我目前正在Java中製作太空射擊遊戲。我能夠讓子彈射擊,敵人從頂部射來,但我不知道如何檢查它們是否相交。我明白Rectangle
類有一個intersects
方法,但我不知道如何將矩形放置在子彈和敵人周圍,因爲我事先並不知道屏幕上有多少個可能。我怎樣才能做到這一點?這裏是我的代碼:我將如何測試Java中2張圖片的碰撞。
Game.java
package main;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
public class Game extends Canvas implements Runnable, KeyListener {
//declare values
private static final long serialVersionUID = 1L;
public static final int WIDTH = 800;
public static final int HEIGHT = 600;
public static final String TITLE = "Space Shooter";
private boolean running = false;
private Thread thread;
private Player player;
private BufferedImage playerImage;
private BufferedImage bulletImage;
private BufferedImage enemyImage;
int playerx;
int playery;
int round = 1;
public Game() {
//
player = new Player((WIDTH/2)-32, HEIGHT-200);
//allocates all file resources
try {
playerImage = ImageIO.read(this.getClass().getResourceAsStream("/resources/player.png"));
bulletImage = ImageIO.read(this.getClass().getResourceAsStream("/resources/bullet.png"));
enemyImage = ImageIO.read(this.getClass().getResourceAsStream("/resources/enemy.png"));
} catch (IOException e) {
e.printStackTrace();
}
addKeyListener(this);
setFocusable(true);
requestFocusInWindow();
}
//starts thread
private synchronized void start() {
if (running)
return;
running = true;
thread = new Thread(this);
thread.start();
}
//stops thread
private synchronized void stop() {
if (!running)
return;
running = false;
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.exit(1);
}
@Override
//game loop
public void run() {
long lastTime = System.nanoTime();
final double amountOfTicks = 60.0;
double ns = 1000000000/amountOfTicks;
double delta = 0;
int updates = 0;
int frames = 0;
long timer = System.currentTimeMillis();
while (running) {
long now = System.nanoTime();
delta += (now - lastTime)/ns;
lastTime = now;
if (delta > 1) {
tick();
updates++;
delta--;
}
Shoot.updateBullets();
Enemy.updateEnemies();
render();
frames++;
if (System.currentTimeMillis() - timer > 1000) {
timer += 1000;
System.out.println(updates + " TICKS, " + frames + " FPS");
updates = 0;
frames = 0;
}
}
stop();
}
//updates sprite locations
public void tick() {
playerx = player.getX();
playery = player.getY();
}
//renders sprites
public void render() {
//setting up triple-buffering
BufferStrategy bs = this.getBufferStrategy();
if (bs == null) {
createBufferStrategy(3);
return;
}
Graphics g = bs.getDrawGraphics();
//////////////////////////////////
g.setColor(Color.BLACK); g.fillRect(0,0,getWidth(), getHeight());
g.drawImage(playerImage, playerx, playery, this);
if (Shoot.allBullets.size() != 0) {
for (int i = 0; i < Shoot.allBullets.size(); i++) {
int bulletx = (int) Shoot.allBullets.get(i).x;
int bullety = (int) Shoot.allBullets.get(i).y;
g.drawImage(bulletImage, bulletx + 21, bullety, this);
}
}
if (Enemy.allEnemies.size() != 0) {
for (int i = 0; i < Enemy.allEnemies.size(); i++) {
int enemyx = (int) Enemy.allEnemies.get(i).x;
int enemyy = (int) Enemy.allEnemies.get(i).y;
g.drawImage(enemyImage, enemyx, enemyy, this);
}
} else {
Enemy.createEnemies(round);
round++;
}
//////////////////////////////////
g.dispose();
bs.show();
}
@Override
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_SPACE) {
Shoot.addBullet(player.getX(), player.getY());
}
}
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_UP) {
player.setY(playery -= 20);
} else if (key == KeyEvent.VK_DOWN) {
player.setY(playery += 20);
} else if (key == KeyEvent.VK_RIGHT) {
player.setX(playerx += 40);
} else if (key == KeyEvent.VK_LEFT) {
player.setX(playerx -= 40);
}
}
public void keyTyped(KeyEvent e) {}
public static void main(String[] args) {
Game game = new Game();
JFrame frame = new JFrame(TITLE);
frame.setSize(WIDTH, HEIGHT);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.add(game);
frame.getContentPane().setBackground(Color.BLACK);
frame.setVisible(true);
game.start();
}
}
Shoot.java
package main;
import java.util.ArrayList;
public class Shoot {
static ArrayList<Point> allBullets = new ArrayList<Point>();
public static void addBullet(int x, int y) {
allBullets.add(new Point(x, y));
}
public static ArrayList<Point> getAllBulletPosistions() {
return allBullets;
}
public static void updateBullets() {
if (allBullets.size() != 0) {
for (int i = 0; i < allBullets.size(); i++) {
allBullets.get(i).y -= 1;
}
}
}
}
Enemy.java
package main;
import java.util.ArrayList;
public class Enemy {
static ArrayList<Point> allEnemies = new ArrayList<Point>();
public static ArrayList<Point> createEnemies(int round) {
for (int i = 0; i < round; i++) {
Point newEnemyLocation = new Point((int) (Math.random()*Game.WIDTH - 64), 0);
if (newEnemyLocation.x < 64) {
newEnemyLocation.x += 70;
}
allEnemies.add(newEnemyLocation);
}
return allEnemies;
}
int validate(int xpos) {
if (xpos > Game.WIDTH - 64) {
xpos -= 64;
}
if (xpos < 64) {
xpos += 64;
}
return xpos;
}
public static ArrayList<Point> updateEnemies() {
if (allEnemies.size() != 0) {
for (int i = 0; i < allEnemies.size(); i++) {
Point enemyLocation = allEnemies.get(i);
if (enemyLocation.y <= Game.HEIGHT) {
allEnemies.get(i).y += 0.1;
} else {
allEnemies.remove(i);
}
}
}
return allEnemies;
}
}
非常感謝!我會嘗試子彈/敵人級的方法,如果不行,我會用你放在這裏的方法。 –
我這樣做,它能夠檢測到碰撞,但現在,當我發射第二顆子彈時,遊戲崩潰並給出以下例外: 線程「線程-1」中的異常java.lang.IndexOutOfBoundsException:Index: 1,大小:1 \t在java.util.ArrayList.rangeCheck(ArrayList.java:638) \t在java.util.ArrayList.get(ArrayList.java:414) \t在main.Game.checkCollisions(遊戲。的java:185) \t在main.Game.tick(Game.java:118) \t在main.Game.run(Game.java:95) \t在java.lang.Thread.run(Thread.java:745 ) –
@thefool對不起,只是看到你爲什麼得到錯誤,我搞砸了,在allEnemys.get中使用「i」,但它應該是'j'我編輯了我的答案,所以現在看看它 – WilliamTaco