如何使对象多次从地面反弹（Java和LWJGL）？

我正在学习制作一个简单的游戏，并成功地编写了一个非常基本的弹跳动作，在按下一个跳跃键后，玩家回到地面并再次弹起，创造出一种愚蠢的物理错觉。我面临的问题是如何实现它，使玩家不反弹一次而是反弹两次，第二次反弹速度较低。换句话说，现在的代码（我将在后面展示）非常简单：有一个“跳跃”的标志，一旦跳跃，标志变为真，在下一帧检查它是否为真，如果是真的，我只需在y轴速度上加上一些速度，玩家就会反弹。但我似乎找不到编码第二次反弹的方法，因为每件事都是在逐帧的基础上发生的。我需要为第二次反弹增加更少的速度，但是只有在第一次反弹发生之后，我现在得到的只是这些速度和一次反弹的总和。我不知道如何欺骗程序添加第一个速度，“等待”直到它落地，然后添加第二个，然后绘制下一帧

以下是单次反弹的代码（它可以工作）

如果（y0）xspeed=xspeed*0.925；
如果（跳转==真）
{
y速度+=4.2；
跳跃=假；
}
//跳跃
if（键盘.isKeyDown（键盘.按键向上））
{
y速度=10；
跳跃=正确；
}

我会将代码重新安排为如下内容：

boolean airborne = false;

while (true) // the main game loop
{
    if (y <= 48 && airborne) // if player just hit the ground
    {
        //  Perform the "bounce" by changing their vertical direction and decreasing its magnitude
        ySpeed = -ySpeed/2.0;

        //  This will stop them from bouncing infinitely.  After the bounce gets too small,
        //  they will finally land on the ground.  I suggest you play around with this number to find one that works well
        if (Math.abs(ySpeed) <= 0.5)
        {
            //  Stop the bouncing
            ySpeed = 0;

            //  Place them on the ground
            airborne = false;
            y = 48;
        }
    }
    //  Apply friction if they are on the ground
    if (!airborne)
    {
        // Friction on ground
        if ((!Keyboard.isKeyDown(Keyboard.KEY_LEFT)) && xspeed < 0) xspeed = xspeed * 0.925;
        if ((!Keyboard.isKeyDown(Keyboard.KEY_RIGHT)) && xspeed > 0) xspeed = xspeed * 0.925;
    }
    //  Apply a jump action if they're pressing the jump button while on the ground
    if (Keyboard.isKeyDown(Keyboard.KEY_UP) && !airborne) 
    {
        airborne = true;
        yspeed = 10;
    }
}

boolean=false；
while（true）//主游戏循环
{
哇，谢谢！那里有很多很棒的知识供我学习。谢谢！
boolean airborne = false;

while (true) // the main game loop
{
    if (y <= 48 && airborne) // if player just hit the ground
    {
        //  Perform the "bounce" by changing their vertical direction and decreasing its magnitude
        ySpeed = -ySpeed/2.0;

        //  This will stop them from bouncing infinitely.  After the bounce gets too small,
        //  they will finally land on the ground.  I suggest you play around with this number to find one that works well
        if (Math.abs(ySpeed) <= 0.5)
        {
            //  Stop the bouncing
            ySpeed = 0;

            //  Place them on the ground
            airborne = false;
            y = 48;
        }
    }
    //  Apply friction if they are on the ground
    if (!airborne)
    {
        // Friction on ground
        if ((!Keyboard.isKeyDown(Keyboard.KEY_LEFT)) && xspeed < 0) xspeed = xspeed * 0.925;
        if ((!Keyboard.isKeyDown(Keyboard.KEY_RIGHT)) && xspeed > 0) xspeed = xspeed * 0.925;
    }
    //  Apply a jump action if they're pressing the jump button while on the ground
    if (Keyboard.isKeyDown(Keyboard.KEY_UP) && !airborne) 
    {
        airborne = true;
        yspeed = 10;
    }
}