SnowField目标效果2-5：解决鼠标冲跳立刻下落问题

问题产生分析：
现象：只有重力为0时，才跳的起来
原因：只有不修改isTouched时才跳的起来，一旦修改则不跳
猜测：可能两个脚本间有延迟
现象2：降落时会在地面上空停顿一下，重力会变一次60
现象3：60面能飞，20面不能飞只能跳/修改顺序后两面都能按住W飞，重力为0
推测：只有离开地面且istouched为true时能飞

问题出在这段代码：有一个细节，键盘操作时，gettop会到顶归零，鼠标操作时，gettop立刻归零，导致一上来就有了60的重力，并且y速度被归零
        //到达顶点速度方向改变，重力归零
        if (deltaPosition.y < 0 && getTop == false && isTouched == false)
        {
            gravity = 60;
            velocity.y = 0;
            getTop = true;
        }

解决办法：为方便调用，我们新建一个脚本，将两个脚本Snowfield01和BaseControllerMouseMove合在一起
将重力方法写进move中，传入的参数改为键盘输入，在move中将重力加到参数上
Vector2 deltaPosition = deltaPos + new Vector2(0, gravity * gravity * Time.deltaTime * -0.001f) ;
这样我们就可以对速度进行更细致的检测
鼠标的移动单独做，我们把鼠标移动产生的速度分量判断放在最后，重力归零代码中

在重力归零代码中，加入判断条件
if ((jumpDirect * velocityMouse + deltaPosition).y < 0 && getTop == false && isTouched == false)
    {
        gravity = 60;
        jumpDirect.y = 0;
        velocity.y = 0;
        getTop = true;
    }
并且不要忘记将jumpDirect.y也归零，不然会再次发生二段跳

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
 
[RequireComponent(typeof(Collider2D))]
public class SnowField02 : MonoBehaviour
{
    private const float MIN_MOVE_DISTANCE = 0.001f;
 
    private new Collider2D collider2D;
    private new Rigidbody2D rigidbody2D;
    private ContactFilter2D contactFilter2D;
    private readonly List<RaycastHit2D> raycastHit2DList = new List<RaycastHit2D>();
    private readonly List<RaycastHit2D> tangentRaycastHit2DList = new List<RaycastHit2D>();
 
    public LayerMask layerMask;
    //[HideInInspector]
    public Vector2 velocity = Vector2.zero;
    public float velocityMouse;
    public Vector2 tangentDirection;
 
    //BaseControllerMouseMove
    public Vector3 mouseLocation;
    public Vector2 jumpDirect;
    public int inAir = 0;
 
    //数值参数
    public float gravity = 60;
    //状态参数
    public bool isTouched = false;//常态为1，表示在地面或接触到碰撞体
    public bool getTop = false;
    private Vector3 theScale = new Vector3(0.5f, 0.5f, 1);
    //调试参数
    public int test;
 
 
    void Start()
    {
        collider2D = GetComponent<Collider2D>();
        rigidbody2D = GetComponent<Rigidbody2D>();
 
        if (rigidbody2D == null)
            rigidbody2D = gameObject.AddComponent<Rigidbody2D>();
 
        rigidbody2D.hideFlags = HideFlags.NotEditable;
        //rigidbody2D.bodyType = RigidbodyType2D.Kinematic;
        rigidbody2D.simulated = true;
        rigidbody2D.useFullKinematicContacts = false;
        rigidbody2D.collisionDetectionMode = CollisionDetectionMode2D.Continuous;
        rigidbody2D.sleepMode = RigidbodySleepMode2D.NeverSleep;
        rigidbody2D.interpolation = RigidbodyInterpolation2D.Interpolate;
        rigidbody2D.constraints = RigidbodyConstraints2D.FreezeRotation;
        rigidbody2D.gravityScale = 0;
 
        contactFilter2D = new ContactFilter2D
        {
            useLayerMask = true,
            useTriggers = false,
            layerMask = layerMask
        };
    }
 
    private void OnValidate()
    {
        contactFilter2D.layerMask = layerMask;
    }
 
    private void Update()
    {
        if (isTouched == true)//腾空时保留速度
        {
            velocity = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));
        }
    }
 
    private void FixedUpdate()
    {
 
        //rigidbody2D.position += jumpDirect * velocityMouse;
        //重力速度加在Input.GetAxisRaw获得的速度上，一起传入Move
        Movement(velocity * Time.deltaTime * 5f);
        MouseController();
        if (isTouched == false && inAir == 1)
        {
            inAir = 2;
        }
        if (isTouched == true && inAir == 2)
        {
            inAir = 0;
            velocityMouse = 0f;
            mouseLocation = Input.mousePosition;
        }
        rigidbody2D.position += jumpDirect * velocityMouse;
    }
 
    private void Movement(Vector2 deltaPos)
    {
 
        Vector2 deltaPosition = deltaPos + new Vector2(0, gravity * gravity * Time.deltaTime * -0.001f) ;
        Vector2 updateDeltaPosition = Vector2.zero;
 
        float distance = deltaPosition.magnitude;
        Vector2 direction = deltaPosition.normalized;
 
        if (distance <= MIN_MOVE_DISTANCE)
            distance = MIN_MOVE_DISTANCE;
 
 
        if (rigidbody2D.Cast(direction, contactFilter2D, raycastHit2DList, distance) == 0)
        {
            isTouched = false;
        }
        else
        {
            isTouched = true;
        }
 
 
 
 
        Vector2 finalDirection = direction;
        float finalDistance = distance;
 
        //理解：hit取自raycastHit2DList//遍历处理碰撞
        foreach (var hit in raycastHit2DList)
        {
            float moveDistance = hit.distance;

            Debug.DrawLine(hit.point, hit.point + hit.normal, Color.white);
            Debug.DrawLine(hit.point, hit.point + direction, Color.yellow);

            float projection = Vector2.Dot(hit.normal, direction);
 
            if (projection >= 0)
            {
                moveDistance = distance;
            }
            else
            {
                tangentDirection = new Vector2(hit.normal.y, -hit.normal.x);
 
                float tangentDot = Vector2.Dot(tangentDirection, direction);
 
                if (tangentDot < 0)
                {
                    tangentDirection = -tangentDirection;
                    tangentDot = -tangentDot;
                }
 
                float tangentDistance = tangentDot * distance;
 
                if (tangentDot != 0)
                {
                    rigidbody2D.Cast(tangentDirection, contactFilter2D, tangentRaycastHit2DList, tangentDistance);
 
                    foreach (var tangentHit in tangentRaycastHit2DList)
                    {
                        Debug.DrawLine(tangentHit.point, tangentHit.point + tangentDirection, Color.magenta);
 
                        if (Vector2.Dot(tangentHit.normal, tangentDirection) >= 0)
                            continue;
 
                        if (tangentHit.distance < tangentDistance)
                            tangentDistance = tangentHit.distance;
                    }
 
                    updateDeltaPosition += tangentDirection * tangentDistance;
                }
            }
 
            if (moveDistance < finalDistance)
            {
                finalDistance = moveDistance;
            }
        }
 
        updateDeltaPosition += finalDirection * finalDistance;
        rigidbody2D.position += updateDeltaPosition;
 
        //重力
        if (isTouched == false)
        {
            gravity += 5f;
        }
        else
        {
            gravity = 60;
            getTop = false;
            if (Input.GetAxisRaw("Horizontal") == 0 || Input.GetAxisRaw("Vertical") != 0)
            {
                gravity = 0;
            }
            if (Input.GetAxisRaw("Horizontal") != 0 && tangentDirection.y > 0)
            {
                gravity = 20;
            }
        }
        if ((jumpDirect * velocityMouse + deltaPosition).y < 0 && getTop == false && isTouched == false)
        {
            gravity = 60;
            jumpDirect.y = 0;
            velocity.y = 0;
            getTop = true;
        }
    }
    void MouseController()
    {
 
        if (!Input.GetMouseButton(0))
        {
            mouseLocation = Input.mousePosition;
        }
        if (Input.GetMouseButton(0) && (mouseLocation - Input.mousePosition).magnitude >= 20)
        {
            if (isTouched == true)
            {
                jumpDirect = (Input.mousePosition - mouseLocation).normalized;
                if (jumpDirect.y > 0 && inAir == 0)
                {
                    //jumpShortOrLong = 2;
                    velocityMouse = 0.3f;
                    inAir = 1;
                    isTouched = false;
                }
            }
 
        }
    }
}