c# – 玩家移动不按预期工作的特定而简单的代码(XNA)

2023年5月23日 125次阅读

问题：有时候,当我的战斗机在一个方向上运行时(因为我按住方向按钮,如A,D,左或右),然后我快速释放该方向的按钮并按下相反方向的按钮,战斗机继续运行第一个提到的方向.这不会一直发生,它是“随机的”.此外,这与跳跃/摔倒无关,因为如果战斗机在空中与否则无关紧要.

我有4个课程,其中战斗机运动在更新方法中受到监管：

输入类,只是一些功能

public static void UpdateNew(GameTime gt)
{
    // fires before any other update is called (before player/level/fighter update...)
    frameTime = (float)gt.ElapsedGameTime.TotalSeconds;
    ksNew = Keyboard.GetState();
    msNew = Mouse.GetState();
}
public static void UpdateOld()
{
     // fires after every other update is called (after player/level/fighter update...)
    ksOld = ksNew;
    msOld = msNew;
    scrollValue = msOld.ScrollWheelValue;
}
public static bool Down(Keys k)
{ return ksNew.IsKeyDown(k); }

玩家类：

Fighter fighter; //set in constructor, it's not null
public void Update()
{
    fighter.RunDirection = Input.Down(rightK).ToInt() - Input.Down(leftK).ToInt();
    fighter.Jump = Input.Down(jumpK);
    fighter.Punch = Input.Clicked(punchK);
}
// where .ToInt() converts bool to 1 if it's true, and to 0 if it's not true

战斗机类

public int              RunDirection
{ set { runMultiplier = MathHelper.Clamp(value, -1, 1); } }

public override void    Update              (float elTime, List<Entity> entities)
{
    // region: checks for jump, works fine

    AddForce(
         // X - Horizontal Force
         ((Math.Abs(Force.X) < runSpeed) ? runMultiplier * runSpeed * 5 * elTime : 0) // movement controls
         + ((runMultiplier == 0) ? -Force.X.Sign() * runSpeed * 5 * elTime : 0) // traction when not moving
         ,
         // Y - Vertical Force
         ((!canJump) ? 900 * elTime : 0) // gravity
         - jumpDecreasingSpeed * elTime // jump
         );

    // region: Check collision and puts force.X or force.Y to 0 when it's colliding with other 
    // entities and put's player next to that entity

    //set bool that stores last direction of looking (left/right)
    if (runMultiplier != 0) lookingRight = runMultiplier > 0;

    //checks if animation should be changed (idle, running, jumping or falling)
    CheckAnimation();

    //update currently playing animation
    currentAnim.Update(elTime);

    //stop fighters horisontal movement if it's small enough
    if (Math.Abs(Force.X) < 1) AddForce(-Force.X, 0);

    // after all calculations, move fighter by the force that is currently imacting him.
    Position += Force * elTime;
}

等级

public void         Update          (float elTime)
{
    // PLAYERS
    p1.Update(); // updates only controls, as mentioned above, not the fighter itself.
    p2.Update();

    // update ENTITIES, player's fighters, and walls (their update method is empty)
    // player's fighters are added to maps "entities" list.
    for (int i = 0; i < map.entities.Count; i++)
        map.entities[i].Update(elTime, map.entities.Where(q => q != map.entities[i]).ToList());
}

每个框架的简要更新顺序
GameMainUpdate
— Input.UpdateNew
— Level.Update
—— Player.Update
—— Fighter.Update
———检查球员是否想要你移动,并增加力量(力度)
———检查碰撞,如果发生碰撞,将力设置为0
———完成所有计算后,将力添加到当前位置
— Input.UpdateOld

问题：为什么会这样？为什么它如此“随机”？我明白这是有原因的,但我不能指责它.

最佳答案 导致它的一种可能情况是当Math.Abs​​(Force.X)> = runSpeed然后你添加0 force.

如果Force.X> = runSpeed则为0

runMultiplier == 0(因立即切换而假)然后为0

AddForce(0 0)

     // X - Horizontal Force
     ((Math.Abs(Force.X) < runSpeed) ? runMultiplier * runSpeed * 5 * elTime : 0) // movement controls
     + ((runMultiplier == 0) ? -Force.X.Sign() * runSpeed * 5 * elTime : 0) // traction when not moving

然后这将永远不会被执行,因为Math.Abs​​(Force.X)> = 1(我假设runspeed是> = 1).

//stop fighters horisontal movement if it's small enough
if (Math.Abs(Force.X) < 1) AddForce(-Force.X, 0);

这是一个可能的原因,为什么在1帧缓冲区内切换键,其中一个方向立即被另一个方向替换,可以使你的力为0;这将导致战斗机继续前一个方向.

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