public Node clone() {
Node node = new Node();
node.plane = this.plane == null ? null : this.plane.clone();
node.front = this.front == null ? null : this.front.clone();
node.back = this.back == null ? null : this.back.clone();
node.polygons = new ArrayList<Polygon>();
for (Polygon polygon : polygons) {
node.polygons.add(polygon.clone());
}
return node;
}
// Remove all polygons in this BSP tree that are inside the other BSP tree
// `bsp`.
public void clipTo(Node bsp) {
this.polygons = bsp.clipPolygons(this.polygons);
if (this.front != null) this.front.clipTo(bsp);
if (this.back != null) this.back.clipTo(bsp);
}