//输入结构体
struct Attributes
{
    float4 positionOS    : POSITION;
    float3 normalOS      : NORMAL;
    float4 tangentOS     : TANGENT;
    float2 texcoord      : TEXCOORD0;
    float2 staticLightmapUV    : TEXCOORD1;
    float2 dynamicLightmapUV    : TEXCOORD2;
    UNITY_VERTEX_INPUT_INSTANCE_ID
};

//输出结构体
struct Varyings
{
    float2 uv                       : TEXCOORD0;

    float3 positionWS                  : TEXCOORD1;    // xyz: posWS

    #ifdef _NORMALMAP
        half4 normalWS                 : TEXCOORD2;    // xyz: normal, w: viewDir.x
        half4 tangentWS                : TEXCOORD3;    // xyz: tangent, w: viewDir.y
        half4 bitangentWS              : TEXCOORD4;    // xyz: bitangent, w: viewDir.z
    #else
        half3  normalWS                : TEXCOORD2;
    #endif

    #ifdef _ADDITIONAL_LIGHTS_VERTEX
        half4 fogFactorAndVertexLight  : TEXCOORD5; // x: fogFactor, yzw: vertex light
    #else
        half  fogFactor                 : TEXCOORD5;
    #endif

    #if defined(REQUIRES_VERTEX_SHADOW_COORD_INTERPOLATOR)
        float4 shadowCoord             : TEXCOORD6;
    #endif

    DECLARE_LIGHTMAP_OR_SH(staticLightmapUV, vertexSH, 7);

#ifdef DYNAMICLIGHTMAP_ON
    float2  dynamicLightmapUV : TEXCOORD8; // Dynamic lightmap UVs
#endif

    float4 positionCS                  : SV_POSITION;
    UNITY_VERTEX_INPUT_INSTANCE_ID
    UNITY_VERTEX_OUTPUT_STEREO
};