uqac-java-pigeon/src/com/rthoni/uqac/pigeon/Pigeon.java

package com.rthoni.uqac.pigeon;

import java.util.List;
import java.util.Random;

/**
 * Created by ZHAJOR on 30/10/2016.
 */
public class Pigeon implements Runnable{
    private int x;
    private int y;
    private String name;
    private Thread t;
    private final Game game;
    private static final int speed = 10;

    /**
     * Create a new pigeon with a random position
     * @param name The pigeon name
     * @param g The pigeon world
     */
    public Pigeon(String name, Game g) {
        Random r = new Random();
        x = r.nextInt(700);
        y = r.nextInt(700);
        this.name = name;
        this.game = g;
    }

    /**
     * The piegon behavior during his life
     */
    @Override
    public void run() {
        while (true) {
            synchronized (game) {
                // Get the food near the pigeon
                List<Food> foods = game.getFoods();
                Food best = new Food();
                int distance = -1;
                for (Food food : foods) {
                    if (distance == -1) {
                        distance = computeDistance(food.getX(), food.getY());
                        best = food;
                    } else if (distance > computeDistance(food.getX(), food.getY())) {
                        distance = computeDistance(food.getX(), food.getY());

                        best = food;
                    }
                }
                // Eat or move if there is a food
                if (distance != -1 && distance <= Pigeon.speed) {
                    this.x = best.getX();
                    this.y = best.getY();
                    game.removeFood(best);
                    System.out.print("Eat by " + this.name + "\n");
                }
                else if (distance != -1){
                    this.computeNewPosition(best.getX(), best.getY());
                }
                // Random move
                else {
                    Random r = new Random();
                    if (r.nextInt(100) > 90 + r.nextInt(8)) {
                        int moveX = r.nextInt(100) -50;
                        int moveY = r.nextInt(100) -50;
                        this.x += moveX;
                        this.y += moveY;
                        if (this.x > game.getWidth())
                            this.x = game.getWidth() - r.nextInt(30);
                        else if (this.x < 0)
                            this.x = r.nextInt(30);
                        if (this.y > game.getHeight())
                            this.y = game.getHeight() - r.nextInt(30);
                        else if (this.y < 0)
                            this.y = r.nextInt(30);
                    }
                }
            }
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * Compute the distance between the pigeon and the food
     * @param x the x position of the food
     * @param y the y position of the food
     * @return the distance
     */
    private int computeDistance(int x, int y) {
        int diffx = this.x > x ? this.x - x : x - this.x;
        int diffy = this.y > y ? this.y - y : y - this.y;
        return diffx + diffy;
    }

    /**
     * Move the pigeon
     * @param x the x position of the food
     * @param y the y position of the food
     */
    private void computeNewPosition(int x, int y) {
        int moves = Pigeon.speed;
        while (moves > 0 ) {
            if (this.x > x) {
                this.x--;
                moves--;
            }
            if (this.x < x) {
                this.x++;
                moves--;
            }
            if (this.y < y) {
                this.y++;
                moves--;
            }
            if (this.y > y) {
                this.y--;
                moves--;
            }
        }
    }

    /**
     * Start the thread
     */
    public void start () {
        System.out.println("New pigeon alive : " +  name );
        if (t == null) {
            t = new Thread (this, name);
            t.start ();
        }
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }
}