// Each #kernel tells which function to compile; you can have many kernels
#pragma kernel FXAA
#pragma multi_compile _ ENABLE_ALPHA

#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
#include "Packages/com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariables.hlsl"
#include "Packages/com.unity.render-pipelines.high-definition/Runtime/Material/Builtin/BuiltinData.hlsl"
#include "Packages/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/FXAA.hlsl"
#include "Packages/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/PostProcessDefines.hlsl"

RW_TEXTURE2D_X(CTYPE, _OutputTexture);
TEXTURE2D_X(_InputTexture);

[numthreads(8,8,1)]
void FXAA(uint3 dispatchThreadId : SV_DispatchThreadID)
{
    UNITY_XR_ASSIGN_VIEW_INDEX(dispatchThreadId.z);
    uint2 positionSS = dispatchThreadId.xy;
    float2 positionNDC = positionSS * _ScreenSize.zw + (0.5 * _ScreenSize.zw);

    CTYPE outColor = Load(_InputTexture, positionSS, 0, 0).CTYPE_SWIZZLE;
    CTYPE beforeFXAA = outColor;

    RunFXAA(_InputTexture, s_linear_clamp_sampler, outColor, positionSS, positionNDC);

#if defined(ENABLE_ALPHA)
    // When alpha processing is enabled, FXAA should not affect pixels with zero alpha
    outColor.xyz = outColor.a > 0 ? outColor.xyz : beforeFXAA.xyz;
#endif

    _OutputTexture[COORD_TEXTURE2D_X(positionSS)] = outColor;
}