Zooming in and out a picture (sfml) using recursion in c++ - c++

Question

Using the following code I am to add a recursive function with out changing anything in the code for it to work:
sf::RenderWindow window(sf::VideoMode(WIDTH, HEIGHT), TITLE);
int stop = 800;
sf::Color colour1(sf::Color::Black), colour2(sf::Color::Red);
// Start the main loop
while (window.isOpen()) {
// Process events
sf::Event event;
while (window.pollEvent(event)) {
// check the type of the event...
switch (event.type) {
// window closed
case sf::Event::Closed:
window.close();
break;
case sf::Event::MouseMoved: //mouse moved
stop = mapXtoMinSize(event.mouseMove.x); // convert x coordinate of mouse to minimum size of square to draw
break;
// we don't process other types of events
default:
break;
} //end switch
} //End-Process events
window.clear(colour2);
}
I just would like to know how to go about doing such.

Answer 1

A recursive function generally goes like this:
int recursive(int x) {
if (x == 0) {
return 0;
} else {
return (x + recursive(x - 1));
}
}
This will sum all the integers from 0 to x, by repeatedly calling itself to compute the sum of (x - 1) and adding this to the result. If the base case, x == 0, is encountered the recursion ends and the calls unwind until they reach the original, by which point the sum has been calculated. Please be more specific.
Without knowing what you are trying to achieve with your recursive function I cannot give you any more advice. I do not know what you mean with you comment "with out changing anything in the code".