#pragma prefer_hlslcc gles
#pragma exclude_renderers d3d11_9x
#pragma target 2.0

#ifndef AA_SHADER_INCLUDED
#define AA_SHADER_INCLUDED

#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"

// 미리 계산된 17x17 가우시안 가중치
static const float gaussianWeights[17][17] = {
    {0.000012, 0.000015, 0.000018, 0.000020, 0.000021, 0.000022, 0.000022, 0.000022, 0.000022, 0.000022, 0.000022, 0.000021, 0.000020, 0.000018, 0.000015, 0.000012, 0.000009},
    {0.000015, 0.000020, 0.000025, 0.000028, 0.000030, 0.000031, 0.000031, 0.000031, 0.000031, 0.000031, 0.000031, 0.000030, 0.000028, 0.000025, 0.000020, 0.000015, 0.000012},
    {0.000018, 0.000025, 0.000031, 0.000035, 0.000037, 0.000038, 0.000039, 0.000039, 0.000039, 0.000039, 0.000038, 0.000037, 0.000035, 0.000031, 0.000025, 0.000018, 0.000015},
    {0.000020, 0.000028, 0.000035, 0.000039, 0.000042, 0.000043, 0.000044, 0.000044, 0.000044, 0.000044, 0.000043, 0.000042, 0.000039, 0.000035, 0.000028, 0.000020, 0.000016},
    {0.000021, 0.000030, 0.000037, 0.000042, 0.000044, 0.000046, 0.000046, 0.000047, 0.000047, 0.000046, 0.000046, 0.000044, 0.000042, 0.000037, 0.000030, 0.000021, 0.000017},
    {0.000022, 0.000031, 0.000038, 0.000043, 0.000046, 0.000047, 0.000048, 0.000048, 0.000048, 0.000048, 0.000047, 0.000046, 0.000043, 0.000038, 0.000031, 0.000022, 0.000018},
    {0.000022, 0.000031, 0.000039, 0.000044, 0.000046, 0.000048, 0.000048, 0.000049, 0.000049, 0.000048, 0.000048, 0.000046, 0.000044, 0.000039, 0.000031, 0.000022, 0.000018},
    {0.000022, 0.000031, 0.000039, 0.000044, 0.000047, 0.000048, 0.000049, 0.000049, 0.000049, 0.000049, 0.000048, 0.000047, 0.000044, 0.000039, 0.000031, 0.000022, 0.000018},
    {0.000022, 0.000031, 0.000039, 0.000044, 0.000047, 0.000048, 0.000049, 0.000049, 0.000049, 0.000049, 0.000048, 0.000047, 0.000044, 0.000039, 0.000031, 0.000022, 0.000018},
    {0.000022, 0.000031, 0.000039, 0.000044, 0.000046, 0.000048, 0.000049, 0.000049, 0.000049, 0.000049, 0.000048, 0.000046, 0.000044, 0.000039, 0.000031, 0.000022, 0.000018},
    {0.000022, 0.000031, 0.000038, 0.000043, 0.000046, 0.000047, 0.000048, 0.000048, 0.000048, 0.000048, 0.000047, 0.000046, 0.000043, 0.000038, 0.000031, 0.000022, 0.000018},
    {0.000021, 0.000030, 0.000037, 0.000042, 0.000044, 0.000046, 0.000046, 0.000047, 0.000047, 0.000046, 0.000046, 0.000044, 0.000042, 0.000037, 0.000030, 0.000021, 0.000017},
    {0.000020, 0.000028, 0.000035, 0.000039, 0.000042, 0.000043, 0.000044, 0.000044, 0.000044, 0.000044, 0.000043, 0.000042, 0.000039, 0.000035, 0.000028, 0.000020, 0.000016},
    {0.000018, 0.000025, 0.000031, 0.000035, 0.000037, 0.000038, 0.000039, 0.000039, 0.000039, 0.000039, 0.000038, 0.000037, 0.000035, 0.000031, 0.000025, 0.000018, 0.000015},
    {0.000015, 0.000020, 0.000025, 0.000028, 0.000030, 0.000031, 0.000031, 0.000031, 0.000031, 0.000031, 0.000031, 0.000030, 0.000028, 0.000025, 0.000020, 0.000015, 0.000012},
    {0.000012, 0.000015, 0.000018, 0.000020, 0.000021, 0.000022, 0.000022, 0.000022, 0.000022, 0.000022, 0.000022, 0.000021, 0.000020, 0.000018, 0.000015, 0.000012, 0.000009},
    {0.000009, 0.000012, 0.000015, 0.000016, 0.000017, 0.000018, 0.000018, 0.000018, 0.000018, 0.000018, 0.000018, 0.000017, 0.000016, 0.000015, 0.000012, 0.000009, 0.000007}
};

void AAFromGreenChannel_float(
    float2 UV,
    UnityTexture2D Tex,
    UnitySamplerState Samp,
    float2 Resolution,
    float Strength,
    out float Out)
{
    float2 texelSize = 1.0 / Resolution;
    float centerG = SAMPLE_TEXTURE2D(Tex, Samp, UV).g;
    float sum = 0;
    float weightSum = 0;
    
    // 미리 계산된 가중치를 사용한 16x16 그리드 샘플링
    for(int y = 0; y < 17; y++)
    {
        for(int x = 0; x < 17; x++)
        {
            float2 offset = float2(x - 8, y - 8) * texelSize;
            float2 sampleUV = UV + offset;
            float weight = gaussianWeights[y][x];
            
            float sampleG = SAMPLE_TEXTURE2D(Tex, Samp, sampleUV).g;
            sum += sampleG * weight;
            weightSum += weight;
        }
    }
    
    float avgG = sum / weightSum;
    float diff = abs(avgG - centerG) * Strength;
    Out = lerp(centerG, avgG, saturate(diff));
}

// half 정밀도 버전도 제공 (성능 최적화용)
void AAFromGreenChannel_half(
    float2 UV,
    UnityTexture2D Tex,
    UnitySamplerState Samp,
    float2 Resolution,
    float Strength,
    out half Out)
{
    Out = (half)AAFromGreenChannel_float(UV, Tex, Samp, Resolution, Strength, Out);
}

#endif