Re: [Linux-fbdev-devel] 2 pm3fb questions/problesm ...

[Geert U. <ge...@li...>]

On Tue, 19 Jun 2001, Sven LUTHER wrote:
> On Tue, Jun 19, 2001 at 02:08:11PM +0000, Petr Vandrovec wrote:
> > for truecolor and 4bpp pseudocolor, 0x0f0f0f0f is correct for
> > 8bpp pseudocolor, 0xXX0f0f0f (*) is for 24/32bpp directcolor,
> > 0x3DEF3DEF for 15bpp, 0x79EF79EF for 16bpp, and you cannot
> > use RGB332 truecolor without information loss.
> 
> mmm, truecolor is when the the rgb value is written directly to the pixel ?
> and pseudo color is when you use a color index table.
> 
> What exactly is direct color ?

truecolor:

    red = (pixel & redmask) >> redshift
    green = (pixel & greenmask) >> greenshift
    blue = (pixel & bluemask) >> blueshift

pseudocolor:

    red = redtable[pixel]
    green = greentable[pixel]
    blue = bluetable[pixel]

directcolor:

    red = redtable[(pixel & redmask) >> redshift]
    green = greentable[(pixel & greenmask) >> greenshift]
    blue = bluetable[(pixel & bluemask) >> blueshift]

To make sure revc always does the correct thing, there should be a 17th entry
in the display->dispsw_data telling the invertion mask.

This should be implemented in 2.5.

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