Re: fb_imageblit semantic

["Petr Vandrovec" <VANDROVE@vc.cvut.cz>]

On 14 Mar 03 at 11:40, Geert Uytterhoeven wrote:
> On Fri, 14 Mar 2003, Petr Vandrovec wrote:
> > On 14 Mar 03 at 10:22, Geert Uytterhoeven wrote:
> > > On Thu, 13 Mar 2003, Petr Vandrovec wrote:
> > > > Why do you pass image.depth == 16 (or 24 or 32) to fb_imageblit
> > > > when logo image is in reality always 8bpp, as quick look at 
> > > > cfb_imageblit revealed?
> > > 
> > > Should indeed be 8.
> > > 
> > > > Should I just assume that image.depth == 1 means that data are
> > > > 1bpp with fgcol/bgcol valid, and all other depths mean 8bpp
> > > > input?
> > > 
> > > This was changed from 1 to 0 in James' latest tree.
> > 
> > WTF? Color depth 0 means that whole picture is single-color, and
> > imageblit degenerates to rectfill in such case. Please, either
> > use 'depth' as source image color depth, or do not name it depth.
> 
> It's 0 (expand [bf]gcol) to differentiate from 1 (copy monochrome).
> 
> Splitting imageblit into separate routines for both operations would be
> trivial, though.

There is no such thing as copy monochrome if target is not monochrome,
you have to put palette somewhere. If you'll look at cfb_imageblit,
you'll find that there is already defined way to do that: code uses
artifically created 256 entry pseudopalette... If target is monochrome,
it just copies data. If target is not monochrome, it has somehow expand
data to fit to screen format. Nothing differs between font painting
and copying 1bpp bitmap to Xbpp display. 

OK, so rule is that if depth=0, input is 1bpp with palette in bgcol/fgcol,
while if depth != 0, then palette is in info->pseudo_palette ?
                                            Thanks,
                                                Petr Vandrovec
                                                vandrove@vc.cvut.cz
                                                



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