SFML multiple objects with random values and their collisions - c++

Question

I'm pretty new with SMFL and C++ for the moment and I've got stuck while I was creating very simple physics simulator with balls.
Its my main.cpp:
#include <SFML/Graphics/RenderWindow.hpp>
#include <SFML/Window/Event.hpp>
#include "ball.hpp"
int main()
{
/*create window settings*/
sf::ContextSettings settings;
/*create window*/
sf::RenderWindow window;
window.create(sf::VideoMode(600, 600), "Simple Physics", sf::Style::Default, settings);
/*create ball(s)*/
Ball ball;
/*Main loop*/
while (window.isOpen())
{
sf::Event event;
while (window.pollEvent(event))
{
if (event.type == sf::Event::Closed)
window.close();
}
window.clear(sf::Color::Black);
// call ball.update(); and ball.draw();
balls.update();
balls.draw(window);
window.display();
}
}
And ball.hpp :
#include <SFML/Graphics/CircleShape.hpp>
class Ball
{
public:
int minXY = 0;
int maxXY = 600;
int ballRadius = rand() % 50 + 5;
int random = rand() % maxXY + 1; //random XY position
// vector for positions
//sf::Vector2f pos{random, random}; -> I Guess this should be included into loop
sf::Vector2f pos{100, 300};
// vector for velocity
sf::Vector2f vel{ 0.1, 0.1 };
void update()
{
// factors influence velocity
// update position based on velocity
pos.x += vel.x;
pos.y += vel.y;
if (pos.x + ballRadius*2 > maxXY || pos.x < minXY) vel.x = -vel.x; //boundary cond
if (pos.y + ballRadius*2 > maxXY || pos.y < minXY) vel.y = -vel.y; //boundary cond
}
void draw(sf::RenderWindow& window)
{
// draw ball to the window using position vector
sf::CircleShape circle(ballRadius);
circle.setPosition(pos.x, pos.y);
circle.setFillColor(sf::Color::White);
window.draw(circle);
}
};
Now, I want to draw multiple cirlcles, with random size, velocity and colors.
They should bounce on collision, i've got some ideas for that but can't really try them without multiple balls.
I've tried to make it with simple for loop, but it's not working.
After reading and watching many tutorials I'm still in this point so it would be great if somebody can help me up with ANY working example or some improvements to my code.

Answer 1

I will not give you working example but I think I can point you in the right direction:
You need some kind of Constructor for your Ball class, and given the example you should probably learn more about classes in general (for example here).
Then you should store balls you spawn from main loop in some kind of container. If you do know the number of balls you want to spawn std::array should be you choice, otherwise std::vector is the way to go.
You need some function to check collisions, static member function of Ball class should do the trick.