using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;
//[ExecuteAlways]
public class RongMao : MonoBehaviour
{
    public int Count = 0;
    //public Shader shader;
    [Header("渲染目标")] 
    public Renderer Target;
    public Shader BaseShader;

    [Header("皮毛物理")] 
    public int LayerCount = 10;
    public float FurLength = 0.5f; 
    public Vector3 FurFore;
    public Texture2D Noise;
    public Texture2D Noise2;
    public Texture2D MainTex;//毛发颜色
    public Texture2D Mask;//不产生毛发区域的灰度遮罩
    
   
    
    [Header("皮毛渲染")] 
    //毛发染色
    public Color FurColor=Color.white;
    public Color ShadowColor=Color.white;
    [Range(0,1)]public float ShadowStrength = 0.3f;
    [Range(0.01f, 1)] public float R = 0.5f;
    [Range(0, 3)] public float _LengthMut = 1;
    
    
    
    //public float FurTenacity=1.0f;
    private GameObject[] layers;

   
   // private Material mat;
    // Start is called before the first frame update
    void Start()
    {
        var t=Target.GetType();
        Debug.Log(t.Name);
        CreateFur();
    }

    // Update is called once per frame
    void Update()
    {
        //if(Count==0) return;
        //UpadteTransform();
        //UpdateMat();
    }
    //更新每层毛发的位置
    void UpadteTransform()
    {
        if (layers == null || layers.Length == 0)
        {
            return;
        }
        for (int i = 0; i < layers.Length; i++)
        {
            //依据层数、毛发长度和毛发硬度计算lerp速度
            //float lerpSpeed = (layers.Length-i) * (1.0f / layers.Length)* FurTenacity;

            //让Shell的位置和旋转Lerp到目标模型
            //后面乘的常数完全是试出来的参数……没有具体物理解释,移动时毛发更新
            //layers[i].gameObject.transform.position = Vector3.Lerp(layers[i].gameObject.transform.position, Target.transform.position, lerpSpeed * Time.deltaTime *20);
            //layers[i].gameObject.transform.rotation = Quaternion.Lerp(layers[i].gameObject.transform.rotation, Target.transform.rotation, lerpSpeed * Time.deltaTime *10);
        }
    }

    void UpdateMat()
    {
        float furOffset = 1.0f / LayerCount;
        for (int i = 0; i < layers.Length; i++)
        {
            Material layerMat = layers[i].GetComponent<Renderer>().material;
            layerMat.SetTexture("_MainTex",MainTex);
            layerMat.SetColor("_Color",FurColor);
           
        
            layerMat.SetFloat("_FurLength",FurLength);
            layerMat.SetTexture("_Noise",Noise);
            layerMat.SetTexture("_Noise2",Noise2);
            layerMat.SetTexture("_Mask",Mask);
            //layerMat.SetTexture("_ValueMask",ValueMask);
            layerMat.SetColor("_ShadowColor",ShadowColor);
            Shader.SetGlobalFloat("_ShadowStrength",ShadowStrength);
            layerMat.SetFloat("_LayerOffset",i*furOffset);
            layerMat.SetFloat("_R",R);
            //layerMat.SetFloat("_LengthMut",_LengthMut);
            Shader.SetGlobalFloat("_LengthMut",_LengthMut);
        }
    }
    //创建毛发
    void CreateFur()
    {
        layers = new GameObject[LayerCount];
        float furOffset = 1.0f / LayerCount;
        for (int i = 0; i < LayerCount; i++)
        {
            GameObject layer = Instantiate(Target.gameObject, Target.transform.position, Target.transform.rotation, Target.transform.parent);
            //layer.transform.position=new Vector3(layer.transform.position.x,layer.transform.position.y-i*0.0004f,layer.transform.position.z-i*0.0004f);
            //layer.hideFlags = HideFlags.HideInHierarchy;
            Material layerMat =new Material(BaseShader);
           
            
            layerMat.SetTexture("_MainTex",MainTex);
            layerMat.SetColor("_Color",FurColor);
           
        
            layerMat.SetFloat("_FurLength",FurLength);
            layerMat.SetTexture("_Noise",Noise);
            layerMat.SetTexture("_Noise2",Noise2);
            layerMat.SetTexture("_Mask",Mask);
            //layerMat.SetTexture("_ValueMask",ValueMask);
            layerMat.SetColor("_ShadowColor",ShadowColor);
           // layerMat.SetFloat("_ShadowStrength",ShadowStrength);
            layerMat.SetFloat("_LayerOffset",i*furOffset);
            layerMat.SetFloat("_R",R);
            //layerMat.SetVector("_FurOffset",FurFore*Mathf.Pow(i*furOffset,FurTenacity)*0.0f);
        
            //Graphics.DrawMesh();
            layerMat.renderQueue = 3000 + i+Count*LayerCount;
           
            
           
           
           
            layer.GetComponent<Renderer>().material=layerMat;
            layers[i] = layer;
        }
       
    }


    //删除创建的游戏毛发
    private void OnDestroy()
    {
        // if (layers == null || layers.length == 0)
        // {
        //     return;
        // }
        //
        // for (int i = 0; i < layers.length; i++)
        // {
        //     destroy(layers[i].gameobject);
        // }
    }
}