SFML flickering renderwindow?

Question

I'm hoping someone can help me out, I'm using SFML 2.1 and when I draw my renderWindow it just keeps flickering, now I know SFML uses two buffers so i'm sure one is not getting drawn at all but I can't understand why.

Here is my loop

while(!quit)
{

    rs.Canvas.pollEvent(gameEvent);
    colour += 1;
    rs.Update(colour);

    if(gameEvent.type == sf::Event::Closed)
        quit = true;

    rs.Canvas.clear( sf::Color(colour,0,0) );

    rs.Canvas.draw( sprite );

    rs.Canvas.display();

    if(colour >= 300)
        quit = true;
}

the rs.Canvas has these set

Canvas.setVerticalSyncEnabled(true);
Canvas.setFramerateLimit(60);

Can anyone see why my renderWindow would flicker?

I'm not familiar with SFML, but could the flickering be caused by you clearing the canvas before drawing to it? Or is it Canvas.display() which actually draws it to the screen? — Brian Gradin
Its ok, I looked into the code and I found I was using Canvas.clear() twice, so basically it was clearing the front buffer and back buffer, so one was never set. its fine now, delete the question :) — Canvas
Could you add the solution as actual answer and accept it, so the question gets marked as solved? — Lukas

DCurro DCurro · Accepted Answer · 2014-05-28T16:31:29

From the SFML 2.0 tutorial, under the section Controlling the framerate:

Never use both setVerticalSyncEnabled and setFramerateLimit at the same time! They would badly mix and make things worse.

http://www.sfml-dev.org/tutorials/2.0/window-window.php#controlling-the-framerate

In the comments of your post, you state that you were calling clear twice on the window. This would effectively treat your window as if it were single buffered. I understand that the effect of this could create some screen tearing, but on my end I am not getting a glaring flicker effect. Make sure to remove your a call to either setting the framerate or to using the vertical sync, just to be sure.

SFML flickering renderwindow?

2 Answers