RE: FW: Sorry the attachment is here

On Sat, 7 Jun 2003, Nitin Mahajan wrote:
> But I read that if uhave a true color setting ,u don't need a colormap,
> Can u please put more light on this?

For truecolor you indeed don't need a colormap.
But for directcolor you do.

Suppose you have a pixel p = (r, g, b). In truecolor mode, the R, G, B
outputs will be:

    R = r
    G = g
    B = b

In directcolor mode, the R, G, B outputs will be:

    R = clut.red[r]
    G = clut.green[g]
    B = clut.blue[b]

> On Sat, 7 Jun 2003, Nitin Mahajan wrote:
> > The colors are definitely in RGB format.
> > Actually Iam getting the fb_fix_screeeninfo.visul as 
> > FB_VISUAL_DIRECTCOLOR. This parameter is affected by the setings of 
> > var_screeninfo. Can u please tell what setings I will have to do in 
> > var_screen_info to get a visual as FB_VISUAL_TRUECOLOR?
> 
> You're right, I forgot about that.
> 
> If the visual is FB_VISUAL_DIRECTCOLOR and you want FB_VISUAL_TRUECOLOR,
> you have to program a linear colormap yourself. I.e. a colormap where
> 
>     clut.red[i] = i;
>     clut.green[i] = i;
>     clut.blue[i] = i;

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds




-------------------------------------------------------
This SF.net email is sponsored by:  Etnus, makers of TotalView, The best
thread debugger on the planet. Designed with thread debugging features
you've never dreamed of, try TotalView 6 free at www.etnus.com.