GDP Labyrinth

Explorer.java

package de.uniwue.gdp.labyrinth;

import de.uniwue.gdp.labyrinth.examples.Examples;
import de.uniwue.gdp.labyrinth.model.Maze;

public class Explorer {

    static Vector2D position = new Vector2D(1, 1);

    // 0: left / west
    // 1: up / north
    // 2: right / east
    // 3: down / south
    static int lookDir = 3;

    static int[][] field;

    static Maze m;


    public static void main(String[] args) {
        m = Examples.example01();
        System.out.println(exploreMaze());
    }
  
    public static String exploreMaze() {
        field = new int[m.width()][m.height()];

        // Initialize field with 0
        for(int i = 0; i < m.width(); i++) {
            for(int j = 0; j < m.height(); j++) {
                field[i][j] = 0;
            }
        }

        // Set edges to walls
        for(int i = 0; i < m.width(); i++) {
            field[i][0] = 1;
            field[i][m.height() - 1] = 1;
        }
        for(int i = 0; i < m.height(); i++) {
            field[0][i] = 1;
            field[m.width() - 1][i] = 1;
        }

        // 0: empty
        // 1: wall
        // 2: visited

        boolean finished = false;

        // Spawn at 1,1, so it is already visited:
        field[1][1] = 2;

        while(!finished) {

            finished = navigateMaze();

            System.out.print(fieldToString(field));
            System.out.println("Position: " + position.x + ", " + position.y + "\n");
        }


        return fieldToString(field);
    }

    static boolean navigateMaze() {
        if (!checkWall(Maze.Direction.AHEAD)) {
            move(Maze.Direction.AHEAD);
        } else if (!checkWall(Maze.Direction.LEFT)) {
            move(Maze.Direction.LEFT);
        } else {
            return true;
        }
        return false;
    }

    static void markWall(int direction) {
        Vector2D v = coordinateAtDir(direction);
        field[v.x][v.y] = 1;
        System.out.println("Marked wall at " + v.x + ", " + v.y);
    }

    static boolean checkWall(int direction) {
        if(m.isWall(direction)) {
            markWall(direction);
            return true;
        }
        return false;
    }

    static void move(int direction) {
        Vector2D v2 = coordinateAtDir(direction);
        field[v2.x][v2.y] = 2;
        m.walk(direction);
        position = v2;
        lookDir = (lookDir + direction + 3) % 4;
    }

    static Vector2D coordinateAtDir(int direction) {
        switch(Math.abs(direction - lookDir)) {
            case 0:
                System.out.println("relative:" + direction + " global:" + lookDir + position.x + ", " + position.y + "->" + position.x + ", " + (position.y - 1) + "\n");
                return new Vector2D(position.x, position.y - 1);
            case 1:
                System.out.println("relative:" + direction + " global:" + lookDir + position.x + ", " + position.y + "->" + (position.x - 1) + ", " + position.y + "\n");
                return new Vector2D(position.x - 1, position.y);
            case 2:
                System.out.println("relative:" + direction + " global:" + lookDir + position.x + ", " + position.y + "->" + position.x + ", " + (position.y + 1) + "\n");
                return new Vector2D(position.x, position.y + 1);
            case 3:
                System.out.println("relative:" + direction + " global:" + lookDir + position.x + ", " + position.y + "->" + (position.x + 1) + ", " + position.y + "\n");
                return new Vector2D(position.x + 1, position.y);
        }
        return null;
    }

    // Utility methods

    static String fieldToString(int[][] f) {
        String result = "";

        for(int i = 0; i < f.length; i++) {
            for(int j = 0; j < f[i].length; j++) {

                if (j == position.x && i == position.y) {

                    switch(lookDir) {
                        case 0:
                            result += "<";
                            break;
                        case 1:
                            result += "^";
                            break;
                        case 2:
                            result += ">";
                            break;
                        case 3:
                            result += "v";
                            break;
                    }
                    continue;
                }

                switch(f[j][i])
                {
                    case 0:
                        result += "=";
                        break;
                    case 1:
                        result += "#";
                        break;
                    case 2:
                        result += ".";
                        break;
                }

            }
            result += "\n";
        }
        return result;
    }

    static class Vector2D{
        int x;
        int y;

        public Vector2D(int x, int y) {
            this.x = x;
            this.y = y;
        }
    }
}