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Inheritance Constructor Problem

Inheritance Constructor Problem

Inheritance Constructor Problem

(OP)
Here is my super class:
#ifndef OPENGLSCENE_H
#define OPENGLSCENE_H

#include <windows.h>
#include <gl\gl.h>
#include <gl\glu.h>
#include <gl\glaux.h>

#include "Globals.h"
#include "Triangle.h"

#define TRUE 1
#define FALSE 0

class OpenGLScene {    
    HGLRC hRC;
    HWND hWnd;
    HINSTANCE hInstance;
    HDC hDC;
    BOOL done;
    bool fullscreen;
    MSG msg;
    GLvoid ReSizeGLScene(GLsizei width, GLsizei height);
    int InitGL(GLvoid);
    BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag);
    
public:
    OpenGLScene (char* title, int width, int height, int bits, bool fullscreenflag);
    GLvoid KillGLWindow(GLvoid);
    virtual void addTriangle (Triangle *T) = 0;
    virtual int DrawGLScene(GLvoid) = 0;
    virtual void DrawTriangle (Triangle *T) = 0;
    int start ();
};

#endif

And below is my derived class:
#include "OpenGlScene.h"


class MyOpenGLScene : public OpenGLScene
{
    Triangle *T;

public:
    MyOpenGLScene(char* title, int width, int height, int bits, bool fullscreenflag);
    void addTriangle(Triangle *T);
    void DrawTriangle(Triangle *T);
    int DrawGLScene();
};

MyOpenGLScene::MyOpenGLScene(char* title, int width, int height, int bits, bool fullscreenflag) {
    title = "Stage 1";
    width = 800;
    height = 600;
    bits = 16;
    fullscreenflag = 0;
}

void addTriangle(Triangle *T) {

}

void DrawTriangle(Triangle *T) {

}

int DrawGLScene() {

    return 0;
}

Now the error : error C2512: 'OpenGLScene' : no appropriate default constructor available
Error executing cl.exe.

I don't know what's wrong...is it my sub class constructor wrong? Please help me!

RE: Inheritance Constructor Problem

Depending on your design, you have to either create a default constructor for your mother class, or to pass parameters to the mother's constructor from the child class.

Since "char* title, int width, int height, int bits, bool fullscreenflag" are parameters that the mother class deals with, I think I would implement it that way :

1) In OpenGLScene, implement the constructor as if you wanted to be able to instanciate an OpenGLScene properly :

OpenGLScene::OpenGLScene(char* title, int width, int height, int bits, bool fullscreenflag) {
    title = "Stage 1";
    width = 800;
    height = 600;
    bits = 16;
    fullscreenflag = 0;
}

2) In MyOpenGLScene, deal with the parameters that are specific to the derived class, and simply pass the others to the mother class' constructor :

MyOpenGLScene::MyOpenGLScene(char* title, int width, int height, int bits, bool fullscreenflag, int IAddedThisOne) : OpenGLScene(title, width, height, bits, fullscreenflag)
{
    // Deal with IAddedThisOne
}

__________

The colon followed by a constructor name tells the compiler how you want to build the class you are inheriting from. If absent, the default constructor is used.


Hope it helps, and that I haven't done too many mistakes.

RE: Inheritance Constructor Problem

Err, well, I copy-pasted something too fast :

The implementation of OpenGLScene::OpenGLScene(char* title, int width, int height, int bits, bool fullscreenflag) should do something usefull with the parameters, of course.

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