 dnl Options.
-AC_ARG_ENABLE(xf86-dga,  [  --enable-xf86-dga       use the XFree86 DGA extension [default=yes]], [WANT_XF86_DGA=$enableval], [WANT_XF86_DGA=yes])
-AC_ARG_ENABLE(fbdev-dga, [  --enable-fbdev-dga      use direct frame buffer access via /dev/fb [default=yes]], [WANT_FBDEV_DGA=$enableval], [WANT_FBDEV_DGA=yes])
-AC_ARG_WITH(esd,       [  --with-esd              support ESD for sound under Linux/FreeBSD [default=yes]], [WANT_ESD=$withval], [WANT_ESD=yes])
-AC_ARG_WITH(gtk,       [  --with-gtk              use GTK user interface [default=yes]], [WANT_GTK=$withval], [WANT_GTK=yes])
-AC_ARG_WITH(mon,       [  --with-mon              use mon as debugger [default=yes]], [WANT_MON=$withval], [WANT_MON=yes])
+AC_ARG_ENABLE(xf86-dga,      [  --enable-xf86-dga       use the XFree86 DGA extension [default=yes]], [WANT_XF86_DGA=$enableval], [WANT_XF86_DGA=yes])
+AC_ARG_ENABLE(xf86-vidmode,  [  --enable-xf86-vidmode   use the XFree86 VidMode extension [default=yes]], [WANT_XF86_VIDMODE=$enableval], [WANT_XF86_VIDMODE=yes])
+AC_ARG_ENABLE(fbdev-dga,     [  --enable-fbdev-dga      use direct frame buffer access via /dev/fb [default=yes]], [WANT_FBDEV_DGA=$enableval], [WANT_FBDEV_DGA=yes])
+AC_ARG_WITH(esd,             [  --with-esd              support ESD for sound under Linux/FreeBSD [default=yes]], [WANT_ESD=$withval], [WANT_ESD=yes])
+AC_ARG_WITH(gtk,             [  --with-gtk              use GTK user interface [default=yes]], [WANT_GTK=$withval], [WANT_GTK=yes])
+AC_ARG_WITH(mon,             [  --with-mon              use mon as debugger [default=yes]], [WANT_MON=$withval], [WANT_MON=yes])
 
 dnl Checks for programs.
 AC_PROG_CC
@@ -86,6 +87,18 @@ else
   DEFINES="$DEFINES -DENABLE_FBDEV_DGA=0"
 fi
 
+dnl We use XFree86 VidMode if possible.
+if [[ "x$WANT_XF86_VIDMODE" = "xyes" ]]; then
+  AC_CHECK_LIB(Xxf86vm, XF86VidModeQueryExtension, [
+    DEFINES="$DEFINES -DENABLE_XF86_VIDMODE=1"
+    LIBS="$LIBS -lXxf86vm"
+  ], [
+    AC_MSG_WARN([Could not find XFree86 VidMode extension, ignoring --enable-xf86-vidmode.])
+    WANT_XF86_VIDMODE=no
+    DEFINES="$DEFINES -DENABLE_XF86_VIDMODE=0"
+  ])
+fi
+
 dnl We use GTK+ if possible.
 UISRCS=../dummy/prefs_editor_dummy.cpp
 if [[ "x$WANT_GTK" = "xyes" ]]; then
@@ -294,6 +307,7 @@ echo
 echo Basilisk II configuration summary:
 echo
 echo XFree86 DGA support .............. : $WANT_XF86_DGA
+echo XFree86 VidMode support .......... : $WANT_XF86_VIDMODE
 echo fbdev DGA support ................ : $WANT_FBDEV_DGA
 echo ESD sound support ................ : $WANT_ESD
 echo GTK user interface ............... : $WANT_GTK