Lua Timer and AppTime()

[diedir]

Hi all

i can't figure out a way to create a timer in LUA,

 

with AppTime() function set on a variable, i can't do any( t1 - t2) compare,

seems to get always the same values.

 

If i try to UpdateAppTime() on a loop, my game slows down as hell.

 

--before loop
starttime = AppTime()
---in loop:
current = AppTime()
elapsedtime = (current - starttime)

 

Could someone give me a hint on what to do ?

 

Thank you

[macklebee]

look at some of the inherent lua functions: os.difftime()

[Rick]

Here is what I do for timers in Lua. Below is usage:

-- This is the timer method that gets called when the interval is up
function MoveTimer(tmr, param1, param2)
  -- Can stop the timer if I want with the below code
  StopTimer(tmr)
end

moveTimer = {}
CreateTimer(moveTimer, 50, MoveTimer)
AddGlobalTimer(moveTimer, 10, "hello")

-- call the below method in your main loop every cycle and it'll manage all the timers for you that you added to AddGlobalTimer()
UpdateGlobalTimers()

 

Below is Timers.lua file I add to my project

 

function CreateTimer(tmr, interval, eventHandler)
tmr.onTick = eventHandler
tmr.lastTime = 0
tmr.interval = interval
tmr.enabled = false
end

function StartTimer(tmr)
tmr.lastTime = os.clock() * 1000
tmr.enabled = true
end

function UpdateTimer(tmr, param1, param2)
if tmr.enabled == true then
	if (os.clock() * 1000) > tmr.lastTime + tmr.interval then
		tmr.lastTime = os.clock() * 1000
		--if param1 ~= nil and param2 == nil then
		tmr.onTick(tmr, param1, param2)
		--else
		--	tmr.onTick(tmr)
		--end
	end
end
end

function StopTimer(tmr)
tmr.enabled = false
end

globalTimers = {}
globalTimerCount = 1
function AddGlobalTimer(tmr, param1, param2)
-- Store off the parameter inside the timer
tmr.parameter1 = param1
tmr.parameter2 = param2

-- Add an index ID
tmr.id = globalTimerCount

-- Insert into global table
globalTimers[globalTimerCount] = tmr

globalTimerCount = globalTimerCount + 1
--table.insert(globalTimers, tmr)
end

function RemoveGlobalTimer(tmr)
-- Setting to nil removes the entry from the table
globalTimers[tmr.id] = nil
end

function UpdateGlobalTimers()
for k,v in pairs(globalTimers) do
	UpdateTimer(v, v.parameter1, v.parameter2)
end
end

[diedir]

Thank you Rick for sharing your code,

it will help me (and others) for setting up timers needed by my racing game

I guessed it was something like this (classes,methods) but couldn't draw it up by myself, really thank you a lot.

i will try to make it work in my scripts.

 

@Macklebee

i tried os.time() and os.difftime(t2 - t1) with no luck, perhaps i messed the code

for me:

putting os.time() in a variable before loop

when a key pressed in the loop : passing os.time() to another variable then: os.difftime(second_var, first_var)

printing value is always "0" or a random fixed number which never change....

 

will try Rick's way, LUA is sometimes discouraging...

i'll put my tests later

 

Thank you both

 

EDIT :

ok i get it to work at last with os.difftime() :

put a func :

function time()
current = os.clock()
end

---before loop i initiate startime:
starttime = os.clock()

---then in my loop (when key pressed for my purpose) :
elapsedtime = os.difftime( os.clock(), starttime) ---here is my diff time show
starttime = time() --- re-assign my starttime

 

Finally it works

need to see now how i can put more timers mixing with Rick's classes

 

Thank you all !

[Rick]

Is that returning ms for you? Looking http://lua-users.org/wiki/OsLibraryTutorial it looks like it's in seconds. Not sure if you require ms accuracy or not, but in mine I multiply os.clock by 1000 to get ms and then I just subtract that the values to get the difference in ms.

[diedir]

No they are seconds afaik,

seconds are enough accurate for me, it's just a toy racing car, nothing elaborate ...

i will dig in it perhaps ms is more cute, i'll see now that's working

[Rick]

guess I ask because I primarily use these for animations which requires ms. I use it for other stuff as well and being in ms let's me use it for more precise timing in ms or less precise timing in seconds. It's more flexible I find. I don't use the fmod() way in the tutorials to do animations. I just find it easier to work with timers to increase the frames myself.