游戏刚开始时，玩家会生成，朝 0 方向（右）看。按下右键（vk_right）将玩家精灵向左转，但方向被设置为将玩家发送到（看起来像）正确的方向。左右键改变角色的方向变量，而上/下键加速/减速角色。
我不太擅长三角学，所以我可能在这里和那里有一些错误（这就是我发布这个的原因）。我似乎无法理解如何让角色朝他“看”的方向移动（方向变量）。
这是 Player.java 类：
package rpg2d;
import java.awt.Image;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.ImageIcon;
public class Player implements KeyListener{
private double x,y,direction;
private double speed;
private final int max_speed;
private int hp,lives;
private Image img;
//other variables
public Player(int x, int y, int hp, int lives, String imgpath) {
this.x = x;
this.y = y;
this.hp = hp;
this.lives = lives;
img = new ImageIcon(this.getClass().getResource(imgpath)).getImage();
//loads the player image from the string path
max_speed = 6;
speed = 0;
direction = 0;
}
//returns the direction the player is 'facing' as an int
public int getDirection() {
return (int)direction;
}
//updates the player's location
public void move() {
x += speed * Math.cos(-1*direction);
y += speed * Math.sin(-1*direction);
}
@Override
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if(key == KeyEvent.VK_LEFT){
turn(.6);
//this is meant to turn the player int a clockwise direction by 0.6
} else if (key == KeyEvent.VK_RIGHT){
turn(-.6);
//counterclockwise by 0.6
}
if (key == KeyEvent.VK_DOWN){
speed -= 0.3;
if(speed < 0) speed = 0;
//decelerate until stopped
} else if (key == KeyEvent.VK_UP){
speed += 0.3;
if(speed > max_speed) speed = max_speed;
//accelerates until it hits maximum speed
}
}
private void turn(double degrees) {
direction += degrees;
if(direction > 180) direction -= 180;
else if(direction < -180) direction += 180;
/* I honestly don't know whether 180 and -180 are the max and min
* for Polar Coordinates, so this could be a problem.
*/
}
@Override
public void keyReleased(KeyEvent e) {
}
@Override
public void keyTyped(KeyEvent arg0) {
}
public int getX() {
return (int)x;
}
public int getY() {
return (int)y;
}
public double getWidth() {
return img.getWidth(null);
}
public double getHeight() {
return img.getHeight(null);
}
public Image getImg() {
return img;
}
}
这是主要的游戏类：
package rpg2d;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Main {
boolean gameRunning = true;
Graphics2D g;
JFrame frame;
JPanel screen;
Player player;
public static void main(String[] args) {
new Main();
}
@SuppressWarnings("serial")
public Main() {
frame = new JFrame("2D RPG Test");
frame.setSize(800,600);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
player = new Player(10,10,100,3,"/img/player.png");
screen = new JPanel() {
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g;
AffineTransform trans = new AffineTransform();
AffineTransform old = new AffineTransform();
trans.setToIdentity();
trans.rotate(Math.toRadians(player.getDirection()),player.getWidth()/2,player.getHeight()/2);
g2d.setTransform(trans);
g2d.drawImage(player.getImg(), player.getX(), player.getY(), (int)player.getWidth(), (int)player.getHeight(), null);
g2d.setTransform(old);
g2d.drawString("X: " + player.getX() + " Y: " + player.getY(), 5,10);
trans.setToIdentity();
}
};
frame.add(screen);
frame.setVisible(true);
screen.addKeyListener(player);
screen.requestFocus();
Thread t = new Thread(new Runnable() {
public void run() {
gameLoop();
}
});
t.setDaemon(false);
t.start();
}
public void update() {
player.move();
}
public void gameLoop() {
final int FPS = 60;
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
update();
screen.repaint();
}
}, 0, FPS);
}
}