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