最近学Shader有点心得，做了一个SLG画线模块。

性能有能再提高的地方，欢迎大佬指点。

 

1.介绍

 

• 画线模块，可用于SLG游戏行军线。
• 多个不同速度、颜色、长度的线在一个DrawCall中实现。
• 材质中ShowLength控制两端显示的长度，AlphaLength控制渐隐长度，AllShowLength是一个临界值，长度小于它的线全部显示，长度大于它的线出现中间渐隐消失效果。（ShowLength、AlphaLength控制这两个效果）
• 只有一个C#脚本文件和一个Shader，100多行代码。

2.使用demo

 

• 画线：int handle=LineManager.Instance.DrawLine(Vector3 start,Vector3 end,Color color,float speed);
• 回收线：LineManager.Instance.BackLine(int handle);

多次调用画线效果：

 

• 线中间不显示，两端渐隐

 

• 线全部显示 

 

3.C#代码部分

using System.Collections.Generic;
using UnityEngine;
using LineHandle = System.Int32;

class LineManager
{
    private GameObject m_root = null;
    private GameObject m_origin = null;
    private Stack<GameObject> m_linePool = null;
    private Dictionary<int, GameObject> m_drawLines = null;
    private int m_index = 0;

    #region 外部接口
    //参数：起始点、终止点、颜色、速度
    public LineHandle DrawLine(www.078881.cn    Vector3 start,Vector3 end,Color color,float speed)
    {
        //从池中拿出
        GameObject line = getFromPool();
        Transform lineTransform = line.transform;
        Transform childTransform = lineTransform.GetChild(0);

        Mesh mesh = childTransform.GetComponent<MeshFilter>().mesh;
        var vertices = mesh.vertices;

        //设置颜色
        var colors = new Color[vertices.Length];
        for (int i = 0; i < colors.Length; i++)
        {
            colors[i] = color;
        }
        mesh.colors = colors;

        //设置浮transform位置朝向，子transform缩放
        Vector3 position = new Vector3((www.leyou2.net/ start.x+end.x)/2,(start.y+end.y)/2,(start.z+end.z)/2);
        Vector3 scale =new Vector3(1,Vector3.Distance(start,end),1);
        Vector3 direction = (end - start).normalized;
        lineTransform.localPosition www.yongshiyule178.com= position;
        childTransform.localScale = scale;
        lineTransform.localRotation =www.meiwanyule.cn  Quaternion.LookRotation(direction);

        //设置Y轴缩放，速度值
        var uv2 = new Vector2[vertices.Length];
        for (int i = 0; i < uv2.Length; i++)
        {
            uv2[i] = new Vector2(childTransform.localScale.y / childTransform.localScale.x, speed);
        }
        mesh.uv2 = uv2;

        //放入字典
        m_drawLines.Add(++m_index, line);

        return m_index;
    }
    //参数：索引
    public void BackLine(LineHandle handle)
    {
        if(m_drawLines.ContainsKey(handle))
        {
            GameObject line = m_drawLines[handle];
            m_drawLines.Remove( www.leyouzaixian2.com handle);
            backToPool(line);
        }
    }
    #endregion

    #region 内部实现
    private void Init()
    {
        m_origin = Resources.Load("DrawLine/Line") as GameObject;
        m_linePool = new Stack<GameObject>(23);
        m_root = new GameObject("LineRoot");
        m_drawLines = new Dictionary<int, GameObject>(23);
        m_index = 0;
    }

    private GameObject getFromPool()
    {
        if (m_linePool.Count==0)
        {
            GameObject gameObject = GameObject.Instantiate(m_origin);
            gameObject.transform.parent = m_root.transform;
            return gameObject;
        }
        else
        {
            return m_linePool.Pop();
        }
    }

    private void backToPool(GameObject line)
    {
        line.transform.localPosition = new Vector3(1000,1000,1000);
        m_linePool.Push(line);
    }
    #endregion

    #region singleton
    private static LineManager _instance = null;
    private LineManager() { Init(); }
    public static LineManager Instance
    {
        get {
            if (_instance==null)
            {
                _instance = new LineManager();
            }
            return _instance;
        }
        private set { }
    }
    #endregion
}

 

4.Shader代码部分

               Shader "lineShader"{                  Properties                  {                      _MainTex("Line Texture",2D) = "white"{}                  _ShowLength("Show Length",Float)=6.0 //展现的长度                  _AlphaLength("Alpha Length",Float)=5.0 //有透明效果的长度                  _AllShowLength("AllShow Length",Float)=10 //临界值，如果线比它短，那么全都显示                  }                   SubShader{                 Tags{ "Queue" = "AlphaTest" "IgnoreProjector" = "True" "RenderType" = "TransparentCutout" }              Pass              {                     Tags{ "LightMode" = "ForwardBase" }                     ZWrite Off                     Blend SrcAlpha OneMinusSrcAlpha                                      CGPROGRAM                  #pragma vertex vert                  #pragma fragment frag                            #include "Lighting.cginc"                            sampler2D _MainTex;                  float4 _MainTex_ST;              float _ShowLength;              float _AlphaLength;              float _AllShowLength;                            struct a2v                  {                      float4 vertex:POSITION;                      float4 texcoord:TEXCOORD0;                      fixed4 color:COLOR0;                  float2 uv2 : TEXCOORD1; //第二套UV：x分量存储y轴缩放，y分量存储滚动速度                               };                            struct v2f                  {                      float4 pos:SV_POSITION;                      float2 uv:TEXCOORD1;                  fixed4 color:COLOR1;                  float2 uv2:TEXCOORD2; //x分量存储Y轴缩放固定值，y分量存储滚动前uv.y                  };                            v2f vert(a2v v)                  {                      v2f o;                      o.pos = UnityObjectToClipPos(v.vertex);                      o.uv.xy = TRANSFORM_TEX(v.texcoord,_MainTex);                      o.uv.y *=v.uv2.x;//Y轴缩放                      o.color=v.color;                                            o.uv2=o.uv;                  o.uv2.x=v.uv2.x; //o.uv2.x存储Y轴缩放固定值，y轴当前uv.y                      o.uv.y -=v.uv2.y* _Time.z; //Y轴随时间偏移                      return o;                  }                            fixed4 frag(v2f i) :SV_Target                  {                      fixed4 color = tex2D(_MainTex,i.uv.xy);                      //后半段透明值与前半段透明值，取最大值                  i.color.a=max(clamp((_ShowLength-(i.uv2.x-i.uv2.y))/_AlphaLength,0,1),clamp((_ShowLength-i.uv2.y)/_AlphaLength,0,1)); //i.uv2.y存储此片元的UV.y                      //当比_AllShowLength小的时候全部显示                      i.color.a+=clamp(_AllShowLength-i.uv2.x,0,1); //大于0                  i.color.a *= color.a;                      return i.color;                  }                            ENDCG                  }                  }                  //Fallback "VertexLit"          }
Shader "lineShader"{
        Properties
        {
            _MainTex("Line Texture",2D) = "white"{}
        _ShowLength("Show Length",Float)=6.0 //展现的长度
        _AlphaLength("Alpha Length",Float)=5.0 //有透明效果的长度
        _AllShowLength("AllShow Length",Float)=10 //临界值，如果线比它短，那么全都显示
        }
         SubShader{
       Tags{ "Queue" = "AlphaTest" "IgnoreProjector" = "True" "RenderType" = "TransparentCutout" }
    Pass
    {
           Tags{ "LightMode" = "ForwardBase" }
           ZWrite Off
           Blend SrcAlpha OneMinusSrcAlpha


        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag

        #include "Lighting.cginc"

        sampler2D _MainTex;
        float4 _MainTex_ST;
    float _ShowLength;
    float _AlphaLength;
    float _AllShowLength;

        struct a2v
        {
            float4 vertex:POSITION;
            float4 texcoord:TEXCOORD0;
            fixed4 color:COLOR0;
        float2 uv2 : TEXCOORD1; //第二套UV：x分量存储y轴缩放，y分量存储滚动速度
        };

        struct v2f
        {
            float4 pos:SV_POSITION;
            float2 uv:TEXCOORD1;
        fixed4 color:COLOR1;
        float2 uv2:TEXCOORD2; //x分量存储Y轴缩放固定值，y分量存储滚动前uv.y
        };

        v2f vert(a2v v)
        {
            v2f o;
            o.pos = UnityObjectToClipPos(v.vertex);
            o.uv.xy = TRANSFORM_TEX(v.texcoord,_MainTex);
            o.uv.y *=v.uv2.x;//Y轴缩放
            o.color=v.color;

        o.uv2=o.uv;
        o.uv2.x=v.uv2.x; //o.uv2.x存储Y轴缩放固定值，y轴当前uv.y
            o.uv.y -=v.uv2.y* _Time.z; //Y轴随时间偏移
            return o;
        }

        fixed4 frag(v2f i) :SV_Target
        {
            fixed4 color = tex2D(_MainTex,i.uv.xy);
            //后半段透明值与前半段透明值，取最大值
        i.color.a=max(clamp((_ShowLength-(i.uv2.x-i.uv2.y))/_AlphaLength,0,1),clamp((_ShowLength-i.uv2.y)/_AlphaLength,0,1)); //i.uv2.y存储此片元的UV.y
            //当比_AllShowLength小的时候全部显示
            i.color.a+=clamp(_AllShowLength-i.uv2.x,0,1); //大于0
        i.color.a *= color.a;
            return i.color;
        }

        ENDCG
        }
        }
        //Fallback "VertexLit"
}