Java 矩形相交始终为真

Question

我正在为学校开发一个项目，并实现了一种检查两个对象是否相交的方法。我已经定义了两个矩形，但是当它检查它们是否相交时，它总是正确的，即使它们位于 JFrame 的相对侧。 Boolean Collision 在开始时设置为 false，x 和 y 是两张照片在屏幕上的坐标。

public Rectangle Bounds() {
    return (new Rectangle(x, y, 225, 225)) ;
}
public Rectangle TrollBounds() {
    return (new Rectangle(x, y, 24, 24)) ;
}
Rectangle hitbox = Bounds() ;
Rectangle Hitbox2 = TrollBounds() ;

检查交叉点的部分

if (hitbox.intersects(Hitbox2)) {
            collision = true ;
            System.out.println("collision") ;
        } else {
            collision = false ;

全类同学

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JPanel;

public class Screen extends JPanel implements Runnable, KeyListener {

int health = 1200;

boolean collision = false ;

BufferedImage Troll ;
int cubex = 600 ;
int cubey = 100 ;

int cubexx = 200 ;
int cubeyy = 200 ;

public boolean running = true ;
BufferedImage Player;
int x = 100 ;
int y = 100 ;

boolean Jumping = false ;
int startJump = 10 ;

public void Jump() {

}

boolean up = false;
boolean down = false;
boolean left = false;
boolean right = false;

public Screen() {
    loadImages();
    Thread thread = new Thread(this);
    thread.start();
}

private void loadImages() {
    try {
        Player = ImageIO.read(getClass().getResource("/sanic.png"));
        Troll = ImageIO.read(getClass().getResourceAsStream("/Trollface.png")) ;
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public void keyPressed(KeyEvent e) {

    if (e.getKeyCode() == KeyEvent.VK_W) {
        up = true ;
    }
    if (e.getKeyCode() == KeyEvent.VK_A) {
        left = true ; 
    }
    if (e.getKeyCode() == KeyEvent.VK_D) {
        right = true ;
    }
    if (e.getKeyCode() == KeyEvent.VK_S) {
        down = true ;
    }
    if (e.getKeyCode() == 31) {
        Jump() ;
    }


}

public void keyReleased(KeyEvent e) {

    if (e.getKeyCode() == 87) {
        up = false ;
    }
    if (e.getKeyCode() == 65) {
        left = false; 
    }
    if (e.getKeyCode() == 68) {
        right = false ;
    }
    if (e.getKeyCode() == 83) {
        down = false ;
    }

}

@Override
public void keyTyped(KeyEvent e) {


}

@Override
public void run() {

    while(running) {
        //gravity

        //gravity
        //Player movement
        if (left) {
            if (x <= -10) {
                x = 1464 ;
            }
            x = x - 2 ;
        }
        if (up) {
            if(y <= -112) {
                y = 910 ;
            }
            y = y - 2 ;
        }
        if (right) {
            if (x >= 1416) {
                x = -24 ;
            }
            x = x + 2;
        }
        if (down) {
            if (y >= 900) {
                y = -10 ;
            }
            y = y + 2 ;
        }
        //Player movement

        //ball movement
        if (cubey > y) {
            cubey-- ;
        }
        if(cubey < y) {
            cubey++ ;
        }
        if (cubex > x) {
            cubex-- ;
        }
        if (cubex < x) {
            cubex++ ;
        }
        //ball movement

        if (hitbox.intersects(Hitbox2)) {
            collision = true ;
            System.out.println("collision") ;
        } else {
            collision = false ;
        }

        if (collision) {
            health -- ;
        }
        System.out.println(collision) ;

        repaint() ;

        try {
            Thread.sleep(3) ;
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g;
    //Graphical loop start
    g.drawImage(Player, x, y, null) ;   
    g.drawImage(Troll, cubex, cubey, null) ;
    g.drawString("SANIC", x, y) ;
    g2d.fillRect(220, 200, health, 50) ;
    //Graphical loop end

}

public Rectangle Bounds() {
    return (new Rectangle(x,y,cubex+225,cubey+225)) ;
}
public Rectangle TrollBounds() {
    return (new Rectangle(cubex,cubey,cubex+24,cubey+24)) ;
}
Rectangle hitbox = Bounds() ;
Rectangle Hitbox2 = TrollBounds() ;

}

Answer 1

如果此代码按照顺序运行，使 hitbox 和 Hitbox2 紧随其后，并且中间不更改 x 和 y，那么它应该返回 true。

它将创建一个从 x, y 到 255, 255 的矩形，以及另一个从 x,y 到 24,24 的矩形，并且这些矩形确实相交。

这是关于 Rectangle 的 JavaDoc & Shape.intersects() 。