chore: bvh draft

src/mesh_bvh.cpp

+#include "mesh_bvh.hpp"
+
+#include "pmp/algorithms/differential_geometry.h"
+
+
+
+
+MeshBVH::MeshBVH(pmp::SurfaceMesh &mesh) : target_mesh(mesh)
+{
+	// Compute face centroids
+	auto fcentroid = mesh.face_property<pmp::Point>("f:centroid");
+    for (auto &&f : mesh.faces())
+        fcentroid[f] = pmp::centroid(mesh, f);
+	
+	auto vertex_positions = mesh.get_vertex_property<pmp::Point>("v:point");
+	std::vector<pmp::Face> faces(mesh.faces_begin(), mesh.faces_end());
+	
+	pmp::BoundingBox bbox;
+
+	for (auto const &face : faces)
+	{
+		for (auto const &&vertex : mesh.vertices(face))
+		{
+			bbox += vertex_positions[vertex];
+		}
+	}
+
+	pmp::Point const bbox_span = bbox.max() - bbox.min();
+	auto const axes = {bbox_span[0], bbox_span[1], bbox_span[2]};
+
+	size_t axis = std::distance(axes.begin(),
+								std::max_element(axes.begin(), axes.end()));
+
+	std::sort(faces.begin(), faces.end(),
+			  [&](auto f1, auto f2)
+			  {
+				  return pmp::centroid(mesh, f1)[axis] > pmp::centroid(mesh, f2)[axis];
+			  });
+
+	_root._bounds = bbox;
+}
\ No newline at end of file

src/mesh_bvh.hpp

+#pragma once
+
+#include <memory>
+#include <vector>
+
+#include "pmp/surface_mesh.h"
+#include "pmp/algorithms/utilities.h"
+
+
+class MeshBVH
+{
+private:
+	struct Node
+	{
+	private:
+		pmp::BoundingBox _bounds;
+		std::unique_ptr<Node> _left, _right;
+		std::vector<pmp::Face> _items;
+
+	public:
+		inline bool is_leaf()
+		{
+			return _left == nullptr && _right == nullptr;
+		}
+	
+	friend MeshBVH;
+	};
+
+	Node _root;
+	pmp::SurfaceMesh const &_target_mesh;
+
+public:
+	MeshBVH() = delete;
+	MeshBVH(pmp::SurfaceMesh &mesh);
+
+	pmp::Face get_closest_face(pmp::Point point);
+
+private:
+	template<typename Iterator>
+	std::unique_ptr<Node> split(Iterator first, Iterator last);
+
+};