change layer names to strings and clean up layer key

include/spark_dsg/dynamic_scene_graph.h

@@ -60,11 +60,29 @@ class DynamicSceneGraph {
   using Layers = std::map<LayerId, SceneGraphLayer::Ptr>;
   //! Dynamic layer container
   using DynamicLayers = std::map<uint32_t, DynamicSceneGraphLayer::Ptr>;
-  //! Callback type
-  using LayerVisitor = std::function<void(LayerKey, BaseLayer*)>;
 
   friend class SceneGraphLogger;
 
+  struct LayerKey {
+    std::optional<LayerId> layer;
+    uint32_t prefix = 0;
+    bool dynamic = false;
+
+    LayerKey() = default;
+    LayerKey(LayerId layer_id);
+    LayerKey(LayerId layer_id, uint32_t prefix);
+    bool isParent(const LayerKey& other) const;
+    bool isValid() const { return layer.has_value(); }
+    operator bool() const { return isValid(); }
+    bool operator==(const LayerKey& other) const;
+    inline bool operator!=(const LayerKey& other) const {
+      return !this->operator==(other);
+    }
+  };
+
+  //! Callback type
+  using LayerVisitor = std::function<void(LayerKey, BaseLayer*)>;
+
   /**
    * @brief Construct the scene graph (with a default layer factory)
    */
@@ -360,13 +378,6 @@ class DynamicSceneGraph {
    */
   bool removeEdge(NodeId source, NodeId target);
 
-  /**
-   * @brief check if a particular node id is a dynamic node
-   * @param source Node to check
-   * @returns Return true if the node is a dynamic node
-   */
-  bool isDynamic(NodeId source) const;
-
   /**
    * @brief Get the number of layers in the graph
    * @return number of layers in the graph
@@ -528,7 +539,7 @@ class DynamicSceneGraph {
   std::shared_ptr<Mesh> mesh() const;
 
   //! Current static layer ids in the graph
-  const LayerIds layer_ids;
+  const LayerIds& layer_ids() const;
 
   //! Any extra information about the graph
   nlohmann::json metadata;
@@ -574,6 +585,7 @@ class DynamicSceneGraph {
   void visitLayers(const LayerVisitor& cb);
 
  protected:
+  LayerIds layer_ids_;
   Layers layers_;
   std::map<LayerId, DynamicLayers> dynamic_layers_;
 
@@ -632,4 +644,6 @@ class DynamicSceneGraph {
  */
 DynamicSceneGraph::LayerIds getDefaultLayerIds();
 
+std::ostream& operator<<(std::ostream& out, const DynamicSceneGraph::LayerKey& key);
+
 }  // namespace spark_dsg

include/spark_dsg/layer_prefix.h

@@ -42,30 +42,6 @@
  */
 namespace spark_dsg {
 
-struct LayerKey {
-  LayerId layer;
-  uint32_t prefix = 0;
-  bool dynamic = false;
-
-  LayerKey();
-
-  LayerKey(LayerId layer_id);
-
-  LayerKey(LayerId layer_id, uint32_t prefix);
-
-  bool isParent(const LayerKey& other) const;
-
-  bool valid() const;
-
-  bool operator==(const LayerKey& other) const;
-
-  inline bool operator!=(const LayerKey& other) const {
-    return !this->operator==(other);
-  }
-};
-
-std::ostream& operator<<(std::ostream& out, const LayerKey& key);
-
 class LayerPrefix {
  public:
   LayerPrefix(char key);
@@ -100,6 +76,4 @@ class LayerPrefix {
   } value_;
 };
 
-std::ostream& operator<<(std::ostream& out, const LayerKey& key);
-
 }  // namespace spark_dsg

include/spark_dsg/scene_graph_types.h

@@ -59,19 +59,20 @@ struct EdgeKey {
  * @note A higher layer id corresponds to parents for interlayer edges
  */
 struct DsgLayers {
-  inline const static LayerId SEGMENTS = 1;  //< Pre-Object node layer (static)
-  inline const static LayerId OBJECTS = 2;   //< Object node layer (static)
-  inline const static LayerId AGENTS = 2;    //< Agents layer (dynamic)
-  inline const static LayerId PLACES = 3;  //< Places node layer (as well as structure)
-  inline const static LayerId STRUCTURE = 3;  //< Struct node layer (as well as places)
-  inline const static LayerId ROOMS = 4;      //< Room node layer
-  inline const static LayerId BUILDINGS = 5;  //< Building node layer
-  inline const static LayerId MESH_PLACES = 20;  //< Mesh (2D) Places node layer
-  inline const static LayerId UNKNOWN =
-      std::numeric_limits<LayerId>::max();  //< Catchall layer ID
-
-  static std::string LayerIdToString(LayerId id);
-  static LayerId StringToLayerId(const std::string& id_str);
+  //< Pre-Object node layer (static)
+  inline const static std::string SEGMENTS = "SEGMENTS";
+  //< Object node layer (static)
+  inline const static std::string OBJECTS = "OBJECTS";
+  //< Agents layer (dynamic)
+  inline const static std::string AGENTS = "AGENTS";
+  //< Places node layer
+  inline const static std::string PLACES = "PLACES";
+  //  //< Mesh (2D) Places node layer
+  inline const static std::string MESH_PLACES = "MESH_PLACES";
+  //< Room node layer
+  inline const static std::string ROOMS = "ROOMS";
+  //< Building node layer
+  inline const static std::string BUILDINGS = "BUILDINGS";
 };
 
 namespace graph_utilities {

include/spark_dsg/scene_graph_utilities.h

@@ -34,22 +34,21 @@
  * -------------------------------------------------------------------------- */
 #pragma once
 #include "spark_dsg/bounding_box.h"
-#include "spark_dsg/layer_prefix.h"
+#include "spark_dsg/scene_graph_types.h"
 #include "spark_dsg/spark_dsg_fwd.h"
 
 namespace spark_dsg {
 
-using SgNodeCallback = std::function<void(const DynamicSceneGraph&, const NodeId)>;
-
-void getAncestorsOfLayer(const DynamicSceneGraph& graph,
-                         NodeId parent,
-                         LayerKey child_layer,
-                         const SgNodeCallback& callback);
+void getNodeAncestorsAtDepth(
+    const DynamicSceneGraph& graph,
+    NodeId parent,
+    size_t depth,
+    const std::function<void(const DynamicSceneGraph&, const NodeId)>& callback);
 
 BoundingBox computeAncestorBoundingBox(
     const DynamicSceneGraph& graph,
     NodeId parent,
-    LayerId child_layer = DsgLayers::PLACES,
+    size_t depth = 1,
     BoundingBox::Type bbox_type = BoundingBox::Type::AABB);
 
 }  // namespace spark_dsg

python/bindings/src/spark_dsg_bindings.cpp

@@ -122,7 +122,6 @@ PYBIND11_MODULE(_dsg_bindings, module) {
       .def_readonly_static("AGENTS", &DsgLayers::AGENTS)
       .def_readonly_static("PLACES", &DsgLayers::PLACES)
       .def_readonly_static("MESH_PLACES", &DsgLayers::MESH_PLACES)
-      .def_readonly_static("STRUCTURE", &DsgLayers::STRUCTURE)
       .def_readonly_static("ROOMS", &DsgLayers::ROOMS)
       .def_readonly_static("BUILDINGS", &DsgLayers::BUILDINGS);
 
@@ -769,7 +768,6 @@ PYBIND11_MODULE(_dsg_bindings, module) {
            [](DynamicSceneGraph& graph, NodeSymbol source, NodeSymbol target) -> bool {
              return graph.removeEdge(source, target);
            })
-      .def("is_dynamic", &DynamicSceneGraph::isDynamic)
       .def("num_layers", &DynamicSceneGraph::numLayers)
       .def("num_dynamic_layers_of_type", &DynamicSceneGraph::numDynamicLayersOfType)
       .def("num_dynamic_layers", &DynamicSceneGraph::numDynamicLayers)