// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.

/*=============================================================================
	PostProcessDilation.usf: PostProcessing dilation of the diffuse SVO content
=============================================================================*/

#include "Common.usf"
#include "PostProcessCommon.usf"


// pixel shader
void MainPS(float4 UVAndScreenPos : TEXCOORD0, out float4 OutColor : SV_Target0)
{
	float2 UV = UVAndScreenPos.xy;
	// screen position in [-1, 1] screen space
	float2 ScreenSpacePos = UVAndScreenPos.zw;
	int3 PixelPos = int3((int2)(ScreenSpacePos * ScreenPosToPixel.xy + ScreenPosToPixel.zw + 0.5f), 0);

	OutColor = InputNew0.Load(PixelPos);

	int2 MaxSize = (int2)ViewportSize;

	#define SAMPLE(x, y)\
	{\
		int3 p = PixelPos + int3(x, y, 0);\
		FLATTEN\
		if(all(OutColor.rgb == 0) && all(p.xy < MaxSize))\
		{\
			OutColor = InputNew0.Load(p);\
		}\
	}

	// take content from neighbors
	SAMPLE(-1,0) SAMPLE( 1,0) SAMPLE(0,-1) SAMPLE(0, 1)

	// not needed
//	SAMPLE(-1,1) SAMPLE( 1,1) SAMPLE(1,-1) SAMPLE(1, 1) SAMPLE(-1,-1) SAMPLE( 1,-1) SAMPLE(-1,-1) SAMPLE(-1, 1)
}