Shader "Hidden/Shader/Adaptation3"
{
    Properties
    {
        // This property is necessary to make the CommandBuffer.Blit bind the source texture to _MainTex
        _MainTex("Main Texture", 2DArray) = "grey" {}
    }

    HLSLINCLUDE

    #pragma target 4.5
    #pragma only_renderers d3d11 playstation xboxone xboxseries vulkan metal switch

    #pragma shader_feature CLIP_DEBUG
    #pragma shader_feature COLOUR_PROCESSING

    #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
    #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Color.hlsl"
    #include "Packages/com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariables.hlsl"
    #include "Packages/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/FXAA.hlsl"
    #include "Packages/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/RTUpscale.hlsl"

    struct Attributes
    {
        uint vertexID : SV_VertexID;
        UNITY_VERTEX_INPUT_INSTANCE_ID
    };

    struct Varyings
    {
        float4 positionCS : SV_POSITION;
        float2 texcoord   : TEXCOORD0;
        UNITY_VERTEX_OUTPUT_STEREO
    };

    Varyings Vert(Attributes input)
    {
        Varyings output;
        UNITY_SETUP_INSTANCE_ID(input);
        UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(output);
        output.positionCS = GetFullScreenTriangleVertexPosition(input.vertexID);
        output.texcoord = GetFullScreenTriangleTexCoord(input.vertexID);
        return output;
    }

    // List of properties to control your post process effect
    //float _Intensity;
    //float _Test;
    //float _Exposure;
    TEXTURE2D_X(_MainTex);
    TEXTURE2D(_Adapt);
    float _Mult;
    float _Clip;

    float4 CustomPostProcess(Varyings input) : SV_Target
    {
        UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);

        // Note that if HDUtils.DrawFullScreen is used to render the post process, use ClampAndScaleUVForBilinearPostProcessTexture(input.texcoord.xy) to get the correct UVs
        //float3 sourceColor = SAMPLE_TEXTURE2D_X(_MainTex, s_linear_clamp_sampler, input.texcoord).xyz;
        float3 sourceColor = SAMPLE_TEXTURE2D_X(_MainTex, s_linear_clamp_sampler, ClampAndScaleUVForBilinearPostProcessTexture(input.texcoord.xy)).xyz;

        //float3 color = lerp(_Test, Luminance(sourceColor), _Intensity) / _Exposure;
        //float3 color = Luminance(sourceColor);
        
        //float mask = Luminance(sourceColor) > _Exposure ? 1 : 0;
        //return float4(mask, mask, mask, 1);

        float2 adaptation = LOAD_TEXTURE2D(_Adapt, int2(0, 0));

        #if CLIP_DEBUG
            if (_Mult * Luminance(sourceColor) < _Clip) {
                return float4(0, 0, 0, 1);
            }
        #endif
        #if COLOUR_PROCESSING
            float luma = Luminance(sourceColor);
            float luminance = luma * _Mult;
            float sigma = /*luminance < 0.03 ? 0.0 :*/ (luminance > 3 ? 1.0 :
                (0.069 / (0.069 + 1.409 * exp(-4.267 * luminance))));

            float3 color = lerp(luma, sourceColor, sigma) * adaptation.x + adaptation.y;
        #else
            float3 color = sourceColor * adaptation.x + adaptation.y;
        #endif

        return float4(color, 1);
    }

    ENDHLSL

    SubShader
    {
        Tags{ "RenderPipeline" = "HDRenderPipeline" }
        Pass
        {
            Name "New Post Process Volume"

            ZWrite Off
            ZTest Always
            Blend Off
            Cull Off

            HLSLPROGRAM
                #pragma fragment CustomPostProcess
                #pragma vertex Vert
            ENDHLSL
        }
    }
    Fallback Off
}