[Python] add API for new ContactModel methods

include/multicontact-api/bindings/python/scenario/contact-model.hpp

@@ -9,6 +9,7 @@
 #include "multicontact-api/scenario/contact-model.hpp"
 #include "multicontact-api/bindings/python/serialization/archive.hpp"
 #include "multicontact-api/bindings/python/utils/printable.hpp"
+#include <eigenpy/eigenpy.hpp>
 
 namespace multicontact_api {
 namespace python {
@@ -16,10 +17,10 @@ namespace python {
 namespace bp = boost::python;
 
 template <typename ContactModel>
-struct ContactModelPythonVisitor
-    : public boost::python::def_visitor<ContactModelPythonVisitor<ContactModel> > {
+struct ContactModelPythonVisitor : public boost::python::def_visitor<ContactModelPythonVisitor<ContactModel> > {
   typedef typename ContactModel::Scalar Scalar;
   typedef scenario::ContactType ContactType;
+  typedef typename ContactModel::Matrix3X Matrix3X;
 
   template <class PyClass>
   void visit(PyClass& cl) const {
@@ -29,6 +30,13 @@ struct ContactModelPythonVisitor
         .def(bp::init<ContactModel>(bp::args("other"), "Copy contructor."))
         .def_readwrite("mu", &ContactModel::m_mu, "Friction coefficient.")
         .def_readwrite("contact_type", &ContactModel::m_contact_type, "Enum that define the type of contact.")
+        .add_property("num_contact_points", &getNumContact, &setNumContact,
+                      "The number of contact points used to model this contact. \n"
+                      "Changing this value will clear the contact_points_positions matrix")
+        .add_property("contact_points_positions", &getContactPositions, &setContactPositions,
+                      "3xnum_contact_points matrix defining the contact points positions in the frame of the contact "
+                      "placement. \n"
+                      "num_contact_points is automatically updated to the number of columns of this matrix.")
         .def(bp::self == bp::self)
         .def(bp::self != bp::self)
         .def("copy", &copy, "Returns a copy of *this.");
@@ -40,10 +48,17 @@ struct ContactModelPythonVisitor
         .def(ContactModelPythonVisitor<ContactModel>())
         .def(SerializableVisitor<ContactModel>())
         .def(PrintableVisitor<ContactModel>());
+
+    ENABLE_SPECIFIC_MATRIX_TYPE(Matrix3X);
   }
 
  private:
   static ContactModel copy(const ContactModel& self) { return ContactModel(self); }
+  // define setter and getter
+  static size_t getNumContact(ContactModel& self) { return self.num_contact_points(); }
+  static void setNumContact(ContactModel& self, const size_t num) { self.num_contact_points(num); }
+  static Matrix3X getContactPositions(ContactModel& self) { return self.contact_points_positions(); }
+  static void setContactPositions(ContactModel& self, const Matrix3X& pos) { self.contact_points_positions(pos); }
 };
 }  // namespace python
 }  // namespace multicontact_api