More framebuffer stuff...
Geert Uytterhoeven
geert at linux-m68k.org
Mon Nov 1 07:25:33 EST 1999
On Sat, 30 Oct 1999, David Riley wrote:
> Well, I found a good site for framebuffer initing (though I should have
> thought of mmap() before). However, now whenever I write to the
> framebuffer, it seems to be using a color map instead of direct color
> (unless I run my program under XF86). I made sure that it is in 32 or
> 16 bit color, and fb_*_screeninfo even reports a packed pixel display
> using direct color. So why the colormap effect? And why not under XF86?
You are confusing directcolor with truecolor.
Directcolor means that the r, g, and b components of a pixel are still passed
through a color map, like
red = rmap[r];
green = gmap[g];
blue = bmap[b];
To make text drawing simpler, the [rgb]maps are loaded with the console
paletter. You should load a linear palette (rmap[i] = gmap[i] = bmap[i] = i)
to emulate a truecolor display.
XF{68,86}_FBDev loads a linear color palette first, that's why it works there.
Gr{oetje,eeting}s,
--
Geert Uytterhoeven -- Linux/{m68k~Amiga,PPC~CHRP} -- geert at linux-m68k.org
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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