Re: [B2-devel] BasiliskII SDL on IRIX

[Brian J. <bjj...@us...>]

I wrote:
> "Thousands" of colors mode squashes the entire
> display into the left half of the window, with an odd green cast.
> Looks like something's not quite right in the 16bpp blitter...

I think I found the problem:  BII was trying to use a 32bpp blitter in
16-bit video mode, so only half of the window was getting filled and
the colors were in the wrong bit positions.  The basic issue was that
driver_window::driver_window(SDL_monitor_desc &m) was setting its
"depth" variable, which is passed to SDL_SetVideoMode, from
screen_depth (which is set at init. time and then never changed.)
However, it was passing the requested Mac video depth as the 3rd
parameter to Screen_blitter_init().  So that parameter did not match
VisualFormat.depth, which broke the assumptions made by
Screen_blitter_init().

This seems to fix it:

bjjsgi> cvs diff -u SDL/video_sdl.cpp
Index: SDL/video_sdl.cpp
===================================================================
RCS file: /cvs/BasiliskII/src/SDL/video_sdl.cpp,v
retrieving revision 1.9
diff -u -r1.9 video_sdl.cpp
--- SDL/video_sdl.cpp   27 Jun 2004 17:31:21 -0000      1.9
+++ SDL/video_sdl.cpp   27 Jul 2004 18:22:20 -0000
@@ -618,7 +618,23 @@
        ADBSetRelMouseMode(mouse_grabbed);

        // Create surface
-       int depth = (VIDEO_MODE_DEPTH <= VIDEO_DEPTH_8BIT ? 8 : screen_depth);
+       int depth;
+       switch (VIDEO_MODE_DEPTH) {
+       case VIDEO_DEPTH_1BIT:
+       case VIDEO_DEPTH_2BIT:
+       case VIDEO_DEPTH_4BIT:
+       case VIDEO_DEPTH_8BIT:
+               depth = 8;
+               break;
+       case VIDEO_DEPTH_16BIT:
+               depth = 16;
+               break;
+       case VIDEO_DEPTH_32BIT:
+               depth = 32;
+               break;
+       default:
+               abort();
+       }
        if ((s = SDL_SetVideoMode(width, height, depth, SDL_HWSURFACE)) == NULL)
                return;

It sets depth based on the requested Mac video depth, rather than the
init. time SDL default depth.

I still have problems changing depths using SGI's Xserver, which
supports multiple visuals at multiple depths at once.  I get BadMatch
errors:

Gdk-ERROR **: BadMatch (invalid parameter attributes)
  serial 1015 error_code 8 request_code 129 minor_code 3

I don't have that problem using Xvnc, which is based on XFree86 and
supports only a single visual depth.  Any suggestions?

						Brian

--------------------------------------------------------------------

  ... He say, "One and one and one is one.  The one thing I can tell you is
      debug till it runs" ...
  If the Beatles had studied computer science