Re: Image/Pixbuf: How to set colour "behind" (semi)-transparent data?

[Toralf Lund <toralf procaptura com>]

Carl Nygard wrote:

> On Mon, 2005-02-28 at 16:20 +0100, Toralf Lund wrote:
>  
>
> > When drawing a pixbuf which has an alpha channel, how do I set the 
> > background colour? I'm talking about the colour that will "shine 
> > through" fully or partially where alpha value<255. (Seems like a grayish 
> > colour is the default; I actually want black instead.)
> >    
>
> I'd think you'd have to draw the bkgr color in the drawable first, then
> draw the pixbuf. 
Hmm. Yes, that may be it. I actually realised after I asked the 
question, that I could change the colour visible through the transparent 
pixels by setting the background of the container (a Gtk::Viewport in my 
case) - rather than setting the background colour of the image itself, 
which has no effect. But maybe that's the same thing as drawing the 
background of the drawable being used, since a Gtk::Image has no window 
of its own?

> I think from what I've seen, it's not a true alpha
> blend, more like on/off pixmap/bkgr.
>
> Regards,
> Carl
>
>