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

#include "common_ps_fxc.h"

sampler InputSampler	: register( s0 );
sampler FilmGrain		: register( s1 );

const float4 vNoiseScale : register( c0 );

struct PS_INPUT
{
	float2 inputImageCoords	: TEXCOORD0;	// Input image having grain added
	float2 filmGrainCoords	: TEXCOORD1;	// Tiling film grain texture
};

float4_color_return_type main( PS_INPUT i ) : COLOR
{
	float3 hsl = RGBtoHSL( tex2D( InputSampler, i.inputImageCoords ) ).rgb;
	float3 hslNoise = tex2D( FilmGrain, i.filmGrainCoords ).rgb * 2.0f - 1.0f;

	hsl.rgb += hslNoise.rgb * vNoiseScale.rgb * float3( 0.5f, 1.0f, 1.0f );

	return FinalOutput( float4 ( hsl.rgb, 1.0f  ), 0, PIXEL_FOG_TYPE_NONE, TONEMAP_SCALE_NONE );
}