#include <QApplication>
#include <QMainWindow>
#include <QTime>
#include <QAction>
#include <QObject>
#include <QDockWidget>

#include "SMesh_type.h"
#include "Scene.h"
#include "Scene_surface_mesh_item.h"
#include "Scene_polygon_soup_item.h"
#include "Scene_polylines_item.h"
#include "Messages_interface.h"

#include <CGAL/Three/Scene_group_item.h>
#include <CGAL/Three/Polyhedron_demo_plugin_helper.h>
#include <CGAL/Three/Polyhedron_demo_plugin_interface.h>
#include <CGAL/Three/Three.h>
#include <CGAL/convex_hull_2.h>

#include <map>
#include <vector>
#include <cstdlib>
#include <ctime>

#include "ui_Surface_mesh_approximation_dockwidget.h"
#include "VSA_wrapper.h"

using namespace CGAL::Three;

class Polyhedron_demo_surface_mesh_approximation_plugin :
  public QObject,
  public Polyhedron_demo_plugin_helper
{
  Q_OBJECT
  Q_INTERFACES(CGAL::Three::Polyhedron_demo_plugin_interface)
  Q_PLUGIN_METADATA(IID "com.geometryfactory.PolyhedronDemo.PluginInterface/1.0")

  typedef boost::property_map<SMesh, CGAL::face_patch_id_t<int> >::type Face_id_map;
  struct Patch_id_pmap : public boost::put_get_helper<std::size_t, Patch_id_pmap>
  {
  public:
    typedef boost::read_write_property_map_tag category;
    typedef std::size_t value_type;
    typedef int& reference;
    typedef face_descriptor key_type;

    Patch_id_pmap(Face_id_map fid_map): m_fid_map(fid_map) {}

    friend void put(Patch_id_pmap pmap, key_type f, value_type id) {
      put(pmap.m_fid_map, f, int(id));
    }

    friend reference get(Patch_id_pmap pmap, key_type f) {
      return get(pmap.m_fid_map, f);
    }

    Face_id_map m_fid_map;
  };

  typedef VSA_wrapper::Indexed_triangle Indexed_triangle;
  typedef std::map<Scene_surface_mesh_item *, VSA_wrapper *> SM_wrapper_map;
  typedef std::pair<Scene_surface_mesh_item *, VSA_wrapper *> SM_wrapper_pair;

public:
  Polyhedron_demo_surface_mesh_approximation_plugin() {
    std::srand(time(0));
  }

  void init(QMainWindow *main_window,
    Scene_interface *scene_interface,
    Messages_interface *message_interface) {
    mw = main_window;
    scene = scene_interface;
    mi = message_interface;

    actionSurfaceMeshApproximation = new QAction("Surface Mesh Approximation", mw);
    actionSurfaceMeshApproximation->setProperty("subMenuName", "Triangulated Surface Mesh Approximation");
    connect(actionSurfaceMeshApproximation, SIGNAL(triggered()), this, SLOT(on_actionSurfaceMeshApproximation_triggered()));

    dock_widget = new QDockWidget("Mesh approximation parameters", mw);
    dock_widget->setVisible(false);
    ui_widget.setupUi(dock_widget);
    mw->addDockWidget(Qt::LeftDockWidgetArea, dock_widget);

    // connect ui actions
    connect(ui_widget.comboMetric, SIGNAL(currentIndexChanged(int)), this, SLOT(on_comboMetric_currentIndexChanged(const int)));
    connect(ui_widget.buttonSeeding, SIGNAL(clicked()), this, SLOT(on_buttonSeeding_clicked()));
    connect(ui_widget.buttonAdd, SIGNAL(clicked()), this, SLOT(on_buttonAdd_clicked()));
    connect(ui_widget.buttonFit, SIGNAL(clicked()), this, SLOT(on_buttonFit_clicked()));
    connect(ui_widget.buttonMeshing, SIGNAL(clicked()), this, SLOT(on_buttonMeshing_clicked()));
    connect(ui_widget.buttonTeleport, SIGNAL(clicked()), this, SLOT(on_buttonTeleport_clicked()));
    connect(ui_widget.buttonSplit, SIGNAL(clicked()), this, SLOT(on_buttonSplit_clicked()));
    // scene item delete action
    if (Scene *scene = dynamic_cast<Scene *>(scene_interface))
      connect(scene, SIGNAL(itemAboutToBeDestroyed(CGAL::Three::Scene_item *)),
        this, SLOT(itemAboutToBeDestroyed(CGAL::Three::Scene_item *)));
  }

  void closure() {
    dock_widget->hide();
  }

  QList<QAction *> actions() const {
    return QList<QAction*>() << actionSurfaceMeshApproximation;
  }

  bool applicable(QAction *) const {
    return qobject_cast<Scene_surface_mesh_item *>(scene->item(scene->mainSelectionIndex()));
  }

  void update_seeds_item(VSA_wrapper &approx, SMesh *pmesh) {
    Scene_polylines_item *seeds_item = approx.visual_items().seeds;
    seeds_item->polylines.clear();
    std::vector<face_descriptor> seeds;
    approx.proxy_seeds(std::back_inserter(seeds));
    BOOST_FOREACH(face_descriptor f, seeds) {
      const halfedge_descriptor h = halfedge(f, *pmesh);
      const Point_3 center = CGAL::centroid(
        pmesh->point(source(h, *pmesh)),
        pmesh->point(target(h, *pmesh)),
        pmesh->point(target(next(h, *pmesh), *pmesh)));
      const EPICK::Vector_3 normal = CGAL::unit_normal(
        pmesh->point(source(h, *pmesh)),
        pmesh->point(target(h, *pmesh)),
        pmesh->point(target(next(h, *pmesh), *pmesh)));
      std::vector<Point_3> polyline;
      polyline.push_back(center);
      polyline.push_back(center + normal);
      seeds_item->polylines.push_back(polyline);
    }
    seeds_item->invalidateOpenGLBuffers();
  }

  template <typename NamedParameters>
  void update_meshing_items(VSA_wrapper &approx, SMesh *pmesh, const NamedParameters &np) {
    approx.extract_mesh(np);

    std::vector<Point_3> anchor_points;
    std::vector<Indexed_triangle> indexed_triangles;
    std::vector<vertex_descriptor> anchor_vertices;
    std::vector<std::vector<std::size_t> > patch_polygons;

    Patch_id_pmap pidmap(get(CGAL::face_patch_id_t<int>(), *pmesh));
    approx.output(CGAL::parameters::face_proxy_map(pidmap)
      .anchors(std::back_inserter(anchor_points))
      .triangles(std::back_inserter(indexed_triangles)));
    approx.anchor_vertices(std::back_inserter(anchor_vertices));
    approx.indexed_boundary_polygons(std::back_inserter(patch_polygons));

    // update triangles item
    std::vector<std::vector<std::size_t> > polygons;
    BOOST_FOREACH(const Indexed_triangle &t, indexed_triangles) {
      std::vector<std::size_t> polygon;
      polygon.push_back(t[0]);
      polygon.push_back(t[1]);
      polygon.push_back(t[2]);
      polygons.push_back(polygon);
    }
    approx.visual_items().triangles->load(anchor_points, polygons);

    // update border polygons item
    approx.visual_items().polygons->polylines.clear();
    BOOST_FOREACH(const std::vector<std::size_t> &border, patch_polygons) {
      std::vector<Point_3> polyline;
      for (std::size_t i = 0; i <= border.size(); ++i)
        polyline.push_back(anchor_points[border[i % border.size()]]);
      approx.visual_items().polygons->polylines.push_back(polyline);
    }
    approx.visual_items().polygons->invalidateOpenGLBuffers();

    // update anchors item
    approx.visual_items().anchors->polylines.clear();
    for (std::size_t i = 0; i < anchor_vertices.size(); ++i) {
      std::vector<Point_3> polyline;
      polyline.push_back(pmesh->point(anchor_vertices[i]));
      polyline.push_back(anchor_points[i]);
      approx.visual_items().anchors->polylines.push_back(polyline);
    }
    approx.visual_items().anchors->invalidateOpenGLBuffers();

    // update patch planes item
    std::vector<std::vector<EPICK::Triangle_3> > patch_triangles(approx.number_of_proxies());
    BOOST_FOREACH(face_descriptor f, faces(*pmesh)) {
      halfedge_descriptor h = halfedge(f, *pmesh);
      patch_triangles[get(pidmap, f)].push_back(EPICK::Triangle_3(
        pmesh->point(source(h, *pmesh)),
        pmesh->point(target(h, *pmesh)),
        pmesh->point(target(next(h, *pmesh), *pmesh))));
    }
    std::vector<EPICK::Plane_3> patch_planes;
    BOOST_FOREACH(const std::vector<EPICK::Triangle_3> &tris, patch_triangles) {
      EPICK::Plane_3 fit_plane;
      CGAL::linear_least_squares_fitting_3(
        tris.begin(), tris.end(), fit_plane, CGAL::Dimension_tag<2>());
      if (!(boost::math::isfinite)(fit_plane.a()) ||
        !(boost::math::isfinite)(fit_plane.b()) ||
        !(boost::math::isfinite)(fit_plane.c()) ||
        !(boost::math::isfinite)(fit_plane.d())) {
        // PCA may return plane with NaN efficients
        // we replace it with an inaccurate plane
        std::cout << "WARNING: Replacing invalide plane." << std::endl;
        fit_plane = EPICK::Plane_3(
          tris.front().vertex(0),
          EPICK::Vector_3(0.0, 0.0, 1.0));
      }
      patch_planes.push_back(fit_plane);
    }

    std::vector<std::vector<Point_3> > patch_points(approx.number_of_proxies());
    BOOST_FOREACH(vertex_descriptor v, vertices(*pmesh)) {
      BOOST_FOREACH(halfedge_descriptor h, CGAL::halfedges_around_target(v, *pmesh)) {
        if (!CGAL::is_border(h, *pmesh)) {
          const std::size_t fidx = get(pidmap, face(h, *pmesh));
          patch_points[fidx].push_back(pmesh->point(v));
        }
      }
    }
    std::vector<Point_3> cvx_hull_points;
    std::vector<std::vector<std::size_t> > cvx_hulls;
    for (std::size_t i = 0; i < approx.number_of_proxies(); ++i) {
      const std::vector<Point_3> &pts = patch_points[i];
      const EPICK::Plane_3 plane = patch_planes[i];
      const Point_3 origin = plane.projection(pts.front());

      EPICK::Vector_3 base1 = plane.base1();
      EPICK::Vector_3 base2 = plane.base2();
      base1 = base1 / CGAL::sqrt(base1.squared_length());
      base2 = base2 / CGAL::sqrt(base2.squared_length());

      EPICK::Line_3 base_linex(origin, base1);
      EPICK::Line_3 base_liney(origin, base2);

      std::vector<EPICK::Point_2> pts_2d;
      BOOST_FOREACH(const Point_3 &p, pts) {
        const Point_3 point = plane.projection(p);
        EPICK::Vector_3 vecx(origin, base_linex.projection(point));
        EPICK::Vector_3 vecy(origin, base_liney.projection(point));
        double x = CGAL::sqrt(vecx.squared_length());
        double y = CGAL::sqrt(vecy.squared_length());
        x = vecx * base1 < 0 ? -x : x;
        y = vecy * base2 < 0 ? -y : y;
        pts_2d.push_back(EPICK::Point_2(x, y));
      }

      std::vector<EPICK::Point_2> cvx_hull_2d;
      CGAL::convex_hull_2(pts_2d.begin(), pts_2d.end(), std::back_inserter(cvx_hull_2d));

      cvx_hulls.push_back(std::vector<std::size_t>());
      BOOST_FOREACH(const EPICK::Point_2 &p, cvx_hull_2d) {
        cvx_hulls.back().push_back(cvx_hull_points.size());
        cvx_hull_points.push_back(origin + p.x() * base1 + p.y() * base2);
      }
    }
    std::vector<CGAL::Color> fcolors;
    BOOST_FOREACH(const QColor &c, approx.proxy_colors())
      fcolors.push_back(CGAL::Color(c.red(), c.green(), c.blue()));
    approx.visual_items().planes->load(cvx_hull_points, cvx_hulls, fcolors, std::vector<CGAL::Color>());
  }

public Q_SLOTS:
  void on_actionSurfaceMeshApproximation_triggered();
  void on_buttonSeeding_clicked();
  void on_buttonFit_clicked();
  void on_buttonAdd_clicked();
  void on_buttonTeleport_clicked();
  void on_buttonSplit_clicked();
  void on_buttonMeshing_clicked();
  void on_comboMetric_currentIndexChanged(const int);
  void itemAboutToBeDestroyed(CGAL::Three::Scene_item *);

private:
  QAction *actionSurfaceMeshApproximation;
  Ui::Surface_mesh_approximation ui_widget;
  QDockWidget *dock_widget;

  QMainWindow *mw;
  Scene_interface *scene;
  Messages_interface *mi;

  SM_wrapper_map m_sm_wrapper_map;
}; // end Polyhedron_demo_surface_mesh_approximation_plugin

void Polyhedron_demo_surface_mesh_approximation_plugin::on_actionSurfaceMeshApproximation_triggered()
{ dock_widget->show(); }

void Polyhedron_demo_surface_mesh_approximation_plugin::on_buttonSeeding_clicked() {
  const Scene_interface::Item_id sm_id = scene->mainSelectionIndex();
  Scene_surface_mesh_item *sm_item = qobject_cast<Scene_surface_mesh_item *>(
    scene->item(sm_id));
  if (!sm_item) {
    CGAL::Three::Three::information(QString("No surface mesh item selected."));
    return;
  }

  QApplication::setOverrideCursor(Qt::WaitCursor);

  SMesh *pmesh = sm_item->face_graph();
  SM_wrapper_map::iterator search = m_sm_wrapper_map.find(sm_item);
  if (search == m_sm_wrapper_map.end())
    search = m_sm_wrapper_map.insert(SM_wrapper_pair(sm_item, new VSA_wrapper(*pmesh))).first;
  VSA_wrapper &approx = *search->second;
  approx.set_metric(static_cast<VSA_wrapper::Metric>(
    ui_widget.comboMetric->currentIndex()));

  QTime time;
  time.start();
  approx.initialize_seeds(CGAL::parameters::seeding_method(
    static_cast<VSA::Seeding_method>(ui_widget.comboMethod->currentIndex()))
    .max_number_of_proxies(ui_widget.nb_proxies->value())
    .min_error_drop(
      ui_widget.enable_error_drop->isChecked() ? ui_widget.error_drop->value() : -1.0)
    .number_of_relaxations(ui_widget.nb_relaxations->value()));
  approx.run(ui_widget.nb_iterations->value());

  Patch_id_pmap pidmap(get(CGAL::face_patch_id_t<int>(), *sm_item->face_graph()));
  approx.output(CGAL::parameters::face_proxy_map(pidmap));

  // new group items
  // leave the memory management to the scene
  Scene_group_item *group = new Scene_group_item(tr("Approximation of %1").arg(sm_item->name()));
  scene->addItem(group);

  Scene_polylines_item *seeds_item = new Scene_polylines_item();
  seeds_item->setName(tr("Seeds"));
  seeds_item->setColor(Qt::red);
  scene->addItem(seeds_item);
  scene->changeGroup(seeds_item, group);

  approx.visual_items().group = group;
  approx.visual_items().seeds = seeds_item;
  approx.visual_items().has_meshing_items = false;
  approx.visual_items().triangles = NULL;
  approx.visual_items().polygons = NULL;
  approx.visual_items().anchors = NULL;
  approx.visual_items().planes = NULL;

  update_seeds_item(approx, pmesh);

  CGAL::Three::Three::information(QString("Done, #proxies = %1. (%2 ms)").arg(
    approx.number_of_proxies()).arg(time.elapsed()));
  sm_item->color_vector() = approx.proxy_colors();
  sm_item->setItemIsMulticolor(true);
  sm_item->computeItemColorVectorAutomatically(false);
  sm_item->setRenderingMode(Flat);
  sm_item->invalidateOpenGLBuffers();
  scene->itemChanged(scene->item_id(sm_item));

  // default non auto-meshing
  ui_widget.checkAutomatic->setChecked(false);

  scene->setSelectedItem(sm_id);

  QApplication::restoreOverrideCursor();
}

void Polyhedron_demo_surface_mesh_approximation_plugin::on_buttonFit_clicked() {
  Scene_surface_mesh_item *sm_item = qobject_cast<Scene_surface_mesh_item *>(
    scene->item(scene->mainSelectionIndex()));
  if (!sm_item) {
    CGAL::Three::Three::information(QString("No surface mesh item selected."));
    return;
  }
  SM_wrapper_map::iterator search = m_sm_wrapper_map.find(sm_item);
  if (search == m_sm_wrapper_map.end() || !search->second->initialized()) {
    CGAL::Three::Three::information(QString("Please initialize seeds first."));
    return;
  }
  SMesh *pmesh = search->first->face_graph();
  VSA_wrapper &approx = *search->second;

  QApplication::setOverrideCursor(Qt::WaitCursor);

  approx.run(1);
  Patch_id_pmap pidmap(get(CGAL::face_patch_id_t<int>(), *pmesh));
  approx.output(CGAL::parameters::face_proxy_map(pidmap));
  update_seeds_item(approx, pmesh);

  CGAL::Three::Three::information(QString("Fit one iteration, #proxies = %1.").arg(approx.number_of_proxies()));

  sm_item->color_vector() = approx.proxy_colors();
  sm_item->setItemIsMulticolor(true);
  sm_item->computeItemColorVectorAutomatically(false);
  sm_item->invalidateOpenGLBuffers();
  scene->itemChanged(scene->item_id(sm_item));

  if (ui_widget.checkAutomatic->isChecked()) {
    if (!approx.visual_items().has_meshing_items) {
      CGAL::Three::Three::information(QString("Please mesh before checking auto meshing."));
      QApplication::restoreOverrideCursor();
      return;
    }
    update_meshing_items(approx, pmesh,
      CGAL::parameters::subdivision_ratio(ui_widget.chord_error->value())
        .relative_to_chord(ui_widget.comboRelative->currentIndex() == 1)
        .with_dihedral_angle(ui_widget.with_dihedral_angle->isChecked())
        .optimize_anchor_location(ui_widget.if_optimize_anchor_location->isChecked())
        .pca_plane(ui_widget.pca_plane->isChecked()));
  }

  QApplication::restoreOverrideCursor();
}

void Polyhedron_demo_surface_mesh_approximation_plugin::on_buttonAdd_clicked() {
  Scene_surface_mesh_item *sm_item = qobject_cast<Scene_surface_mesh_item *>(
    scene->item(scene->mainSelectionIndex()));
  if (!sm_item) {
    CGAL::Three::Three::information(QString("No surface mesh item selected."));
    return;
  }
  SM_wrapper_map::iterator search = m_sm_wrapper_map.find(sm_item);
  if (search == m_sm_wrapper_map.end() || !search->second->initialized()) {
    CGAL::Three::Three::information(QString("Please initialize seeds first."));
    return;
  }
  SMesh *pmesh = search->first->face_graph();
  VSA_wrapper &approx = *search->second;

  QApplication::setOverrideCursor(Qt::WaitCursor);

  if (approx.add_one_proxy() == 0) {
    CGAL::Three::Three::information(QString("No proxy added, #proxies = %1.").arg(approx.number_of_proxies()));
    QApplication::restoreOverrideCursor();
    return;
  }
  CGAL::Three::Three::information(QString("One proxy added, #proxies = %1.").arg(approx.number_of_proxies()));

  Patch_id_pmap pidmap(get(CGAL::face_patch_id_t<int>(), *pmesh));
  approx.output(CGAL::parameters::face_proxy_map(pidmap));
  update_seeds_item(approx, pmesh);

  sm_item->color_vector() = approx.proxy_colors();
  sm_item->setItemIsMulticolor(true);
  sm_item->computeItemColorVectorAutomatically(false);
  sm_item->invalidateOpenGLBuffers();
  scene->itemChanged(scene->item_id(sm_item));

  if (ui_widget.checkAutomatic->isChecked()) {
    if (!approx.visual_items().has_meshing_items) {
      CGAL::Three::Three::information(QString("Please mesh before checking auto meshing."));
      QApplication::restoreOverrideCursor();
      return;
    }
    update_meshing_items(approx, pmesh,
      CGAL::parameters::subdivision_ratio(ui_widget.chord_error->value())
        .relative_to_chord(ui_widget.comboRelative->currentIndex() == 1)
        .with_dihedral_angle(ui_widget.with_dihedral_angle->isChecked())
        .optimize_anchor_location(ui_widget.if_optimize_anchor_location->isChecked())
        .pca_plane(ui_widget.pca_plane->isChecked()));
  }

  QApplication::restoreOverrideCursor();
}

void Polyhedron_demo_surface_mesh_approximation_plugin::on_buttonTeleport_clicked() {
  Scene_surface_mesh_item *sm_item = qobject_cast<Scene_surface_mesh_item *>(
    scene->item(scene->mainSelectionIndex()));
  if (!sm_item) {
    CGAL::Three::Three::information(QString("No surface mesh item selected."));
    return;
  }
  SM_wrapper_map::iterator search = m_sm_wrapper_map.find(sm_item);
  if (search == m_sm_wrapper_map.end() || !search->second->initialized()) {
    CGAL::Three::Three::information(QString("Please initialize seeds first."));
    return;
  }
  SMesh *pmesh = search->first->face_graph();
  VSA_wrapper &approx = *search->second;

  QApplication::setOverrideCursor(Qt::WaitCursor);

  if (approx.teleport_one_proxy() == 0) {
    CGAL::Three::Three::information(QString("No proxy teleported, #proxies = %1.").arg(approx.number_of_proxies()));
    QApplication::restoreOverrideCursor();
    return;
  }
  Patch_id_pmap pidmap(get(CGAL::face_patch_id_t<int>(), *pmesh));
  approx.output(CGAL::parameters::face_proxy_map(pidmap));
  update_seeds_item(approx, pmesh);

  CGAL::Three::Three::information(QString("One proxy teleported, #proxies = %1.").arg(approx.number_of_proxies()));

  sm_item->color_vector() = approx.proxy_colors();
  sm_item->setItemIsMulticolor(true);
  sm_item->computeItemColorVectorAutomatically(false);
  sm_item->invalidateOpenGLBuffers();
  scene->itemChanged(scene->item_id(sm_item));

  if (ui_widget.checkAutomatic->isChecked()) {
    if (!approx.visual_items().has_meshing_items) {
      CGAL::Three::Three::information(QString("Please mesh before checking auto meshing."));
      QApplication::restoreOverrideCursor();
      return;
    }
    update_meshing_items(approx, pmesh,
      CGAL::parameters::subdivision_ratio(ui_widget.chord_error->value())
        .relative_to_chord(ui_widget.comboRelative->currentIndex() == 1)
        .with_dihedral_angle(ui_widget.with_dihedral_angle->isChecked())
        .optimize_anchor_location(ui_widget.if_optimize_anchor_location->isChecked())
        .pca_plane(ui_widget.pca_plane->isChecked()));
  }

  QApplication::restoreOverrideCursor();
}

void Polyhedron_demo_surface_mesh_approximation_plugin::on_buttonSplit_clicked() {
  Scene_surface_mesh_item *sm_item = qobject_cast<Scene_surface_mesh_item *>(
    scene->item(scene->mainSelectionIndex()));
  if (!sm_item) {
    CGAL::Three::Three::information(QString("No surface mesh item selected."));
    return;
  }
  SM_wrapper_map::iterator search = m_sm_wrapper_map.find(sm_item);
  if (search == m_sm_wrapper_map.end() || !search->second->initialized()) {
    CGAL::Three::Three::information(QString("Please initialize seeds first."));
    return;
  }
  SMesh *pmesh = search->first->face_graph();
  VSA_wrapper &approx = *search->second;

  QApplication::setOverrideCursor(Qt::WaitCursor);

  if (!approx.split(ui_widget.split_proxy_idx->value(),
    ui_widget.split_nb_sections->value(),
    ui_widget.split_nb_relaxations->value())) {
    CGAL::Three::Three::information(QString("No proxy splitted, #proxies = %1.").arg(approx.number_of_proxies()));
    QApplication::restoreOverrideCursor();
    return;
  }
  CGAL::Three::Three::information(QString("One proxy splitted, #proxies = %1.").arg(approx.number_of_proxies()));

  Patch_id_pmap pidmap(get(CGAL::face_patch_id_t<int>(), *pmesh));
  approx.output(CGAL::parameters::face_proxy_map(pidmap));
  update_seeds_item(approx, pmesh);

  sm_item->color_vector() = approx.proxy_colors();
  sm_item->setItemIsMulticolor(true);
  sm_item->computeItemColorVectorAutomatically(false);
  sm_item->invalidateOpenGLBuffers();
  scene->itemChanged(scene->item_id(sm_item));

  if (ui_widget.checkAutomatic->isChecked()) {
    if (!approx.visual_items().has_meshing_items) {
      CGAL::Three::Three::information(QString("Please mesh before checking auto meshing."));
      QApplication::restoreOverrideCursor();
      return;
    }
    update_meshing_items(approx, pmesh,
      CGAL::parameters::subdivision_ratio(ui_widget.chord_error->value())
        .relative_to_chord(ui_widget.comboRelative->currentIndex() == 1)
        .with_dihedral_angle(ui_widget.with_dihedral_angle->isChecked())
        .optimize_anchor_location(ui_widget.if_optimize_anchor_location->isChecked())
        .pca_plane(ui_widget.pca_plane->isChecked()));
  }

  QApplication::restoreOverrideCursor();
}

void Polyhedron_demo_surface_mesh_approximation_plugin::on_buttonMeshing_clicked() {
  Scene_surface_mesh_item *sm_item = qobject_cast<Scene_surface_mesh_item *>(
    scene->item(scene->mainSelectionIndex()));
  if (!sm_item) {
    CGAL::Three::Three::information(QString("No surface mesh item selected."));
    return;
  }
  SM_wrapper_map::iterator search = m_sm_wrapper_map.find(sm_item);
  if (search == m_sm_wrapper_map.end() || !search->second->initialized()) {
    CGAL::Three::Three::information(QString("Please initialize seeds first."));
    return;
  }
  SMesh *pmesh = search->first->face_graph();
  VSA_wrapper &approx = *search->second;

  QApplication::setOverrideCursor(Qt::WaitCursor);

  // and meshing items to group
  CGAL::Three::Scene_group_item *group = approx.visual_items().group;
  Scene_polygon_soup_item *triangles_item = new Scene_polygon_soup_item();
  triangles_item->setName(tr("Triangle soup"));
  triangles_item->setColor(Qt::lightGray);
  triangles_item->setRenderingMode(FlatPlusEdges);
  triangles_item->setVisible(true);
  scene->addItem(triangles_item);
  scene->changeGroup(triangles_item, group);

  Scene_polylines_item *polygons_item = new Scene_polylines_item();
  polygons_item->setName(tr("Patch polygons"));
  polygons_item->setColor(Qt::red);
  polygons_item->setVisible(true);
  scene->addItem(polygons_item);
  scene->changeGroup(polygons_item, group);

  Scene_polylines_item *anchors_item = new Scene_polylines_item();
  anchors_item->setName(tr("Anchors"));
  anchors_item->setColor(Qt::blue);
  anchors_item->setVisible(true);
  scene->addItem(anchors_item);
  scene->changeGroup(anchors_item, group);

  Scene_polygon_soup_item *planes_item = new Scene_polygon_soup_item();
  planes_item->setName(tr("Patch planes"));
  planes_item->setColor(Qt::yellow);
  planes_item->setRenderingMode(FlatPlusEdges);
  planes_item->setVisible(true);
  scene->addItem(planes_item);
  scene->changeGroup(planes_item, group);

  approx.visual_items().has_meshing_items = true;
  approx.visual_items().triangles = triangles_item;
  approx.visual_items().polygons = polygons_item;
  approx.visual_items().anchors = anchors_item;
  approx.visual_items().planes = planes_item;

  update_meshing_items(approx, pmesh,
    CGAL::parameters::subdivision_ratio(ui_widget.chord_error->value())
      .relative_to_chord(ui_widget.comboRelative->currentIndex() == 1)
      .with_dihedral_angle(ui_widget.with_dihedral_angle->isChecked())
      .optimize_anchor_location(ui_widget.if_optimize_anchor_location->isChecked())
      .pca_plane(ui_widget.pca_plane->isChecked()));

  sm_item->setVisible(false);

  CGAL::Three::Three::information(QString("Meshing done."));

  QApplication::restoreOverrideCursor();
}

void Polyhedron_demo_surface_mesh_approximation_plugin::on_comboMetric_currentIndexChanged(const int) {
  Scene_surface_mesh_item *sm_item = qobject_cast<Scene_surface_mesh_item *>(
    scene->item(scene->mainSelectionIndex()));
  if (!sm_item) {
    CGAL::Three::Three::information(QString("No surface mesh item selected."));
    return;
  }
  SM_wrapper_map::iterator search = m_sm_wrapper_map.find(sm_item);
  if (search == m_sm_wrapper_map.end())
    return;
  search->second->initialized() = false;

  sm_item->color_vector().clear();
  sm_item->setItemIsMulticolor(false);
  sm_item->invalidateOpenGLBuffers();
  scene->itemChanged(scene->item_id(sm_item));
}

void Polyhedron_demo_surface_mesh_approximation_plugin::itemAboutToBeDestroyed(CGAL::Three::Scene_item *scene_item)
{
  if (Scene_surface_mesh_item *sm_item = qobject_cast<Scene_surface_mesh_item *>(scene_item)) {
    SM_wrapper_map::iterator search = m_sm_wrapper_map.find(sm_item);
    if (search != m_sm_wrapper_map.end()) {
      delete search->second;
      m_sm_wrapper_map.erase(sm_item);
    }
  }
}

#include "Surface_mesh_approximation_plugin.moc"
