Re: Question on gdk_gc_set_clip_mask()

[Matthew Hiller <matthew hiller yale edu>]

On Wed, 16 Feb 2000, andy ritger wrote:

> 
> in you pixdrawer macro, you need to add:
> 
> 	gdk_gc_set_clip_origin (drawable, x, y);
> 
> To position the mask relative to the drawable.

	Yeah. (Though I pass in widget->style->black_gc instead of
drawable.) That doesn't impede the drawing from happening. On the other
hand, this doesn't seem to prevent the white halo from being generated
when pixmaps start colliding either, so I guess I'm more-or-less where I
started.

	In fact, as a result of this I think I now have a grasp of how
clip masks work. If I guess correctly, they're sort've a stamp substrate
that gets drawn onto the drawable along with one's pixmap. Now, if there
were a way for me to take a snapshot of the area where each pixmap is
being drawn, I'd be in business.

> Also, this may be a dumb question, but does "-1, -1" work for the
> dimensions to copy?  I've always explicitly given the desired dimensions;
> does "-1, -1" imply the dimensions of the source pixmap?

	Yup. I think it's mentioned in the tutorial somewhere; the API
docs don't have a description of what you can do with the arguments of
gdk_draw_pixmap last I checked, so you wouldn't have found it there.

Matt