ShooterGame

gistfile1.java

import java.awt.Color;
import java.awt.event.KeyEvent;
import java.util.*;

public class ShooterGame extends GamePanel {

	public static void main(String[] args) {
		new ShooterGame(500,500);
	}
	
	public enum Side {
		LEFT, RIGHT, UP, DOWN
	}
	
	public static Random rand = new Random();
	
	public int _player_x, _player_y;
	public boolean _player_dead = false;
	public Side _last_facing;
	public ArrayList<Bullet> _player_bullets = new ArrayList<Bullet>();
	public ArrayList<Enemy> _enemies = new ArrayList<Enemy>(); 
	
	public ShooterGame(int width, int height) {
		super(width, height);
		
		_player_x = this.get_width()/2;
		_player_y = this.get_height()/2;
		_last_facing = Side.UP;
	}
	
	@Override
	public void update() {
		this.clear();
		if (_player_dead) {
			_g.setColor(Color.red);
			_g.drawString("(Press R to respawn)", this.get_width()/2-60, this.get_height()/2);
			if (this.is_key_down(KeyEvent.VK_R)) {
				_player_x = this.get_width()/2;
				_player_y = this.get_height()/2;
				_player_bullets.clear();
				_enemies.clear();
				_player_dead = false;
				
			}
			
		} else {
			_g.setColor(Color.black);
			_g.drawString("Arrow keys to move, CTRL to shoot", 0, this.get_height());
			
			update_player();
			update_enemies();
			update_bullets();
		}
	}
	
	private void update_player() {
		if (this.is_key_down(KEY_UP)) {
			_player_y-=3;
			_last_facing = Side.UP;
		}
		if (this.is_key_down(KEY_DOWN)) {
			_player_y+=3;
			_last_facing = Side.DOWN;
		}
		if (this.is_key_down(KEY_LEFT)) {
			_player_x-=3;
			_last_facing = Side.LEFT;
		}
		if (this.is_key_down(KEY_RIGHT)) {
			_player_x+=3;
			_last_facing = Side.RIGHT;
		}
		
		if (this.is_key_down(KeyEvent.VK_CONTROL)) {
			int bvx = 0, bvy = 0;
			if (_last_facing == Side.LEFT) {
				bvx = -8;
				
			} else if (_last_facing == Side.RIGHT) {
				bvx = 8;
				
			} 
			
			if (_last_facing == Side.UP) {
				bvy = -8;
				
			} else if (_last_facing == Side.DOWN) {
				bvy = 8;
				
			}
			
			Bullet neu = new Bullet(_player_x, _player_y, bvx, bvy);
			_player_bullets.add(neu);
			
		}
		
		_g.setColor(Color.green);
		_g.fillOval(_player_x-5, _player_y-5, 10, 10);
	}
	
	private void update_bullets() {
		for (int i_bullet = _player_bullets.size()-1; i_bullet >= 0; i_bullet--) {
			Bullet itr_bullet = _player_bullets.get(i_bullet);
			itr_bullet.update(this);
			
			if (!this.point_on_screen(itr_bullet._x, itr_bullet._y)) {
				_player_bullets.remove(itr_bullet);
			}
		}
	}
	
	private void update_enemies() {
		for (int i_enemy = _enemies.size()-1; i_enemy >= 0; i_enemy--) {
			Enemy itr_enemy = _enemies.get(i_enemy);
			itr_enemy.update(this);
			
			boolean do_remove = false;
			for (int i_bullet = _player_bullets.size()-1; i_bullet >= 0; i_bullet--) {
				Bullet itr_bullet = _player_bullets.get(i_bullet);
				if (is_collide(itr_enemy._x, itr_enemy._y, itr_bullet._x, itr_bullet._y, 5 + 3)) {
					_player_bullets.remove(itr_bullet);
					do_remove = true;
					break;
				}
			}
			if (do_remove) {
				_enemies.remove(itr_enemy);
				continue;
			}
			
			if (is_collide(itr_enemy._x, itr_enemy._y, _player_x, _player_y, 5 + 5)) {
				_player_dead = true;
			}
		}
		
		if (rand.nextInt(20)==0) {
			int side = rand.nextInt(4);
			int ex = 0, ey = 0;
			
			if (side == 0) {
				ex = rand.nextInt(this.get_width());
				
			} else if (side == 1) {
				ex = rand.nextInt(this.get_width());
				ey = this.get_height();
				
			} else if (side == 2) {
				ey = rand.nextInt(this.get_height());
				
			} else {
				ex = this.get_width();
				ey = rand.nextInt(this.get_height());
			}
			_enemies.add(new Enemy(ex,ey));
		}
	}
	

	
	private boolean point_on_screen(int x, int y) {
		return (x > 0) && (x < this.get_width()) && (y > 0) && (y < this.get_height());
	}
	
	public boolean is_collide(int x1, int y1, int x2, int y2, int radius_sum){
		double dist = Math.sqrt(Math.pow(x2-x1, 2) + Math.pow(y2-y1, 2));
		return dist <= radius_sum;
	}
	
	public class Bullet {
		public int _x, _y, _vx, _vy;
		public Bullet(int x, int y, int vx, int vy) {
			_x = x;
			_y = y;
			_vx = vx;
			_vy = vy;
		}
		public void update(ShooterGame game) {
			_x += _vx;
			_y += _vy;
			game._g.setColor(Color.blue);
			game._g.fillOval(_x-3, _y-3, 6, 6);
		}
	}
	
	public class Enemy {
		
		public int _x, _y;
		public Enemy(int x, int y) {
			_x = x;
			_y = y;
		}
		public void update(ShooterGame game) {
			if (rand.nextInt(2)==0) {
				if (_x > game._player_x) {
					_x-=2;
				} else {
					_x+=2;
				}
				
			} else {
				if (_y > game._player_y) {
					_y-=2;
				} else {
					_y+=2;
				}
				
			}
			game._g.setColor(Color.red);
			game._g.fillOval(_x-5, _y-5, 10, 10);
			
		}
	}
	

}