how to use gtk_gc_set_tile() ?

[Nancy Mazur <Nancy Mazur cs kuleuven ac be>]

Hi,

I've been trying to play around with gdk_gc_set_tile(), 
but I don't seem to understand how it works.
Given some background pixmap, I'd like to draw some other pixmap
unto it, but in a tiled way. I thought that gdk_gc_set_tile would
lead me to the solution. If so.. can someone perhaps give me an
example of how to use it? 

at this moment I tried something like:

	gc = widget->style->fg_gc[GTK_STATE_NORMAL];
	pixmap = gdk_pixmap_new (widget->window,
                widget->allocation.width,
                widget->allocation.height, -1);
        gdk_gc_set_tile ( gc, raster);
        gdk_draw_pixmap ( pixmap, gc, raster, 0, 0, 0, 0,
                        rw, rh);
		/* where rh, and rw are the height and width
		   of the raster-pixmap */

This doesn't do what I would want it to do.. 
anybody ideas? 

Many thx in advance,
Nancy