Unity2D-Dash && SpeedUp

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Introduction

原理：

角色位置改变时，每隔一段时间记录角色的位置，然后在记录的位置上放置一个图片，在图片出现之后过一段时间就让图片渐渐消失

简述实现步骤：

1.在Unity中Create Empty(空物体)，在其下面放置角色的图片

​编辑

2.写代码

3.测试，修复Bug

最终效果：

Dash and SpeedUp

PlayerDash.cs(脚本挂在player上面)

变量声明

    [Header("Player")]
    private SpriteRenderer playerSr;
    private Rigidbody2D rb;
    private Vector2 movement = Vector2.zero;

    public float spriteRate = 0.02f;

    [Header("UpgradeSpeed")]
    public float upSpeed = 5f;
    public float upSpeedTime = 5f;
    public float spriteUpSpeedRate = 0.25f;
    private bool isUpSpeeding = false;
    private GameObject[] spritePoolSpeedUp;
    private float upCounter = 0;

    [Header("Dash")]
    public float dashTime = 0.1f;
    public float dashSpeed = 20f;
    public float dashRate = 2f;
    private Vector2 dir= Vector2.zero;
    private bool isDashing = false;
    private float dashRateCounter = 0f;
    private GameObject[] spritePoolDash;
    private float couter = 0f;

Awake()

private void Awake()
{
    rb = GetComponent<Rigidbody2D>();
    playerSr = GetComponent<SpriteRenderer>();

    //找到Hierarchy面板中放置Dash图片的空物体
    Transform dashPool = GameObject.Find("SpritePoolDash").transform;
    spritePoolDash = new GameObject[dashPool.childCount];
    for (int i = 0; i < spritePoolDash.Length; i++)
    {
        spritePoolDash[i] = dashPool.GetChild(i).gameObject;
    }

    //找到Hierarchy面板中放置SpeedUp图片的空物体
    Transform speedUpPool = GameObject.Find("SpritePoolSpeedUp").transform;
    spritePoolSpeedUp = new GameObject[speedUpPool.childCount];
    for (int i = 0; i < spritePoolSpeedUp.Length; i++)
    {
        spritePoolSpeedUp[i] = speedUpPool.GetChild(i).gameObject;
    }
}

Update()

private void Update()
    {
        movement.x = Input.GetAxisRaw("Horizontal");
        movement.y = Input.GetAxisRaw("Vertical");

        //如果冷却时间 > 0，开始冷却倒计时
        if (dashRateCounter > 0)
        {
            dashRateCounter -= Time.deltaTime;
        }

        //按下空格键，并且角色正在移动，Dash
        if (Input.GetKeyDown(KeyCode.Space) && movement != Vector2.zero)
        {
            //如果正在Dash 或 SpeedUp 或 Dash技能的冷却时间 > 0，则不执行Dash方法
            if (isDashing || isUpSpeeding || dashRateCounter > 0)
                return;
            dir = movement.normalized * 5;
            StartCoroutine(Dash());
        }
        //按下“B”键，SpeedUp
        if (Input.GetKeyDown(KeyCode.B))
        {
            if (isDashing || isUpSpeeding)
                return;
            StartCoroutine(UpGradeSpeed());
        }
    }

Dash部分

private IEnumerator Dash()
{
    //重置冷却计时器
    dashRateCounter = dashRate;

    //图片出现时间间隔
    spriteRate = 0.02f;
    //
    StartCoroutine(DashSprites());

    couter = 0;
    //记录player当前的状态，正在冲刺，不可以进行其他技能的操作
    isDashing = true;

    while (couter <= dashTime)
    {
        couter += Time.deltaTime;        

        //角色朝着按键方向Dash
        rb.position = Vector2.MoveTowards(rb.position, rb.position + dir, dashSpeed * Time.deltaTime);
        if (couter > dashTime)
        {
            isDashing = false;
        }
        yield return null;
     }
}
//放置图片
private IEnumerator DashSprites()
{
    for (int i = 0; i < spritePool.Length; i++)
    {
        //将图片设为可见
        spritePool[i].SetActive(true);
        //重置图片的颜色(其实是重置其透明度，重置alpha为255)
        spritePool[i].GetComponent<SpriteRenderer>().color = Color.white;
        //设置图片的朝向，与角色图片的朝向一致
        spritePool[i].GetComponent<SpriteRenderer>().flipX = playerSr.flipX;
        //在角色当前的位置上放置一张图片
        spritePool[i].transform.position = transform.position;
        //相隔0.02秒放置一张
        yield return new WaitForSeconds(spriteRate);
     }
}

SpeedUp部分

private IEnumerator UpGradeSpeed()
{
    //修改图片出现的时间间隔
    spriteRate = 0.25f;

    isUpSpeeding = true;
    StartCoroutine(UpSpeedSprites());

    //设置一个计时器
    upCounter = upSpeedTime;

    while (upCounter >= 0f)
    {
        //计时器>=0就让其倒计时
        upCounter -= Time.deltaTime;

        rb.position = Vector2.MoveTowards(rb.position, rb.position + movement, upSpeed * Time.deltaTime);

        //SpeedUp结束
        if (upCounter <= 0)
        {
            isUpSpeeding = false;
        }
        yield return null;
    }
}

private IEnumerator UpSpeedSprites()
{
    for (int i = 0; i < spritePoolUpSpeed.Length; i++)
    {
        spritePoolUpSpeed[i].SetActive(true);
        spritePoolUpSpeed[i].GetComponent<SpriteRenderer>().color = Color.white;
        spritePoolUpSpeed[i].GetComponent<SpriteRenderer>().flipX = playerSr.flipX;

        spritePoolUpSpeed[i].transform.position = transform.position;

        yield return new WaitForSeconds(spriteRate);
    }
}

SpriteFade.cs(脚本挂在以下物体上面)

​编辑

using System.Collections;
using UnityEngine;

public class SpriteFade : MonoBehaviour
{
    //图片从 不透明 到 透明 的速率
    public float spriteFadeTime = 0.01f;
    //获取脚本所挂在的物体的图片的SpriteRenderer,用来改变其颜色
    private SpriteRenderer sr;

    private void Awake()
    {
        sr = GetComponent<SpriteRenderer>();
    }

    private void Update()
    {
        //如果图片在Hierarchy面板上面显示(表示触发了Dash技能,图片出现了)
        if (gameObject.activeInHierarchy)
        {
            StartCoroutine(FadeSprite());
        }
    }

    private IEnumerator FadeSprite()
    {
        while (gameObject.activeInHierarchy)
        {
            //渐渐消失
            sr.color = Color.Lerp(sr.color, Color.clear, spriteFadeTime * Time.deltaTime);
            //消失之后，将图片隐藏
            if(sr.color == Color.clear)
            {
                gameObject.SetActive(false);
            }
            //每帧执行
            yield return null;
        }

    }
}

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