#include "bindless_structs.hlsli"

float3 GetLocalDir(float Side, float3 GlobalInvocationID)
{
    float HalfSide = Side / 2;
    float AxisSign = 2.0f * (0.5f - (GlobalInvocationID.z % 2));
    
    float3 LocalDir;
    if (GlobalInvocationID.z < 2)
    {
        LocalDir = float3(AxisSign * HalfSide, HalfSide - GlobalInvocationID.y, (HalfSide - GlobalInvocationID.x) * AxisSign);
    }
    else if (GlobalInvocationID.z < 4)
    {
        LocalDir = float3(GlobalInvocationID.x - HalfSide, AxisSign * HalfSide, AxisSign * (GlobalInvocationID.y - HalfSide));
    }
    else
    {
        LocalDir = float3((GlobalInvocationID.x - HalfSide) * AxisSign, HalfSide - GlobalInvocationID.y, HalfSide * AxisSign);
    }
    return normalize(LocalDir);
}