element_requirements.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
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 * Copyright(C) 2021-2026                                                    *
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#ifndef VCL_MESH_REQUIREMENTS_ELEMENT_REQUIREMENTS_H
#define VCL_MESH_REQUIREMENTS_ELEMENT_REQUIREMENTS_H
 
#include <vclib/mesh/exceptions.h>
#include <vclib/mesh/mesh.h>
 
namespace vcl {
 
template<uint ELEM_ID, MeshConcept MeshType>
bool isElementContainerCompact(const MeshType& m)
{
    return (m.template count<ELEM_ID>() == m.template containerSize<ELEM_ID>());
}
 
template<uint ELEM_ID, uint COMP_ID, MeshConcept MeshType>
bool isPerElementComponentAvailable(const MeshType& m)
{
    if constexpr (mesh::HasElementContainer<MeshType, ELEM_ID>) {
        using Container = mesh::ContainerOfElementType<ELEM_ID, MeshType>;
        using Element   = Container::ElementType;
        if constexpr (comp::HasOptionalComponentOfType<Element, COMP_ID>) {
            return m.template isPerElementComponentEnabled<ELEM_ID, COMP_ID>();
        }
        else {
            return comp::HasComponentOfType<Element, COMP_ID>;
        }
    }
    else {
        return false;
    }
}
 
template<uint ELEM_ID, uint COMP_ID, MeshConcept MeshType>
bool enableIfPerElementComponentOptional(MeshType& m)
{
    if constexpr (mesh::HasElementContainer<MeshType, ELEM_ID>) {
        using Container = mesh::ContainerOfElementType<ELEM_ID, MeshType>;
        using Element   = Container::ElementType;
        if constexpr (comp::HasOptionalComponentOfType<Element, COMP_ID>) {
            m.template enablePerElementComponent<ELEM_ID, COMP_ID>();
            return true;
        }
        else {
            return comp::HasComponentOfType<Element, COMP_ID>;
        }
    }
    else {
        return false;
    }
}
 
template<uint ELEM_ID, MeshConcept MeshType>
void requireElementContainerCompactness(const MeshType& m)
{
    if (!isElementContainerCompact<ELEM_ID>(m))
        throw MissingCompactnessException(
            elementEnumString<ELEM_ID>() +
            " Container of the Mesh is not compact.");
}
 
template<uint ELEM_ID, uint COMP_ID, MeshConcept MeshType>
void requirePerElementComponent(const MeshType& m)
{
    // TODO C++26: use elementEnumString<ELEM_ID>() and
    // componentEnumString<COMP_ID>() in static_assert messages
    static_assert(
        mesh::HasElementContainer<MeshType, ELEM_ID>,
        "The input Mesh does not have a Container of the given Element ID.");
 
    using ElementType = MeshType::template ElementType<ELEM_ID>;
 
    static_assert(
        comp::HasComponentOfType<ElementType, COMP_ID>,
        "The Element of the input Mesh does not have a Component of the given "
        "Component ID.");
 
    if (!isPerElementComponentAvailable<ELEM_ID, COMP_ID>(m)) {
        throw MissingComponentException(
            "Per " + std::string(elementEnumString<ELEM_ID>()) + " " +
            std::string(componentEnumString<COMP_ID>()) +
            " Component is not enabled.");
    }
}
 
} // namespace vcl
 
#endif // VCL_MESH_REQUIREMENTS_ELEMENT_REQUIREMENTS_H