Re: [gtk-list] Re: Getting the mask out of a pixmap

[Havoc Pennington <rhp zirx pair com>]

On Sun, 2 May 1999, katre wrote:
> 
> Yes, i did this for XPM's, which was how I figured out how to use
> gdk_gc_set_clip_mask.  However, the pixmaps I am currently using are
> GdkPixmaps that I am allocating myself and drawing on myself.  There is no way
> to set the mask?

You can use a clip mask to draw, but there is no way to "get the mask out"
(there isn't a mask in there).

>  I have also tried simply drawing to the bitmask at the same
> time that I draw to the pixmap, however I get the same error message.  Am I
> missing a basic facet of drawing to GdkBitmaps, or is this impossible?
> 

Your GC must match the depth of the drawable. i.e. you have to create a
special GC for drawing on the bitmap. You can't copy the pixmap to the
bitmap or vice versa; you can only use the bitmap as a mask.

At least, that's my guess. You might post the error message ("BadMatch"
would be the error if your GC/drawables don't ahve matching depths).

Havoc