Re: Emacs and Gnome Canvas

[YAMAMOTO Mitsuharu]

>>>>> On Fri, 16 Jul 2010 14:42:00 +0200, Jan Djärv <address@hidden> said:

> If you for example have double buffer, you can split expose from
> update display.  When an expose comes, you just copy the area from
> the backing store to the window.  But for updating the display, you
> draw normally, but to the backing store.  Then when you are done,
> you copy it to the window.

How do you copy the backing store to the window?  The whole area, or
divide the updated area to some collection of rectangles?  The former
is too inefficient for small updates.  For the latter, how do you
determine such rectangles?  Isn't that task no easier than creating
rectangles for dirty areas?

                                     YAMAMOTO Mitsuharu
                                address@hidden