to_nddata()

template<typename T >
requires (ArithmeticData<T> && DataVariantElement<T>)

std::optional< CompositeProjection > MayaFlux::Kakshya::CompositeSlice::to_nddata

(

std::string_view

field_name

)

const

Materialize one exact-type arithmetic field as homogeneous NDData.

Template Parameters

T	Declared field type and supported DataVariant element type.

Parameters

field_name

Field to project.

Returns

Owning values, presence mask, and dimension metadata; or std::nullopt if the field is absent from the layout or has another type. Missing values are zero-filled and marked absent in the mask.

Definition at line 217 of file CompositeAccess.hpp.

{
    const auto field_index = layout().find_field(field_name);
    if (!field_index || layout().fields()[*field_index].type != std::type_index(typeid(T)))
        return std::nullopt;
 
    std::vector<T> values(m_count);
    std::vector<uint8_t> presence(m_count, 0);
    for (size_t i = 0; i < m_count; ++i) {
        const auto element = at(i);
        if (!element)
            return std::nullopt;
        if (auto value = element->get<T>(field_name)) {
            values[i] = *value;
            presence[i] = 1;
        }
    }
 
    CompositeProjection result;
    result.values = std::move(values);
    result.presence = std::move(presence);
    result.dimensions.emplace_back(std::string(field_name), m_count, 1, DataDimension::Role::CUSTOM);
    return result;
}

References MayaFlux::Kakshya::DataDimension::CUSTOM, MayaFlux::Kakshya::CompositeProjection::dimensions, MayaFlux::Kakshya::CompositeProjection::presence, type, value, values, and MayaFlux::Kakshya::CompositeProjection::values.