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我试图用java做一个太空射击游戏，但它不工作。我目前正在研究产生敌人。为了保住所有敌人的位置，我使用了一个名为allEnemies的ArrayList。 ArrayList充满了Point对象。我通过在游戏循环中调用updateEnemies()来更新游戏。雪碧无法正常移动的Java
最初，我通过1例敌人的y位置增量，但这是太快了，所以我就在试图改变0.2慢下来。一旦我达到0.2，精灵就会在顶部产生，但不会向下移动。我为超过1的任何值工作，包括小数，但不低于任何值。这里是我的代码：
Enemy.java
package main;
import java.awt.Point;
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);
allEnemies.add(newEnemyLocation);
}
return allEnemies;
}
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 += 0.2;
} else {
allEnemies.remove(i);
}
}
}
return allEnemies;
}
}
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).getX();
int bullety = (int) Shoot.allBullets.get(i).getY();
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).getX();
int enemyy = (int) Enemy.allEnemies.get(i).getY();
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 += 20);
} else if (key == KeyEvent.VK_LEFT) {
player.setX(playerx -= 20);
}
}
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();
}
}
你需要具体什么问题是...... –
问题是，当我设置敌方精灵以小于1的速度递增时，它根本不移动。 –