private void expandCell(
S2CellId parent, List <S2CellId> cells, IDictionary <S2CellId, S2CellId> parentMap)
{
cells.Add(parent);
if (parent.Level == kMaxExpandLevel)
{
return;
}
var i = 0;
var j = 0;
int?orientation = 0;
var face = parent.ToFaceIjOrientation(ref i, ref j, ref orientation);
JavaAssert.Equal(face, parent.Face);
var pos = 0;
for (var child = parent.ChildBegin; !child.Equals(parent.ChildEnd);
child = child.Next)
{
// Do some basic checks on the children
JavaAssert.Equal(child.Level, parent.Level + 1);
Assert.True(!child.IsLeaf);
int?childOrientation = 0;
JavaAssert.Equal(child.ToFaceIjOrientation(ref i, ref j, ref childOrientation), face);
JavaAssert.Equal(
childOrientation.Value, orientation.Value ^ S2.PosToOrientation(pos));
parentMap.Add(child, parent);
expandCell(child, cells, parentMap);
++pos;
}
}