private static TileGridOptions defaultOptions(TileGridOptions options)
{
options.Extent = options.Extent ?? new Double[] {
-half_size, -half_size, half_size, half_size
};
options.Resolutions = TileGrid.ResolutionsFromExtent(options.Extent);
options.Origin = Extent.GetCorner(options.Extent, Extent.Corner.TopLeft);
return(options);
}