//=============================================================================
//                                                                            
//                               OpenMesh                                     
//        Copyright (C) 2003 by Computer Graphics Group, RWTH Aachen          
//                           www.openmesh.org                                 
//                                                                            
//-----------------------------------------------------------------------------
//                                                                            
//                                License                                     
//                                                                            
//   This library is free software; you can redistribute it and/or modify it 
//   under the terms of the GNU Lesser General Public License as published   
//   by the Free Software Foundation, version 2.1.                           
//                                                                             
//   This library is distributed in the hope that it will be useful, but       
//   WITHOUT ANY WARRANTY; without even the implied warranty of                
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         
//   Lesser General Public License for more details.                           
//                                                                            
//   You should have received a copy of the GNU Lesser General Public          
//   License along with this library; if not, write to the Free Software       
//   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                 
//                                                                            
//-----------------------------------------------------------------------------
//                                                                            
//   $Revision$
//   $Date$
//                                                                            
//=============================================================================


#ifndef OPENMESHAPPS_QGLVIEWERWIDGET_HH
#define OPENMESHAPPS_QGLVIEWERWIDGET_HH


//== INCLUDES =================================================================


#include <OpenMesh/Core/Geometry/VectorT.hh>
#include <QGLWidget>
#include <QMenu>
#include <string>
#include <vector>


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


class QPopupMenu;


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

  
class QGLViewerWidget : public QGLWidget
{

  Q_OBJECT
  
public:
   
  // Default constructor.
  QGLViewerWidget( QWidget* _parent=0, const char* _name=0 );

  // Destructor.
  virtual ~QGLViewerWidget();

  /* 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
  void add_draw_mode(std::string _s);

  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_; }
  void set_modelview_matrix(const GLdouble _modelview_matrix[16])
  { memcpy(modelview_matrix_, _modelview_matrix, 16*sizeof(GLdouble)); }
  void set_projection_matrix(const GLdouble _projection_matrix[16])
  { memcpy(projection_matrix_, _projection_matrix, 16*sizeof(GLdouble)); }

  float fovy() const { return 45.0f; }

protected:

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

  double performance(void);

private slots:  

  // popup menu clicked
  void slotPopupMenu(int _id);  
  
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();

protected:
  // 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_;
  unsigned int              draw_mode_;
  unsigned int              n_draw_modes_;
  std::vector<std::string>  draw_mode_names_;



  // 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
//=============================================================================