How to only get one input per key press during a loop?

[wh1t3crayon]

So I want a game piece to only move one square at a time when an arrow key is pressed, but the game loop is checking for if they key is pressed way too quickly and the piece moves between 5 and 7 pieces if I press the arrow key really quickly. Here is the code

void Engine::Go(){
        while(window.isOpen()){
                if(timeElapsed.asSeconds() >= 100){
                        timeElapsed = clock.restart();
                }
                ProcessInput();
                UpdateCPU();
                Render();
                timeElapsed += clock.getElapsedTime();
        }
}

void Engine::ProcessInput(){
        while(window.pollEvent(event)){
                if(event.type == (sf::Event::Closed))
                        window.close();
        }
        //process movement detection of piece
       
                int temp = level.GetGamePieces().size();
                if(sf::Keyboard::isKeyPressed(sf::Keyboard::Left)){
                        level.GetGamePieces().at(temp - 1).GetPieceSprite().move(-10, 0);
                        std::cout << "left";
                       
                }
                else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Right)){
                        level.GetGamePieces().at(temp - 1).GetPieceSprite().move(10,0);
                        std::cout << "right";
                       
                }
                else{
                        level.GetGamePieces().at(temp - 1).GetPieceSprite().move(0,10);
                        std::cout << "down";
               
        }
}

So the code is moving the piece more than once when they key is pressed. How would I get the piece to move only once when the key is pressed?

[Strelok]

Use the keypressevent instead of polling the os for the state of the key so that the key press will happen only once

[wh1t3crayon]

Use the keypressevent instead of polling the os for the state of the key so that the key press will happen only once

How do I use that code though? Here is what I have

if(event.type == (sf::Event::KeyPressed)){
                        switch(event.type){
                                case //left arrow key is pressed
                        }
                }

But what goes in the commented section to get the key pressed event? Also, is this what you meant?

[Strelok]

Holy documentation

[wh1t3crayon]

Wait wait don't just send me on my way to some documentation. Ok so why isn't this code moving the piece left or right? It just moves it down at multiple times a second:

while(window.pollEvent(event)){
                if(event.type == (sf::Event::Closed))
                        window.close();
                //process movement detection of piece  
                if(event.type == (sf::Event::KeyPressed)){
                        switch(event.type){
                        case sf::Keyboard::Left:
                                level.GetGamePieces().at(temp - 1).GetPieceSprite().move(-10, 0);
                                std::cout << "left";
                                break;
                        case sf::Keyboard::Right:
                                level.GetGamePieces().at(temp - 1).GetPieceSprite().move(10,0);
                                std::cout << "right";
                                break;
                        }
                }
        }
        if(timeElapsed.asMilliseconds() >= 1000){
                level.GetGamePieces().at(temp - 1).GetPieceSprite().move(0,10);
                std::cout << "down";
                timeElapsed = clock.restart();
        }

[Strelok]

Have you read the Official documentation (not some documentation) thoroughly?

if (event.key.code == sf::Keyboard::Left) // event.key.CODE

And also note:

If a key is held, multiple KeyPressed events will be generated, at the default OS delay (ie. the same delay that applies when you hold a letter in a text editor). To disable repeated KeyPressed events, you can call window.setKeyRepeatEnabled(false). On the contrary, obviously, KeyReleased events can never be repeated.

[Hapax]

Yeah, it's event.key.code for the actual key, not event.type.

Also, I'm not understanding your timing code. It looks like it's doing something wrongly.
It seems to be adding the accumulated clock's currently elapsed time (up to 100 seconds) each time, so at 99 seconds, it'll be adding 99 seconds onto the previously elapsed time, rather than the elapsed time being at 99 seconds.
Not sure what the 100 seconds thing is for but it looks like you should be doing something more like:

        if(timeElapsed.asSeconds() >= 100){
            timeElapsed = sf::Time::Zero;
        }
        // ...
        timeElapsed += clock.restart();

or

        if(timeElapsed.asSeconds() >= 100){
            timeElapsed = clock.restart();
        }
        // ...
        timeElapsed = clock.getElapsedTime();