Re: Heads-up: Potentially breaking changes to the GDK drawing model pushed

[Paul Davis <paul linuxaudiosystems com>]

On Sat, Jun 21, 2014 at 10:35 AM, Jean Brefort <jean brefort normalesup org> wrote:

In gnumeric this arised when we draw an animated rectangle around the
selected rectangle. When using the draw event, we need to repaint
everything inside the rectangle and this made gnumeric quite
unresponsive when there were many cells displayed at once.

i don't believe that this is true, but thanks for the explanation.

A draw/expose event contains a list of rectangles which need not be contiguous. It is only a matter of convenience to use the GdkRectangle that is also supplied. You can invalidate the "border" around the cell. We do this in ardour, especially in our new canvas, where we frequently queue discontiguous areas of the screen for drawing - when we render we do not draw the union of all these areas, just each rectangle in the list of regions.