Labyrinth Cell Automata in Java

CellAutomataPanel.java

import javax.swing.*;
import java.awt.*;

public class CellAutomataPanel extends JPanel {
    public int[][] field = new int[40][40];
    public Turmit turmit = new Turmit();

    @Override
    public void paint(Graphics g) {
        super.paint(g);

        drawField(g);
    }

    private void drawField(Graphics g) {
        for(int x=0; x<40; x++){
            for(int y=0; y<40; y++){

                int colorNumber = field[x][y];              // получаем номер цвета клетки поля по x,y
                Color color = colorWithNumber(colorNumber); // получаем цвет по номеру цвета
                g.setColor(color);                          // устанавливаем цвет для рисования

                g.fillRect(x*10, y*10, 10, 10);             // рисуем квадрат
            }
        }
    }

    private Color colorWithNumber(int number){
        Color[] colors = new Color[]{
                Color.BLACK, Color.RED, Color.GREEN, Color.BLUE,
                Color.GRAY, Color.YELLOW, Color.ORANGE, Color.PINK,
                Color.CYAN, Color.MAGENTA, new Color(52, 99, 255), new Color(85, 159, 255),
                new Color(36, 130, 100), new Color(130, 0, 255), new Color(196, 255, 101), new Color(255, 116, 153),
        };

        return colors[number];
    }

    public void nextStep(){
        turmit.nextStep(field);
        this.repaint();
    }
}

LabyrinthCellAutomata.java

import javax.swing.*;
import java.awt.event.ActionEvent;

public class LabyrinthCellAutomata {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Лабиринт");
        frame.setSize(400, 400);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        CellAutomataPanel myPanel = new CellAutomataPanel();

        frame.setContentPane(myPanel);
        frame.setVisible(true);

        startTimer(myPanel);
    }

    private static void startTimer(CellAutomataPanel myPanel) {
        Timer timer = new Timer(1, new AbstractAction() {
            @Override
            public void actionPerformed(ActionEvent e) {
                myPanel.nextStep();
            }
        });

        timer.start();
    }
}

Turmit.java

import java.util.HashMap;

public class Turmit {
    public String state = "A";
    public String direction = "up";
    public int x = 20;
    public int y = 20;

    public void nextStep(int[][] field){
        int color = field[x][y];     // получем цвет клетки где находится тьюрмит (x, y)
        Rule rule = findRule(state, color);

        field[x][y] = rule.nextColor;   // красим клетку в новый цвет
        state = rule.nextState;         // меняем состояния тьюрмита на новый

        if(rule.turn == -1){                     // Если нужно повернуть налево
            if(direction.equals("up")){        // Если текущее направление вверх
                direction = "left";           // то меняем на лево
            } else if(direction.equals("left")){  // Если текущее направление  налево
                direction = "down";              // то меняем вниз
            } else if(direction.equals("down")){  // и т.д.
                direction = "right";
            } else if(direction.equals("right")){
                direction = "up";
            }
        } else if(rule.turn == 1){             // Если нужно повернуть направо
            if(direction.equals("up")){
                direction = "right";
            } else if(direction.equals("left")){
                direction = "up";
            } else if(direction.equals("down")){
                direction = "left";
            } else if(direction.equals("right")){
                direction = "down";
            }
        }

        // После того как повернули тьюрмит, двигаем его на одну клетка по направлению

        if(direction.equals("up")){
            y -= 1;
        } else if(direction.equals("down")){
            y += 1;
        } else if(direction.equals("left")){
            x -= 1;
        } else  if(direction.equals("right")){
            x += 1;
        }

    }

    public Rule findRule(String state, int color){
        HashMap<String, Rule> rules = new HashMap<>();

        rules.put("A0", new Rule(1, -1, "A"));
        rules.put("A1", new Rule(2, -1, "A"));
        rules.put("A2", new Rule(3, -1, "A"));
        rules.put("A3", new Rule(4, -1, "A"));
        rules.put("A4", new Rule(5, -1, "A"));
        rules.put("A5", new Rule(6, 1, "B"));
        rules.put("B0", new Rule(1, 1, "A"));
        rules.put("B5", new Rule(6, -1, "B"));
        rules.put("B6", new Rule(7, -1, "B"));
        rules.put("B7", new Rule(8, -1, "B"));
        rules.put("B8", new Rule(9, -1, "B"));
        rules.put("B9", new Rule(10, -1, "B"));
        rules.put("B10", new Rule(11, -1, "B"));
        rules.put("B11", new Rule(12, -1, "B"));
        rules.put("B12", new Rule(13, -1, "B"));
        rules.put("B13", new Rule(14, -1, "B"));
        rules.put("B14", new Rule(15, -1, "B"));
        rules.put("B15", new Rule(0, -1, "B"));

        return rules.get(state+color);
    }

    class Rule{
        public int nextColor;
        public int turn;
        public String nextState;

        public Rule(int color, int turn, String state){
            this.nextColor = color;
            this.turn = turn;
            this.nextState = state;
        }
    }
}