// RUN: %dxc -E main -T cs_6_0 %s | FileCheck %s

// CHECK: threadId
// CHECK: textureLoad
// CHECK: sampleLevel
// CHECK: Exp
// CHECK: dot3
// CHECK: Log
// CHECK: textureStore


//
// Copyright (c) Microsoft. All rights reserved.
// This code is licensed under the MIT License (MIT).
// THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY
// IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR
// PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.
//
// Developed by Minigraph
//
// Author:  James Stanard 
//

#include "ShaderUtility.hlsli"
#include "PostEffectsRS.hlsli"

Texture2D<float3> SrcColor : register( t0 );
StructuredBuffer<float> Exposure : register( t1 );
Texture2D<float3> bloom : register( t2 );
RWTexture2D<float3> DstColor : register( u0 );
RWTexture2D<float> OutLuma : register( u1 );
SamplerState LinearSampler : register( s0 );

cbuffer ConstantBuffer_x : register( b0 )
{
	float2 g_RcpBufferDim;
	float g_BloomStrength;
	float g_LumaGamma;
};

[RootSignature(PostEffects_RootSig)]
[numthreads( 8, 8, 1 )]
void main( uint3 DTid : SV_DispatchThreadID )
{
	float2 TexCoord = (DTid.xy + 0.5) * g_RcpBufferDim;

	// Load HDR and bloom
	float3 hdrColor = SrcColor[DTid.xy] + g_BloomStrength * bloom.SampleLevel( LinearSampler, TexCoord, 0 );

	// Tone map to LDR and convert to greyscale
	float luma = RGBToLuminance( ToneMap(hdrColor * Exposure[2]) );

	float logLuma = LinearToLogLuminance(luma, g_LumaGamma);

	DstColor[DTid.xy] = luma.xxx;
	OutLuma[DTid.xy] = logLuma;
}