/**
 * @ Version: SCREEN SPACE SHADERS - UPDATE 21
 * @ Description: IL - Blur Phase
 * @ Modified time: 2024-08-18 08:11
 * @ Author: https://www.moddb.com/members/ascii1457
 * @ Mod: https://www.moddb.com/mods/stalker-anomaly/addons/screen-space-shaders
 */

#include "screenspace_common.h"
#include "settings_screenspace_IL.h"

uniform float4 blur_setup; // x: | y: | z: Buffer width | w: Buffer Height
uniform float4 ao_setup;

Texture2D ao_image;
Texture2D s_hud_mask;

float4 main(p_screen I) : SV_Target
{
	float2 tc = I.tc0 * blur_setup.x;

	float4 base_image = ao_image.SampleLevel(smp_linear, tc, 0);

	float4 blur = 0;

	float2 buffer_pixel_size = 1.0 / blur_setup.zw;
	
	float radius = 1.0 / ao_setup.x;

	float2 offset = float2(radius, radius) * ao_setup.w * blur_setup.y; // 0.25 ~ 0.5 ~ 0.75f ~ 1.0f
	float2 blur_tc = 0;

	float r = 2.0f;
	
	[unroll (G_IL_BLUR_SAMPLES)]
	for (int i = 0; i < G_IL_BLUR_SAMPLES; i++) 
	{
		r += 1.0f / r; 
		offset = mul(offset, pp_rotation_matrix);
		
		blur_tc = tc + (offset * (r - 1.0f) * buffer_pixel_size);

		float3 BlurSample = ao_image.SampleLevel(smp_linear, blur_tc, 0).rgb;
		
		if (any(blur_tc < 0) || any(blur_tc > radius))
			blur += base_image;
		else
			blur.rgb += BlurSample.rgb;
	}
	blur /= G_IL_BLUR_SAMPLES;

	return blur.rgba;
	
}