Re: [Linux-fbdev-devel] Re: [PATCH]: image.depth fix to accomodate monochrome cards

[Antonino D. <ad...@po...>]

On Sat, 2003-01-11 at 03:43, Geert Uytterhoeven wrote:
> On Fri, 10 Jan 2003, James Simmons wrote:
> > > I think we still have several corner cases, such as TRUECOLOR with bpp
> > > <= 8, I'm not sure if that works.
> > 
> > The matorx millenium has such a mode. So such things do exist.
> >  
> > > -	if (image->depth == 1) {
> > > +	if (image->depth == 0) {
> > 
> > P.S
> > 
> >    I'm just not to crazy about the depth equal zero thing. I just pitcure 
> > developers having a hard time with it.
> 
> Monochrome color expansion just works differently: it expands the zeroes and
> ones in a bitmap based on fg_color and bg_color, while image drawing draws an
> image containing colormap indices to the frame buffer.
> 
> Do you have a better suggestion?
> 

If James is a bit skeptical about this, how about doing it this way:

If image.fg_color and image.bg_color == 0, then each byte of image.data
is an index to the pseudo_palette, or the actual pixel, whatever the
case may be.  Otherwise, image.data is a monochrome bitmap that should
be expanded using fg_color and bg_color.

No other changes will be needed except that mono cards have to test for
fg_color and bg_color, and we need to memset the fb_image structure to 0
in fb_set_logo(). Non-mono cards will continue testing for image.depth.

Do you think this will work?  The only problem I can think of is a color
expansion request where both bg and fg is 0.

Or to totally eliminate the above possibility, add an extra field in
struct fb_image to denote color expansion vs logo drawing.  Again, only
mono cards will need to do this test.

Tony