Loop Run

Everton Fonseca

How do loop run 60FPS on qml?

SGaist

Hi,

Pretty well when you have the right hardware.

More seriously, what exactly are you looking for ?

Everton Fonseca

I'm looking this way

// Qml javascript
item{

// init object

Component.onCompled: {

 // here being a parallel thread
  While (runningGame)
 {
       Update ()
       ...
       Sleep SPF 60
    
 } // end while

} // end event onCompled

} // end Item

This is possible to do, do you have any example of a game in the qml that does it?

SGaist

No, I don't have any example doing it like that and I don't think it's a good idea either.

What would you do in that loop ?

Everton Fonseca

Update all objects

mrjj

@Everton-Fonseca
But any object will update/draw itself is its state changes?

Everton Fonseca

That same design change status, how do I do that?

SGaist

What kind of update do you have in mind ?

Here you have a small game sample that doesn't need any infinite loop.

tekojo

It sounds like you are thinking in the traditional way (the way people think of real time operating systems).

QML wasn't designed with this idea in mind. It goes design and objects first. The framework will then get you the FPS your hardware can handle (probably 60, or whatever your graphics card usually outputs to your monitor).
Of course QML provides timers, but they also work automatically, you do not need to "sleep" them.

Everton Fonseca

thanks = D

Galbarad

i'm using timer for updating game state
30 mks give 33FPS and this working on mobile

Timer {
        id: tMain;
        interval: 30;
        running: false;
        repeat: true
        onTriggered: {
            var diff = Qt.core.move();
            if (diff > 0) {
                CTL.checkGameState(diff);
            }
        }
    }

my game with main loop in timer
https://play.google.com/store/apps/details?id=net.is.games.CatchTheGhost

Everton Fonseca

well very good, thanks = D brother

Suares

@Everton-Fonseca
I would suggest moving your main game loop from qml to C++ code. It's only my suggestion.
I think you've already checked this but one more time here is good explanation how you can get 60 FPS.
Use Qt Quick module only for rendering. Ideally logic should be written in C++ IMHO.

Everton Fonseca

@Suares
thanks = D

GTDev

If you're interested in game development with Qt, you can also have a look at V-Play Engine. V-Play also has some good tutorials to show how to implement games with mainly QML.

Best,
GT

johngod

From my experience, QML timer is all but accurate betwen plataforms.
I have experienced significant speed diferencies between linux and windows, wich makes the game characters move with very diferent speeds on diferent plataforms. This can be a problem and make the game unplayable.

Iinitially I tought that Timer was just a QTimer exposed to QML, but has AFAIK thet are not related at all.
QTimer seems to provide a much better accuracy, so what I did was to created a new c++ class that uses QTimer, and expose it to QML. In the end, I got a MyTimer qml entity with similar Timer sintaxe, but with much better results.