Error creating subclasses

[agerlach]

Howdy, I think my problem is more of an issue with my understanding of C++ then of Qt, but I'm using Qt so I'll post my question here.

A little background on the problem... What I am try to do is implement a surface matching algorithm which can be trained on any 3D surface mesh. To train the algorithm a 2D histogram is generated for each vertex on the surface mesh and stored in a database. Surface matching is then performed by taking a new 3D surface mesh of the same object, randomly selecting a few vertices, calculating the 2D histogram for those vertices, and then comparing them to the 2D histograms that are stored in the database.

What I would like to do is setup a core class that contains all the methods that are required in both the training and matching phases, ie. calculating a 2D histogram, and then subclass that core class with a training and matching class. First off, is this the general approach I should be taking?

So I generated a class called siCore which works fine

class siCore :public QThread
{
    Q_OBJECT
public:
    friend class MainWindow;
    siCore(MainWindow *gui);
    void run();
 
signals:
    void updateMainThreadStatus(QString statusLog);
    void updateMainThreadProgress(int progValue);
 
    MainWindow  *appWindow;
};

class siCore :public QThread
{
    Q_OBJECT
public:
    friend class MainWindow;
    siCore(MainWindow *gui);
    void run();

signals:
    void updateMainThreadStatus(QString statusLog);
    void updateMainThreadProgress(int progValue);

    MainWindow  *appWindow;
};

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I then generated class called siTrainer that inherits from siCore

#include "sicore.h"
 
class siTrainer : public siCore
{
 
public:
    siTrainer();
 
};

#include "sicore.h"

class siTrainer : public siCore
{

public:
    siTrainer();

};

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but when I compile this simple example I get the following error:

'siCore' : no appropriate default constructor available - sitrainer.cpp

I'm sure it is something simple, but what am I doing wrong here?

[Zlatomir]

Define a constructor with no arguments...
And don't forget the class destructor, and make it virtual (for all base classes), like this:

class siCore {
public:
    siCore(){...}
//...
    virtual ~siCore(){//... actual cleaning of dynamic allocated resources
                               }
};

class siCore {
public:
    siCore(){...}
//...
    virtual ~siCore(){//... actual cleaning of dynamic allocated resources
                               }
};

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[agerlach]

Thanks, I knew it would be simple!