Well I'm learning lua and I got a question, I'm trying to create a reading function bool in lua.
I have a function that disables or enables as I score true or false.
This function is called just useappenabled that I am not able to apply it on the Moon, before I used in the form of libconfig and functioned normally before was written as follows.
The file is as follows:
Enableapp =
{
Useapp = true;
};
Now reading before shaped libconfig was the following, note that the useappenabled function is applied to the input value, i.e. true or false if I put on the Useapp.
if (config_lookup(&onf, "Enableapp"))
if (config_setting_lookup_bool(cf, "Useapp", &SelectValue))
useappenabled = SelectValue;
So I tried changing the code libconfig to lua, however I am not able to read the useappenabled function, the code is as follows in the lua.
lua_getglobal(L, "Enableapp");
lua_pushstring(L, "Useapp");
lua_tonumber(L, useappenabled);
I believe the problem is lua_tonumber, I need to do something more or less like this:
useappenabled = value_the_Useapp;
But I'm starting lua now, can anybody tell me how can I apply the function useappenabled to equal the Useapp value.
not able to apply it on the Moon
That's an issue with most Earthly software. The usual difficulty is reaching the Moon.
I need to do something more or less like this:
useappenabled = value_the_Useapp;
lua_getglobal(L, "Enableapp"); // push the table onto the stack
lua_getfield(L, -1, "Useapp"); // index table with "Useapp" and push result onto the stack
useappenabled = lua_toboolean(L, -1); // get the value off the top of the stack into your C code
Related
I have a Lua function where I build a table of value and attempt to add it to a global table with a named key.
The key name is pulled from the function arguments. Basically, it's a filename, and I'm pairing it up with data about the file.
Unfortunately, the global table always comes back nil. Here's my code: (let me know if you need to see more)
(Commented parts are other attempts, although many attempts have been deleted already)
Animator = Class{}
function Animator:init(atlasfile, stringatlasfriendlyname, totalanimationstates, numberofframesperstate, booleanstatictilesize)
-- Define the Animator's operation mode. Either static tile size or variable.
if booleanstatictilesize ~= false then
self.isTileSizeStatic = true
else
self.isTileSizeStatic = false
end
-- Define the total animation states (walking left, walking right, up down, etc.)
-- And then the total frames per state.
self.numAnimationStates = totalanimationstates or 1
self.numAnimationFrames = numberofframesperstate or 2
-- Assign the actual atlas file and give it a programmer-friendly name.
self.atlasname = stringatlasfriendlyname or removeFileExtension(atlasfile, 'animation')
generateAnimationQuads(atlasfile, self.atlasname, self.numAnimationStates, self.numAnimationFrames)
end
function generateAnimationQuads(atlasfile, atlasfriendlyname, states, frames)
spriteWidthDivider = atlasfile:getWidth() / frames
spriteHeightDivider = atlasfile:getHeight() / states
animationQuadArray = generateQuads(atlasfile, spriteWidthDivider, spriteHeightDivider)
animationSetValues = {atlasarray = animationQuadArray, width = spriteWidthDivider, height = spriteHeightDivider}
--gAnimationSets[#gAnimationSets+1] = atlasfriendlyname
gAnimationSets[atlasfriendlyname] = animationSetValues
--table.insert(gAnimationSets, atlasfriendlyname)
end
Note: when using print(atlasfriendlyname) and print(animationSetValues), neither are empty or nil. They both contain values.
For some reason, the line(s) that assign the key pair to gAnimationSets does not work.
gAnimationSets is defined a single time at the top of the program in main.lua, using
gAnimationSets = {}
Animator class is called during the init() function of a character class called Bug. And the Bug class is initialized in the init() function of StartState, which extends from BaseState, which simply defines dummy init(), enter(), update() etc. functions.
StartState is invoked in main.lua using the StateMachine class, where it is passed into StateMachine as a value of a global table declared in main.lua.
gAnimationSets is declared after the table of states and before invoking the state.
This is using the Love2D engine.
Sorry that I came here for help, I've been picking away at this for hours.
Edit: more testing.
Trying to print the animationQuadArray at the index gTextures['buganimation'] always returns nil. Huh?
Here's gTextures in Main.lua
gTextures = {
['background'] = love.graphics.newImage('graphics/background.png'),
['main'] = love.graphics.newImage('graphics/breakout.png'),
['arrows'] = love.graphics.newImage('graphics/arrows.png'),
['hearts'] = love.graphics.newImage('graphics/hearts.png'),
['particle'] = love.graphics.newImage('graphics/particle.png'),
['buganimation'] = love.graphics.newImage('graphics/buganimation.png')
}
Attempting to return gTextures['buganimation'] returns a file value as normal. It's not empty.
My brain is so fried right now I can't even remember why I came to edit this. I can't remember.
Global table in Main.lua, all other functions can't access it.
print(gTextures['buganimation']) works inside the function in question. So gTextures is absolutely accessible.
Table isn't empty. AnimationSetValues is not empty.
I'm adding second answer because both are correct in context.
I ended up switching IDE's to VS Code and now the original one works.
I was originally using Eclipse LDT with a Love2D interpreter and in that environment, my original answer is correct, but in VS Code, the original is also correct.
So Dimitry was right, they are equivalent, but something about my actual Eclipse setup was not allowing that syntax to work.
I switched to VS Code after I had another strange syntax problem with the interpreter where goto syntax was not recognized and gave a persistent error. The interpreter thought goto was the name of a variable.
So I switched, and now both things are fixed. I guess I just won't use LDT for now.
Solution: Lua syntax. Brain Fry Syndrome
I wrote:
animationSetValues = {atlasarray = animationQuadArray, width = spriteWidthDivider, height = spriteHeightDivider}
Should be:
animationSetValues = {['atlasfile']=atlasfile, ['atlasarray']=animationQuadArray, ['width']=spriteWidthDivider, ['height']=spriteHeightDivider}
Edit: I'm fully aware of how to use answers. This was posted here to reserve my spot for an answer so I could edit it later when I returned back home, which is exactly what I'm doing right now. I'll keep the old post for archival purposes.
Original:
I solved it. I apologize for not posting the solution right now. My brain is melted into gravy.
I will post it tomorrow. Just wanted to "answer" saying no need to help. Solved it.
Solution is basically, "oh it's just one of those Lua things". Wonderful. I'm having so much fun with this language - you can tell by my blank expression.
From the language without line endings or brackets, but forced print parentheses... ugh. I'm going back to C# when this class is done.
Actually I am writting a programming language in Lua. It was quite fun. I've wrote a bit of standard library (stack op and simple io). Then I've thought about labels. It would look like in assembly. While and for loop aren't funny in any bit so programming in that language can be quite challenging. Here are some requirements for this system:
Label stack (or array, dictionary) must be accessible from global context.
Jump instruction handler will be in separate file.
This is how my label-handling function look like:
function handleLabel(name,currentLine)
end
I have no idea how to implement this kind of magic. First I've thought about that:
LabelLineIDS = {}
Labels = {}
Labelamount = 1;
function handleLabel(name,currentLine)
LabelLineIDS[Labelamount]=currentline
Labels[Labelamount]=name
Labelamount=Labelamount+1
end
-- In file "jump.lua":
local function has_value (tab, val)
for index, value in ipairs(tab) do
if value == val then
return index
end
end
print ("Error: Label not defined.") -- Bail out.
os.exit(1)
end
local function _onlabel()
local labelName = globalparams --Globalparams variable contain parameters to each function, at the moment
--this will contain label name. It _can_ be nil.
return LabelLineIDS[has_value(Labels, labelName)]
end
CurrLine = _onlabel() --Currline - current line that get's parsed.
--1 command per one line.
But I'm unsure is this well written or even work. Can you give me idea how to parse labels in my programming language (and write jump functions)? Or if my code is pretty ok at the moment, can you help me to improve it?
Using line counter in my parser I've decided to implement gotos like we can see in BASIC. Thanks everyone for help.
This code is for a modding engine, Unitale base on Unity Written in Lua
So I am trying to use a Boolean Variable in my script poseur.lua, so when certain conditions are met so I can pass it to the other script encounter.lua, where a engine Predefined functions is being uses to make actions happens base on the occurring moment.
I tried to read the engine documentation multiple times, follow the exact syntax of Lua's fonction like GetVar(), SetVar(), SetGobal(),GetGlobal().
Searching and google thing about the Language, post on the subreddit and Game Exchange and tried to solve it by myself for hours... I just can't do it and I can't understand why ?
I will show parts of my codes for each.
poseur:
-- A basic monster script skeleton you can copy and modify for your own creations.
comments = {"Smells like the work\rof an enemy stand.",
"Nidhogg_Warrior is posing like his\rlife depends on it.",
"Nidhogg_Warrior's limbs shouldn't\rbe moving in this way."}
commands = {"GREET", "JUMP", "FLIRT", "CRINGE"}
EndDialougue = {" ! ! !","ouiii"}
sprite = "poseur" --Always PNG. Extension is added automatically.
name = "Nidhogg_Warrior"
hp = 99
atk = 1
def = 1
check = "The Nidhogg_Warrior is\rsearching for the Nidhogg"
dialogbubble = "rightlarge" -- See documentation for what bubbles you have available.
canspare = false
cancheck = true
GreetCounter = 5
Berserk = false
encounter:
-- A basic encounter script skeleton you can copy and modify for your own creations.
encountertext = "Nidhogg_Warrior is\rrunning frantically"
nextwaves = {"bullettest_chaserorb"}
wavetimer = 5.0
arenasize = {155, 130}
music = "musAncientGuardian"
enemies = {"poseur"}
require("Monsters.poseur")
enemypositions = {{0, 0}}
-- A custom list with attacks to choose from.
-- Actual selection happens in EnemyDialogueEnding().
-- Put here in case you want to use it.
possible_attacks = {"bullettest_bouncy", "bullettest_chaserorb", "bullettest_touhou"}
function EncounterStarting()
-- If you want to change the game state immediately, this is the place.
Player.lv = 20
Player.hp = 99
Player.name = "Teemies"
poseur.GetVar("Berserk")
end
Thank you for reading.
The answer to my problem was to use SetGobal(), GetGobal().
For some reasons my previous attempt to simply use SetGobal()Resulted in nil value despite writing it like that SetGobal("Berserk",true) gave me a nill value error, as soon as I launch the game.
But I still used them wrong. First I needed to put it SetGobal() at the end of the condition instead of at the start of the the poseur.lua script because the change of value... for some reasons was being overwritten by it first installment.
And to test the variable in the function in my encounter.lua, I needed to write it like that
function EnemyDialogueStarting()
-- Good location for setting monster dialogue depending on how the battle is going.
if GetGlobal("Jimmies") == true then
TEEEST()
end
end
Also any tips an suggestions are still welcome !
Well firstly, in lua simple values like bool and number are copied on assignment:
global={}
a=2
global.a=a--this is a copy
a=4--this change won't affect value in table
print(global.a)--2
print(a)--4
Secondly,
SetGobal and the other mentioned functions are not part of lua language, they must be related to your engine. Probably, they use word 'Global' not as lua 'global' but in a sense defined by engine.
Depending on the engine specifics these functions might as well do a deep copy of any variable they're given (or might as well not work with complicated objects).
I have a problem which i suppose must be very common and most of you would have faced it.
I have written a program in lua, say main.lua which on receiving key event should modify the coordinates and display the geometry figure.
This lua code calls reg.c, where it kind of registers.
Now in reg.c i have a function engine which receives the key pressed and passes it to the lua function responsible for key handling.
But by the time key event comes, lua code is done with the registration and exits, thus the call from engine() becomes illegal memory access leading to segmentation fault.
Also i suppose we can't have lua call hanging in reg function, and call engine function from somewhere else.
Then what should be the solution, please guide me through this.
#jacob: here is the prototype of what i am trying to achieve:
function key_handler() //this function will get the latest key pressed from some other function
{
draw.image();
draw.geometry();
...
...
while(1)
{
//draw Points until some condition goes wrong
}
}
Now, once entered into key_handler, while he is busy drawing the points unless and until the failing condition occurs, i am unable to receive key pressed till that time.
I hope this explanation is much simpler and have made my point, and will help others to understand the problem.
I am really sorry, but i am not good at expressing or making others understand.
One more thing, i ahve followed the C syntax to explain, however this is completely implemented in lua
Your code snippet is still largely non-informative (ideally one should be able to just run your code in a stock Lua interpreter and see your problem). If you're describing a Lua problem, use Lua code to describe it.
However I'm beginning to see where you want to go.
The thing you need to could do is have a coroutine that's called in your key handler, which passes an argument back to your handler:
function isContinue() --just to simulate whatever function you use getting keypresses.
-- in whatever framework you're using there will probably be a function key_pressed or the like.
print('Initialize checking function')
while true do
print('Continue looping?')
local ans = io.read():match('[yY]')
local action
if not ans then
print('Do what instead?')
action = io.read()
if action:match('kill') then -- abort keychecker.
break
end
end
coroutine.yield(ans,action)
end
print('finalizing isContinue')
return nil,'STOP' -- important to tell key_handler to quit too, else it'll be calling a dead coroutine.
end
function key_handler()
local coro = coroutine.create(isContinue)
local stat,cont,action
while true do
print'Draw point'
stat,cont,action = coroutine.resume(coro)
if not stat then
print('Coroutine errored:',cont)
elseif not cont then
print('isContinue interrupted keyhandler')
print("We'll "..action.." instead.")
break
end
end
print('finalizing key_handler')
end
key_handler()
-- type something containing y or Y to continue, all else aborts.
-- when aborting, you get asked what to do instead of continuing,
--- with "kill" being a special case.
This should be self explanatory. You should probably take a good look at Programming in Lua, chapter 9: Coroutines.
The big difficulty (well, if you're not accustomed to collaborative threading) is that a coroutine should yield itself: it's not the calling function that's in charge of returning control.
Hope this helps you.
I'm trying to get a handle on how OOP is done in Lua, and I thought I had a simple way to do it but it isn't working and I'm just not seeing the reason. Here's what I'm trying:
Person = { };
function Person:newPerson(inName)
print(inName);
p = { };
p.myName = inName;
function p:sayHello()
print ("Hello, my name is " .. self.myName);
end
return p;
end
Frank = Person.newPerson("Frank");
Frank:sayHello();
FYI, I'm working with the Corona SDK, although I am assuming that doesn't make a difference (except that's where print() comes from I believe). In any case, the part that's killing me is that inName is nil as reported by print(inName)... therefore, myName is obviously set to nil so calls to sayHello() fail (although they work fine if I hardcode a value for myName, which leads me to think the basic structure I'm trying is sound, but I've got to be missing something simple). It looks, as far as I can tell, like the value of inName is not being set when newPerson() is called, but I can't for the life of me figure out why; I don't see why it's not just like any other function call.
Any help would be appreciated. Thanks!
Remember that this:
function Person:newPerson(inName)
Is equivalent to this:
function Person.newPerson(self, inName)
Therefore, when you do this:
Person.newPerson("Frank");
You are passing one parameter to a function that expects two. You probably don't want newPerson to be created with :.
Try
Frank = Person:newPerson("Frank");