How do I do a wait() function?

[aadenboy]

How would I have the code pause when I want it to with a wait() function? I'm not sure how to make one.

[nesbox]

There is no wait function, but you can do something like this

local t=0
function TIC()
    cls(12)
    t=t+1
    
    -- wait 2 seconds
    if t<2*60 then return end
    
    print("HELLO WORLD!",84,64)
end

[aadenboy]

what if I wanted to do that inside of a function?

[joshgoebel]

You really can't. But you might want to look into coroutines or fibers. Some languages make this easier than others to have functions that can wait/yield.

Then your TIC function just sets up your fiber/coroutine and passes control to it every frame.

But really it's not a common pattern most people use.

Sorry I don't have an example.

[aadenboy]

I figured out how to use coroutines, and made some code, thanks!

-- part of a function
if chrData.inv[chrData.selected] ~= nil then
			if success and chrData.inv[chrData.selected].placeable then
				tiles[#tiles+1] = {
					position = {
						xPos = math.round(((x - 4) + xOffset) / 8),
						yPos = math.round(((y - 4) + yOffset) / 8)
					},
					type = chrData.inv[chrData.selected].linkedblock
				}
				nextcode = coroutine.create(function ()
           table.remove(chrData.inv, chrData.selected)
         end)
				wait(5)
			end
		end

-- part of TIC()

if dowait then
		waittime = waittime + 1
		
		if waittime >= ending * 60 then
			waittime = 0
			dowait = false
			coroutine.resume(nextcode)
		end
	end

Edit: wait is a function that just assigns two variables

[farvardin]

I was looking for something similar.
At the moment I'm using this

function wait(a)
	t1=time()
	t2=time()
	while ((t2-t1)<=a)
	do
		t2=time()
	end
end

and I can wait(1000) one second for example. But the problem is when the wait function is working, the mouse is stalled and it just looks ugly.

I don't really understand your function.

[franalbani]

function sleep(duration_ms)
  t0 = time()
  while time() - t0 < duration_ms
  do
  end
end

[farvardin]

just to be helpful, since no one mentioned this yet, instead of "burning CPU" with some kind of wait function, if you need to delay some action, if possible it's better to use the modulo, for example instead of:

wait(500)
dosomething()

use:

if t%30 == 0 then
dosomething()
end

[atesin]

what about something like...

delayTimer=0

function TIC()

  if delayTimer > 0 then
    delayTimer = delayTimer -1
    return
  end

  -- do stuff
  
  while someCondition do
    -- do more stuff

    -- DELAY like emulation
    if otherCondition() then
      delayTimer = 30
      return
    end
  end
  
  -- do even more stuff
end 

this is quick, but it has the disadvantage that can't resume the program flow where were left

i learned this the hard way... in my ignorance, i did while true then end making tic-80 eat all my real cpu, i had to kill it through task manager and lose all my unsaved work xD... then l learn to call return instead (i guess tic-80 does stuff while outside TIC() like read keyboard)

[atesin]

version 2: using time() instead

-- global variable
delayTimer=time()-2000 -- this prevents delay trigger at program start

function TIC()

  -- check for a 2 seconds delay (the good way, see note below)
  if time()-delayTimer<2000 then return end
 
  doSomething()

  if needsDelay() then -- set delay and skip further execution
    delayTimer=time()
    return
  end

  doSomethingNew()
end

time difference has to be calculated everytime to avoid delay imprecisions
when time() overflows, wraps around 0 (resets) and starts counting again
(actually also fails with delays near INT_MAX, but such huge delays are unlikely)

[AdriProg2000]

@nesbox Can you add a function sleep() or wait()?