initial

materialsystem/stdshaders/sample4x4delog_ps2x.fxc

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+//========== Copyright (c) Valve Corporation, All rights reserved. ==========//
+
+#define HDRTYPE HDR_TYPE_NONE
+#include "common_ps_fxc.h"
+
+sampler TexSampler	: register( s0 );
+
+struct PS_INPUT
+{
+	float2 coordTap0				: TEXCOORD0;
+	float2 coordTap1				: TEXCOORD1;
+	float2 coordTap2				: TEXCOORD2;
+	float2 coordTap3				: TEXCOORD3;
+};
+
+float AlphaConst : register( c0 );
+
+float4 main( PS_INPUT i ) : COLOR
+{
+	float3 s0, s1, s2, s3;
+
+	// Sample 4 taps. We use the trick of sampling four taps with bilinear in order
+	// to average 16 texels.
+	s0 = tex2D( TexSampler, i.coordTap0);
+	s1 = tex2D( TexSampler, i.coordTap1);
+	s2 = tex2D( TexSampler, i.coordTap2);
+	s3 = tex2D( TexSampler, i.coordTap3);
+	float avglum=0.25*(s0.x+s1.x+s2.x+s3.x);
+	float elum=exp(avglum);
+	
+	return FinalOutput( float4(elum,elum,elum,1), 0, PIXEL_FOG_TYPE_NONE, TONEMAP_SCALE_NONE );
+}
+