[Linux-fbdev-users] RE: FW: Sorry the attachment is here

[Nitin M. <Ni...@so...>]

But What if I want to set the mode to TRUE_COLOR?
In that case we need not worry about colormaps.
Regards


Nitin Mahajan
Socrates Software India Pvt Ltd...
mail:ni...@so...
Ph:51101667. Mobile : 9448260513
======================================
The Lord gave us two ends -- one to sit on and the other to think with.
Success depends on which one we use the most.


-----Original Message-----
From: Geert Uytterhoeven [mailto:ge...@li...] 
Sent: Saturday, June 07, 2003 10:01 PM
To: Nitin Mahajan
Cc: lin...@li...
Subject: 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 --
ge...@li...

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


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