   ROPs in DirectDraw
  I want to use ROPs in DirectDraw.Therefore this code:DDBLTFX BltFx;BltFx.dwROP = SRCINVERT;valDebug = lpDDSBack->Blt( &TileAimRect, lpDDSGfx, &TileRootRect, DDBLT_WAIT | DDBLT_ROP, &BltFx);But the call returns the error message -2147024809 (Invalid argument). I suppose SRCINVERT is not right. But ROP constants should be the same as in Win32.Any idea? Anyone used ROPs in C/C++?  