Re: Redisplay problems?

[Stefan Monnier]

> How does all this relate to moving blocks of pixels?

0 - frame gets deiconified, we don't redraw anything.
1 - we recompute desired matrices.
2 - we compare matrices and see that the top part of the frame can be drawn
    be copying the pixels from the bottom part (assuming here incorrectly
    that those pixels are in sync with the current matrices).
3 - we copy the incorrect pixels and consider ourselves happy to have
    redisplayed the top-part of the frame :-(

I think this can't happen, which is why I think it's OK not to redraw
anything at step 0.


        Stefan