#include "common.h"

uniform half3x4                        m_v2w                ;
uniform	float4		screen_res;

struct	_input
{
	float4	hpos : POSITION;
#ifdef        USE_VTF
	float4	tc0  : TEXCOORD0;		// tc.xy, tc.w = tonemap scale
#else
	float2	tc0  : TEXCOORD0;		// tc.xy
#endif
	float2	tcJ	 : TEXCOORD1;		// jitter coords
};

struct	v2p
{
	float2	tc0 : TEXCOORD0;
	float2	tc1 : TEXCOORD1;
};

float4	main(_input I) : COLOR0
{
        //float4 	P	= tex2D         (s_position,      I.tc0);                // position.(mtl or sun)

	// FIXME: Should add a half-texel offset to I.tc0 here
	// This would fix horizontal line issue
	float4 	P0	= tex2D         (s_position,      I.tc0 + 0.5f * screen_res.zw );                // position.(mtl or sun)
	float4 	P1	= tex2D         (s_position,      I.tc0 - 0.5f * screen_res.zw );                // position.(mtl or sun)
	float4 	P2	= tex2D         (s_position,      I.tc0 + 0.5f * float2(screen_res.z, -screen_res.w) );                // position.(mtl or sun)
	float4 	P3	= tex2D         (s_position,      I.tc0 + 0.5f * float2(-screen_res.z, screen_res.w) );                // position.(mtl or sun)

	float4 P = P0;
	if (P1.z < P.z) P = P1;	
	if (P2.z < P.z) P = P2;	
	if (P3.z < P.z) P = P3;

#if SSAO_OPT_DATA == 2	
	return  float4(P.zzzz);
#else	//	USE_HBAO == 2	
	P 		= tex2D         (s_position,      I.tc0 - 0.5f * screen_res.zw);
	return  float4(P.zzzz);
#endif	//	USE_HBAO == 2
}