Shader "Samples/RebindingUI/SimpleLit"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
        _Glossiness ("Smoothness", Range(0,1)) = 0.5
        _Metallic ("Metallic", Range(0,1)) = 0.0
    }

    SubShader
    {
        Tags { "RenderType"="Opaque" "RenderPipeline"="UniversalPipeline" "Queue"="Geometry" }

        Pass
        {
            Name "ForwardLit"
            Tags { "LightMode"="UniversalForward" }

            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS _MAIN_LIGHT_SHADOWS_CASCADE _MAIN_LIGHT_SHADOWS_SCREEN
            #pragma multi_compile _ _SHADOWS_SOFT
            #pragma multi_compile _ _ADDITIONAL_LIGHTS
            #pragma multi_compile_fog

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"

            TEXTURE2D(_MainTex);
            SAMPLER(sampler_MainTex);

            CBUFFER_START(UnityPerMaterial)
                float4 _MainTex_ST;
                half4 _Color;
                half _Glossiness;
                half _Metallic;
            CBUFFER_END

            struct Attributes
            {
                float4 positionOS : POSITION;
                float3 normalOS   : NORMAL;
                float2 uv         : TEXCOORD0;
            };

            struct Varyings
            {
                float4 positionCS  : SV_POSITION;
                float2 uv          : TEXCOORD0;
                float3 normalWS    : TEXCOORD1;
                float3 positionWS  : TEXCOORD2;
                float  fogFactor   : TEXCOORD3;
            };

            Varyings vert(Attributes input)
            {
                Varyings output;
                VertexPositionInputs posInputs = GetVertexPositionInputs(input.positionOS.xyz);
                output.positionCS = posInputs.positionCS;
                output.positionWS = posInputs.positionWS;
                output.normalWS   = TransformObjectToWorldNormal(input.normalOS);
                output.uv         = TRANSFORM_TEX(input.uv, _MainTex);
                output.fogFactor  = ComputeFogFactor(posInputs.positionCS.z);
                return output;
            }

            half4 frag(Varyings input) : SV_Target
            {
                half4 albedo = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, input.uv) * _Color;

                InputData inputData = (InputData)0;
                inputData.positionWS = input.positionWS;
                inputData.normalWS   = normalize(input.normalWS);
                inputData.viewDirectionWS = GetWorldSpaceNormalizeViewDir(input.positionWS);
                inputData.shadowCoord = TransformWorldToShadowCoord(input.positionWS);

                SurfaceData surfaceData = (SurfaceData)0;
                surfaceData.albedo     = albedo.rgb;
                surfaceData.alpha      = albedo.a;
                surfaceData.metallic   = _Metallic;
                surfaceData.smoothness = _Glossiness;
                surfaceData.occlusion  = 1.0;

                half4 color = UniversalFragmentPBR(inputData, surfaceData);
                color.rgb = MixFog(color.rgb, input.fogFactor);
                return color;
            }
            ENDHLSL
        }

        Pass
        {
            Name "ShadowCaster"
            Tags { "LightMode"="ShadowCaster" }

            ZWrite On
            ZTest LEqual
            ColorMask 0

            HLSLPROGRAM
            #pragma vertex ShadowVert
            #pragma fragment ShadowFrag
            #pragma multi_compile _ _CASTING_PUNCTUAL_LIGHT_SHADOW

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"

            float3 _LightDirection;
            float3 _LightPosition;

            struct Attributes
            {
                float4 positionOS : POSITION;
                float3 normalOS   : NORMAL;
            };

            struct Varyings
            {
                float4 positionCS : SV_POSITION;
            };

            Varyings ShadowVert(Attributes input)
            {
                Varyings output;
                float3 posWS    = TransformObjectToWorld(input.positionOS.xyz);
                float3 normalWS = TransformObjectToWorldNormal(input.normalOS);

                #if _CASTING_PUNCTUAL_LIGHT_SHADOW
                    float3 lightDir = normalize(_LightPosition - posWS);
                #else
                    float3 lightDir = _LightDirection;
                #endif

                output.positionCS = TransformWorldToHClip(ApplyShadowBias(posWS, normalWS, lightDir));
                #if UNITY_REVERSED_Z
                    output.positionCS.z = min(output.positionCS.z, UNITY_NEAR_CLIP_VALUE);
                #else
                    output.positionCS.z = max(output.positionCS.z, UNITY_NEAR_CLIP_VALUE);
                #endif
                return output;
            }

            half4 ShadowFrag(Varyings input) : SV_Target
            {
                return 0;
            }
            ENDHLSL
        }
    }

    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200

        CGPROGRAM
        #pragma surface surf Standard fullforwardshadows
        #pragma target 3.0

        sampler2D _MainTex;
        half _Glossiness;
        half _Metallic;
        fixed4 _Color;

        struct Input
        {
            float2 uv_MainTex;
        };

        void surf(Input IN, inout SurfaceOutputStandard o)
        {
            fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo     = c.rgb;
            o.Metallic   = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha      = c.a;
        }
        ENDCG
    }

    FallBack "Diffuse"
}