position_of()

template<typename PointT >

std::optional< PointT > MayaFlux::Kinesis::SpatialIndex< PointT >::position_of

(

uint32_t

id

)

const

Read the position of an entity from the published snapshot.

Parameters

id	Entity id.

Returns

Position, or std::nullopt if id is not present in the snapshot.

Definition at line 322 of file SpatialIndex.cpp.

{
#ifdef MAYAFLUX_PLATFORM_MACOS
    auto [snap, slot] = acquire_snapshot();
    if (!snap) {
        return std::nullopt;
    }
    auto it = snap->id_to_slot.find(id);
    std::optional<PointT> result = (it != snap->id_to_slot.end())
        ? std::optional<PointT>(snap->positions[it->second])
        : std::nullopt;
    release_snapshot(slot);
    return result;
#else
    auto snap_ptr = m_snapshot.load(std::memory_order_acquire);
    if (!snap_ptr) {
        return std::nullopt;
    }
    auto it = snap_ptr->id_to_slot.find(id);
    if (it == snap_ptr->id_to_slot.end()) {
        return std::nullopt;
    }
    return snap_ptr->positions[it->second];
#endif
}