Lua programming for DCS questions - Mission info

[TigersharkBAS]

Hi there,

Two questions (hoping Speed and other knowledgable ED people may answer).

 

1. Getting Mission data from export.lua by accessing Mission environment in RAM

 

I know you can load a mission file in the export.lua and get mission info that way. I would like to read the mission table from RAM though.

 

I believe that net.dostring_in holds the secret but I have no idea how I would actually code this. Can anyone write a function that shows me how this would work?

 

2. Is it possible to get JTAC data from the game?

For example, after a 9 line is read out by the JTAC you can send that down a socket in export.lua?

 

 

Help and replies very much appreciated.

[Speed]

Tigershark,

Sorry for not answering sooner, I just have a lot of stuff going on right now, and what you really need is the kind of detailed answer that will take nearly an hour to make.

 

In the meantime, I can give you an overview.

 

First of all, the phrase,

 

"Getting Mission data from export.lua by accessing Mission environment in RAM"

 

doesn't make much sense, unless I'm interpreting it wrong.

 

export.lua is in the "export" Lua environment. It can't access the "mission" environment.

 

First of all, I would like to know why you think you absolutely need to get mission data through RAM. It only adds between 50 to maybe 1000 milliseconds of simulation load time to get the mission through C: instead, and it can be done easily. After you have found the mission data over C:, then it's forever accessible to you via RAM (because you saved it to a Lua variable) and it takes only nanoseconds to access.

 

Anyway, if it truly is a hard requirement to get it solely through RAM, then you have a few options.

 

- net environment mod: access mission data via net.dostring_in("mission", <lua code>). Drawback: you could interfere with other net environment mods like Slmod or Servman; that said, it wouldn't be hard for me to make Slmod v7 look for your mod and run it. Net can also access the main simulation Lua environment. The problem with net is that if you used it, your mod would only work when you were a multiplayer host.

 

- MissionScripting.lua: mission scripting is passed env.mission, which is all the mission data. You could send this data out of mission scripting via LuaSocket. Drawback: you would interfere with Slmod which also uses MissionScripting.lua, but it wouldn't be hard for me to make Slmod v7 look for your mod and run it if it exists.

 

- main simulation environment mod- this is probably the prefered option. The debriefing module receives the mission table, but it remains a local variable inside functions. You could make it save the mission table to the global environment.

 

- Final option: I created a function that will get you the mission data in any Lua environment that has io and lfs modules available to it, but it goes through C:.

------------------------------------------------------------

 

The functions that build the 9-line exist in ./Sounds/Speech/NATO.lua. This is part of a module in the main simulation Lua environment. So you would need to modify the appropriate function that generates a 9-line to either save that data to the global environment or send it over UDP via LuaSocket to whatever environment you will use.

 

Anyway, as you can see, I never mentioned export in a single breath. Export is pretty useless for what you want to do, forget about it.

 

Anyway, what you need is obviously a main simulation Lua environment mod. You could base it out of autoexec.lua. You don't need to actually modify the debriefing.lua and NATO.lua files, you merely need to modify the functions that those files create. Redefine them to do your code in addition to ED's code.

[Speed]

Ok, here's a quick example.

 

 

At the end of autoexec.lua, add this:

 

--Beginning of TigersharkBAS mod
do
local missionData -- stores mission data for TigersharkBAS's mod.

local oldFunc = {}
oldFunc.extractMissionData = debriefing.extractMissionData

debriefing.extractMissionData = function(mission)  -- redefinition of debriefing.extractMissionData
	missionData = mission
	
	-------------------------------------------------------------------------------------------
	--[[ASSUMING that debriefing.extractMissionData only runs one time, at mission start,
	    then you maybe can use it as a "on mission load" event to start your "main" program 
		loop (and kill the old loop).]]
	if tigershark.mainId then
		timer.removeFunction(tigershark.mainId)
	end
	tigershark.main()
	--------------------------------------------------------------------------------------------
	
	return oldFunc.extractMissionData(mission)  -- now do the old extractMissionData function.
end

-- do the JTAC 9-line redefinition the same way.

-- If you need a "main" program loop, then you can construct one like this:
tigershark = {}
tigershark.main = function()
	-- your main code...
	
	

	tigershark.mainId = timer.scheduleFunction(tigershark.main, nil, timer.getTime() + 0.05)  -- tigershark.main will run 20 times a second.
end

end

Edited January 17, 2013 by Speed

[Skitter]

Hi, not sure if I'm hijacking the thread. I'm trying to program a unit to to switch from hold and start moving after another unit receive some damage.

 

I've placed this

 

Unit.getLife(truck1) < 2

 

Where "truck1" is the name of the unit to receive damage. Anyway, that crashes the engine, because there's something wrong with the grammar of it. Could you tell me how can I program this (if truck1's life less than 2) please?

[Grimes]

Try Unit.getLife(Unit.getByName('truck1')) < 1.

 

http://en.wiki.eagle.ru/wiki/Simulator_Scripting_Engine/DCS:_World_1.2.1/Part_2#Unit

 

getLife is a value between 0 and 1.0.

[Skitter]

Thanks, but I get the same error as before "Unexpected symbol next to '<'".

Any idea?

P.s I don't put the dot at the end, do I ?

[Grimes]

How exactly are you using it?

 

if  Unit.getLife(Unit.getByName('truck1')) < 1 then
-- do whatever
end

[Skitter]

I'm trying to use it in a waypoint (waypoint actions). It is going to be the "stop condition" for hold command.

Do I use 'if', 'then', 'end' ?

 

Thanks for help so far, it is my first contact with lua scripting.

[Grimes]

From my example change -- do whatever to

 

return true

[Skitter]

I understand now. Thanks a lot :thumbup:

[Speed]

Hi, not sure if I'm hijacking the thread. I'm trying to program a unit to to switch from hold and start moving after...

 

Cukier, for future reference, questions involving the simulator scripting engine belong in the Mission Builder's Corner. ;)

[TigersharkBAS]

Speed..thanks a lot for your answers. I still have a lot more questions but I let me try and take the advice you have given me, digest it and see if I can figure some things out myself before I hassle you again. Thanks very much!

[TigersharkBAS]

Hi speed. I sent you a PM. Did you get it? Having trouble understanding your table serialisation function.