[Bug 32086] New: LBA2 black screen above diagonal from bottom left to upper right

http://bugs.winehq.org/show_bug.cgi?id=32086

Bug #: 32086
           Summary: LBA2 black screen above diagonal from bottom left to
                    upper right
           Product: Wine
           Version: 1.5.15
          Platform: x86
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: directx-d3d
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]
    Classification: Unclassified

Created attachment 42299
  --> http://bugs.winehq.org/attachment.cgi?id=42299
wine-1.5.15 terminal output in full screen mode

DirectDrawRenderer=opengl became the default some time ago.

As of 1.5.15, Little Big Adventure 2 aka. LBA2 displays a black screen above a
diagonal from bottom left to upper right across its 640x480 virtual desktop.

fixme:x11drv:X11DRV_desktop_SetCurrentMode Cannot change screen BPP from 32 to
8
err:d3d_surface:d3dfmt_p8_init_palette This code should never get entered for
DirectDraw!, expect problems
-- indeed

The black diagonal persists across all menus, intro videos and game play.
Moving the virtual desktop around you momentarily unhides the missing half
screen.

Reopened bug #23921 is about using DirectDrawRenderer=gdi

The black triangle also affects full screen mode.  Terminal output is attached.

Does OpenGL decompose the rectangular window into two triangles?