serialization: add computeMemoryFootprint

This function is useful when performing binary serialization (size of the allocated buffer)

CMakeLists.txt

@@ -181,8 +181,9 @@ SET(${PROJECT_NAME}_HEADERS
   include/hpp/fcl/serialization/BVH_model.h
   include/hpp/fcl/serialization/collision_data.h
   include/hpp/fcl/serialization/collision_object.h
-  include/hpp/fcl/serialization/geometric_shapes.h
   include/hpp/fcl/serialization/eigen.h
+  include/hpp/fcl/serialization/geometric_shapes.h
+  include/hpp/fcl/serialization/memory.h
   include/hpp/fcl/serialization/OBB.h
   include/hpp/fcl/serialization/RSS.h
   include/hpp/fcl/serialization/OBBRSS.h

include/hpp/fcl/serialization/BVH_model.h

@@ -11,6 +11,7 @@
 #include "hpp/fcl/serialization/BV_node.h"
 #include "hpp/fcl/serialization/BV_splitter.h"
 #include "hpp/fcl/serialization/collision_object.h"
+#include "hpp/fcl/serialization/memory.h"
 
 namespace boost
 {
@@ -314,4 +315,22 @@ namespace boost
   }
 }
 
+namespace hpp {
+namespace fcl {
+
+namespace internal
+{
+  template<typename BV>
+  struct memory_footprint_evaluator< ::hpp::fcl::BVHModel<BV> >
+  {
+    static size_t run(const ::hpp::fcl::BVHModel<BV> & bvh_model)
+    {
+      return static_cast<size_t>(bvh_model.memUsage(false));
+    }
+  };
+}
+
+} // namespace fcl
+} // namespace hpp
+
 #endif // ifndef HPP_FCL_SERIALIZATION_BVH_MODEL_H

include/hpp/fcl/serialization/memory.h

+//
+// Copyright (c) 2021 INRIA
+//
+
+#ifndef HPP_FCL_SERIALIZATION_MEMORY_H
+#define HPP_FCL_SERIALIZATION_MEMORY_H
+
+namespace hpp {
+namespace fcl {
+
+namespace internal
+{
+  template<typename T>
+  struct memory_footprint_evaluator
+  {
+    static size_t run(const T &) { return sizeof(T); }
+  };
+}
+
+  /// \brief Returns the memory footpring of the input object.
+  /// For POD objects, this function returns the result of sizeof(T)
+  ///
+  /// \param[in] object whose memory footprint needs to be evaluated.
+  ///
+  /// \return the memory footprint of the input object.
+  template<typename T>
+  size_t computeMemoryFootprint(const T & object)
+  {
+    return internal::memory_footprint_evaluator<T>::run(object);
+  }
+
+} // namespace fcl
+} // namespace hpp
+
+#endif // ifndef HPP_FCL_SERIALIZATION_MEMORY_H

test/serialization.cpp

@@ -46,6 +46,7 @@
 #include <hpp/fcl/serialization/AABB.h>
 #include <hpp/fcl/serialization/BVH_model.h>
 #include <hpp/fcl/serialization/geometric_shapes.h>
+#include <hpp/fcl/serialization/memory.h>
 
 #include "utility.h"
 #include "fcl_resources/config.h"
@@ -287,3 +288,25 @@ BOOST_AUTO_TEST_CASE(test_shapes)
     test_serialization(plane,plane_copy);
   }
 }
+
+BOOST_AUTO_TEST_CASE(test_memory_footprint)
+{
+  Sphere sphere(1.);
+  BOOST_CHECK(sizeof(Sphere) == computeMemoryFootprint(sphere));
+  
+  std::vector<Vec3f> p1;
+  std::vector<Triangle> t1;
+  boost::filesystem::path path(TEST_RESOURCES_DIR);
+  
+  loadOBJFile((path / "env.obj").string().c_str(), p1, t1);
+
+  BVHModel<OBBRSS> m1;
+
+  m1.beginModel();
+  m1.addSubModel(p1, t1);
+  m1.endModel();
+  
+  std::cout << "computeMemoryFootprint(m1): " << computeMemoryFootprint(m1) << std::endl;
+  BOOST_CHECK(sizeof(BVHModel<OBBRSS>) < computeMemoryFootprint(m1));
+  BOOST_CHECK(m1.memUsage(false) == computeMemoryFootprint(m1));
+}