[Bug 7643] Supreme Commander crashes during play

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=7643

------- Additional Comments From [e-mail]  2007-12-03 19:24 -------
I did some testing, and it turns out that's not completely correct either.

The correct way is "((top/4) * pitch) + (left * 4)" for DXT2-5 and "((top/4) *
pitch) + (left * 2)" for DXT1.

eg. if you do LockRect with top = 60 and left = 60, that's 15 4x4 blocks down
from the top. It's also 15 4x4 blocks from the left, but each 4x4 block consists
of 16 bytes for DXT2-5 so you end up with "(left/4) * 16", which simplifies to
"left * 4". DXT1 has only 8 bytes per block, so that becomes "left * 2".