Introduce a TreeTraits struct to differentiate between sparse and adaptive trees

Signed-off-by: Dan Bailey <danbailey@ilm.com>

Author: danrbailey

openvdb/openvdb/Types.h

@@ -236,6 +236,30 @@ using make_index_sequence =
 
 ////////////////////////////////////////
 
+/// @brief An enum to distinguish between different types of Tree representation.
+enum class TreeRepresentation : uint32_t {Unknown = 0, Sparse = 1, Adaptive = 2, End = 3};
+
+/// @brief A TreeTraits struct that can be used to query properties of an input T.
+template<typename T>
+struct TreeTraits
+{
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Unknown;
+};
+
+template <typename T>
+constexpr bool isSparseTree()
+{
+    return TreeTraits<T>::Representation == TreeRepresentation::Sparse;
+}
+
+template <typename T>
+constexpr bool isAdaptiveTree()
+{
+    return TreeTraits<T>::Representation == TreeRepresentation::Adaptive;
+}
+
+////////////////////////////////////////
+
 
 template<typename T, bool = IsSpecializationOf<T, math::Vec2>::value ||
                             IsSpecializationOf<T, math::Vec3>::value ||

openvdb/openvdb/adaptive/AdaptiveGrid.h

@@ -282,6 +282,31 @@ struct TreeAdapter<adaptive::AdaptiveAccessor<_TreeType> >
 };
 
 
+////////////////////////////////////////
+
+// Overload the TreeTraits struct to declare a const/non-const AdaptiveTree as adaptive
+
+template<typename ValueT>
+struct TreeTraits<adaptive::AdaptiveTree<ValueT>>
+{
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Adaptive;
+};
+
+template<typename ValueT>
+struct TreeTraits<const adaptive::AdaptiveTree<ValueT>>
+{
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Adaptive;
+};
+
+// Overload the TreeTraits struct to declare an AdaptiveAccessor as adaptive
+
+template<typename TreeT>
+struct TreeTraits<adaptive::AdaptiveAccessor<TreeT>>
+{
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Adaptive;
+};
+
+
 ////////////////////////////////////////
 
 

openvdb/openvdb/tree/Tree.h

@@ -2125,6 +2125,28 @@ Tree<RootNodeType>::print(std::ostream& os, int verboseLevel) const
 }
 
 } // namespace tree
+
+
+////////////////////////////////////////
+
+// Overload the TreeTraits struct to declare a const/non-const Tree as sparse
+
+template<typename NodeT>
+struct TreeTraits<tree::Tree<NodeT>>
+{
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Sparse;
+};
+
+template<typename NodeT>
+struct TreeTraits<const tree::Tree<NodeT>>
+{
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Sparse;
+};
+
+
+////////////////////////////////////////
+
+
 } // namespace OPENVDB_VERSION_NAME
 } // namespace openvdb
 

openvdb/openvdb/tree/ValueAccessor.h

@@ -1021,6 +1021,19 @@ class ValueAccessorImpl final :
 }; // ValueAccessorImpl
 
 } // namespace tree
+
+
+////////////////////////////////////////
+
+// Overload the TreeTraits struct to declare a const/non-const ValueAccessorImpl as sparse
+
+template<typename TreeT, bool IsSafeT, typename MutexT, typename IndexSequenceT>
+struct TreeTraits<tree::ValueAccessorImpl<TreeT, IsSafeT, MutexT, IndexSequenceT>>
+{
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Sparse;
+};
+
+
 } // namespace OPENVDB_VERSION_NAME
 } // namespace openvdb