2D Java Platformer中的碰撞错误

Question

我目前正在使用Java开发没有库的2D平台程序。当播放器左右移动，直线移动时，碰撞正常工作。但是，当玩家跌落或跳跃时与瓷砖水平碰撞时，玩家会进入瓷砖内部并可以在其中向左/向右移动，但不会掉落并且不能跳跃。

这里有我的碰撞检测代码：

protected boolean collision(double xa, double ya)
{
    boolean solid = false;

    for (int c = 0; c < 4; c++)
    {
        int xt = (int) Math.round(((x + xa) + c % 2 * 9 - 1) / Tile.SIZE);
        int yt = (int) Math.round(((y + ya) + c / 2 * 14 - 2) / Tile.SIZE);

        if (level.getTile(xt, yt).isSolid()) solid = true;
    }


    return solid;
}

移动方法：

public void move(double xa, double ya)
{
    if (!collision(xa, ya))
    {
        x += xa;
    }

    if (!collision(0, ya))
    {
        y += ya;
    }
}

和播放器更新方法：

public void update()
{
    boolean left = Keyboard.isKeyDown(KeyEvent.VK_A);
    boolean right = Keyboard.isKeyDown(KeyEvent.VK_D);
    boolean jump = Keyboard.isKeyDown(KeyEvent.VK_SPACE);
    boolean mousePressed = Mouse.isMousePressed();

    double xa = 0;
    double ya = 0;

    if (left && !right)
    {
        moving = true;
        xFlip = true;
        xa -= currentSpeed;
    }
    else if (right && !left)
    {
        moving = true;
        xFlip = false;
        xa += currentSpeed;
    }
    else
    {
        moving = false;
    }

    if (onGround)
    {
        yVel = 0;
        currentSpeed = speed;
        jumped = false;
        this.jump.reset();

        if (jump)
        {
            yVel = -5;
            currentSpeed = speed + jumpSpeedIncrease;
            run.reset();
            idle.reset();
            idleTimer = 0;
            jumped = true;
        }
        else if (moving)
        {
            run.update();
            sprite = run.getSprite();
            idle.reset();
            idleTimer = 0;
        }
        else if (!moving)
        {
            if (idleTimer <= idleSleepTimeSeconds * Main.getDesiredUps())
            {
                idleTimer++;
                idle.update();
                sprite = idle.getSprite();
            }
            else
            {
                idle.reset();
                sprite = Sprite.PLAYER_IDLE4;
            }

            run.reset();
        }

        if (!punching && mousePressed && ++punchTimer >= punchTimerSeconds * Main.getDesiredUps())
        {
            punchTimer = 0;
            punching = true;
        }

        if (punching && (!punch.finished() || punch.isReset()))
        {
            punch.update();
            sprite = punch.getSprite();
        }
        else if (punching && punch.finished())
        {
            punching = false;
            punch.reset();
        }
    }
    else
    {
        yVel += .25;

        if (!jumped)
        {
            ya += yVel;
        }

        if (collision(0, yVel)) yVel = 0;
    }

    if (jumped)
    {
        this.jump.update();
        sprite = this.jump.getSprite();
        ya += yVel;
    }

    groundYA = ya + .5;
    onGround = collision(0, groundYA) && groundYA > 0;
    move(xa, ya);
}

以下是我发布的有关发生的确切视频： https://www.youtube.com/watch?v=JIoKMuTeuow

如果有人有任何想法，请告诉我！

编辑：修复了帖子中的一些语法并添加了更多标签