Migrate Python bindings from SWIG to nanobind

rpt/interface.hpp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <cstdint>
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -7,7 +9,41 @@
 
 // =================================================================================================
 
-// Forward declaration of the class, that swig does not try to parse all its dependencies.
+using RaggedPoses2D = std::vector<std::vector<std::vector<std::array<float, 3>>>>;
+using NestedPoses3D = std::vector<std::vector<std::array<float, 4>>>;
+
+// =================================================================================================
+
+struct PoseBatch2D
+{
+    std::vector<float> data;
+    std::vector<uint32_t> person_counts;
+    size_t num_views = 0;
+    size_t max_persons = 0;
+    size_t num_joints = 0;
+
+    float &at(size_t view, size_t person, size_t joint, size_t coord);
+    const float &at(size_t view, size_t person, size_t joint, size_t coord) const;
+
+    RaggedPoses2D to_nested() const;
+    static PoseBatch2D from_nested(const RaggedPoses2D &poses_2d);
+};
+
+struct PoseBatch3D
+{
+    std::vector<float> data;
+    size_t num_persons = 0;
+    size_t num_joints = 0;
+
+    float &at(size_t person, size_t joint, size_t coord);
+    const float &at(size_t person, size_t joint, size_t coord) const;
+
+    NestedPoses3D to_nested() const;
+    static PoseBatch3D from_nested(const NestedPoses3D &poses_3d);
+};
+
+// =================================================================================================
+
 class TriangulatorInternal;
 
 // =================================================================================================
@@ -18,7 +54,6 @@ public:
     /**
      * Triangulator to predict poses from multiple views.
      *
-     *
      * @param min_match_score Minimum score to consider a triangulated joint as valid.
      * @param min_group_size Minimum number of camera pairs that need to see a person.
      */
@@ -26,19 +61,29 @@ public:
         float min_match_score = 0.95,
         size_t min_group_size = 1);
 
+    ~Triangulator();
+
     /**
-     * Calculate a triangulation.
+     * Calculate a triangulation using a padded pose tensor.
      *
-     *
-     * @param poses_2d List of shape [views, persons, joints, 3], containing the 2D poses.
+     * @param poses_2d Padded poses of shape [views, max_persons, joints, 3].
      * @param cameras List of cameras.
      * @param roomparams Room parameters (room size, room center).
      * @param joint_names List of 2D joint names.
      *
-     * @return List of shape [persons, joints, 4], containing the 3D poses.
+     * @return Pose tensor of shape [persons, joints, 4].
      */
-    std::vector<std::vector<std::array<float, 4>>> triangulate_poses(
-        const std::vector<std::vector<std::vector<std::array<float, 3>>>> &poses_2d,
+    PoseBatch3D triangulate_poses(
+        const PoseBatch2D &poses_2d,
+        const std::vector<Camera> &cameras,
+        const std::array<std::array<float, 3>, 2> &roomparams,
+        const std::vector<std::string> &joint_names);
+
+    /**
+     * Compatibility overload for callers that still produce ragged nested vectors.
+     */
+    NestedPoses3D triangulate_poses(
+        const RaggedPoses2D &poses_2d,
         const std::vector<Camera> &cameras,
         const std::array<std::array<float, 3>, 2> &roomparams,
         const std::vector<std::string> &joint_names);
@@ -50,5 +95,5 @@ public:
     void print_stats();
 
 private:
-    TriangulatorInternal *triangulator;
+    std::unique_ptr<TriangulatorInternal> triangulator;
 };