Objects table(active/inactive) - removing and adding

[Strutyk]

I'll try to explain.
I have four characters. Every 3 seconds a random character is taken from

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mansPool

Then the chosen random character gets to

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mansArray

and removed from

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mansPool

Then a random character moves.
When it reaches a certain point - is removed from the

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mansArray

and is added back into the

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mansPool

to participate in the random sample.
That is - until the character on the screen, it does not participate in a random sample of

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mansPool

[zorg]

[wiki]love.math.random[/wiki]
table.insert, table.remove

[pgimeno]

Ok, so it's not just one active man at a time, but something more like this:

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local function activateMan()
    if #mansPool == 0 then return end
    mansArray[#mansArray+1] = table.remove(mansPool, love.math.random(1, #mansPool))
end

local function deactivateMan(man)
    for i = 1, #mansArray do
        if mansArray[i] == man then
            mansPool[#mansPool+1] = table.remove(mansArray, i)
            break
        end
    end
end

You would call activateMan every 3 seconds. You would call deactivateMan each time a man reaches the certain point, passing it which one did.

Makes sense now?

[Strutyk]

Today, I feel better and understood
But I have a question. Is this good practice use this function to check?

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function checkActive()
	rand = mansPool[math.random(#mansPool)]
    if rand.active == true then 
    	return checkActive()
    end    
    randName = rand.name
    rand.active = true
    table.insert(mansArray, rand)
end

[pgimeno]

If rand.active is set when you remove the man from mansPool, there should be no element with .active set to true in it. It makes no sense to check it. But then that code does not remove it, so I'm confused again.

[Strutyk]

Yes this function is not remove man from pool. In my project I have two pool. In the first pool objects are added and removed. In the second poll objects are active, inactive. function checkActive() used for the second pool. But I have my doubts, when using this function. Is there a better option for check object(s) on the activie/inactive?

[ivan]

Good example by pgimeno.
Personally, I would change the code a little bit:

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local pool = {}
local active = {}

-- initialize pool
for i = 1, 100 do
  table.insert(pool, {})
end

local function activate(x, y)
  local t = table.remove(pool) or {}
  -- re-initialize
  t.x = x
  t.y = y
  -- activate
  table.insert(active, t)
  return t
end

local function deactivate(t)
  for i = 1, #active do
    if active[i] == t then
      table.remove(active, i)
      table.insert(pool, t)
      break
    end
  end
end

The idea being - take the last element from the pool and re-initialize its values.

PS. This approach is useful when you need to activate a lot of objects (such as particles) at once.

math.random(#mansPool)

Just be careful since math.random will raise an error when #mansPool == 0.

second poll objects are active, inactive

Seems like one pool of inactive objects should be enough.

[Strutyk]

Yep, mansPool is manual control - the number of objects on the screen - less than the size of the pool.
Second pool for dynamically added objects

[Strutyk]

Maybe I need to use debug (memory usage, graphics, etc.), and then it will be clear which code is more appropriate for my situation?

[Strutyk]

Thank you all very much for help with tips and code, you helped me alot! Hoping the practice will come to understand where best to use what code