README.wscons
changeset 1187 19d8949b4584
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     1 ==============================================================================
       
     2 Using the Simple DirectMedia Layer with OpenBSD/wscons
       
     3 ==============================================================================
       
     4 
       
     5 The wscons SDL driver can be used to run SDL programs on OpenBSD
       
     6 without running X.  So far, the driver only runs on the Sharp Zaurus,
       
     7 but the driver is written to be easily extended for other machines.
       
     8 The main missing pieces are blitting routines for anything but 16 bit
       
     9 displays, and keycode maps for other keyboards.  Also, there is no
       
    10 support for hardware palettes.
       
    11 
       
    12 There is currently no mouse support.
       
    13 
       
    14 To compile SDL with support for wscons, use the
       
    15 "--enable-video-wscons" option when running configure.  I used the
       
    16 following command line:
       
    17 
       
    18 ./configure --disable-oss --disable-ltdl --enable-pthread-sem \
       
    19 	    --disable-esd --disable-arts --disable-video-aalib  \
       
    20 	    --enable-openbsdaudio --enable-video-wscons \
       
    21 	    --prefix=/usr/local --sysconfdir=/etc
       
    22 
       
    23 
       
    24 Setting the console device to use
       
    25 =================================
       
    26 
       
    27 When starting an SDL program on a wscons console, the driver uses the
       
    28 current virtual terminal (usually /dev/ttyC0).  To force the driver to
       
    29 use a specific terminal device, set the environment variable
       
    30 SDL_WSCONSDEV:
       
    31 
       
    32 bash$ SDL_WSCONSDEV=/dev/ttyC1 ./some-sdl-program
       
    33 
       
    34 This is especially useful when starting an SDL program from a remote
       
    35 login prompt (which is great for development).  If you do this, and
       
    36 want to use keyboard input, you should avoid having some other program
       
    37 reading from the used virtual console (i.e., do not have a getty
       
    38 running).
       
    39 
       
    40 
       
    41 Rotating the display
       
    42 ====================
       
    43 
       
    44 The display can be rotated by the wscons SDL driver.  This is useful
       
    45 for the Sharp Zaurus, since the display hardware is wired so that it
       
    46 is correctly rotated only when the display is folded into "PDA mode."
       
    47 When using the Zaurus in "normal," or "keyboard" mode, the hardware
       
    48 screen is rotated 90 degrees anti-clockwise.
       
    49 
       
    50 To let the wscons SDL driver rotate the screen, set the environment
       
    51 variable SDL_VIDEO_WSCONS_ROTATION to "CW", "CCW", or "UD", for
       
    52 clockwise, counter clockwise, and upside-down rotation respectively.
       
    53 "CW" makes the screen appear correct on a Sharp Zaurus SL-C3100.
       
    54 
       
    55 When using rotation in the driver, a "shadow" frame buffer is used to
       
    56 hold the intermediary display, before blitting it to the actual
       
    57 hardware frame buffer.  This slows down performance a bit.
       
    58 
       
    59 For completeness, the rotation "NONE" can be specified to use a shadow
       
    60 frame buffer without actually rotating.  Unsetting
       
    61 SDL_VIDEO_WSCONS_ROTATION, or setting it to '' turns off the shadow
       
    62 frame buffer for maximum performance.
       
    63 
       
    64 
       
    65 Running MAME
       
    66 ============
       
    67 
       
    68 Since my main motivation for writing the driver was playing MAME on
       
    69 the Zaurus, I'll give a few hints:
       
    70 
       
    71 XMame compiles just fine under OpenBSD.
       
    72 
       
    73 I'm not sure this is strictly necessary, but set
       
    74 
       
    75 MY_CPU = arm
       
    76 
       
    77 in makefile.unix, and
       
    78 
       
    79 CFLAGS.arm = -DLSB_FIRST -DALIGN_INTS -DALIGN_SHORTS
       
    80 
       
    81 in src/unix/unix.max
       
    82 
       
    83 to be sure.
       
    84 
       
    85 The latest XMame (0.101 at this writing) is a very large program.
       
    86 Either tinker with the make files to compile a version without support
       
    87 for all drivers, or, get an older version of XMame.  My recommendation
       
    88 would be 0.37b16.
       
    89 
       
    90 When running MAME, DO NOT SET SDL_VIDEO_WSCONS_ROTATION!  Performace
       
    91 is MUCH better without this, and it is COMPLETELY UNNECESSARY, since
       
    92 MAME can rotate the picture itself while drawing, and does so MUCH
       
    93 FASTER.
       
    94 
       
    95 Use the Xmame command line option "-ror" to rotate the picture to the
       
    96 right.
       
    97 
       
    98 
       
    99 Acknowledgments
       
   100 ===============
       
   101 
       
   102 I studied the wsfb driver for XFree86/Xorg quite a bit before writing
       
   103 this, so there ought to be some similarities.
       
   104 
       
   105 
       
   106 --
       
   107 Staffan Ulfberg <staffan@ulfberg.se>