AdvancedLangtonsAnt.java

package Challenge_173_Intermediate;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Scanner;

import javax.imageio.ImageIO;

public class AdvancedLangtonsAnt{
	public static int steps;
	public static final Color[] colors = { Color.WHITE, Color.BLACK, Color.RED, Color.GREEN, Color.BLUE, Color.CYAN, Color.MAGENTA, Color.YELLOW, Color.GRAY };
	public static char[] turns;

	public static void main(String[] args){
		System.out.println("Enter 9 turning conditions and the amount of steps");
		Scanner s = new Scanner(System.in);
		char[] c = s.nextLine().toCharArray();
		if(c.length < colors.length || c.length > colors.length){
			System.err.println("Too few/many turning condidtions for colors!\nUsing already defined turns!");
			turns = new char[] { 'L', 'R', 'L', 'R', 'L', 'R', 'L', 'R', 'L' };
		}else{
			turns = c;
		}
		steps = s.nextInt();
		s.close();

		Ant ant = new Ant(500, 500, 0);
		for(int i = 0; i < steps; i++){
			//this is here so my ant wraps around the grid (stil doesn't work correctly)
			if(ant.x >= Ant.grid.length - 1) ant.x = 100;
			if(ant.x <= 1) ant.x = Ant.grid.length - 100;
			if(ant.y >= Ant.grid[0].length - 1) ant.x = 100;
			if(ant.y <= 1) ant.y = Ant.grid[0].length - 100;

			try{
				ant.step();
			}catch(ArrayIndexOutOfBoundsException e){
				saveImage();
				System.err.println("ArrayIndexOutOfBoundsException caught at step " + (i + 1) + ". Exiting now!");
				System.exit(1);
			}
		}

		saveImage();
		System.out.println("Done");
	}

	private static void saveImage(){
		BufferedImage img = new BufferedImage(Ant.grid.length, Ant.grid[0].length, BufferedImage.TYPE_INT_RGB);
		for(int x = 0; x < Ant.grid.length; x++){
			for(int y = 0; y < Ant.grid[0].length; y++){
				img.setRGB(x, y, Ant.grid[x][y].getRGB());
			}
		}
		File path = new File(System.getProperty("user.home") + "/Desktop/AdvancedLangtonnsAnt.png");
		try{
			ImageIO.write(img, "png", path);
		}catch(IOException e){
			e.printStackTrace();
		}
	}
}

Ant.java

package Challenge_173_Intermediate;

import java.awt.Color;

public class Ant{

	public int x, y;
	public int direction = 0;	//up=0, right=1, down=2, left=3
	public static Color[][] grid = new Color[1000][1000];

	public Ant(int x, int y, int direction){
		this.x = x;
		this.y = y;
		this.direction = direction;

		initGrid();
	}

	private void initGrid(){
		for(int x = 0; x < grid.length; x++){
			for(int y = 0; y < grid[0].length; y++){
				grid[x][y] = Color.WHITE;
			}
		}
	}

	public void move(){

		if(direction == 0){
			move(0, 1);
		}else if(direction == 1){
			move(1, 0);
		}else if(direction == 2){
			move(0, -1);
		}else if(direction == 3){
			move(-1, 0);
		}
	}

	public void move(int x, int y){
		this.x += x;
		this.y += y;
	}

	public void step(){
		Color current = grid[this.x][this.y];

		for(int i = 0; i < AdvancedLangtonsAnt.colors.length; i++){
			if(AdvancedLangtonsAnt.colors[i].equals(current)){
				turn(AdvancedLangtonsAnt.turns[i]);
				break;
			}
		}
		changeColor();
		move();
	}

	public void changeColor(){
		Color current = grid[this.x][this.y];

		for(int i = 0; i < AdvancedLangtonsAnt.colors.length; i++){
			if(AdvancedLangtonsAnt.colors[i].equals(current)){
				if(i < AdvancedLangtonsAnt.colors.length - 1) grid[this.x][this.y] = AdvancedLangtonsAnt.colors[i + 1];
				else grid[this.x][this.y] = AdvancedLangtonsAnt.colors[0];
				break;
			}
		}
	}

	public void turn(char turn){
		if(turn == 'L') turnLeft();
		if(turn == 'R') turnRight();
	}

	public void turnLeft(){
		this.direction--;
		if(this.direction < 0) this.direction = 3;
	}

	public void turnRight(){
		this.direction++;
		if(this.direction > 3) this.direction = 0;
	}
}