/**
 * @ Version: SCREEN SPACE SHADERS - UPDATE 22
 * @ Description: Volumetric Combine Phase
 * @ Modified time: 2024-11-25 08:42
 * @ Author: https://www.moddb.com/members/ascii1457
 * @ Mod: https://www.moddb.com/mods/stalker-anomaly/addons/screen-space-shaders
 */

#include "common.h"

Texture2D vol_point;

#ifndef USE_MSAA
	Texture2D vol_buffer;
#else
	#ifndef SM_5
		Texture2DMS<float4,MSAA_SAMPLES> vol_buffer;
	#else
		Texture2DMS<float4>	vol_buffer;
	#endif
#endif


float4 main ( p_screen I ) : SV_Target
{

#ifndef USE_MSAA
	float3 vol_a = vol_buffer.SampleLevel(smp_rtlinear, I.tc0, 0).rgb;
#else
	
	float2 tc = I.tc0.xy * screen_res.xy;

	float3 vol_a = vol_buffer.Load(int3(tc, 0), 0);
	[unroll] for(int iSample = 1; iSample < MSAA_SAMPLES; ++iSample)
	{
		vol_a += vol_buffer.Load(int3(tc, 0), iSample);
	}
	vol_a /= MSAA_SAMPLES;

#endif

	float3 vol_b = vol_point.SampleLevel(smp_rtlinear, I.tc0, 0).rgb;

	return float4(saturate(vol_a + vol_b), 0);
}