anchor.diff:  
               aBitmap.Canvas.Fill.Color := colors.fillColor;
               aBitmap.Canvas.FillArc(point, radiusPoint, startAngle, sweepAngle, 1);
  -//            radiusPoint := PointF(15, 15);
  -//            aBitmap.Canvas.Stroke.Color := colors.fillColor;
  -//            aBitmap.Canvas.Stroke.Thickness := 7;
  -//            aBitmap.Canvas.DrawArc(point, radiusPoint, startAngle, sweepAngle, 1);
   
               startAngle := 90;
               stopAngle := (360 - sweepAngle) + startAngle;
  
positive.code:     try
        aBitmap.Canvas.Clear(0);
        aBitmap.Canvas.Fill.Kind := TBrushKind.Solid;
        bufferExtent := aExtent.Inflate(1.2);
        for isgop in (fCurrentSlice as TSliceLocation).fLocations do
        begin
          if bufferExtent.Intersects(isgop.Value.fExtent) and (fRefSlice as TSliceLocation).fLocations.TryGetValue(isgop.Key, refLoc) then
  
negative.code:           end;
          end;
        end;
        Result := gtsOk;
      finally
        aBitmap.Canvas.EndScene;
  