Shader "Unlit/MaoFaF"
{
    Properties
    {
        _MainTex("MainTex",2D)="white"{}//毛皮颜色
        _Noise ("Noise", 2D) = "white" {}//毛发形状贴图
        _Noise2 ("Noise", 2D) = "white" {}//毛发形状扰动贴图
        _Mask("Mask",2D)="white"{}
        _Color("Color",color)=(1,1,1,1)//毛发的染色
        _LayerOffset("LayerOffset",float)=0.1//当前层的偏移量
        _FurLength("FurLength",float)=1//总体毛发长度
       
        
        //_ShadowStrength("FurShadow",Range(0,1))=0.5//从根部到顶部阴影颜色过渡曲线
        _ShadowColor("ShadowColor",color)=(1,1,1,1)//由根部到顶部阴影的颜色
       
        _R("R",Range(0,1))=0.5
        //_LengthMut("LengthMut",Range(0,5))=1
        //[Enum(Off,0,On,1)]_ZWriteMode("ZWrite Mode", Int) = 1
       //_FurOffset("FurOffset",vector)=(0,1,0,0)//毛发偏移方向
       
    }
    SubShader
    {
        Tags { "RenderType" = "Transparent" "IgnoreProjector" = "True" "Queue" = "Transparent" }
        //LOD 100
       
        Pass
        {
            Blend SrcAlpha OneMinusSrcAlpha 
            Cull Front 
            ZWrite off //[_ZWriteMode]
          
            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile _ LIGHTMAP_ON
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS //接受主光源阴影
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE //投射主光源的阴影
            #pragma multi_compile _ _SHADOWS_SOFT //软阴影
            #pragma multi_compile _ _ADDITIONAL_LIGHTS //附加光源

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"
            
            
            struct appdata
            {
                float4 vertex : POSITION;
                float3 normal:NORMAL;
                float4 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
                float3 wpos:TEXCOORD1;
                float3 wnormal:TEXCOORD2;
                
            };

            TEXTURE2D( _MainTex); SAMPLER(sampler_MainTex);
            

            TEXTURE2D( _Mask);SAMPLER(sampler_Mask);
    

            
            TEXTURE2D(_Noise);SAMPLER(sampler_Noise);
            TEXTURE2D(_Noise2);SAMPLER(sampler_Noise2);
            float4 _Color;
            float4 _Noise_ST;
            float _LayerOffset;
            //float3 _FurOffset;
            float _FurLength;
           
            float3 _ShadowColor;

            float _ShadowStrength;
            float _R;
            float _LengthMut;
            
            float rand(float3 seed, float Min, float Max)
            {
                float f = sin(dot(seed, float3(127.1, 337.1, 256.2)));
                f = -1 + 2 * frac(f * 43785.5453123);
                 return  lerp(Min, Max, f);
                   
            }
            float RandomRange_float(float2 Seed, float Min, float Max)
            {
                float randomno =  frac(sin(dot(Seed, float2(12.9898, 78.233)))*43758.5453);
                return  lerp(Min, Max, randomno);
            }
            float Remap(float x,float inMin,float inMax,float toMin ,float toMax)
            {
                return (x-inMin)/(inMax-inMin)*(toMax-toMin)+toMin;
            }
            v2f vert (appdata v)
            {
                v2f o;
               
                v.vertex.xyz=v.vertex.xyz+v.normal.xyz*(_LayerOffset*0.8)*_FurLength*_LengthMut;
                //v.vertex.xyz+=mul(unity_WorldToObject,_FurOffset);//不需要位移
                o.vertex = TransformObjectToHClip(v.vertex);
                o.wpos=mul(UNITY_MATRIX_M,v.vertex);
                o.uv = v.uv;
               
                o.wnormal=(mul(v.normal,(float3x3)unity_WorldToObject));

               
                return o;
            }
           // [earlydepthstencil]
            float4 frag (v2f i) : SV_Target
            {
                
              

                
                float3 albedo = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex,i.uv.xy).rgb ;
               

                float3 color = albedo*0.8;//diffuse +specular+rim+ambient ;
                //从底部到顶部阴影过渡
               //color =lerp(_ShadowColor,color,saturate(pow( _LayerOffset,1)+0.5));
                
                float mask = SAMPLE_TEXTURE2D(_Mask, sampler_Mask,i.uv).r;
               mask=Remap(mask,0,1,0.5,1);
               //修改毛发的密度与重复度
                float3 noise2 = SAMPLE_TEXTURE2D(_Noise2, sampler_Noise2,i.uv*10+i.uv*(1-mask)*5);
                float3 noise = SAMPLE_TEXTURE2D(_Noise,sampler_Noise, i.uv*30+noise2*30+i.uv*(1-mask)*50);
              
                noise=lerp(noise2,noise,0.6);
                
                float alpha = (saturate(noise*2) - (_LayerOffset )-(1-mask));
                
                
                return float4((color)*1,saturate(alpha*1));

               
              
                
            }
            ENDHLSL
        }

    }
}