Re: cairo drawing commands to gdk_invalidate_region

[Paul Davis <paul linuxaudiosystems com>]

On Tue, Aug 17, 2010 at 4:39 AM, Dov Grobgeld <dov grobgeld gmail com> wrote:
> Thanks, but this is not what I am looking for.
>
> Here is a description of my flow, which might e.g. be used to draw a rubber
> band box:


based on an IRC exchange about this a couple of days ago, the answer
is two-fold:

1) you assume that cairo_clip() was called with ev->region before
draw() is invokved
2) you call something like cairo_clip_rectangle_lists() to get the
list of rects that need to be redrawn

there have been some suggestions that one should ignore this and just
redraw everything and let cairo clipping deal with it, but i think
this is clearly wrong when the drawing is computationally expensive.

--p