text: #ifndef MAINWINDOW_H
  #define MAINWINDOW_H
  
  #include <QMainWindow>
  
  namespace Ui {
  class MainWindow;
  }
  
  class MainWindow : public QMainWindow
  {
      Q_OBJECT
  
  public:
      explicit MainWindow(QWidget *parent = 0);
      ~MainWindow();
      void mousePressEvent(QMouseEvent *ev);
  
  private slots:
       void dda(int,int,int,int);
       void on_pushButton_clicked();
       void on_pushButton_2_clicked();
  
       void on_pushButton_3_clicked();
  
      // void on_radioButton_toggled(bool checked);
  
       void on_verticalSlider_valueChanged(int value);
  
       void on_verticalSlider_2_valueChanged(int value);
  
       void on_verticalSlider_3_valueChanged(int value);
  
       void on_pushButton_4_clicked();
  
  private:
      Ui::MainWindow *ui;
      int a[20],b[20];
      int x1,y1,x2,y2,vertices;
      bool start;
  };
  
  #endif // MAINWINDOW_H
  