Pointing to a function that is a class member – GLFW setKeycallback

by

The code examples provided in the other answers don’t describe how to redirect your callback to a per-object member function, with possibly any number of objects. Making your class a singleton will constrain your design and will not scale to multiple glfw windows.

The scalable solution is to set the glfw window user pointer to your object and then fetch it in the callback, and call the member function :

class MyGlWindow
{
public:
     void mouseButtonPressed();
};

void makeWindow()
{
    GLFWwindow* glfwWindow;
    MyGlWindow* myWindow;

    /* ... Initialize everything here ... */

    glfwSetWindowUserPointer(glfwWindow, myWindow);

    auto func = [](GLFWwindow* w, int, int, int)
    {
        static_cast<MyGlWindow*>(glfwGetWindowUserPointer(w))->mouseButtonPressed( /* ... */ );
    }

    glfwSetMouseButtonCallback(glfwWindow, func);
}

This solution is shorter and will work for any number of windows.

More Related Contents:

  1. How do you pass a member function pointer?
  2. Matrix Printing using Pointers [closed]
  3. Questions regarding constructors
  4. Pointer to class data member “::*”
  5. Function does not change passed pointer C++
  6. Return array in a function
  7. What is the point of function pointers?
  8. Is passing pointer argument, pass by value in C++?
  9. What is the ‘this’ pointer?
  10. Returning a pointer of a local variable C++
  11. How to create two classes in C++ which use each other as data?
  12. Function pointer vs Function reference
  13. C++ correct way to return pointer to array from function
  14. Do class functions/variables have to be declared before being used?
  15. Why use a const member function?
  16. C++ inherit from multiple base classes with the same virtual function name
  17. Explanation of function pointers
  18. Function pointer as parameter
  19. How to create a template function within a class? (C++)
  20. Pointer to array of unspecified size “(*p)[]” illegal in C++ but legal in C
  21. About Pointers To Functions in function declarations
  22. array of pointers as function parameter
  23. Why am I able to make a function call using an invalid class pointer
  24. Function returning array but main showing garbage [duplicate]
  25. Template type deduction in C++ for Class vs Function?
  26. non-const pointer argument to a const double pointer parameter
  27. Is the pointer guaranteed to preserve its value after `delete` in C++?
  28. Difference between using character pointers and character arrays
  29. What do I need to do before deleting elements in a vector of pointers to dynamically allocated objects?
  30. How does the friend keyword (Class/Function) break encapsulation in C++?

Leave a Comment