Re: [Linux-fbdev-users] FB_VISUAL_TRUECOLOR vs.FB_VISUAL_DIRECTCOLOR

[Sean D'E. <se...@de...>]

On Sun, Aug 06, 2006 at 11:27:49AM +0800, Antonino A. Daplas wrote:
> James Lehman wrote:
> > But if I leave the fb at 8 bpp and my code changes the bpp at runtime to 32,
> > it looks like the first 16 console colors have been written into the color
> > map.
> > 
> 
> Try switching the VC to KD_GRAPHICS mode before you run your app. Then
> switch it back to KD_TEXT on exit, ie:
> 
> fd = open("/dev/tty0", FLAG);
> ioctl(fd, KDSETMODE, KD_GRAPHICS);
> 
> Let me know if doing the above still writes the console palette to the
> cmap. That will be a bug.
> 
> Tony

I have tried this, and no, KD_GRAPHICS does not seem to work, I think if you do not set to graphics mode while running, then you can restore the cmap by switching to graphics then text on exit.

I have found also that matroxfb does not need to set the cmap but nvidiafb does.

Does anyone know a use for directcolor other than gamma correction?

thanks.