sample

class Ball
{
    bool enabled = false;
    Vec2 position;
}

Ball balls[100];

void update()
{
    
}

void addNewBall(Vec2 position)
{
    for(int i=0;i<100;++i)
    {
        if(!balls[i].enabled)
        {
            balls[i].enabled = true;
            balls[i].position = position;

            return;
        }
    }
}