Re: [XBoard-devel] gtk-branch

[John Cheetham]

> At 12:08 10-11-2011 +0100, Michel Van den Bergh wrote:
>> This is normally how drawing should be done. Otherwise you have
>> flicker.
> 
> Well, it seems the old XBoard code did not need this, because it was
> extremely clever in finding out what covered what, and only copied
> the visible parts. But this code has been disabled now, and the GTK
> code for dragging the piece is of the more straightforward 'background
> first' type.
> 
> The dragging is only a minor cosmetic problem, though. The problem
> in animateMoving is far worse; there the stuff that is supposed to be
> drawn gets really overwritten by the background (presumably through
> undesired calls to DrawPosition in the expose-event handler), so that
> it is permanently erased.
>

I'm not an expert in this (or in cairo used for the atomic explosions) so I 
can't add much.
I had intended to look into the AnimationFrame routine soon though which I 
think is causing most of the problems. I think this routine needs rewriting for 
the animations to work properly.

One way to do it might be to reinstate the old Xt code (including the 
CalcUpdateRects, Intersect etc routines). The commands used  in the Xt version 
(GC, Pixmap, point, xcopyarea) have GDK equivalents and it may be worth trying 
to just convert that existing code to GDK. Another way might be to use 
GdkPixbufAnimation or Cairo. I can't say which is the best way until I've 
looked into it a bit more.

I'll also look into changing the edit position menu to use upclicks which was 
mentioned previously.