http://bugs.winehq.org/show_bug.cgi?id=34125
--- Comment #18 from Ken Sharp kennybobs@o2.co.uk 2013-08-07 11:20:18 CDT --- That link is five years old. This slightly newer one suggests WineD3D is not used. https://forums.virtualbox.org/viewtopic.php?f=2&t=15436
This needs testing on a real Windows install.