// 带模板测试参数的简单受光 Shader：Ref/Comp/Pass 全部做成材质属性。
// 用它可以搭出“只在模板值等于 1 的地方可见”的物体（传送门里的世界），或者“画的时候顺便写模板”的物体（X 光的角色）。
Shader "Cookbook/Ch16/StencilLit"
{
    Properties
    {
        [MainTexture] _BaseMap ("Base Map", 2D) = "white" {}
        [MainColor] _BaseColor ("Color", Color) = (0.8, 0.8, 0.8, 1)
        [Toggle] _Unlit ("Unlit (backdrop)", Float) = 0
        [Enum(UnityEngine.Rendering.CullMode)] _Cull ("Cull", Float) = 2
        [IntRange] _StencilRef ("Stencil Ref", Range(0, 255)) = 1
        [Enum(UnityEngine.Rendering.CompareFunction)] _StencilComp ("Stencil Comp", Float) = 8   // Always
        [Enum(UnityEngine.Rendering.StencilOp)] _StencilPass ("Stencil Pass Op", Float) = 0      // Keep
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" "RenderPipeline"="UniversalPipeline" "Queue"="Geometry" }

        HLSLINCLUDE
        #include "Assets/Cookbook/Ch16/Ch16Common.hlsl"
        CBUFFER_START(UnityPerMaterial)
            float4 _BaseMap_ST;
            half4 _BaseColor;
            float _Unlit, _Cull, _StencilRef, _StencilComp, _StencilPass;
        CBUFFER_END
        TEXTURE2D(_BaseMap); SAMPLER(sampler_BaseMap);
        ENDHLSL

        Pass
        {
            Name "ForwardLit"
            Tags { "LightMode"="UniversalForwardOnly" }
            Cull [_Cull]
            Stencil
            {
                Ref  [_StencilRef]
                Comp [_StencilComp]
                Pass [_StencilPass]
            }
            HLSLPROGRAM
            #pragma vertex Ch16Vert
            #pragma fragment frag
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS _MAIN_LIGHT_SHADOWS_CASCADE _MAIN_LIGHT_SHADOWS_SCREEN
            #pragma multi_compile_fragment _ _SHADOWS_SOFT _SHADOWS_SOFT_LOW _SHADOWS_SOFT_MEDIUM _SHADOWS_SOFT_HIGH
            half4 frag(Varyings i) : SV_Target
            {
                half3 albedo = SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, TRANSFORM_TEX(i.uv, _BaseMap)).rgb * _BaseColor.rgb;
                if (_Unlit > 0.5) return half4(albedo, 1);
                return half4(SimpleLighting(albedo, normalize(i.normalWS), i.positionWS, 0.3h), 1);
            }
            ENDHLSL
        }

        Pass
        {
            Name "ShadowCaster"
            Tags { "LightMode"="ShadowCaster" }
            ZWrite On ZTest LEqual ColorMask 0 Cull [_Cull]
            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            float4 vert(Attributes v) : SV_POSITION { return Ch16ShadowPositionCS(v.positionOS.xyz, v.normalOS); }
            half4 frag() : SV_Target { return 0; }
            ENDHLSL
        }

        Pass
        {
            Name "DepthOnly"
            Tags { "LightMode"="DepthOnly" }
            ZWrite On ColorMask R Cull [_Cull]
            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            float4 vert(Attributes v) : SV_POSITION { return TransformObjectToHClip(v.positionOS.xyz); }
            half4 frag() : SV_Target { return 0; }
            ENDHLSL
        }
    }
}