anchor.diff:  
   procedure TSliceDiffGeometryDoublePolygonLR.PolygonComputation(aXDCommon, aYDCommon, aXDExtra, aYDExtra, aXPrev, aYPrev, aXCurr, aYCurr: Double; aColor: TGeoColors; aBitmap: FMX.Graphics.TBitmap);
   var
  -  polyPoints: TArray<Double>;
  -  polygonCommon, polygonExtra: TPolygon;
  -begin
  -  setLength(polygonCommon, 5);
  -  polyPoints := [aXPrev, aYPrev, aXCurr, aYCurr, aXCurr+aXDCommon, aYCurr+aYDCommon, aXPrev+aXDCommon, aYPrev+aYDCommon];
  -  ConstructPolygon(polyPoints, polygonCommon);
  +  polygon: TPolygon;
  +  defaultColor: TGeoColors;
  +begin
  +  setLength(polygon, 5);
  +  ConstructPolygon(aXPrev, aYPrev, aXCurr, aYCurr, aXCurr+aXDCommon, aYCurr+aYDCommon, aXPrev+aXDCommon, aYPrev+aYDCommon, polygon);
  +
  +  defaultColor := TGeoColors.Create(TAlphaColorRec.Lightsteelblue,TAlphaColorRec.Lightsteelblue);
  +  DrawFillPolygon(defaultColor, aBitmap, polygon);
   
     if abs(aXDCommon) <> abs(aXDExtra) then
     begin
  -    setLength(polygonExtra, 5);
  -    polyPoints := [polygonCommon[3].X, polygonCommon[3].Y, polygonCommon[2].X, polygonCommon[2].Y, aXCurr+aXDExtra, aYCurr+aYDExtra, aXPrev+aXDExtra, aYPrev+aYDExtra];
  -    ConstructPolygon(polyPoints, polygonExtra);
  -  end;
  -
  -  DrawFillPolygon(aColor, aBitmap, polygonCommon, polygonExtra, abs(aXDCommon), abs(aXDExtra));
  +    ConstructPolygon(polygon[3].X, polygon[3].Y, polygon[2].X, polygon[2].Y, aXCurr+aXDExtra, aYCurr+aYDExtra, aXPrev+aXDExtra, aYPrev+aYDExtra, polygon);
  +    DrawFillPolygon(aColor, aBitmap, polygon);
  +  end;
   end;
   
   function TSliceDiffGeometryDoublePolygonLR.ComputeCoordinateDist(aWidth, aActiveValue, aRefValue, aCapacityFactor, aXY_Diff, aPerpDist: Double; aIsCommonPoly: Boolean): Double;
  
positive.code:                   begin
                      xn := yCurr-yPrev;
                      yn := xPrev-xCurr;
                      pointDist := ComputeDistanceBetweenPoints(xn, yn);
  
                      if validL then
                      begin
  
negative.code:   FreeAndNil(canvasLock);
    Log.Finish();
  end.
  