DirectX blitter bug

[Mike Hearn]

Lords of Magic works perfectly EXCEPT that rendering is corrupted when it
is using DirectX "fast blitting"; they provide a software emulated
workaround for some truly ancient cards (Matrox Mystique anyone?) and the
game works well in this mode. But it should work properly in DirectX
accelerated mode too.

The kind of corruption varies but it appears as, for instance, mouse
trails which to me suggests some kind of co-ordinate system problem.

The demo is here:

ftp://ftp.sierra.com/pub/sierra/lordsofmagic/demos/si_lordsofmagic_demo.exe

and it installs cleanly on the master branch.

If any DirectDraw gurus want to take a look, please do! I bet this problem
affects other games too....

thanks -mike