io/viewers/viewer3D-11-extension.cpp

Example of extension of Viewer3D interface by deriving the class Viewer3D::Extension. Here we have added a callback to the "Shift+R" keypressed event, which adds a point randomly in the domain.

See also

moduleQGLExtension

Extending the Viewer3D interface: just press

Shift+R and you have new points added randomly in the scene."

 
#include <iostream>
 
#include "DGtal/base/Common.h"
#include "DGtal/helpers/StdDefs.h"
#include "DGtal/io/viewers/Viewer3D.h"
 
using namespace std;
using namespace DGtal;
using namespace Z3i;
 
// Standard services - public :
 
// Deriving from Viewer3D::Extension to add new callbacks to events.
struct RandomPointKeyExtension : public Viewer3D<Space, KSpace>::Extension
{
  RandomPointKeyExtension()
  {
  }
 
  // Here we override the "key pressed" event, and a point randomly in
  // the scene if the key "Shift+R" is pressed.
  virtual bool keyPressEvent( Viewer & viewer, QKeyEvent * event )
  {
    bool handled = false;
    // Get event modifiers key
    const Qt::KeyboardModifiers modifiers = event->modifiers();
    if ( ( event->key() == Qt::Key_R ) && ( modifiers == Qt::ShiftModifier ) )
    {
      Point p = viewer.space().lowerBound();
      Point q = viewer.space().upperBound();
      Point d = q - p;
      Point a( ( rand() % d[ 0 ] ) + p[ 0 ], ( rand() % d[ 1 ] ) + p[ 1 ],
               ( rand() % d[ 2 ] ) + p[ 2 ] );
      viewer << a;
      viewer << Viewer::updateDisplay;
      trace.info() << "Adding point " << a << std::endl;
      handled = true;
    }
    return handled;
  }
 
  // We also override the Viewer3D::init method to add a key
  // description in the help window.
  virtual void init( Viewer & viewer )
  {
    viewer.setKeyDescription( Qt::ShiftModifier + Qt::Key_R,
                              "Creates a random digital point." );
  }
 
  // We also override the Viewer3D::helpString method to add a
  // description to the viewer.
  virtual QString helpString( const Viewer & /*viewer*/ ) const
  {
    QString text( "<h2> Random point Viewer3D </h2>" );
    text += "Press Shift+R to add points.";
    return text;
  }
};
 
int main( int argc, char ** argv )
{
 
  QApplication application( argc, argv );
 
  Point p1( 0, 0, 0 );
  Point p2( 5, 5, 5 );
  Point p3( 2, 3, 4 );
  Domain domain( p1, p2 );
 
  typedef Viewer3D<> MyViewer;
  KSpace K;
  K.init( p1, p2, true );
  MyViewer viewer( K );
  viewer.setExtension( new RandomPointKeyExtension );
  viewer.show();
  viewer << domain;
  viewer << p1 << p2 << p3;
 
  viewer << MyViewer::updateDisplay;
  return application.exec();
}
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