Add parameter container to python bindings

Author: RainerKuemmerle

python/core/py_core.cpp

@@ -37,6 +37,7 @@ void declareCore(py::module& m) {
 
   declareEigenTypes(m);
   declareParameter(m);
+  declareParameterContainer(m);
   declareG2OBatchStatistics(m);
 
   declareJacobianWorkspace(m);

python/core/py_optimizable_graph.cpp

@@ -10,6 +10,7 @@
 #include "g2o/core/robust_kernel.h"  // IWYU pragma: keep
 
 namespace g2o {
+class ParameterContainer;
 
 void declareOptimizableGraph(py::module& m) {
   using CLS = OptimizableGraph;
@@ -235,6 +236,10 @@ void declareOptimizableGraph(py::module& m) {
           py::keep_alive<1, 2>());  // Parameter* -> bool
   cls.def("parameter", &CLS::parameter,
           "id"_a);  // int -> Parameter*
+  cls.def(
+      "parameters",
+      [](CLS& self) -> ParameterContainer& { return self.parameters(); },
+      py::return_value_policy::reference_internal);
 
   cls.def("verify_information_matrices", &CLS::verifyInformationMatrices,
           "verbose"_a = false);  // bool -> bool

python/core/py_parameter.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <g2o/core/parameter.h>
+#include <g2o/core/parameter_container.h>
 
 #include "g2opy.h"
 
@@ -14,4 +15,18 @@ inline void declareParameter(py::module& m) {
       .def("element_type", &Parameter::elementType);
 }
 
+inline void declareParameterContainer(py::module& m) {
+  py::classh<ParameterContainer>(m, "ParameterContainer")
+      .def(py::init<>())
+      .def("add_parameter", &ParameterContainer::addParameter, "parameter"_a,
+           py::keep_alive<1, 2>())
+      .def("get_parameter", &ParameterContainer::getParameter, "id"_a)
+      .def("detach_parameter", &ParameterContainer::detachParameter, "id"_a)
+      .def("clear", &ParameterContainer::clear)
+      .def("size", &ParameterContainer::size)
+      .def("__len__", [](const ParameterContainer& self) {
+        return static_cast<py::ssize_t>(self.size());
+      });
+}
+
 }  // end namespace g2o

python/tests/test_core.py

@@ -75,6 +75,30 @@ def test_connected_components(self, simple_se2_graph):
         assert simple_se2_graph.num_connected_components(1) == 2
 
 
+class TestParameterContainer:
+    """Tests for OptimizableGraph parameter container access."""
+
+    def test_optimizer_parameters(self):
+        optimizer = g2o.SparseOptimizer()
+        parameters = optimizer.parameters()
+        assert len(parameters) == 0
+
+        camera_parameters = g2o.CameraParameters(1.0, [0.0, 0.0], 0.0)
+        camera_parameters.set_id(42)
+
+        assert optimizer.add_parameter(camera_parameters)
+        assert len(parameters) == 1
+
+        parameter = parameters.get_parameter(42)
+        assert parameter is not None
+        assert parameter.id() == 42
+
+        detached = parameters.detach_parameter(42)
+        assert detached is not None
+        assert detached.id() == 42
+        assert len(parameters) == 0
+
+
 class TestBlockSolvers:
     """Test BlockSolver configurations."""