Perfect!  An instant ~2x performance boost, and my dignity restored!  :-) Thank you so much Carl for this information,  - Marty <tt>Carl Worth <cworth@cworth.org> wrote on 03/06/2007 04:07:02 PM: > > So, copying the sub-piece of big_surface of interest would be as > simple as this: > >    cairo_t *cr = cairo_create (small_surface); >    cairo_set_source_surface (cr, big_surface, -x, -y); >    cairo_rectangle (cr, 0, 0, width, height); >    cairo_fill (cr); > > The interesting thing to note here, (and what will hopefully be an > "Ah-ha!" moment for some readers), is that cairo does not have any > drawing operation that is "paint an image". Instead, cairo has a much > more general notion where you can use an image, (or other more general > patterns, such as gradients), as the source pattern. And with that, > you can draw any shape you want, and the appropriate pieces of the > source surface will appear within that shape. > > Does that make sense? Give the above sequence a try and let us know > how it goes. > > > Congratulations on Cairo version 1.4.0.  It's really a super package. > > Thanks! I hope you have lots of fun with it. > > > p.s. I'm using rcairo on Red Hat, if that matters. > > I'm not up on ruby syntax, but hopefully it is extremely > straightforward for you to translate the above from C to ruby. > > -Carl </tt>