- // else: !transparent
-
- // must be opaque then as otherwise we shouldn't be
- // using the mask at all
- wxASSERT_MSG( IsOpaque(a), _T("logic error") );
+ else // !transparent
+ {
+ // must be opaque then as otherwise we shouldn't be
+ // using the mask at all
+ wxASSERT_MSG( IsOpaque(a), _T("logic error") );
+
+ // if we couldn't find a unique colour for the
+ // mask, we can have real pixels with the same
+ // value as the mask and it's better to slightly
+ // change their colour than to make them
+ // transparent
+ if ( r == rMask && g == gMask && b == bMask )
+ {
+ r++;
+ }
+ }