On Fri, Mar 21, 2003 at 04:41:57PM +0100, Denis Oliver Kropp wrote: > But I don't like the fact that the surface of the crtc2 > layer contains the data of the sub picture layer, too.
Well it's just how the hw works. It's just that anyone who uses the sub-picture layer should be aware of these things. I should probably convert the table from the G400 specs to DirectFB terminology. > > Now that I think of it the rgb only palette stuff doesn't really matter > > since it should only affect lookups. We can still set the alpha for the > > entries and sub-picture layer's SetPalette can do it's stuff with them. > > You mean that the pixel alpha is written using the palette entry alpha? No. What I mean is that we simply take the alpha of the first two entries and stick them in c2bpp15halpha and c2bpp15lalpha registers. What these do is define 8 bit alpha values to correspond to the 1 bit alpha of ARGB1555. So when a pixel has alpha 0 the blender actually uses the value in c2bpp15lalpha and same for alpha 1 and c2bpp15halpha. I think there's no point in trying to maintain a relationship between crtc2->SetColor()'s 8 bit alpha value and what's written in these registers. Too much work and since there are only two values it really can't work. If a user wants to use only the CRTC2 layer they shouldn't even touch the sub-picture settings in which case the defaults should be fine. Defaults being color = black and c2bpp15lalpha = 0x00 and c2bpp15halpha = 0xff. So I think I should only add the 15bpp alpha setup to SetPalette() and make sure Disable() reprograms the registers with the default values. Of course Disable() isn't really used for now so sub-picture users should take care to set sensible defaults if they stop using the sub-picture but continue to use the CRTC2 layer. -- Ville Syrj�l� [EMAIL PROTECTED] http://www.sci.fi/~syrjala/ -- Info: To unsubscribe send a mail to [EMAIL PROTECTED] with "unsubscribe directfb-dev" as subject.
