Limiting FPS in 0.9.0

[aidenn]

Hi,

I've been seraching for a bit now, but only found outdated examples for 0.8.0. What's the proper way to limit FPS in 0.9.0?

[Azhukar]

Code: Select all

local t = 0
local fps = 1/30
function love.update(dt)
	t=t+dt
	if (t < fps) then return end
	t=t%fps

	print("30 times per second")
end

You can also turn on vsync in conf.lua.

[aidenn]

But that only makes an action happen 30 times in a second. I'd like to have proper framelimiting for everything.

Vsync in LÖVE, unfortunately, tends to drop single frames here and there.

[Automatik]

Try this:

Code: Select all

local fps = 1/30
function love.update(dt)
   if (dt < fps) then
       love.timer.sleep(fps-dt)
   end
end

[Azhukar]

Try this:

Code: Select all

local fps = 1/30
function love.update(dt)
   if (dt < fps) then
       love.timer.sleep(fps-dt)
   end
end

love.timer.sleep((fps-dt)*2)

[aidenn]

Thanks, it kind-of works, but it's not really what I had in mind.

Let me tell you why I need it first:

I'm doing my first proper LÖVE project I've been meaning to do since oh so long. Today I did collisions, which worked nicely. However, when I gave the game to my friend with a really crappy PC, collisions went a bit glitchy due to lower FPS. It's not really broken, but it DOES behave differently, even with proper dt usage.

So, if I limit the framerate, I can develop collisions and movement targeting that exact FPS which will behave identically on all systems. Two options there: I can use Vsync or I can use a hard framerate cap. Vsync kinda works, but people may not want it, which leaves the second option. Earlier I wrote that Vsync loses a frame or two here or there... that FPS limit example kills any semblance of smoothness, probably because love.update() isn't really the place to do it.

I saw this post back when I was searching, which looks like something I might want: http://love2d.org/forums/viewtopic.php? ... 184#p75184, however we don't have getMicroTime() anymore and I'm once again in a stump.

[Azhukar]

I'm doing my first proper LÖVE project I've been meaning to do since oh so long. Today I did collisions, which worked nicely. However, when I gave the game to my friend with a really crappy PC, collisions went a bit glitchy due to lower FPS. It's not really broken, but it DOES behave differently, even with proper dt usage.

Then you only need to limit the amount of times your physics update gets called and pass it a fixed dt value instead of one you get from update.

In other words: use the method from my first post and pass your physics update 1/30 instead of dt. That way the most the game will do when it cannot reach 30fps is run slower.

I saw this post back when I was searching, which looks like something I might want: http://love2d.org/forums/viewtopic.php? ... 184#p75184, however we don't have getMicroTime() anymore and I'm once again in a stump.

love.timer.getMicroTime() is now love.timer.getTime().

[aidenn]

Oooh, that explains so much. Thanks! I guess I don't need to limit FPS arbitrarily anymore. I have a question though - is it accurate? That is, can updates achieved this way synchronize perfectly with Hz 1:1?

BTW, out of curiousity I tried to test that limiter I linked with getTime() but couldn't get it to work anyway.

[Azhukar]

That is, can updates achieved this way synchronize perfectly with Hz 1:1?

I wouldn't rely on that.

[aidenn]

That's a bummer. Any way to do clean and healthy frame-Hz relationship with LÖVE?