Added --disable-dga configure option to disable DGA entirely

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%4017

configure.in

@@ -347,7 +347,7 @@ dnl See if the NAS audio interface is supported
 CheckNAS()
 {
     AC_ARG_ENABLE(nas,
-[  --enable-nas		support the NAS audio API [default=yes]],
+[  --enable-nas		  support the NAS audio API [default=yes]],
 		, enable_nas=yes)
     if test x$enable_audio = xyes -a x$enable_nas = xyes; then
 	AC_MSG_CHECKING(for NAS audio support)
@@ -474,25 +474,30 @@ CheckX11()
                     fi
                 fi
             fi
+            AC_ARG_ENABLE(dga,
+[  --enable-dga            allow use of X11 DGA code [default=yes]],
+                          , enable_dga=yes)
             AC_ARG_ENABLE(video-x11-dgamouse,
 [  --enable-video-x11-dgamouse  use X11 DGA for mouse events [default=yes]],
                           , enable_video_x11_dgamouse=yes)
-            AC_MSG_CHECKING(for XFree86 DGA 1.0 support)
-            video_x11_dga=no
-            AC_TRY_COMPILE([
-             #include <X11/Xlib.h>
-             #include <X11/extensions/xf86dga.h>
-            ],[
-            ],[
-            video_x11_dga=yes
-            ])
-            AC_MSG_RESULT($video_x11_dga)
-            if test x$video_x11_dga = xyes; then
-                CFLAGS="$CFLAGS -DXFREE86_DGAMOUSE"
-                if test x$enable_video_x11_dgamouse = xyes; then
-                    CFLAGS="$CFLAGS -DDEFAULT_DGAMOUSE"
+            if test x$enable_dga = xyes; then
+                AC_MSG_CHECKING(for XFree86 DGA 1.0 support)
+                video_x11_dga=no
+                AC_TRY_COMPILE([
+                 #include <X11/Xlib.h>
+                 #include <X11/extensions/xf86dga.h>
+                ],[
+                ],[
+                video_x11_dga=yes
+                ])
+                AC_MSG_RESULT($video_x11_dga)
+                if test x$video_x11_dga = xyes; then
+                    CFLAGS="$CFLAGS -DXFREE86_DGAMOUSE"
+                    if test x$enable_video_x11_dgamouse = xyes; then
+                        CFLAGS="$CFLAGS -DDEFAULT_DGAMOUSE"
+                    fi
+                    SYSTEM_LIBS="$SYSTEM_LIBS -lXxf86dga"
                 fi
-                SYSTEM_LIBS="$SYSTEM_LIBS -lXxf86dga"
             fi
             AC_ARG_ENABLE(video-x11-xv,
 [  --enable-video-x11-xv   use X11 XvImage extension for video [default=yes]],
@@ -687,7 +692,7 @@ dnl rcg04172001 Set up the Null video driver.
 CheckDummyVideo()
 {
     AC_ARG_ENABLE(video-dummy,
-[  --enable-video-dummy   use dummy video driver [default=no]],
+[  --enable-video-dummy    use dummy video driver [default=no]],
                   , enable_video_dummy=no)
     if test x$enable_video_dummy = xyes; then
       CFLAGS="$CFLAGS -DENABLE_DUMMYVIDEO"

docs.html

@@ -16,6 +16,7 @@ be found at the <A HREF="http://www.libsdl.org/"> main SDL page</A>.
 Major changes since SDL 1.0.0:
 </H2>
 <UL>
+	<LI> 1.2.1: Added --disable-dga configure option to disable DGA entirely
 	<LI> 1.2.1: Fixed stuck keys when changing the video mode
 	<LI> 1.2.1: Fixed double-mouse event bug on Windows using OpenGL
 	<LI> 1.2.1: Fixed 320x200 video mode on framebuffer console