// By Haw-ren Fang, TA of cmsc420 section 0401, Spring 2002

import java.lang.*;
import java.io.*;

public interface Quadtree {
	// set the root node of the quadtree
	public void setRoot(Quadnode root);

	// returns the root of the quadtree
	public Quadnode getRoot();

	// returns true if the quadtree has a node contains the patch
	// with name patchName.
	// This is mainly for grading purpose.
	public boolean containsNodeWithPatchName(String patchName);

	// It should have some more methods, such as:
	// (1) Given a point, find the smallest patch containing it, if any.
	// (2) Given a point, find all the patches adjacent to it.
	// However, they are not required in this project.

	// constructs the 2 quadtrees representing floor and wall respectively.
	// returns them as a LightInteractionObject.
	// Feps and Aeps are the arguments for the pseudo code refine().
	// Conceptually, you may treat it as a static method.
	public LightInteractionObject lightInteraction(Patch floor, Patch wall, double Feps, double Aeps) throws NonPositiveEpsException;
}