<< DuckyLove | FinalProjectsTrailIndex | Perspective Floor >>

Various interactive mazes could be made. This one just constructs a maze using the Recursive backtracker algorithm described here

For a visual demonstration of the algorithm, Click here

This will make a new maze on a mouse click. To see it in action, click here

Cell.java

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.ArrayList;

/**
 * @author Chris Thiel, OFMCap 
 * @version 16 May 2012
 */

public class Cell 
{
	public static final int GAP=10, SIZE=40, LEFT=40, TOP=60;
	public static final int NORTH=0, SOUTH=1, EAST=2, WEST=3;

	private int visits, row, col;
	private boolean[] wall;
	private Rectangle box;

	public Cell(int r, int c)
	{
		visits=-1;
		row=r;
		col=c;
		wall=new boolean[4];
		box = new Rectangle (LEFT+col*(SIZE+GAP), TOP+row*(SIZE+GAP), SIZE, SIZE);
		for (int i=0;i<4;i++)
			wall[i]=true;
	}
	/**
	 * 
	 * @return a random neighboring Cell, or null if all neighbors have been visited
	 */
	public Cell randomNeighbor(Cell[][] m){
		ArrayList<Cell> n = new ArrayList<Cell>();
		//NORTH
		if (row>0 && m[row-1][col].getVisits()<0)
			n.add(m[row-1][col]);
		//SOUTH
		if (row<m.length-1 && m[row+1][col].getVisits()<0)
			n.add(m[row+1][col]);
		//WEST
		if (col>0 && m[row][col-1].getVisits()<0)
			n.add(m[row][col-1]);
		//EAST
		if (col<m[0].length-1 && m[row][col+1].getVisits()<0)
			n.add(m[row][col+1]);
		if (n.size()<1)
			return null;
		return n.get((int)(n.size()*Math.random()));
	}
	public void draw(Graphics g, Color c)
	{
		Color oldColor=g.getColor();
		g.setColor(c);

		if (visits==1)
			g.setColor(Color.GREEN);
		if (visits>1)
			g.setColor(Color.RED);

		g.fillRect(box.x, box.y, box.width, box.height);
		if (!wall[SOUTH])
			g.fillRect(box.x, box.y+SIZE, box.width, GAP);
		if (!wall[EAST])
			g.fillRect(box.x+SIZE, box.y, GAP, box.width);

		g.setColor(oldColor);
	}
	public Rectangle getBox(){return box;}
	public int getRow(){return row;}
	public int getCol(){return col;}
	public int getVisits(){return visits;}
	public void setVisits(int i){visits=i;}
	public void incVisits(){visits++;}
	public void setWall(int direction, boolean value){
		wall[direction]=value;
	}
	/**
	 * removes the walls between this cell and the other cell
	 * @param other
	 */
	public void removeWall(Cell other) {
		if (other.getRow()>row){//other cell is below this one
			this.setWall(SOUTH, false);
			other.setWall(NORTH, false);
		}
		if (other.getRow()<row){//other cell is above this one
			this.setWall(NORTH, false);
			other.setWall(SOUTH, false);
		}
		if (other.getCol()>col){//other cell is east of this one
			this.setWall(EAST, false);
			other.setWall(WEST, false);
		}
		if (other.getCol()<col){//other cell is west this one
			this.setWall(WEST, false);
			other.setWall(EAST, false);
		}


	}
}

MazeMaker.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;

/**
 * @author Chris Thiel, OFMCap 
 * @version 16 May 2012 (Applet)
 * @version 5 Sept 2021 (Application)
 */

public class MakeMaze extends JPanel implements MouseListener
{
    public static final int ROWS=10, COLS=10; 
    public static final int WIDTH=575, HEIGHT=620;
    private Cell[][] m;
    String message="Making Maze";

    public static void main(String[] args) {
        MakeMaze app= new MakeMaze();
        JFrame window = new JFrame("Make Maze");
        window.setSize(WIDTH, HEIGHT);
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.getContentPane().add(app);
        window.setVisible(true);

    }

    public MakeMaze()
    {

        message="Making First Maze";
        makeMaze();
        message="First Maze done.";
        this.addMouseListener(this);
    }

    public void makeMaze()
    {
        m = new Cell[ROWS][COLS];
        for (int r=0;r<ROWS;r++)
            for(int c=0;c<COLS;c++)
                m[r][c]=new Cell(r,c);
        Cell currentCell=m[ROWS-1][0];
        currentCell.incVisits();
        ArrayList<Cell> stack=new ArrayList<Cell>();
        while (unvisitedCells()){
            Cell choice=currentCell.randomNeighbor(m);
            if (choice!=null){
                stack.add(0, currentCell);
                currentCell.removeWall(choice);
                currentCell=choice;
                currentCell.incVisits();
            }else{
                stack.remove(0);
                currentCell=stack.get(0);
            }
            repaint();
        }
    }

    private boolean unvisitedCells(){
        int r=0;
        while(r<ROWS){
            int c=0;
            while(c<COLS)
                if(m[r][c].getVisits()<0){
                    return true;
                }else{
                    c++;
                }
            r++;
        }
        return false;
    }

    public void paintComponent(Graphics g)
    {
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, WIDTH, HEIGHT);
        g.setColor(Color.BLACK);
        g.drawString(message, 20, 20);
        int left = Cell.LEFT-Cell.GAP;
        int top = Cell.TOP-Cell.GAP;
        int width = COLS*(Cell.SIZE+Cell.GAP)+Cell.GAP;
        int height = ROWS*(Cell.SIZE+Cell.GAP)+Cell.GAP;
        g.fillRect(left, top, width,height );
        for (int r = 0; r < ROWS; r++)
            for(int c=0;c<COLS;c++)
                m[r][c].draw(g, Color.YELLOW);
        int bottom =    height;    
        int delta = Cell.SIZE+ 1*Cell.GAP;
        for(int r = 1; r <= ROWS; r++)
            g.drawString(""+r, 5, bottom - (r-1)*delta);
        for(int c = 1; c <= COLS; c++)
            g.drawString(""+c, c*delta + 30, height+delta + 15 );
    }

    public void update(Graphics g)
    {
        paint(g); 
    }

    @Override
    public void mouseClicked(MouseEvent e) {}

    @Override
    public void mouseEntered(MouseEvent e) {}

    @Override
    public void mouseExited(MouseEvent e) {}

    @Override
    public void mousePressed(MouseEvent e) {}

    @Override
    public void mouseReleased(MouseEvent e) {
        message="Making new Maze";
        makeMaze();
        message="Maze Done";
        repaint();
    }

}