Create the temporary buffer to the size of the interesction of the

Create the temporary buffer to the size of the interesction of the

1999-11-22  Federico Mena Quintero  <federico@redhat.com>

	* src/gnome-canvas-pixbuf.c (gnome_canvas_pixbuf_draw): Create the
	temporary buffer to the size of the interesction of the bounding
	box and the expose area, not the whole expose area.  This speeds
	up things a lot.

	* src/gdk-pixbuf-render.c (gdk_pixbuf_render_threshold_alpha): Do
	not paint black on the mask, since we already cleared it in a
	single gdk_draw_rectangle() operation.