java - 如何确保游戏在其他计算机上运行速度不会更快？

Question

我正在制作一个游戏，现在我只是在修改图像绘制、按键输入等。现在我只有一个皮卡丘用方向键移动(游戏与口袋妖怪无关，皮卡丘只是我选择的图像)，我想确保游戏不会因为软件功能而在其他计算机上运行得更快(就像皮卡丘从 A 点到 B 点比另一台计算机更快一样，而不仅仅是它)像其他游戏一样有点滞后)

我相信我做得对，因为我听说不要将引擎绑在框架上，框架唯一做的就是显示它的 X、Y 等。其他一切都是在框架之外完成的。

这是我的代码:

package net.trenterprises;

import java.awt.MouseInfo;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;

public class Main implements KeyListener {

static JLabel LabelImage = null;
static ArrayList<String> KeysPressed = new ArrayList<String>();
static int UP = 38;
static int DOWN = 40;
static int LEFT = 37;
static int RIGHT = 39;

public static void main(String[] args) {
    Window TestWindow = new Window("Mouse Location", null);
    KeyListener listener = new Main();
    TestWindow.addKeyListener(listener);
    TestWindow.setLayout(null);
    int MouseX = 0;
    int MouseY = 0;
    JLabel MouseLabel = new JLabel("???");
    MouseLabel.setSize(MouseLabel.getPreferredSize());
    TestWindow.add(MouseLabel);
    try {
        BufferedImage CUPCAKES = (ImageIO.read(new URL("http://img3.wikia.nocookie.net/__cb20140328192412/pokemon/images/thumb/0/0d/025Pikachu.png/200px-025Pikachu.png")));
        LabelImage = new JLabel(new ImageIcon(CUPCAKES));
        TestWindow.add(LabelImage);
        LabelImage.setSize(LabelImage.getPreferredSize());
    } catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    LabelImage.setBounds(0, 0, LabelImage.getSize().width, LabelImage.getSize().height);
    new PikaMoveUp().start();
    new PikaMoveDown().start();
    new PikaMoveLeft().start();
    new PikaMoveRight().start();
    while(true) {
        MouseX = (MouseInfo.getPointerInfo().getLocation().x);
        MouseY = (MouseInfo.getPointerInfo().getLocation().y);
        MouseLabel.setText("Mouse X: " + MouseX + "\n Mouse Y: " + MouseY);
        MouseLabel.setSize(MouseLabel.getPreferredSize());
        MouseLabel.setBounds(0, 0, MouseLabel.getSize().width, MouseLabel.getSize().height);
    }
}

public static int getPikaX() {
    return LabelImage.getX();
}

public static int getPikaY() {
    return LabelImage.getY();
}

public static void setPikachuPosition(int x, int y) {
    LabelImage.setBounds(x, y, LabelImage.getSize().width, LabelImage.getSize().height);
}

@Override
public void keyTyped(KeyEvent e) {
}

@Override
public void keyPressed(KeyEvent e) {
    int Char = (int) e.getKeyChar();
    int Keycode = (int) e.getKeyCode();
    if(Char == 65535) {
        if(Keycode == UP) {
            if(!KeysPressed.contains(Keycode + "")) {
                KeysPressed.add(Keycode + "");
            }
        }
        if(Keycode == DOWN) {
            if(!KeysPressed.contains(Keycode + "")) {
                KeysPressed.add(Keycode + "");
            }
        }
        if(Keycode == LEFT) {
            if(!KeysPressed.contains(Keycode + "")) {
                KeysPressed.add(Keycode + "");
            }
        }
        if(Keycode == RIGHT) {
            if(!KeysPressed.contains(Keycode + "")) {
                KeysPressed.add(Keycode + "");
            }
        }
    }
}

@Override
public void keyReleased(KeyEvent e) {
    int Char = (int) e.getKeyChar();
    int Keycode = (int) e.getKeyCode();
    if(Char == 65535) {
        if(Keycode == UP) {
            while(KeysPressed.contains(Keycode + "")) {
                KeysPressed.remove(Keycode + "");
            }
        }
        if(Keycode == DOWN) {
            while(KeysPressed.contains(Keycode + "")) {
                KeysPressed.remove(Keycode + "");
            }
        }
        if(Keycode == LEFT) {
            while(KeysPressed.contains(Keycode + "")) {
                KeysPressed.remove(Keycode + "");
            }
        }
        if(Keycode == RIGHT) {
            while(KeysPressed.contains(Keycode + "")) {
                KeysPressed.remove(Keycode + "");
            }
        }
    }
}

class PikaMoveUp extends Thread implements Runnable {
    public void run() {
        while(true) {
            try {
                while(Main.KeysPressed.contains(Main.UP + "")) {
                    Thread.sleep(5);
                    Main.setPikachuPosition(Main.getPikaX(), Main.getPikaY() - 1);
                }
            }
            catch(Exception E) {
                E.printStackTrace();
            }
        }
    }
}

class PikaMoveDown extends Thread implements Runnable {
    public void run() {
        while(true) {
            try {
                while(Main.KeysPressed.contains(Main.DOWN + "")) {
                    Thread.sleep(5);
                    Main.setPikachuPosition(Main.getPikaX(), Main.getPikaY() + 1);
                }
            }
            catch(Exception E) {
                E.printStackTrace();
            }
        }
    }
}

class PikaMoveLeft extends Thread implements Runnable {
    public void run() {
        while(true) {
            try {
                while(Main.KeysPressed.contains(Main.LEFT + "")) {
                    Thread.sleep(5);
                    Main.setPikachuPosition(Main.getPikaX() - 1, Main.getPikaY());
                }
            }
            catch(Exception E) {
                E.printStackTrace();
            }
        }
    }
}

class PikaMoveRight extends Thread implements Runnable {
    public void run() {
        while(true) {
            try {
                while(Main.KeysPressed.contains(Main.RIGHT + "")) {
                Thread.sleep(5);
                Main.setPikachuPosition(Main.getPikaX() + 1, Main.getPikaY());
            }
        }
        catch(Exception E) {
            E.printStackTrace();
        }
    }
}

Answer 1

您通常会看到 delta-timing或fixed-timestep实现到游戏循环中。

Delta 计时使用基于测量每帧之间时间的 delta 变量。您可以将所有转换乘以delta，以使游戏在多台计算机上以相同的速度运行。这很顺利且易于实现，但您必须记住将所有转换乘以delta。

另一方面，固定时间步长以某种方式控制帧之间的时间，从而消除了对增量变量的需要。众所周知，它有点不稳定/难以实现，但您不再需要在任何地方应用delta。

虽然您可以自己实现它，但切换到 LibGDX 或 Slick2D 等实际游戏库会更容易，他们会在其中为您处理它(以及更多更多)。

此外，使用过多线程也可能导致性能不稳定。在基本游戏循环中更新时，可以以更简洁的方式完成移动；

if(Main.KeysPressed.contains(Main.LEFT + ""))
    Main.setPikachuPosition(Main.getPikaX() - 1, Main.getPikaY());