[Bug 16087] New: wine spews innumerable "Unable to check compatibility for Format..." errors in some games

http://bugs.winehq.org/show_bug.cgi?id=16087

Summary: wine spews innumerable "Unable to check compatibility
                    for Format..." errors in some games
           Product: Wine
           Version: 1.1.8
          Platform: Other
        OS/Version: other
            Status: UNCONFIRMED
          Severity: trivial
          Priority: P2
         Component: directx-d3d
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Created an attachment (id=17312)
 --> (http://bugs.winehq.org/attachment.cgi?id=17312)
avoids silly error messages

In dlls/wined3d/directx.c there is a function called
IWineD3DImpl_IsPixelFormatCompatibleWithRenderFmt which tries to compute if a
certain WINED3DFORMAT is compatible with a certain WineD3D_PixelFormat.

The function has separate paths for WGL_TYPE_RGBA_ARB (integer) and
WGL_TYPE_RGBA_FLOAT_ARB (float) WineD3D_PixelFormats. The float path explicitly
tests several WINED3DFORMATs, which seems OK. The integer part, however, tries
getColorBits() on the WINED3DFORMAT and prints an error if it doesn't get a
"correct" answer.

However, getColorBits() always throws an error for float formats, thus when
comparing an integer WineD3D_PixelFormat with a float WINED3DFORMAT the
function always outputs two errors instead of just saying "no".

The attached patch checks if the format is one where getColorBits works and
avoids spewing the error messages is that case. This duplicates the check in
getColorBits, so it's a bit of a hack, but a correct fix would need adding a
few more functions, so someone more experienced should do it. The patch is
against 1.1.8.

Fallout3 in particular is plagued by this problem: at every start-up wine spews
out errors for half a minute.