I am trying to code a gui that is dynamically assigned. I have four teams. I am getting stuck at a certain point. I want to make a function that, when a player joins the game, checks if the other teams have already scored to update their labels. It looks like this:
local function updateAllLabelsLateArrival(redPoints, bluePoints, yellowPoints, greenPoints)
game.Players.LocalPlayer.PlayerGui.ScreenGui.ReallyRedTeam.Points.Text = redPoints
game.Players.LocalPlayer.PlayerGui.ScreenGui.ReallyBlueTeam.Points.Text = bluePoints
game.Players.LocalPlayer.PlayerGui.ScreenGui.NewYellerTeam.Points.Text = yellowPoints
game.Players.LocalPlayer.PlayerGui.ScreenGui.LimeGreenTeam.Points.Text = greenPoints
end
The function is remotely triggered from a server-side script when a player joins. The problem I have is that not all four labels might exist. Suppose a green team player joins in when there is only a red team player already playing. It will come back with the error
ReallyBlueTeam is not a valid member of ScreenGui
I thought wrapping each line in an if statement to check if the label exists, like so:
if game.Players.LocalPlayer.PlayerGui.ScreenGui.ReallyRedTeam then game.Players.LocalPlayer.PlayerGui.ScreenGui.ReallyRedTeam.Points.Text = redPoints end
But this is giving the same error. So my question is, how do I check that a label has been created before updating the points? thanks
Assuming this is a localcsript, you can use WaitForChild() which will yield until the label has been created!
game.Players.LocalPlayer.PlayerGui:WaitForChild("ScreenGui"):WaitForChild("ReallyRedTeam"):WaitForChild("Points").Text = redPoints
More information about WaitForChild here!
Alternatively, if you don't know for definite they will be created, you can use FindFirstChild. This won't yield.
if game.Players.LocalPlayer.PlayerGui.ScreenGui:FindFirstChild("ReallyRedTeam") then
print("it exists")
end
More information about FindFirstChild here!
Hope that helps!
If you want them all on one line each then the best to use would be FindFirstChild() as #jjwood1600 has said. I would also recommend making use of a variable to shorten your GUI paths as you can see below:
local function updateAllLabelsLateArrival(redPoints, bluePoints, yellowPoints, greenPoints)
local userGui = game.Players.LocalPlayer.PlayerGui.ScreenGui
if userGui:FindFirstChild("ReallyRedTeam") then userGui.ReallyRedTeam.Points.Text = redPoints end
if userGui:FindFirstChild("ReallyBlueTeam") then userGui.ReallyBlueTeam.Points.Text = bluePoints end
if userGui:FindFirstChild("NewYellerTeam") then userGui.NewYellerTeam.Points.Text = yellowPoints end
if userGui:FindFirstChild("LimeGreenTeam") then userGui.LimeGreenTeam.Points.Text = greenPoints end
end
In normal Lua you can indeed do the if statements the way you did where you don't use FindFirstChild but Roblox's own version RBX.Lua doesn't.
Related
I am facing the following issue: In our project, we have a main class with a main method called "run". This method calls hundreds of other functions, classes etc.
We are now calling this run method in a test in a for loop multiple times, something like that:
for(float test_time = 0; test_time < 10.0; test_time += 0.005){
outputStruct = mainClass.run(inputStruct);
}
I now want to save all local variables of all functions and methods and all member variables of all included objects that are seen when this for loop is executed. And I want to have a snapshot of this for each loop iteration. So in this example, there should be like 2000 snapshots of all my variables.
Is this somehow possible? I see that GDB has some "trace" functionality, but it's not clear for me how I can tell GDB that it should save everything that was "seen" while executing the mainClass.run method. It should "only" remember the last state of each member and local variable. And when test_time increments, it can finalize the current snapshot and create a new one for the next time slot.
Is something like this possible? Since our usecase is some physics based scenario, it is every interesting to see how certain values change over time in a plot later. I don't mind what the format of the output file of GDB is, it will be parsed later anyway, as long as the information is somehow inside. Of course, the cleaner the file looks the better :).
Thank you for your support guys!
I'm pretty new to lua scripting, but want to incorporate scripting into my game engine. Currently I have lua linked up to c++ in a basic manner where I can call methods from c++ classes and vise-versa. Lua scripts are setup as components and you can essentially attach scripts to a game object. However, I'm having an issue where my variables are being reset each time a script is called. Here is a basic example of a script:
--lua script--
input = InputManager()
function initalize()
end
function update()
if(input:KeyDown(KEY_SPACE)) then
print("Random before: ", input.random)
input.random = input.random + 10
print("Random after: ", input.random)
end
end
Initialize is called when the script component is attached and update is called every frame. In this example, in my c++ InputManager class that I bind up to lua, I have a integer random that is initialized to 5. I'm using lunafive properties to control the getting and setting of variables.
When I hit space i expect the first iteration to print out:
Random before: 5
Random after: 15
And then the next iteration:
Random before: 15
Random after: 25
However, every iteration I get that first result of 5 and 15. I realize this is because I'm loading the script each update method so it is probably just creating a new instance of InputManager.
How do I go about creating an instance of an object (i.e InputManager) and maintain that same instance every time I call update.
That way I could do something like this:
input = nil
function initalize()
input = InputManager()
end
function update()
print(input.random)
end
and not have an undefined instance of input once update is called. Hopefully this all makes sense, if not I can clarify! Any help is much appreciated!
I have one file "example.lua":
local function manipulate(something)
return string.rep(something, 3) -- repeats the given string
end
function apiFunction(somethingelse)
return manipulate(somethingelse)
end
and another files (main.lua) task is to "load"/"do" it:
loadAPI("example.lua", "externAPI") --< the part i need help with
externAPI.apiFunction("Test") --> should return TestTestTest
the thing that should happen is, that example.lua gets executed just like
dofile("example.lua")
but everything globally "defined" within example.lua (in this case the apiFunction) moves to the new generated global "externAPI" table and the rest (ie. manipulate) is hidden and only available from inside the example.lua file.
I've seen this bahaviour before in the minecraft mod "ComputerCraft" in which there is a function called "os.loadAPI("/somepath/sha-2") and it would define the definitions in the sha-2-chunk in the due to the name specified "sha-2"-table.
I've been searching for this sort of scoping/redirecting stuff for a while but there are no solutions putting the stuff into the new table.
I've been thinking of parsing the _G table after new indexes and move those to the new table but I'm sure there are some lua-magicians out here that know a much cleaner, better working solution to this.
All this is in one C lua_state* , so if there are any solutions adding this loadAPI function in C/C++ and just registrating it at the state this would be fine, too.
I've also looked at "require", but didn't seem to understand whether it does what I need.
Using Lua 5.2.3
Hope i didn't forget anything.
Thanks in advance :)
~InDieTasten
Try this:
function loadAPI(f,g)
_G[g]=setmetatable({},{__index=_G})
loadfile(f,"bt",_G[g])()
end
loadAPI("example.lua", "externAPI")
print(externAPI.apiFunction("Test"))
I am trying to add the instance of an object that I click on to a list on my control object. However when I do so it says that the reference is not set to an instance of an object. The code I have to instantiate the list on the control object is:
public List<Transform> selected = new List<Transform>();
And I tried to add to it to that list using this code attached to the unit:
if (!selected)
{
// Set selected state
selected = true;
// Add to Selected List
control.GetComponent<ForwardCommandScript>().selected.Add(this.transform);
// Set material colour brighter
oldColour = gameObject.renderer.material.color;
newColour = oldColour + new Color(0.2f, 0.2f, 0.2f);
gameObject.renderer.material.color = newColour;
}
I have tried with transform as well. Later I will try to remove it by finding a reference id that was set when the unit is instantiated so should I try to add the script instead of the object if I need to find its variables and then delete the game object attached to the script. I have tried with the GameObject, transform and the class. I wanted to use the class so I can easily access the variables. I have posted this on unity answers and forums but no one replied in the week it was up and I don't like reposting the same stuff on the same site.
Cheers, Scobbo
Your error NullReferenceException: Object reference not set to an instance of an object states that something in the associated line is null. Since the error message doesn't state which part is null, you have to split your code up and check which part is failing.
I'm not sure how you split it up, but try it this way:
var script = control.GetComponent<ForwardCommandScript>();
if (script == null) Debug.Log("script not found");
if (script.selected == null) Debug.Log("selected is null");
script.selected.Add(this.transform);
Now you should get one of the two messages in your debug log before the exception raises. Either the script was not found and you have to check if it is correctly assigned to the game object and if control is the correct game object, or selected is null which should not happen if you initialized it like you posted...
Thanks for adding the complete Error Message :)
you need to replace
control.GetComponent<ForwardCommandScript>().selected.Add(this.transform);
with
control.GetComponent<ForwardCommandScript>().selected.Add(transform);
because
this
is a reference to the script and not the GameObject. you could also use gameObject.transform which transform is just an abbreviation for
I'm working on a game engine in C++ using Lua for NPC behaviour. I ran into some problems during the design.
For everything that needs more than one frame for execution I wanted to use a linked list of processes (which are C++ classes). So this:
goto(point_a)
say("Oh dear, this lawn looks really scruffy!")
mowLawn()
would create a GotoProcess object, which would have a pointer to a SayProcess object, which would have a pointer to a MowLawnProcess object. These objects would be created instantly when the NPC is spawned, no further scripting needed.
The first of these objects will be updated each frame. When it's finished, it will be deleted and the next one will be used for updating.
I extended this model by a ParallelProcess which would contain multiple processes that are updated simultaneously.
I found some serious problems. Look at this example: I want a character to walk to point_a and then go berserk and just attack anybody who comes near. The script would look like that:
goto(point_a)
while true do
character = getNearestCharacterId()
attack(character)
end
That wouldn't work at all with my design. First of all, the character variable would be set at the beginning, when the character hasn't even started walking to point_a. Then, then script would continue adding AttackProcesses forever due to the while loop.
I could implement a WhileProcess for the loop and evaluate the script line by line. I doubt this would increase readability of the code though.
Is there another common approach I didn't think of to tackle this problem?
I think the approach you give loses a lot of the advantages of using a scripting language. It will break with conditionals as well as loops.
With coroutines all you really need to do is:
npc_behaviour = coroutine.create(
function()
goto(point_a)
coroutine.yield()
say("Oh dear, this lawn looks really scruffy!")
coroutine.yield()
mowLawn()
coroutine.yield()
end
)
goto, say and mowLawn return immediately but initiate the action in C++. Once C++ completes those actions it calls coroutine.resume(npc_behaviour)
To avoid all the yields you can hide them inside the goto etc. functions, or do what I do which is have a waitFor function like:
function waitFor(id)
while activeEvents[id] ~= nil do
coroutine.yield()
end
end
activeEvents is just a Lua table which keeps track of all the things which are currently in progress - so a goto will add an ID to the table when it starts, and remove it when it finishes, and then every time an action finishes, all coroutines are activated to check if the action they're waiting for is finished.
Have you looked at Finite State Machines ? If I were you I wouldn't use a linked list but a stack. I think the end result is the same.
stack:push(action:new(goto, character, point_a))
stack:push(action:new(say, character, "Oh dear, this lawn was stomped by a mammoth!"))
stack:push(action:new(mowLawn, character))
Executing the actions sequentially would give something like :
while stack.count > 0 do -- do all actions in the stack
action = stack:peek() -- gets the action on top of the stack
while action.over ~= true do -- continue action until it is done
action:execute() -- execute is what the action actually does
end
stack:pop() -- action over, remove it and proceed to next one
end
The goto and other functions would look like this :
function goto(action, character, point)
-- INSTANT MOVE YEAH
character.x = point.x
character.y = point.y
action.over = true -- set the overlying action to be over
end
function attack(action, character, target)
-- INSTANT DEATH WOOHOO
target.hp = 0
action.over = true -- attack is a punctual action
end
function berserk(action, character)
attack(action, character, getNearestCharacterId()) -- Call the underlying attack
action.over = false -- but don't set action as done !
end
So whenever you stack:push(action:new(berserk, character)) it will loop on attacking a different target every time.
I also made you a stack and action implementation in object lua here. Haven't tried it. May be bugged like hell. Good luck with your game !
I don't know the reasons behind you design, and there might be simpler / more idiomatic ways to it.
However, would writing a custom "loop" process that would somehow take a function as it's argument do the trick ?
goto(point_a)
your_loop(function ()
character = getNearestCharacterId()
attack(character)
end)
Since Lua has closures (see here in the manual), the function could be attached to your 'LoopProcess', and you call this same function at each frame. You would probably have to implement your LoopProcess so that that it's never removed from the process list ...
If you want your loop to be able to stop, it's a bit more complicated ; you would have to pass another function containing the test logic (and again, you LoopProcess would have to call this every frame, or something).
Hoping I understood your problem ...