Window blinking

[tayyab91]

Hello everyone,
I started using sfml a few days ago. I have to use it for a project.
Here is a code that i wrote just to understand its features.

#include <SFML/Audio.hpp>
#include <SFML/Graphics.hpp>
#include <iostream>


using namespace std ;

const int MAX = 100 ;
const float rectSize = 40 ;
const float nextRect = 40 ;

bool contains(const sf::RectangleShape & rect, const sf::Vector2i& position );

int main()
{

     // Create the main window
     sf::RenderWindow window(sf::VideoMode(800,600), "BattleShip");



     sf::RectangleShape r1[MAX] ;
     int nbRect=0 ;

     for(int lig = 0 ; lig < 10 ; lig++)
     {
         for(int col = 0 ; col < 10 ; col++)
         {
             r1[nbRect].setSize(sf::Vector2f(rectSize,rectSize));
             r1[nbRect].setPosition(200+(col*nextRect),100+(lig*nextRect));
             r1[nbRect].setFillColor(sf::Color::Cyan);
             r1[nbRect].setOutlineThickness(1);
             r1[nbRect].setOutlineColor(sf::Color::Black);
             window.draw(r1[nbRect]);
             nbRect++ ;
         }
     }


     // Update the window
     window.display();

     while (window.isOpen())
     {
         // Process events
         sf::Event event;


         while (window.pollEvent(event))
         {
             // Close window : exit
             if (event.type == sf::Event::Closed)
                 window.close();

             if(event.type == sf::Event::MouseButtonPressed && sf::Event::MouseLeft)
             {
                 int cpt=0 ;
                 while(!(contains(r1[cpt],sf::Mouse::getPosition(window))))
                 {
                     cpt++ ;

                 }

                 r1[cpt].setFillColor(sf::Color::Red) ;
                 window.draw(r1[cpt]);
                 r1[cpt].setOutlineThickness(1);
                 r1[cpt].setOutlineColor(sf::Color::Black);
             }
         }
         window.display();

     }

    return EXIT_SUCCESS;
}


bool contains(const sf::RectangleShape & rect, const sf::Vector2i& position )
{
    sf::Vector2f vec ;

    vec = rect.getPosition();
    return((vec.x <= position.x) && (vec.x + rectSize >= position.x) && (vec.y <= position.y) && (vec.y + rectSize >= position.y)) ;
}
 

There is no error at compilation but the rectangles created blink. I searched for the problem and what i understood is that it is due to double buffering. I tried to follow some suggestions(using clear() ) but i couldn't solve the problem. I would really appreciate if someone could help me(an example code).

Thanks in advance.

[Laurent]

What you draw is not persistent, you must draw everything everytime you refresh the window (ie. every iteration of your main loop).

[tayyab91]

I tried to do that but the program stops working after execution.

[tayyab91]

And i have another question. Won't it be a little bit heavy to draw everything, everytime in the loop?

[mateandmetal]

On every loop iteration do:
1) Clear the window ... window.clear()
2) Draw all your graphics
3) window.display ()

Won't it be a little bit heavy to draw everything, everytime in the loop?

No. This is how the video cards works currently.

[tayyab91]

Thanks guys. It seems to be working