anchor.diff:        else Result.Expand(point.X, point.Y);
       end;
     end;
  +  //Result.Expand(Result.xMin-aBufferLon, Result.yMin-aBufferLat);
  +  //Result.Expand(Result.xMax+aBufferLon, Result.yMax+aBufferLat);
   end;
   
   function TExtentHelper.Height: Double;
  
positive.code:   tce: TTileCacheEntry;
  begin
    Result  := gtsRestart; // sentinel
    tileFileName := aCacheFolder+TimeFolder+aFileName;
    // get or create tile cache entry
    // lock list and then lock found or created item; unlock list first so items can be accessed in parallel
    TMonitor.Enter(tilesCache);
  
negative.code:     try
        aBitmap.Canvas.Clear(0);
        aBitmap.Canvas.Fill.Kind := TBrushKind.Solid;
        // draw geometries
        for isgop in fGeometries do
        begin
          if aExtent.Intersects(isgop.Value.fExtent) then
  