Re: [Linux-fbdev-devel] clipping

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

On Fri, 10 Jan 2003, James Simmons wrote:
> > > I thought about this. Originally I did have this function but removed it.
> > > WHat do you think Geert?
> > 
> > Yes, that's OK.
> > 
> > But I was most concerned about fb_ops.fb_imageblit(), since clipping impacts
> > fb_image.data as well. IIRC, all (most?) current clipping implementations
> > modify fb_image.{dx,dy,width,height} only, without updating fb_image.data.
> 
> Good point. Of course we could ignore pieces of data in that image instead 
> of altering the data. Altering the entire data would be expensive.

Actually I thought about modifying the fb_image.data pointer only. But indeed,
for monochrome expansion you may have to modify the data, since pixel
boundaries in a bitmap don't correspond to byte boundaries.

Alternatively, if fb_image would countain sx and sy fields (cfr. fb_copyarea),
we can just alter (a copy of) sx and sy when clipping.

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