java - 如何实现两个不可旋转矩形之间的碰撞响应

Question

我需要帮助制作一个自上而下的射击游戏，我不知道如何阻止我的玩家直接穿过方 block ，下面是我的 Player 类和 keyInput 类。 我是游戏编程的新手，我搜索了很多不同的解决方案，但不知道如何实现它们...... (抱歉，如果我不是很详细，我只是不知道如何正确解释我的代码) * 图像是运行代码时发生的情况，我可以移动播放器

package main;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;

public class Player extends GameObject{

    Handler handler;


    private int timer = 20;
    private boolean canFire = false;
    public static int direction = 1;
    public Player(int x, int y, ID id , Handler handler) {
        super(x, y, id);
        this.handler = handler;



    }
    public Rectangle getBounds() {
        return new Rectangle (x, y, 16, 16);

    }
    public void tick() {
        x += velX;
        y += velY;


        x = Game.clamp(x, 0, Game.WIDTH - 31);
        y = Game.clamp(y, 1, Game.HEIGHT - 54);
        if(timer >= 0) timer --;





        if(KeyInput.facing[0] == "Up") {

            direction = 4;
        } else if(KeyInput.facing[1] == "Down") {

            direction = 3;
        }else if(KeyInput.facing[2] == "Left") {

            direction = 2;
        }else if(KeyInput.facing[3] == "Right") {

            direction = 1;
        }


        if(KeyInput.Fire == true) {
            if(timer <=0)
            {

                handler.addObject(new Bullet(x + 8, y + 8,ID.Bullet, handler, direction));
            timer = 20;
            }

        }


        collision();
    }

    private void collision() {
        for (int i = 0; i < handler.object.size(); i++) {
        GameObject tempObject = handler.object.get(i);

        if(tempObject.getId() == ID.Block)
        {
            if(getBounds().intersects(tempObject.getBounds()))
            {
                //collision events

            }
        }
    }

} 
    public void render(Graphics g) {

        g.setColor(Color.white);
        g.fillRect((int)x,(int)y,24,24);


}

}

package main;

import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

public class KeyInput  extends KeyAdapter{

    private Handler handler;
        private boolean[] keyDown = new boolean[4]; 
        private double Multi = 1;
        public static String[] facing = new String[4];
        public static boolean Fire = false;


    public KeyInput(Handler handler) {
        this.handler = handler;
        keyDown[0] = false;
        keyDown[1] = false;
        keyDown[2] = false;
        keyDown[3] = false;
        facing[0] = "";
        facing[1] = "";
        facing[2] = "";
        facing[3] = "";
        }   
    public void keyPressed(KeyEvent e) {
        int key = e.getKeyCode();

            GameObject tempObject = handler.object.get(0);

        if (key == KeyEvent.VK_W) {tempObject.setVelY((int)(-3* Multi)); keyDown[0] = true;facing[0] = "Up";}

        if (key == KeyEvent.VK_S) {tempObject.setVelY((int)(3* Multi)); keyDown[1] = true;facing[1] = "Down";}

        if (key == KeyEvent.VK_A) {tempObject.setVelX((int) (-3* Multi)); keyDown[2] = true;facing[2] = "Left";}

        if (key == KeyEvent.VK_D) {tempObject.setVelX((int)(3 * Multi)); keyDown[3] = true;facing[3] = "Right";}

        if (key == KeyEvent.VK_SHIFT) {Multi = 2.2;}

        if (key == KeyEvent.VK_SPACE) {Fire = true;}

        if(key == KeyEvent.VK_ESCAPE) System.exit(0); 
        }

    public void keyReleased(KeyEvent e) {

        int key = e.getKeyCode();
        GameObject tempObject = handler.object.get(0);
        if (key == KeyEvent.VK_W)  {keyDown[0] = false;facing[0] = "";}//tempObject.setVelY(0); 
        if (key == KeyEvent.VK_S) {keyDown[1] = false;facing[1] = "";}//tempObject.setVelY(0);
        if (key == KeyEvent.VK_A) {keyDown[2] = false;facing[2] = "";}//tempObject.setVelX(0);
        if (key == KeyEvent.VK_D) {keyDown[3] = false; facing[3] = "";}//tempObject.setVelX(0);
        if (key == KeyEvent.VK_SHIFT) {Multi = 1;}
        if (key == KeyEvent.VK_SPACE) {Fire = false;}

    if(!keyDown[0] && !keyDown[1]) tempObject.setVelY(0);
    if(!keyDown[2] && !keyDown[3]) tempObject.setVelX(0);
    }
    }   

Answer 1

至少可以使用两种策略来应对碰撞:纠正或预防。

校正意味着您移动角色，然后检查它是否发生碰撞，如果发生碰撞，则应用校正。这意味着，您找到玩家应该所在的位置并相应地移动它。这称为“响应碰撞”。

另一方面，预防意味着在移动之前进行一些检查，然后仅将玩家移动到碰撞点。例如，这需要一些光线转换技术。

就您的情况而言，考虑到代码的组织方式，您可能希望实现“更正”方法。

您有一段代码可以检查是否发生冲突(我假设它有效)。当检测到碰撞时，您可以调用某种方法来纠正位置。

private void collision() {
    for (int i = 0; i < handler.object.size(); i++) {
        GameObject tempObject = handler.object.get(i);

        if(tempObject.getId() == ID.Block)
        {
            if(getBounds().intersects(tempObject.getBounds()))
            {
                //collision events

            }
        }
    }
}

gamedev stackexchange 上有一个有趣的问题，您可以查看如何实现碰撞响应:https://gamedev.stackexchange.com/questions/160248/2d-rectangle-collision-resolution

我强烈建议使用具体化 vector 而不是简单的数字来表示位置和速度。从长远来看，它使一切变得更容易理解。