[Bug 3902] Unnormal slowness in Heroes 4 (X11DRV_BitBlt?)

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=3902

------- Additional Comments From [e-mail]  2005-30-11 12:44 -------
This looks like a reasonable optimization to me. Enlarging the rectangle is a  
cheap operation, so it shouldn't slow things down. I'd start by doing it only  
in the BitBlt.

Note that *all* image modifying GDI operations need to either invalidate  
LastModRect or update it (union with current operation's rect), there's no 
middle ground. Since invalidation is a matter of setting one coordinate of the 
rectangle to some magic value, it's cheap too.

Then DoUpdateDIBSection looks whether the rectangle is valid, and if so only 
copies the indicated part of the DIB around. Otherwise it reverts to current 
behaviour. After it finishes, the rectangle needs to be set to a zero-sized 
rectangle.