/*
* Copyright (c) 2022 - 2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
*
* NVIDIA CORPORATION, its affiliates and licensors retain all intellectual
* property and proprietary rights in and to this material, related
* documentation and any modifications thereto. Any use, reproduction,
* disclosure or distribution of this material and related documentation
* without an express license agreement from NVIDIA CORPORATION or
* its affiliates is strictly prohibited.
*/

#include "/Engine/Private/Common.ush"
#include "/Engine/Private/FastMath.ush"
#include "/Engine/Private/ScreenPass.ush"

#ifndef THREADGROUP_SIZEX
#define THREADGROUP_SIZEX		8
#endif
#ifndef THREADGROUP_SIZEY
#define THREADGROUP_SIZEY		8
#endif
#define THREADGROUP_TOTALSIZE	(THREADGROUP_SIZEX * THREADGROUP_SIZEY)



float AlphaThreshold;
Texture2D Backbuffer;
//SamplerState VelocityTextureSampler;
//SCREEN_PASS_TEXTURE_VIEWPORT(Velocity)

//Texture2D DepthTexture;
//SamplerState DepthTextureSampler;

RWTexture2D<float4> OutUIHintTexture;
//SCREEN_PASS_TEXTURE_VIEWPORT(CombinedVelocity)


[numthreads(THREADGROUP_SIZEX, THREADGROUP_SIZEY, 1)]
void UIHintExtractionMain(
	uint2 GroupId : SV_GroupID,
	uint2 DispatchThreadId : SV_DispatchThreadID,
	uint2 GroupThreadId : SV_GroupThreadID,
	uint GroupIndex : SV_GroupIndex)
{
	
	
	//uint2 PixelPos = min(DispatchThreadId + Velocity_ViewportMin, Velocity_ViewportMax - 1);
	
	
	//uint2 OutputPixelPos = CombinedVelocity_ViewportMin + DispatchThreadId;
	
	
	// TODO viewrects
	uint2 PixelPos = DispatchThreadId;
	uint2 OutPixelPos = DispatchThreadId;
	float4 ColorAlpha = Backbuffer[PixelPos];
	
	OutUIHintTexture[OutPixelPos] = (ColorAlpha.a > AlphaThreshold) ? ColorAlpha : float4(0.0, 0.0, 0.0, 0.0);
	
}