Updated tutorial 404 to use features of newer pybind11 version,

Introduced typedefs

python/modules/py_igl_viewer.cpp

@@ -188,9 +188,15 @@ py::class_<igl::viewer::ViewerCore> viewercore_class(me, "ViewerCore");
     })
 
     .def_readwrite("lighting_factor",&igl::viewer::ViewerCore::lighting_factor)
-
     .def_readwrite("model_zoom",&igl::viewer::ViewerCore::model_zoom)
 
+    .def_property("trackball_angle",
+    [](const igl::viewer::ViewerCore& core) {return Eigen::Quaterniond(core.trackball_angle.cast<double>());},
+    [](igl::viewer::ViewerCore& core, const Eigen::Quaterniond& q)
+    {
+      core.trackball_angle = Eigen::Quaternionf(q.cast<float>());
+    })
+
     .def_property("model_translation",
     [](const igl::viewer::ViewerCore& core) {return Eigen::MatrixXd(core.model_translation.cast<double>());},
     [](igl::viewer::ViewerCore& core, const Eigen::MatrixXd& v)
@@ -316,13 +322,13 @@ py::class_<igl::viewer::ViewerCore> viewercore_class(me, "ViewerCore");
 // UI Enumerations
     py::class_<igl::viewer::Viewer> viewer_class(me, "Viewer");
 
-    #ifdef IGL_VIEWER_WITH_NANOGUI
-    py::object fh = (py::object) py::module::import("nanogui").attr("FormHelper");
-    py::class_<nanogui::FormHelper> form_helper_class(me, "FormHelper", fh);
+//    #ifdef IGL_VIEWER_WITH_NANOGUI
+//    py::object fh = (py::object) py::module::import("nanogui").attr("FormHelper");
+//    py::class_<nanogui::FormHelper> form_helper_class(me, "FormHelper", fh);
 
-    py::object screen = (py::object) py::module::import("nanogui").attr("Screen");
-    py::class_<nanogui::Screen> screen_class(me, "Screen", screen);
-    #endif
+//    py::object screen = (py::object) py::module::import("nanogui").attr("Screen");
+//    py::class_<nanogui::Screen> screen_class(me, "Screen", screen);
+//    #endif
 
     py::enum_<igl::viewer::Viewer::MouseButton>(viewer_class, "MouseButton")
         .value("Left", igl::viewer::Viewer::MouseButton::Left)

python/modules/py_typedefs.cpp

@@ -0,0 +1,12 @@
+py::class_<RotationList>(m, "RotationList")
+    .def(py::init<>())
+    .def("pop_back", &RotationList::pop_back)
+    /* There are multiple versions of push_back(), etc. Select the right ones. */
+    .def("append", (void (RotationList::*)(const Eigen::Quaterniond &)) &RotationList::push_back)
+    .def("back", (Eigen::Quaterniond &(RotationList::*)()) &RotationList::back)
+    .def("__len__", [](const RotationList &v) { return v.size(); })
+    .def("__getitem__", [](const RotationList &v, int b) { return v.at(b); })
+    .def("__setitem__", [](RotationList &v, int b, Eigen::Quaterniond &c) { return v.at(b) = c; })
+    .def("__iter__", [](RotationList &v) {
+       return py::make_iterator(v.begin(), v.end());
+}, py::keep_alive<0, 1>());

python/modules/py_typedefs.h

@@ -0,0 +1,5 @@
+typedef std::vector<Eigen::Quaterniond,Eigen::aligned_allocator<Eigen::Quaterniond> > RotationList;
+PYBIND11_MAKE_OPAQUE(RotationList);
+
+//typedef std::vector<Eigen::Vector3d> TranslationList;
+//PYBIND11_MAKE_OPAQUE(TranslationList);

python/modules/py_vector.cpp

@@ -68,7 +68,7 @@ py::class_<Type> bind_eigen_2(py::module &m, const char *name,
         })
         .def("__init__", [](Type &m, py::buffer b) {
             py::buffer_info info = b.request();
-            if (info.format != py::format_descriptor<Scalar>::value())
+            if (info.format != py::format_descriptor<Scalar>::value)
                 throw std::runtime_error("Incompatible buffer format!");
             if (info.ndim == 1) {
                 new (&m) Type(info.shape[0], 1);
@@ -319,7 +319,7 @@ py::class_<Type> bind_eigen_2(py::module &m, const char *name,
                 m.data(),                /* Pointer to buffer */
                 sizeof(Scalar),          /* Size of one scalar */
                 /* Python struct-style format descriptor */
-                py::format_descriptor<Scalar>::value(),
+                py::format_descriptor<Scalar>::value,
                 2,                       /* Number of dimensions */
                 { (size_t) m.rows(),     /* Buffer dimensions */
                   (size_t) m.cols() },
@@ -735,6 +735,9 @@ void python_export_vector(py::module &m) {
     .def("conjugate",[](Eigen::Quaterniond& q) {
         return q.conjugate();
     })
+    .def("normalize",[](Eigen::Quaterniond& q) {
+        return q.normalize();
+    })
     .def("slerp",[](Eigen::Quaterniond& q, double & t, Eigen::Quaterniond other) {
         return q.slerp(t, other);
     })