Re: GdkBitmap structure - 3 questions

[Sven Neumann <sven gimp org>]

Hi,

"Germano Rizzo" <manomano ciaoweb it> writes:

>     In my program I use gdk-pixbuf; actually I'm using some bitmaps, loaded
> from the alpha channel of some PNG files. Now, I'd have to do three things:
> - have the possibility to 'negative-image' them; now I'm using two different
> files for a bitmap and its negative... I guess there should be a way!!
> - have the possibility to merge two of them (e.g copying one into another
> one, then 'painting' the white areas of another into it)

You can compose the bitmaps using gdk_draw_pixmap(). By setting the GC 
you can choose between different modes like GDK_INVERT, GDK_OR, GDK_AND, 
...


Salut, Sven