// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#if FEATURE_LEVEL >= FEATURE_LEVEL_SM5
float SampleDeviceZFromSceneTexturesTempCopy(float2 UV)
{
	return SceneDepthTexture.SampleLevel(SceneDepthTextureSampler, UV, 0).r;
}
#endif

#ifndef GBUFFER_LAYOUT
#define GBUFFER_LAYOUT 0
#endif

#if GBUFFER_LAYOUT == 0

void EncodeGBufferToMRT(inout FPixelShaderOut Out, FGBufferData GBuffer, float QuantizationBias)
{
	float4 MrtFloat1 = 0.0f;

	MrtFloat1.x = GBuffer.PrecomputedShadowFactors.x;
	MrtFloat1.y = GBuffer.PrecomputedShadowFactors.y;
	MrtFloat1.z = GBuffer.PrecomputedShadowFactors.z;
	MrtFloat1.w = GBuffer.PrecomputedShadowFactors.w;

	Out.MRT[1] = MrtFloat1;
	Out.MRT[2] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[3] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[4] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[5] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[6] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[7] = float4(0.0f, 0.0f, 0.0f, 0.0f);
}


FGBufferData  DecodeGBufferDataDirect(float4 InMRT1,
		 
	float CustomNativeDepth,
	float4 AnisotropicData,
	uint CustomStencil,
	float SceneDepth,
	bool bGetNormalizedNormal,
	bool bChecker)
{
	FGBufferData Ret = (FGBufferData)0;
	Ret.WorldNormal = float3(0,0,1);
	Ret.Depth = 0.f;
	Ret.ShadingModelID = 1;
	Ret.PrecomputedShadowFactors.x = InMRT1.x;
	Ret.PrecomputedShadowFactors.y = InMRT1.y;
	Ret.PrecomputedShadowFactors.z = InMRT1.z;
	Ret.PrecomputedShadowFactors.w = InMRT1.w;
	
	Ret.WorldTangent = AnisotropicData.xyz;
	Ret.Anisotropy = AnisotropicData.w;

	GBufferPostDecode(Ret,bChecker,bGetNormalizedNormal);

	Ret.CustomDepth = ConvertFromDeviceZ(CustomNativeDepth);
	Ret.CustomStencil = CustomStencil;
	Ret.Depth = SceneDepth;
	

	return Ret;
}


#if FEATURE_LEVEL >= FEATURE_LEVEL_SM5

// @param PixelPos relative to left top of the rendertarget (not viewport)
FGBufferData DecodeGBufferDataUV(float2 UV, bool bGetNormalizedNormal = true)
{
	float CustomNativeDepth = Texture2DSampleLevel(SceneTexturesStruct.CustomDepthTexture, SceneTexturesStruct_CustomDepthTextureSampler, UV, 0).r;
	int2 IntUV = (int2)trunc(UV * View.BufferSizeAndInvSize.xy * View.BufferToSceneTextureScale.xy);
	uint CustomStencil = SceneTexturesStruct.CustomStencilTexture.Load(int3(IntUV, 0)) STENCIL_COMPONENT_SWIZZLE;
	float SceneDepth = CalcSceneDepth(UV);
	float4 AnisotropicData = Texture2DSampleLevel(SceneTexturesStruct.GBufferFTexture, SceneTexturesStruct_GBufferFTextureSampler, UV, 0).xyzw;

	float4 InMRT1 = Texture2DSampleLevel(SceneTexturesStruct.GBufferETexture, SceneTexturesStruct_GBufferETextureSampler, UV, 0).xyzw;

	FGBufferData Ret = DecodeGBufferDataDirect(InMRT1,
		 
		CustomNativeDepth,
		AnisotropicData,
		CustomStencil,
		SceneDepth,
		bGetNormalizedNormal,
		CheckerFromSceneColorUV(UV));

	return Ret;
}


// @param PixelPos relative to left top of the rendertarget (not viewport)
FGBufferData DecodeGBufferDataUint(uint2 PixelPos, bool bGetNormalizedNormal = true)
{
	float CustomNativeDepth = SceneTexturesStruct.CustomDepthTexture.Load(int3(PixelPos, 0)).r;
	uint CustomStencil = SceneTexturesStruct.CustomStencilTexture.Load(int3(PixelPos, 0)) STENCIL_COMPONENT_SWIZZLE;
	float SceneDepth = CalcSceneDepth(PixelPos);
	float4 AnisotropicData = SceneTexturesStruct.GBufferFTexture.Load(int3(PixelPos, 0)).xyzw;

	float4 InMRT1 = SceneTexturesStruct.GBufferETexture.Load(int3(PixelPos, 0)).xyzw;

	FGBufferData Ret = DecodeGBufferDataDirect(InMRT1,
		 
		CustomNativeDepth,
		AnisotropicData,
		CustomStencil,
		SceneDepth,
		bGetNormalizedNormal,
		CheckerFromPixelPos(PixelPos));

	return Ret;
}


// @param PixelPos relative to left top of the rendertarget (not viewport)
FGBufferData DecodeGBufferDataSceneTextures(float2 UV, bool bGetNormalizedNormal = true)
{
	uint CustomStencil = 0;
	float CustomNativeDepth = 0;
	float DeviceZ = SampleDeviceZFromSceneTexturesTempCopy(UV);
	float SceneDepth = ConvertFromDeviceZ(DeviceZ);
	float4 AnisotropicData = GBufferFTexture.SampleLevel(GBufferFTextureSampler, UV, 0).xyzw;

	float4 InMRT1 = GBufferETexture.SampleLevel(GBufferETextureSampler, UV, 0).xyzw;

	FGBufferData Ret = DecodeGBufferDataDirect(InMRT1,
		 
		CustomNativeDepth,
		AnisotropicData,
		CustomStencil,
		SceneDepth,
		bGetNormalizedNormal,
		CheckerFromSceneColorUV(UV));

	return Ret;
}


// @param PixelPos relative to left top of the rendertarget (not viewport)
FGBufferData DecodeGBufferDataSceneTexturesLoad(uint2 PixelCoord, bool bGetNormalizedNormal = true)
{
	uint CustomStencil = 0;
	float CustomNativeDepth = 0;
	float DeviceZ = SceneDepthTexture.Load(int3(PixelCoord, 0)).r;
	float SceneDepth = ConvertFromDeviceZ(DeviceZ);
	float4 AnisotropicData = GBufferFTexture.Load(int3(PixelCoord, 0)).xyzw;

	float4 InMRT1 = GBufferETexture.Load(int3(PixelCoord, 0)).xyzw;

	FGBufferData Ret = DecodeGBufferDataDirect(InMRT1,
		 
		CustomNativeDepth,
		AnisotropicData,
		CustomStencil,
		SceneDepth,
		bGetNormalizedNormal,
		CheckerFromPixelPos(PixelCoord));

	return Ret;
}


#endif

#endif

#if GBUFFER_LAYOUT == 1

void EncodeGBufferToMRT(inout FPixelShaderOut Out, FGBufferData GBuffer, float QuantizationBias)
{
	float4 MrtFloat1 = 0.0f;
	float4 MrtFloat2 = 0.0f;

	MrtFloat1.x = GBuffer.Velocity.x;
	MrtFloat1.y = GBuffer.Velocity.y;
	MrtFloat1.z = GBuffer.Velocity.z;
	MrtFloat1.w = GBuffer.Velocity.w;
	MrtFloat2.x = GBuffer.PrecomputedShadowFactors.x;
	MrtFloat2.y = GBuffer.PrecomputedShadowFactors.y;
	MrtFloat2.z = GBuffer.PrecomputedShadowFactors.z;
	MrtFloat2.w = GBuffer.PrecomputedShadowFactors.w;

	Out.MRT[1] = MrtFloat1;
	Out.MRT[2] = MrtFloat2;
	Out.MRT[3] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[4] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[5] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[6] = float4(0.0f, 0.0f, 0.0f, 0.0f);
	Out.MRT[7] = float4(0.0f, 0.0f, 0.0f, 0.0f);
}


FGBufferData  DecodeGBufferDataDirect(float4 InMRT1,
	float4 InMRT2,
		 
	float CustomNativeDepth,
	float4 AnisotropicData,
	uint CustomStencil,
	float SceneDepth,
	bool bGetNormalizedNormal,
	bool bChecker)
{
	FGBufferData Ret = (FGBufferData)0;
	Ret.WorldNormal = float3(0,0,1);
	Ret.Depth = 0.f;
	Ret.ShadingModelID = 1;
	Ret.Velocity.x = InMRT1.x;
	Ret.Velocity.y = InMRT1.y;
	Ret.Velocity.z = InMRT1.z;
	Ret.Velocity.w = InMRT1.w;
	Ret.PrecomputedShadowFactors.x = InMRT2.x;
	Ret.PrecomputedShadowFactors.y = InMRT2.y;
	Ret.PrecomputedShadowFactors.z = InMRT2.z;
	Ret.PrecomputedShadowFactors.w = InMRT2.w;
	
	Ret.WorldTangent = AnisotropicData.xyz;
	Ret.Anisotropy = AnisotropicData.w;

	GBufferPostDecode(Ret,bChecker,bGetNormalizedNormal);

	Ret.CustomDepth = ConvertFromDeviceZ(CustomNativeDepth);
	Ret.CustomStencil = CustomStencil;
	Ret.Depth = SceneDepth;
	

	return Ret;
}


#if FEATURE_LEVEL >= FEATURE_LEVEL_SM5

// @param PixelPos relative to left top of the rendertarget (not viewport)
FGBufferData DecodeGBufferDataUV(float2 UV, bool bGetNormalizedNormal = true)
{
	float CustomNativeDepth = Texture2DSampleLevel(SceneTexturesStruct.CustomDepthTexture, SceneTexturesStruct_CustomDepthTextureSampler, UV, 0).r;
	int2 IntUV = (int2)trunc(UV * View.BufferSizeAndInvSize.xy * View.BufferToSceneTextureScale.xy);
	uint CustomStencil = SceneTexturesStruct.CustomStencilTexture.Load(int3(IntUV, 0)) STENCIL_COMPONENT_SWIZZLE;
	float SceneDepth = CalcSceneDepth(UV);
	float4 AnisotropicData = Texture2DSampleLevel(SceneTexturesStruct.GBufferFTexture, SceneTexturesStruct_GBufferFTextureSampler, UV, 0).xyzw;

	float4 InMRT1 = Texture2DSampleLevel(SceneTexturesStruct.GBufferVelocityTexture, SceneTexturesStruct_GBufferVelocityTextureSampler, UV, 0).xyzw;
	float4 InMRT2 = Texture2DSampleLevel(SceneTexturesStruct.GBufferETexture, SceneTexturesStruct_GBufferETextureSampler, UV, 0).xyzw;

	FGBufferData Ret = DecodeGBufferDataDirect(InMRT1,
		InMRT2,
		 
		CustomNativeDepth,
		AnisotropicData,
		CustomStencil,
		SceneDepth,
		bGetNormalizedNormal,
		CheckerFromSceneColorUV(UV));

	return Ret;
}


// @param PixelPos relative to left top of the rendertarget (not viewport)
FGBufferData DecodeGBufferDataUint(uint2 PixelPos, bool bGetNormalizedNormal = true)
{
	float CustomNativeDepth = SceneTexturesStruct.CustomDepthTexture.Load(int3(PixelPos, 0)).r;
	uint CustomStencil = SceneTexturesStruct.CustomStencilTexture.Load(int3(PixelPos, 0)) STENCIL_COMPONENT_SWIZZLE;
	float SceneDepth = CalcSceneDepth(PixelPos);
	float4 AnisotropicData = SceneTexturesStruct.GBufferFTexture.Load(int3(PixelPos, 0)).xyzw;

	float4 InMRT1 = SceneTexturesStruct.GBufferVelocityTexture.Load(int3(PixelPos, 0)).xyzw;
	float4 InMRT2 = SceneTexturesStruct.GBufferETexture.Load(int3(PixelPos, 0)).xyzw;

	FGBufferData Ret = DecodeGBufferDataDirect(InMRT1,
		InMRT2,
		 
		CustomNativeDepth,
		AnisotropicData,
		CustomStencil,
		SceneDepth,
		bGetNormalizedNormal,
		CheckerFromPixelPos(PixelPos));

	return Ret;
}


// @param PixelPos relative to left top of the rendertarget (not viewport)
FGBufferData DecodeGBufferDataSceneTextures(float2 UV, bool bGetNormalizedNormal = true)
{
	uint CustomStencil = 0;
	float CustomNativeDepth = 0;
	float DeviceZ = SampleDeviceZFromSceneTexturesTempCopy(UV);
	float SceneDepth = ConvertFromDeviceZ(DeviceZ);
	float4 AnisotropicData = GBufferFTexture.SampleLevel(GBufferFTextureSampler, UV, 0).xyzw;

	float4 InMRT1 = GBufferVelocityTexture.SampleLevel(GBufferVelocityTextureSampler, UV, 0).xyzw;
	float4 InMRT2 = GBufferETexture.SampleLevel(GBufferETextureSampler, UV, 0).xyzw;

	FGBufferData Ret = DecodeGBufferDataDirect(InMRT1,
		InMRT2,
		 
		CustomNativeDepth,
		AnisotropicData,
		CustomStencil,
		SceneDepth,
		bGetNormalizedNormal,
		CheckerFromSceneColorUV(UV));

	return Ret;
}


// @param PixelPos relative to left top of the rendertarget (not viewport)
FGBufferData DecodeGBufferDataSceneTexturesLoad(uint2 PixelCoord, bool bGetNormalizedNormal = true)
{
	uint CustomStencil = 0;
	float CustomNativeDepth = 0;
	float DeviceZ = SceneDepthTexture.Load(int3(PixelCoord, 0)).r;
	float SceneDepth = ConvertFromDeviceZ(DeviceZ);
	float4 AnisotropicData = GBufferFTexture.Load(int3(PixelCoord, 0)).xyzw;

	float4 InMRT1 = GBufferVelocityTexture.Load(int3(PixelCoord, 0)).xyzw;
	float4 InMRT2 = GBufferETexture.Load(int3(PixelCoord, 0)).xyzw;

	FGBufferData Ret = DecodeGBufferDataDirect(InMRT1,
		InMRT2,
		 
		CustomNativeDepth,
		AnisotropicData,
		CustomStencil,
		SceneDepth,
		bGetNormalizedNormal,
		CheckerFromPixelPos(PixelCoord));

	return Ret;
}


#endif

#endif