Re: [Tuxpaint-devel] some more investigation on grass plugin

[Albert C. <aca...@gm...>]

On Dec 11, 2007 12:24 PM, Alessandro Pasotti <apa...@gm...> wrote:
> 2007/12/11, Albert Cahalan <aca...@gm...>:
> > On Dec 10, 2007 10:53 AM, Alessandro Pasotti <apa...@gm...> wrote:
> >
> > > the api passes to the plugin a getpixel function pointer chosen from
> > > the getpixels pool with the canvas color depth, which could be
> > > different from the color depth of the image.
> > >
> > > Since I'm running the test in a Xephyr maemo SDK emulator, the color
> > > depth is probably lower than a standard true color X display.
> >
> > Maybe we need two getpixel functions. Maybe we need to go
> > back to the old way, where the getpixel function looks at the
> > surface to determine the type.
>
> Thanks Albert for the insight, so do you agree that we have a bug here?

Sure.

> I'm sorry but I dont' feel skilled enough to fix this problem, I agree
> with you that low color depth is quite rare nowaday, but I'm trying to
> port tp to a Linux embedded device wich probaly has limited graphics
> capabilities.

Me too. The OLPC XO uses a 5:6:5 framebuffer. I'll probably
use 8:8:8 internally though. If I had a really fast CPU and not
much RAM, then I'd consider using 5:5:5 (not 5:6:5). I hate
that option though, because merely loading and saving an image
would reduce the colors.

> The strange thing is that the previous version .17 is working fine on
> this device (just a bit slow with grass tool).

Probably you changed VIDEO_BPP.

Maybe VIDEO_BPP should always be 32.
That's 8:8:8 with padding for alignment.
Lots of things can be simplified this way.