Jerky gameplay

[dabbertorres]

Your example is not jerky on my machine.

You could try logging the time per frame and see if it ever jumps to a large or small amount than the average. Maybe your machine is having a hard time keep the framerate at 60fps?

[Jycerian]

Your example is not jerky on my machine.

You could try logging the time per frame and see if it ever jumps to a large or small amount than the average. Maybe your machine is having a hard time keep the framerate at 60fps?

Yeah I will check that tomorrow and post back, do you experience any 'tearing' in the shape at any point?

[Jesper Juhl]

Not sure it's relevant, but I saw the comment

Maybe your machine is having a hard time keep the framerate at 60fps?

and I just wanted to point out that; the first thing you should do (IMHO) is make your drawing independent of the actual frame rate, since it will fluctuate regardless of setFramerateLimit/setVerticalSyncEnabled or whatever you do yourself.
If you don't take a variable frame-rate into account (you really have to) you will see jerky movement.
If you haven't already read it, then the Fix Your Timestep article is a great place to start.

[dabbertorres]

Your example is not jerky on my machine.

You could try logging the time per frame and see if it ever jumps to a large or small amount than the average. Maybe your machine is having a hard time keep the framerate at 60fps?

Yeah I will check that tomorrow and post back, do you experience any 'tearing' in the shape at any point?

Nope, looks fine.

And yep, that's where I was headed next in replying, Jesper!

[Jesper Juhl]

And yep, that's where I was headed next in replying, Jesper!

Huh? I really don't know what to make of that..

[dabbertorres]

Sorry, I meant, that I assumed he'd ask how to solve separating the rendering and the logic, and then I was going to reply with something along the lines of what you replied with.

[Jycerian]

Hihi, no I know how to seperate the logic and render and to apply a fixed timestep. But again this does not resolve the issue. Maby its my machine? I am really not sure. It seems everyone else can run it just fine? I can play League of Legends on all low settings with 60 fps and super smooth, but can't have a square move across my screen without being sometimes 'jerky' and the 'tearing'. So weird.

[Jycerian]

Your example is not jerky on my machine.

You could try logging the time per frame and see if it ever jumps to a large or small amount than the average. Maybe your machine is having a hard time keep the framerate at 60fps?

Timed my timestep with setFramerateLimit(60)

[dabbertorres]

Hmm, looks fine to me. I'm not sure what to make of it.

[Jycerian]

I am not sure if this will help but this is my DxDiag, anyone got an idea what causes the tearing and jerky movement?

[underww]

I think this is because of the floating numbers of the sprite's position.
Try to use an integer value for velocity.

For example

        if (isMovingUp)
                velocity.y = -1.f;
        if (isMovingDown)
                velocity.y = 1.f;
        if (isMovingLeft)
                velocity.x = -1.f;
        if (isMovingRight)
                velocity.x = 1.f;

        rect.move(velocity);
 

[Jycerian]

How would you go about this using deltatime? Because that is a floating point number. In my example my player velocity.x would be something like 1.5.

[Hapax]

How would you go about this using deltatime?

You could round() or floor() the value when setting the sprite position if you want to keep it to an integer value.
This can improve the sprite's display quality but is more likely to cause jerky movement than to solve it.

[Jycerian]

How would you go about this using deltatime?

You could round() or floor() the value when setting the sprite position if you want to keep it to an integer value.
This can improve the sprite's display quality but is more likely to cause jerky movement than to solve it.

'

Alright, do you have any insight in my problem? You seem like a well established community member, ever stumbled across something like this?

[Hapax]

Unfortunately, I have unsure which exact problem you're getting and what its effect is. The code that causes you to have the problem doesn't seem to cause it for others so we can't see it. I suppose you could record a video of it but it's possible that it wouldn't capture the "jerkiness", or may even create some of its own.

As you may've also noticed, the word jerky is slightly ambiguous.