csgo/cstrike15_src/materialsystem/stdshaders/Downsample_ps2x.fxc

//========== Copyright (c) Valve Corporation, All rights reserved. ==========//

#include "common_ps_fxc.h"

sampler TexSampler	: register( s0 );

struct PS_INPUT
{
	float2 coordTap0				: TEXCOORD0;
	float2 coordTap1				: TEXCOORD1;
	float2 coordTap2				: TEXCOORD2;
	float2 coordTap3				: TEXCOORD3;
};

float4 main( PS_INPUT i ) : COLOR
{
	float4 s0, s1, s2, s3;

	// Sample 4 taps
	s0 = tex2D( TexSampler, i.coordTap0 );
	s1 = tex2D( TexSampler, i.coordTap1 );
	s2 = tex2D( TexSampler, i.coordTap2 );
	s3 = tex2D( TexSampler, i.coordTap3 );

	// store grayscale version of buffer in alpha
	float4 vResult = ( s0 + s1 + s2 + s3 ) * 0.25f;
	vResult.a = dot( float3( 0.3f, 0.59f, 0.11f ), vResult.rgb );

	return vResult;
}