Factorio Forums

1. Game call an event different from on_tick, let's call this event A
2. A call is associated to a function that put some values in a global table, like global.B
3. Let's call on_tick each 60 tick and take one item from global.B do something and wait.

{
    ...
    {entity.surface, entity.position}
    ...
}

function doThings(event)
	game.print(#global.B)
	if event.tick % 60 == 0 and #global.B> 0 then
		local i, entry = next(global.B)	
		if entry then				
			doSomething(entry)
			table.remove(global.B, i)
		end
	end
end
...
script.event(...on_tick, doThings)

DaveMcW wrote: Tue Dec 03, 2019 8:10 pm If you do something wrong to an array-style table, it will become associative, and array functions will not work correctly.

Linver wrote: Wed Dec 11, 2019 1:30 pm Honktown,
in my implementation I don't iterate on a table that I modify constantly, I say to the on nth tick callback to take the first sure element and remove it if no one have compute it before. I test it with a constant input and unstable one. No errors.
My initial misunderstand was in the filter declaration on "on chuck generated" event (noticed by Pyrofire).
Thank u anyway for the suggestion.

Optera wrote: Thu Dec 12, 2019 6:36 am My preferred way to spread entity iteration over multiple ticks would be to use a global associative array and use next.

Code: Select all

function OnTick(event)
  if global.Entity_Index and not global.MyEntities[global.Entity_Index] then
    -- the index is no longer valid, probably because the associated entity was removed
    global.Entity_Index = nil
    return
  end
  
  for i=1, i<updates_per_tick, 1 do
    local unit_number, entity= next(global.MyEntities, global.Entity_Index)
    if entity then
      global.Entity_Index = unit_number
      -- do stuff with your entity
    else
      -- we reached the end of global.MyEntities
      global.Entity_Index = nil
      return
  end  
end

Advantages:
+ the same code will work for 1 entity every n ticks, m entities every tick or m entities every n ticks
+ performance is much better than using modulo or some other form of calculation on the entire array to find the current pointer
+ adding and removing entities can be done at any time and is (somewhat) gracefully handled
+ adding, removing entities doesn't require loops

Disadvantages:
- If done wrong it will produce weird errors

Optera wrote: Thu Dec 12, 2019 6:36 am + performance is much better than using modulo or some other form of calculation on the entire array to find the current pointer

local on_tick = function(event)

  local bucket = script_data.depots[event.tick % depot_update_rate]
  if bucket then
    for unit_number, depot in pairs (bucket) do
      if not (depot.entity.valid) then
        bucket[unit_number] = nil
      else
        depot:update()
      end
    end
  end

end

Klonan wrote: Thu Dec 12, 2019 6:09 pm

Optera wrote: Thu Dec 12, 2019 6:36 am + performance is much better than using modulo or some other form of calculation on the entire array to find the current pointer

With modulo, you can modulo by the update rate to find the 'bucket' that you want to update, instead of checking the modulo for each key value:

Code: Select all

local on_tick = function(event)

  local bucket = script_data.depots[event.tick % depot_update_rate]
  if bucket then
    for unit_number, depot in pairs (bucket) do
      if not (depot.entity.valid) then
        bucket[unit_number] = nil
      else
        depot:update()
      end
    end
  end

end

Klonan wrote: Thu Dec 12, 2019 6:09 pm

Optera wrote: Thu Dec 12, 2019 6:36 am + performance is much better than using modulo or some other form of calculation on the entire array to find the current pointer

With modulo, you can modulo by the update rate to find the 'bucket' that you want to update, instead of checking the modulo for each key value:

Code: Select all

local on_tick = function(event)

  local bucket = script_data.depots[event.tick % depot_update_rate]
  if bucket then
    for unit_number, depot in pairs (bucket) do
      if not (depot.entity.valid) then
        bucket[unit_number] = nil
      else
        depot:update()
      end
    end
  end

end