Tetris clone lag after moving window

[TmCrafz]

Hi 
I have a little problem with my Tetris clone.
When I move the Window, often my game begin to lag. The framerate fall down to 2-4 fps.
I don´t have any idea what can be the reason of the problem and which part of my code can be part of this.
In my earlier games I didn´t had problems like this.
I use Windows 7, Visual Studio Express 2013 and SFML 2.1.
Thanks for help
Feuerstern

[zsbzsb]

Show your code where you handle delta time. Or maybe I could try to guess.... zsbzsb pulls out his crystal_ball.exe

[Strelok]

MinimalCodeNotFoundException

[TmCrafz]

Thanks for the answers.

Show your code where you handle delta time. Or maybe I could try to guess.... zsbzsb pulls out his crystal_ball.exe

I dont use delta time in this game.
I have used frapes to check the frames.

I have find the code who is the problem.
The for loop is to much, and needs to much performance and i lose much fps with this.
But I dont understand why this effect is much higher after moving the window.

bool isStoneOnStoredStone(sf::RectangleShape storedStones[10][22], Stone &actualStone)
{
        for (unsigned y{ 0 }; y != 22; ++y)
                {
                        for (unsigned x{ 0 }; x != 10; ++x)
                        {
                                if ((actualStone.shapeA.getPosition().y + 20.f == storedStones[x][y].getPosition().y && actualStone.shapeA.getPosition().x == storedStones[x][y].getPosition().x) ||
                                        (actualStone.shapeB.getPosition().y + 20.f == storedStones[x][y].getPosition().y && actualStone.shapeB.getPosition().x == storedStones[x][y].getPosition().x) ||
                                        (actualStone.shapeC.getPosition().y + 20.f == storedStones[x][y].getPosition().y && actualStone.shapeC.getPosition().x == storedStones[x][y].getPosition().x) ||
                                        (actualStone.shapeD.getPosition().y + 20.f == storedStones[x][y].getPosition().y && actualStone.shapeD.getPosition().x == storedStones[x][y].getPosition().x))
                                {
                                        return true;
                                }
                        }
                }      
        return false;
}
 

[Strelok]

Run a profiler and make sure the performance hog is caused by this.