[SOLVED] Error Base class has incomplete type

beginners
#1 
class ofBaseDraws;
class ofRectangle;

class ROI : public ofBaseDraws, public ofRectangle {
    
    public :
    
    void draw(float _x, float _y) const;
    void draw(float _x, float _y, float _w, float _h) const;
    float getWidth() const;
    float getHeight() const;
};

gives me the error :

Base class has incomplete type

What am i doing wrong ?

thanks

#2

you need to include the header in order to be able to extend, forward declaration like you are doing there with:

class ofBaseDraws;
class ofRectangle;

won’t work since the compiler needs to know the details of the class to be able to extend

#3

Thanks for the answer. So should i use instead :

#include <ofRectangle.h>
#include <ofBaseTypes.h>

I mean i am not sure where ofBaseDraws class is defined. ofBaseTypes.h seems the one but i am not sure.

Thanks again.

#4

By the way, i am now having an error when declaring this ROI class.

in my kinectTracker.h i am declaring :

#include <ofxKinect.h>
#include <ofxOpenCv.h>
#include "ROI.h"

class kinectTracker {

public:
    kinectTracker();
    ~kinectTracker();
    
    ROI roi;

private:
    
    ofxKinect kinect;
    
};

then i have the error :

Field type ‘ROI’ is an abstract class

Thanks for your suggestions

#5

Ok so i figured out that ofBaseDraws is part of ofBaseTypes and includes 4 pure virtual methods. I thought i could implement them in const but it turns out it can’t !

so i replaced :

void draw(float _x, float _y) const;
void draw(float _x, float _y, float _w, float _h) const;
float getWidth() const;
float getHeight() const;

with :

void draw(float _x, float _y);
void draw(float _x, float _y, float _w, float _h);
float getWidth();
float getHeight();

in my ROI class and everything seems ok now.

Thanks for your help.

#6

we’ve changed that for next release where those methods will be const but by now they have to be non const

#7

image.jpg880×782 142 KB

I was getting this error then adding the const to the virtual function solved it. Now I am getting the weirdest error, I can not call functions on the flow object all the classes are hidden?

#8

With the help of @NickHardeman if you make the object a pointer it worked ---- but why?

#9

probably ofxCv;;FlowFarneback doens’t have a const draw