[Bug 58575] Low performance in an old Directx8 Sonic fangame in wined3d

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=58575

--- Comment #4 from Zak  ---
I made an interesting discovery today: looks like the performance is also
related to some wined3d deficiency after all, specifically in the dx8
implementation. I used d3d8to9 to convert the game to d3d9, and suddenly I was
getting about 20fps more - a solid almost 2 times increase. Also, judging by
Stian Low's test results in https://bugs.winehq.org/show_bug.cgi?id=58671, the
performance drop appeared after wine 10. Wine 9.21 and 10 rc3 still run at 60
fps, then the game broke at 10.1, and then the fps problems stayed.