Java平台与平台的碰撞

Question

我迫切需要帮助。我已经花了3个小时拉我的头发，因为我不知道如何通过一个平台工作来解决我的问题！

我希望玩家能够在平台上跳跃，而不是在它上面出现故障，或者让它掉进去。但是，如果玩家举起左箭头键或右箭头键并与平台边缘接触，也会出现这种情况！我真的需要你的帮助，我可以将平台碰撞的简单方面与我的代码一起使用。

这是我的代码：

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

public class Form1 extends Applet implements Runnable, KeyListener
{
private Image dbImage;
private Graphics dbg;

Thread t1;

int x = 300;
int y = 300;

boolean jumping = false;
double yVel = 0;
double termVel = 10;
int loop_cnt = 0;
int start_cnt = loop_cnt;
boolean falling = false;
boolean left, right, up, down;
double counter2 = 4;
int counter;
int num = 7;
int prevY = y;
int prevX = x;
int d = 0;
Rectangle player;

Rectangle platform;

public void init()
{
    setSize(600, 400);
}

public void start()
{
    player = new Rectangle();

    platform = new Rectangle();
    addKeyListener(this);
    t1 = new Thread(this);
    t1.start();
}

public void stop()
{
}

public void destroy()
{
}

@Override
public void run()
{
    while (true)
    {

        //this code will be used if the player is on a platform and then walks off it by pressing either right or left
        if (y <= 300 && !up)
        {
            y += 10;
        }

        if (left)
        {
            prevX = x;
            x -= 2;
        }

        if (right)
        {
            prevX = x;
            x += 2;
        }
        if (up)
        {
            counter2 += 0.05;
            prevY = y;
            y = y + (int) ((Math.sin(counter2) + Math.cos(counter2)) * 5);

            if (counter2 >= 7)
            {
                counter2 = 4;
                up = false;
            }
        }
        if (y >= 300)
        {
            falling = false;
            y = 300;
        }

        repaint();

        try
        {
            t1.sleep(17);
        } 
        catch (InterruptedException e)
        {
            e.printStackTrace();
        }
    }
}

public Rectangle IntersectPlatform()
{
    return platform;
}

public void update(Graphics g)
{
    dbImage = createImage (this.getSize().width, this.getSize().height);
    dbg = dbImage.getGraphics();
    // initialize buffer
    if (dbImage == null)
    {
    }

    // clear screen in background
    dbg.setColor(getBackground());
    dbg.fillRect(0, 0, this.getSize().width, this.getSize().height);

    // draw elements in background
    dbg.setColor(getForeground());
    paint(dbg);
    // draw image on the screen
    g.drawImage(dbImage, 0, 0, this);
}

public void paint(Graphics g)
{
    String string = String.valueOf(y);

    g.setColor(Color.RED);

    g.fillRect(x, y, 40, 100);

    player.setBounds(x, y, 40, 100);

    g.setColor(Color.BLUE);

    platform.setBounds(180, 300, 100, 40);
    g.fillRect(180, 300, 100, 40);


    g.drawString(string, 100, 100);
}

@Override
public void keyPressed(KeyEvent e)
{
    switch (e.getKeyCode())
    {
    case KeyEvent.VK_RIGHT:

        right = true;
        break;
    case KeyEvent.VK_LEFT:
        left = true;
        break;
    case KeyEvent.VK_UP:
        up = true;
        break;
    case KeyEvent.VK_DOWN:
        down = true;
        break;
    }
}

@Override
public void keyReleased(KeyEvent e)
{
    switch (e.getKeyCode())
    {
    case KeyEvent.VK_RIGHT:
        right = false;
        break;
    case KeyEvent.VK_LEFT:
        left = false;
        break;
    case KeyEvent.VK_UP:
        break;
    case KeyEvent.VK_DOWN:
        down = false;
        break;
    }
}

@Override
public void keyTyped(KeyEvent arg0)
{
    // TODO Auto-generated method stub

}

}