public void Place(ISprite sprite, bool snapToTile, int?radius)
{
if (Session == null)
{
throw new InvalidOperationException();
}
placeOnTile = snapToTile;
placeRadius = radius ?? -1;
placeGob = new Gob(-1);
placeGob.SetSprite(new Delayed <ISprite>(sprite));
var mc = Geometry.ScreenToMap(ToAbsolute(Host.MousePosition));
placeGob.Position = placeOnTile ? Geometry.Tilify(mc) : mc;
Session.Objects.AddLocal(placeGob);
}