To: sdl@libsdl.org

From: Staffan Ulfberg <staffan@ulfberg.se>
Date: 19 Nov 2005 01:00:48 +0100
Subject: [SDL] New driver for OpenBSD/wscons

Hello,

I've written an SDL driver for OpenBSD/wscons (console mode, somewhat
resembling the functionality of the svga driver for Linux).  I use it
for playing MAME on my Sharp Zaurus.  The alternative is to play under
X, which is slower.

I asked how to submit the driver a few days ago, and posted a link to
the patch in a follow-up, so maybe it was missed?

Anyway, the patch is on the web at:

http://multivac.fatburen.org/SDL-wscons.patch

Comments?

Staffan

README.wscons

@@ -0,0 +1,107 @@
+==============================================================================
+Using the Simple DirectMedia Layer with OpenBSD/wscons
+==============================================================================
+
+The wscons SDL driver can be used to run SDL programs on OpenBSD
+without running X.  So far, the driver only runs on the Sharp Zaurus,
+but the driver is written to be easily extended for other machines.
+The main missing pieces are blitting routines for anything but 16 bit
+displays, and keycode maps for other keyboards.  Also, there is no
+support for hardware palettes.
+
+There is currently no mouse support.
+
+To compile SDL with support for wscons, use the
+"--enable-video-wscons" option when running configure.  I used the
+following command line:
+
+./configure --disable-oss --disable-ltdl --enable-pthread-sem \
+	    --disable-esd --disable-arts --disable-video-aalib  \
+	    --enable-openbsdaudio --enable-video-wscons \
+	    --prefix=/usr/local --sysconfdir=/etc
+
+
+Setting the console device to use
+=================================
+
+When starting an SDL program on a wscons console, the driver uses the
+current virtual terminal (usually /dev/ttyC0).  To force the driver to
+use a specific terminal device, set the environment variable
+SDL_WSCONSDEV:
+
+bash$ SDL_WSCONSDEV=/dev/ttyC1 ./some-sdl-program
+
+This is especially useful when starting an SDL program from a remote
+login prompt (which is great for development).  If you do this, and
+want to use keyboard input, you should avoid having some other program
+reading from the used virtual console (i.e., do not have a getty
+running).
+
+
+Rotating the display
+====================
+
+The display can be rotated by the wscons SDL driver.  This is useful
+for the Sharp Zaurus, since the display hardware is wired so that it
+is correctly rotated only when the display is folded into "PDA mode."
+When using the Zaurus in "normal," or "keyboard" mode, the hardware
+screen is rotated 90 degrees anti-clockwise.
+
+To let the wscons SDL driver rotate the screen, set the environment
+variable SDL_VIDEO_WSCONS_ROTATION to "CW", "CCW", or "UD", for
+clockwise, counter clockwise, and upside-down rotation respectively.
+"CW" makes the screen appear correct on a Sharp Zaurus SL-C3100.
+
+When using rotation in the driver, a "shadow" frame buffer is used to
+hold the intermediary display, before blitting it to the actual
+hardware frame buffer.  This slows down performance a bit.
+
+For completeness, the rotation "NONE" can be specified to use a shadow
+frame buffer without actually rotating.  Unsetting
+SDL_VIDEO_WSCONS_ROTATION, or setting it to '' turns off the shadow
+frame buffer for maximum performance.
+
+
+Running MAME
+============
+
+Since my main motivation for writing the driver was playing MAME on
+the Zaurus, I'll give a few hints:
+
+XMame compiles just fine under OpenBSD.
+
+I'm not sure this is strictly necessary, but set
+
+MY_CPU = arm
+
+in makefile.unix, and
+
+CFLAGS.arm = -DLSB_FIRST -DALIGN_INTS -DALIGN_SHORTS
+
+in src/unix/unix.max
+
+to be sure.
+
+The latest XMame (0.101 at this writing) is a very large program.
+Either tinker with the make files to compile a version without support
+for all drivers, or, get an older version of XMame.  My recommendation
+would be 0.37b16.
+
+When running MAME, DO NOT SET SDL_VIDEO_WSCONS_ROTATION!  Performace
+is MUCH better without this, and it is COMPLETELY UNNECESSARY, since
+MAME can rotate the picture itself while drawing, and does so MUCH
+FASTER.
+
+Use the Xmame command line option "-ror" to rotate the picture to the
+right.
+
+
+Acknowledgments
+===============
+
+I studied the wsfb driver for XFree86/Xorg quite a bit before writing
+this, so there ought to be some similarities.
+
+
+--
+Staffan Ulfberg <staffan@ulfberg.se>

configure.in

@@ -1645,6 +1645,37 @@ CheckQtopia()
     fi
 }
 
+dnl Set up the wscons video driver if enabled
+CheckWscons()
+{
+    AC_ARG_ENABLE(video-wscons,
+[  --enable-video-wscons   use wscons video driver [default=no]],
+                  , enable_video_wscons=no)
+    if test x$enable_video = xyes -a x$enable_video_wscons = xyes; then
+        AC_MSG_CHECKING(for wscons support)
+        video_wscons=no
+        AC_LANG_C
+        AC_TRY_COMPILE([
+       #include <sys/time.h>
+       #include <dev/wscons/wsconsio.h>
+        ],[
+        ],[
+        video_wscons=yes
+        ])
+        AC_MSG_RESULT($video_wscons)
+        if test x$video_wscons = xyes; then
+            CFLAGS="$CFLAGS -DENABLE_WSCONS"
+            VIDEO_SUBDIRS="$VIDEO_SUBDIRS wscons"
+            VIDEO_DRIVERS="$VIDEO_DRIVERS wscons/libvideo_wscons.la"
+        else
+      AC_MSG_ERROR([
+*** Failed to find wscons includes.])
+        fi
+      AC_LANG_C
+    fi
+}
+
+
 dnl Set up the PicoGUI video driver if enabled
 CheckPicoGUI()
 {
@@ -2210,6 +2241,7 @@ case "$target" in
         CheckNAS
         CheckX11
         CheckAAlib
+	CheckWscons
         CheckOpenGL
         CheckPTHREAD
         CheckSIGACTION
@@ -3088,6 +3120,7 @@ src/video/photon/Makefile
 src/video/picogui/Makefile
 src/video/ps2gs/Makefile
 src/video/qtopia/Makefile
+src/video/wscons/Makefile
 src/video/quartz/Makefile
 src/video/riscos/Makefile
 src/video/svga/Makefile

src/video/Makefile.am

@@ -9,7 +9,7 @@ DIST_SUBDIRS = dummy x11 dga nanox fbcon directfb vgl svga ggi aalib \
                wincommon windib windx5 \
                maccommon macdsp macrom riscos quartz \
                bwindow ps2gs photon cybergfx epoc picogui \
-               ataricommon xbios gem dc qtopia XFree86
+               ataricommon xbios gem dc qtopia XFree86 wscons
 
 DRIVERS = @VIDEO_DRIVERS@
 

src/video/SDL_sysvideo.h

@@ -411,6 +411,9 @@ extern VideoBootStrap GEM_bootstrap;
 #ifdef ENABLE_QTOPIA
 extern VideoBootStrap Qtopia_bootstrap;
 #endif
+#ifdef ENABLE_WSCONS
+extern VideoBootStrap WSCONS_bootstrap;
+#endif
 #ifdef ENABLE_PICOGUI
 extern VideoBootStrap PG_bootstrap;
 #endif

src/video/SDL_video.c

@@ -63,6 +63,9 @@ static VideoBootStrap *bootstrap[] = {
 #ifdef ENABLE_QTOPIA
 	&Qtopia_bootstrap,
 #endif
+#ifdef ENABLE_WSCONS
+	&WSCONS_bootstrap,
+#endif
 #ifdef ENABLE_FBCON
 	&FBCON_bootstrap,
 #endif

src/video/wscons/Makefile.am

@@ -0,0 +1,14 @@
+## Makefile.am for SDL using the wscons video driver
+
+noinst_LTLIBRARIES = libvideo_wscons.la
+libvideo_wscons_la_SOURCES = $(WSCONS_SRCS)
+
+# The SDL wscons video driver sources
+WSCONS_SRCS = 			\
+	SDL_wsconsvideo.h	\
+	SDL_wsconsevents.c	\
+	SDL_wsconsevents_c.h	\
+	SDL_wsconsmouse.c	\
+	SDL_wsconsmouse_c.h	\
+	SDL_wsconsvideo.c
+