/* ========================================================================= *
 *                                                                           *
 *                               OpenMesh                                    *
 *           Copyright (c) 2001-2022, RWTH-Aachen University                 *
 *           Department of Computer Graphics and Multimedia                  *
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 * This file is part of OpenMesh.                                            *
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 * ========================================================================= */




#ifndef OPENMESHAPPS_QGLVIEWERWIDGET_HH
#define OPENMESHAPPS_QGLVIEWERWIDGET_HH


//== INCLUDES =================================================================
#include <OpenMesh/Core/Geometry/VectorT.hh>
#include <string>
#include <vector>
#include <map>
#if QT_VERSION_MAJOR < 6
    #include <QGLWidget>
#else
    #include <QtOpenGLWidgets/QOpenGLWidget>
#endif

//== FORWARD DECLARATIONS =====================================================

class QMenu;
class QActionGroup;
class QAction;

//== CLASS DEFINITION =========================================================

#if QT_VERSION_MAJOR < 6
class QGLViewerWidget : public QGLWidget
#else
class QGLViewerWidget : public QOpenGLWidget
#endif
{
  Q_OBJECT

  
public:
  #if QT_VERSION_MAJOR < 6
  typedef QGLWidget Super;
  #else
  typedef QOpenGLWidget Super;
  #endif
   
  // Default constructor.
  explicit QGLViewerWidget( QWidget* _parent=0 );

  // Destructor.
  virtual ~QGLViewerWidget();

private:

  void init(void);

public:

#if QT_VERSION_MAJOR > 5
  /* Updates the gui - used to provide backwards compability */
  void updateGL();
#endif

  /* Sets the center and size of the whole scene. 
     The _center is used as fixpoint for rotations and for adjusting
     the camera/viewer (see view_all()). */
  void set_scene_pos( const OpenMesh::Vec3f& _center, float _radius );  

  /* view the whole scene: the eye point is moved far enough from the
     center so that the whole scene is visible. */
  void view_all();

  /// add draw mode to popup menu, and return the QAction created
  QAction *add_draw_mode(const std::string& _s);

  /// delete draw mode from popup menu
  void del_draw_mode(const std::string& _s);

  const std::string& current_draw_mode() const 
  { return draw_mode_ ? draw_mode_names_[draw_mode_-1] : nomode_; }

  float radius() const { return radius_; }
  const OpenMesh::Vec3f& center() const { return center_; }

  const GLdouble* modelview_matrix() const  { return modelview_matrix_;  }
  const GLdouble* projection_matrix() const { return projection_matrix_; }

  float fovy() const { return 45.0f; }

  QAction* findAction(const char *name);
  void addAction(QAction* action, const char* name);
  void removeAction(const char* name);
  void removeAction(QAction* action);

protected:

  // draw the scene: will be called by the painGL() method.
  virtual void draw_scene(const std::string& _draw_mode);

  double performance(void);
  
  void setDefaultMaterial(void);
  void setDefaultLight(void);

private slots:  

  // popup menu clicked
  void slotDrawMode(QAction *_mode);  
  void slotSnapshot( void );

  
private: // inherited

  // initialize OpenGL states (triggered by Qt)
  void initializeGL();

  // draw the scene (triggered by Qt)
  void paintGL();

  // handle resize events (triggered by Qt)
  void resizeGL( int w, int h );

protected:
   
  // Qt mouse events
  virtual void mousePressEvent( QMouseEvent* );
  virtual void mouseReleaseEvent( QMouseEvent* );
  virtual void mouseMoveEvent( QMouseEvent* );
  virtual void wheelEvent( QWheelEvent* );
  virtual void keyPressEvent( QKeyEvent* );

private:
   
  // updates projection matrix
  void update_projection_matrix();

  // translate the scene and update modelview matrix
  void translate(const OpenMesh::Vec3f& _trans);

  // rotate the scene (around its center) and update modelview matrix
  void rotate(const OpenMesh::Vec3f& _axis, float _angle);

  OpenMesh::Vec3f  center_;
  float            radius_;
	      
  GLdouble    projection_matrix_[16],
              modelview_matrix_[16];


  // popup menu for draw mode selection
  QMenu*               popup_menu_;
  QActionGroup*        draw_modes_group_;
  typedef std::map<QString,QAction*> ActionMap;
  ActionMap            names_to_actions;
  unsigned int              draw_mode_;
  unsigned int              n_draw_modes_;
  std::vector<std::string>  draw_mode_names_;
  static std::string        nomode_;



  // virtual trackball: map 2D screen point to unit sphere
  bool map_to_sphere(const QPoint& _point, OpenMesh::Vec3f& _result);

  QPoint           last_point_2D_;
  OpenMesh::Vec3f  last_point_3D_;
  bool             last_point_ok_;

};


//=============================================================================
#endif // OPENMESHAPPS_QGLVIEWERWIDGET_HH
//=============================================================================

