package zmf.game.shoot;
import java.util.Random;

/**
 * @author jcf
 * @Description: Airplane----敵機(jī)既是飛行物
 * @date 2018-03-28 11:17:16
 */
public class Airplane extends FlyingObject implements Enemy{
 /** 敵機(jī)走步的步數(shù) **/
 private int speed = 2;
 public Airplane(){
 image = ShootGame.airplane;
 width = image.getWidth();
 height = image.getHeight();
 Random rand = new Random();
 x = rand.nextInt(ShootGame.WIDTH - this.width);
 //y:負(fù)的敵機(jī)的高
 y = -this.height;
 
 
 }
 
 @Override
 public int getScore(){
 return 5;
 }

 @Override
 public void step(){
 y += speed;
 }

 /**
 * 是否越界
 * @return
 */
 @Override
 public boolean outOfBounds(){
 //敵機(jī)的y坐標(biāo)大于窗口的高
 return this.y > ShootGame.HEIGHT;
 
 }

}

package zmf.game.shoot;
import java.awt.image.BufferedImage;

/**
 * @author jcf
 * @Description: 飛行物主類(lèi)
 * @date 2018-03-28 11:17:16
 */
public abstract class FlyingObject {
 /** 圖片命名--java包自有的 **/
 protected BufferedImage image;
 /** 寬 **/
 protected int width;
 /** 高 **/
 protected int height;
 /** x坐標(biāo) **/
 protected int x;
 /** y坐標(biāo) **/
 protected int y;

 /**
 * 飛行物走步
 */
 public abstract void step();

 /**
 * 是否越界
 * @return
 */
 public abstract boolean outOfBounds();

 /**
 * 敵人被子彈撞
 * @param bullet
 * @return
 */
 public boolean shootBy(Bullet bullet){
 //this:敵人 other：子彈
 int x1 = this.x;
 int x2 = this.x + this.width;
 int y1 = this.y;
 int y2 = this.y + this.height;
 int x = bullet.x;
 int y = bullet.y;
 return x > x1 && x < x2
 &&
 y > y1 && y < y2;
 }
 
}