anchor.diff:    FMaskData      := nil;
     FMaskDataSize  := 0;
     FMasked        := False;
  +  FMaskPoint     := Point(0, 0);
   end;
   
   destructor TfpgImageBase.Destroy;
  
positive.code:     Exit; //==>
  
    AllocateMask;
  
    p := FImageData;
    if x < 0 then
  
negative.code:     FImageDataSize: integer;
      FMaskData: pointer;
      FMaskDataSize: integer;
      FMaskPoint: TPoint;
      procedure   DoFreeImage; virtual; abstract;
      procedure   DoInitImage(acolordepth, awidth, aheight: integer; aimgdata: Pointer); virtual; abstract;
      procedure   DoInitImageMask(awidth, aheight: integer; aimgdata: Pointer); virtual; abstract;
  