Re: Re: FBdev updates.

On  5 Mar 03 at 20:22, James Simmons wrote:

quoted

  And one (or two...) generic questions: why is not pseudo_palette
u32* pseudo_palette, or even directly u32 pseudo_palette[17] ?

pseudo_palette was originally designed to be a pointer to some kind of 
data for color register programming. For example many PPC graphics cards 
have a color register region. Now you could have that point to 
pseudo_palette.  Note pseudo_palette is only visiable in fbmem.c for the 
logo drawing code. Personally I liek to see that hidden.

cfbfillrect? cfbimageblit? Both use pseudo_palette, and both convert
it to u32*.
 

quoted

And why we do not fill this pseudo_palette with
i * 0x01010101U for 8bpp pseudocolor and i * 0x11111111U for 4bpp
pseudocolor? This allowed me to remove couple of switches and tests
from acceleration fastpaths (and from cfb_imageblit and cfb_fillrect,
but I did not changed these two in my benchmarks below).

??? Does your accel engine require these kinds of values?

Yes. It is 32bit engine, and so it wants 32bit value. And even if 
not, code doing

if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
    p->fix.visual == FB_VISUAL_DIRECTCOLOR)
      fg = p->pseudo_palette[rect->color];
else
      fg = rect->color;

is horrible. Two conditional jumps on each rectangle. If you'll do
always lookup through pseudo_palette, not only that you get rid of
these jumps, you can also remove calls to pixel_to_pat32 (and accompanying
tables & lookups), as you do this expansion at set_var time,
instead of at blit/clear time.
                                            Best regards,
                                                Petr Vandrovec
                                                vandrove@vc.cvut.cz
                                                



-------------------------------------------------------
This SF.net email is sponsored by: Etnus, makers of TotalView, The debugger 
for complex code. Debugging C/C++ programs can leave you feeling lost and 
disoriented. TotalView can help you find your way. Available on major UNIX 
and Linux platforms. Try it free. www.etnus.com