Use an enum to distinguish between sparse vs adaptive trees

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

Author: danrbailey

openvdb/openvdb/Types.h

@@ -236,15 +236,27 @@ using make_index_sequence =
 
 ////////////////////////////////////////
 
-/// @brief A Traits struct that can be used to query properties of an input T.
+/// @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
 {
-    static const bool IsSparse = false;
-    static const bool IsAdaptive = false;
+    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;
+}
 
 ////////////////////////////////////////
 

openvdb/openvdb/adaptive/AdaptiveGrid.h

@@ -289,24 +289,21 @@ struct TreeAdapter<adaptive::AdaptiveAccessor<_TreeType> >
 template<typename ValueT>
 struct TreeTraits<adaptive::AdaptiveTree<ValueT>>
 {
-    static const bool IsSparse = false;
-    static const bool IsAdaptive = true;
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Adaptive;
 };
 
 template<typename ValueT>
 struct TreeTraits<const adaptive::AdaptiveTree<ValueT>>
 {
-    static const bool IsSparse = false;
-    static const bool IsAdaptive = true;
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Adaptive;
 };
 
 // Overload the TreeTraits struct to declare an AdaptiveAccessor as adaptive
 
 template<typename TreeT>
 struct TreeTraits<adaptive::AdaptiveAccessor<TreeT>>
 {
-    static const bool IsSparse = false;
-    static const bool IsAdaptive = true;
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Adaptive;
 };
 
 

openvdb/openvdb/tools/Interpolation.h

@@ -631,7 +631,7 @@ BoxSampler::getValues(ValueT (&data)[N][N][N], const TreeT& inTree, Coord ijk)
 {
     // This algorithm is only defined for sparse grids
 
-    if constexpr (TreeTraits<TreeT>::IsSparse) {
+    if constexpr (isSparseTree<TreeT>()) {
         data[0][0][0] = inTree.getValue(ijk); // i, j, k
 
         ijk[2] += 1;
@@ -750,7 +750,7 @@ inline bool
 BoxSampler::sample(const TreeT& inTree, const Vec3R& inCoord,
                    typename TreeT::ValueType& result)
 {
-    if constexpr (TreeTraits<TreeT>::IsSparse) {
+    if constexpr (isSparseTree<TreeT>()) {
         using ValueT = typename TreeT::ValueType;
 
         const Vec3i inIdx = local_util::floorVec3(inCoord);
@@ -765,7 +765,7 @@ BoxSampler::sample(const TreeT& inTree, const Vec3R& inCoord,
         result = BoxSampler::trilinearInterpolation(data, uvw);
 
         return hasActiveValues;
-    } else if constexpr (TreeTraits<TreeT>::IsAdaptive) {
+    } else if constexpr (isAdaptiveTree<TreeT>()) {
         // As an example, return the background value.
         // This is where the logic that could sample against an adaptive tree would live.
         // Extract the tree from the Tree or ValueAccessor
@@ -783,7 +783,7 @@ template<class TreeT>
 inline typename TreeT::ValueType
 BoxSampler::sample(const TreeT& inTree, const Vec3R& inCoord)
 {
-    if constexpr (TreeTraits<TreeT>::IsSparse) {
+    if constexpr (isSparseTree<TreeT>()) {
 
         using ValueT = typename TreeT::ValueType;
 
@@ -797,7 +797,7 @@ BoxSampler::sample(const TreeT& inTree, const Vec3R& inCoord)
         BoxSampler::getValues(data, inTree, Coord(inIdx));
 
         return BoxSampler::trilinearInterpolation(data, uvw);
-    } else if constexpr (TreeTraits<TreeT>::IsAdaptive) {
+    } else if constexpr (isAdaptiveTree<TreeT>()) {
         // As an example, return the background value.
         // This is where the logic that could sample against an adaptive tree would live.
         // Extract the tree from the Tree or ValueAccessor

openvdb/openvdb/tree/Tree.h

@@ -2134,15 +2134,13 @@ Tree<RootNodeType>::print(std::ostream& os, int verboseLevel) const
 template<typename NodeT>
 struct TreeTraits<tree::Tree<NodeT>>
 {
-    static const bool IsSparse = true;
-    static const bool IsAdaptive = false;
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Sparse;
 };
 
 template<typename NodeT>
 struct TreeTraits<const tree::Tree<NodeT>>
 {
-    static const bool IsSparse = true;
-    static const bool IsAdaptive = false;
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Sparse;
 };
 
 

openvdb/openvdb/tree/ValueAccessor.h

@@ -1030,8 +1030,7 @@ class ValueAccessorImpl final :
 template<typename TreeT, bool IsSafeT, typename MutexT, typename IndexSequenceT>
 struct TreeTraits<tree::ValueAccessorImpl<TreeT, IsSafeT, MutexT, IndexSequenceT>>
 {
-    static const bool IsSparse = true;
-    static const bool IsAdaptive = false;
+    constexpr static TreeRepresentation Representation = TreeRepresentation::Sparse;
 };