Can I use custom C API functions from Lua bytecode?

I'm thinking of precompiling Lua noscripts I upload to an unmanned vehicle that has a custom C API noscript runner thing. Would this be possible/feasible?

https://redd.it/1k3x9au
@r_lua

Confused with OR operator

"if The logical operators are and, or, and not. Like control structures, all logical operators consider false and nil as false and anything else as true. The operator and returns its first argument if it is false; otherwise, it returns its second argument. The operator or returns its first argument if it is not false; otherwise, it returns its second argument:


print(4 and 5) --> 5
print(nil and 13) --> nil
print(false and 13) --> false
print(4 or 5) --> 4
print(false or 5) --> 5

Both and and or use short-cut evaluation, that is, they evaluate their second operand only when necessary."


I might be being dumb here, but as I understand OR in most operations, it evaluates true when either side is evaluated to be true, so shouldn't the last statement be printing false? I see that it says that they only evaluate the second operand when necessary, but wouldn't the first operand being false in an OR statement cause it to look at the second?

https://redd.it/1k42jt2
@r_lua

I want to learn how to code with Lua - how do I start? where do I start?

For those who have experience with Lua, how did you start? where did you start?

All I know of Lua is that it is considered "simple" and that it is used for games - I really would like to somewhat grasp Lua so I can start considering making games myself.

https://redd.it/1k4ktdk
@r_lua

Do I need require for each TU?

I'm not super familiar with LUA. I have an entry point of so called main noscript - entry.lua, I have a Logger.lua that has the tools for exactly what it says. Main noscripts has access to logger via require. Now I have to use logging tools in Events.lua - do I also need a require or because Events.lua is already "included" in main noscript the logging definitions are exposed higher up the chain and I can use them? And if I dont - any potentials side-effects form including them via require to appease luals?

https://redd.it/1k4lisq
@r_lua

A simple noscript to generate html code.

I just wanted to share this code to generate html code from lua, i made this because i don't like writing html and for fun to do something in lua. Any sugestions to improve it?

https://gitlab.com/-/snippets/4836971

https://redd.it/1k5qng1
@r_lua

Differences between Lua and LuaJIT?

Hi all. I've been a casual user of Lua for years and of LuaJIT for just a few months. I am not clear on all of the differences I need to know when writing code.

I know that integer division (//) is not implemented in LuaJIT and that LuaJIT has increased interoperability with C (which I haven't yet used). Yesterday I wrote a bit of code for LuaJIT that produces differently formatted output between Lua (5.4) and LuaJIT (5.1).

It worries me that there might be more gotchas lurking and a cheat sheet of everything a Lua programmer should know when switching to LuaJIT would be really useful (before I start diving into Lua version changes and seeing of this is a Lua version difference and not a Lua/LuaJIT difference).

Can anyone help?

https://redd.it/1k60myn
@r_lua

simulate MicroLua on Mac?

Hi all,

I'm trying to make a DS game to be run via MicroLua DS on DSi. I'm using a 2020 MacBook Pro M1 computer.


To test my program, I first tried using MicroLua Simulator https://sourceforge.net/p/microlua/wiki/MicroLuaSimulator/ but I couldn't compile it.


Then I tried Desmume, using the instructions given here: https://sourceforge.net/p/microlua/wiki/DeSmuME/ but the gba slot it mentions was nowhere to be found.


what do?

https://redd.it/1k69cww
@r_lua

I need help making a roblox noscript
https://redd.it/1k72ug3
@r_lua

is there a way i can make my noscript smaller?

i'm new to lua i just made a rock paper scissors game but i want to make the noscript smaller is there a way i can do that?
math.randomseed(os.time())



table = {"rock", "paper", "scissors"}



number = math.random(1, 3)



print ("Welcome to Rock Paper Scissors!\nChoose Your Move!")



move = string.lower(io.read("*l"))



if move == "rock" then

if number == 1 then

print("Tie!")

elseif number == 2 then

print ("You Lose!")

else

print ("You Win!")

end

end

if move == "paper" then

if number == 1 then

print("You Win!")

elseif number == 2 then

print ("Tie!")

else

print ("You Lose!")

end

end

if move == "scissors" then

if number == 1 then

print("You Lose!")

elseif number == 2 then

print ("You Win!")

else

print ("You Lose!")

end

end

print (table[number])

https://redd.it/1k83lvu
@r_lua

working on a laser targeting system. i am using a public lua radar that has the option to mark as a friendly(iff) or a target (lok) and i added a laser locking mode. it works except that it marks them as friendly's not target's. for stormworks

T={}F={}MT=10;MD=200;pi2=math.pi*2;p4=pi2/4;m=0;w,h=0,0;c=math.cos;r=table.remove;s=math.sin;srt=math.sqrt;tria=screen.drawTriangleF;sdc=screen.drawCircle;ot=output.setNumber;ip=input.getNumber;stc=screen.setColor;dL=screen.drawLine;function clr()for a,b in pairs(T)do b.lok=false end end;sb=output.setBool;function onTick()u,l=0,0;isP=input.getBool(2)tx=ip(23)ty=ip(24)cm=math.fmod((ip(22)+1.25)*pi2,pi2)Gx=ip(25)Gy=ip(26)rg=ip(28)alt=ip(29)ro=ip(30)*pi2;ptc=ip(31)*pi2;n=4;while n<12 do fx=ip(n)fy=ip(n+1)fz=ip(n+2)table.insert(F,{x=fx,y=fy,z=fz})n=n+3 end;if isP then t=idx(T,tx,ty)if t\~=nil then clr()sb(2,true)T[t\].lok=true else clr()sb(2,false)end end

\------------ laser mode start

select_x = input.getNumber(7)

select_y = input.getNumber(8)



if select_x \~= 0 and select_y \~= 0 then

local foundTarget = idx(T, select_x, select_y)

if foundTarget \~= nil then

clr()

T[foundTarget\].lok = true

sb(2, true)

end

end

\---------------laser mode end

;tg={tgt=input.getBool(1),d=ip(1),az=ip(2)*pi2,el=ip(3)*pi2,ttl=100,hd=0,spd=1,spdx=1,spdy=1,spdz=1,ti=m,br=0,lok=false,iff=false}h_dst=tg.d*c(tg.el)tg.tgx,tg.tgy,tg.tgz=cpT(Gx,Gy,alt,tg,ro,ptc,cm)if tg.tgt and h_dst>30 and h_dst<rg then e_t=nil;nrdst=math.huge;ni=nil;for e,f in ipairs(T)do px,py=nil,nil;dlt=(tg.ti-f.ti)/60;dist=srt((f.tgx-tg.tgx)\^2+(f.tgy-tg.tgy)\^2+(f.tgz-tg.tgz)\^2)if f.spd>50 then px=f.tgx+f.spdx*dlt;py=f.tgy+f.spdy*dlt;pz=f.tgz+f.spdz*dlt end;if px==nil or py==nil then if dist<=MD and dist<nrdst then nrdst=dist;e_t=f;ni=e end else sph=srt((tg.tgx-px)\^2+(tg.tgx-py)\^2+(tg.tgx-pz)\^2)if sph<=MD or dist<MD then e_t=f;ni=e end end end;if e_t then rz=tg.d/rg;tg.x=w/2+rz*w*2*math.cos(tg.az-p4)tg.y=h+rz*h*2*math.sin(tg.az-p4)dq=srt((tg.tgx-e_t.tgx)\^2+(tg.tgy-e_t.tgy)\^2+(tg.tgz-e_t.tgz)\^2)dlt=(tg.ti-e_t.ti)/60;spdx=(e_t.tgx-tg.tgx)/dlt;spdy=(e_t.tgy-tg.tgy)/dlt;spdz=(e_t.tgz-tg.tgz)/dlt;spd=srt(spdx\^2+spdy\^2)e_t.d=tg.d;e_t.az=tg.az;e_t.el=tg.el;e_t.x=tg.x;e_t.y=tg.y;e_t.ttl=100;e_t.iff=tg.iff;if dq>20 and math.abs(spd-e_t.spd)<200 then e_t.tgz=tg.tgz;e_t.tgy=tg.tgy;e_t.tgx=tg.tgx;e_t.spd=spd;e_t.spdx=spdx;e_t.spdy=spdy;e_t.spdz=spdz;hdg=cdH(e_t,tg)e_t.hd=hdg end;e_t.ti=tg.ti else if ni then r(T,ni)end;tg.id=#T+1;table.insert(T,tg)end end;if#T>MT then r(T,1)end;for a,tg in pairs(T)do for a,n in ipairs(F)do d=srt((tg.tgx-n.x)\^2+(tg.tgy-n.y)\^2+(tg.tgz-n.z)\^2)if d<50 then tg.iff=true end end;r_=tg.d/rg;h_dst=tg.d*c(tg.el)tg.x=w/2+r_*w*2*c(tg.az-p4)tg.y=h+r_*h*2*s(tg.az-p4)tg.ttl=tg.ttl-1;if tg.ttl<=0 then r(T,a)end;if h_dst>rg then r(T,a)end;if tg.lok then ot(7,tg.spd)ot(8,math.deg(tg.hd))ot(1,tg.tgx)ot(2,tg.tgy)ot(3,tg.tgz)ot(10,tg.az)ot(11,tg.el)end end;ot(5,#T)m=m+1 end;function onDraw()w=screen.getWidth()h=screen.getHeight()stc(0,255,0,255)for i,b in pairs(T)do dh(b,i)end end;function dh(tg,i)xd,xy=tg.x,tg.y;o=tg.hd;if tg.iff then stc(0,255,255,tg.ttl+150)else stc(0,255,0,tg.ttl+150)end;g=2;if tg.tgz>200 then g=3 elseif tg.tgz>400 then g=5 end;x1,y1=xd+g*c(o),xy+g*s(o)o=o+2*math.pi/3;x2,y2=xd+g*c(o),xy+g*s(o)o=o+2*math.pi/3;x3,y3=xd+g*c(o),xy+g*s(o)if tg.tgz<50 then if tg.lok then stc(255,150,0)screen.drawText(xd-4,xy,"[+\]")else screen.drawText(xd,xy,"+")end else if tg.lok then stc(255,150,0)tria(x1,y1,x2,y2,x3,y3)else screen.drawTriangle(x1,y1,x2,y2,x3,y3)end;dL(x1,y1,x1+4*s(tg.hd+p4),y1-4*c(tg.hd+p4))end end;function cdH(o,n)hd=cm-math.atan(n.spdy-o.spdy,n.spdx-o.spdx)-p4;return hd end;function idx(j,k,p)for e,b in pairs(j)do if k<=b.x+2 and k>=b.x-2 and p<=b.y+2 and p>=b.y-2 then return e end end;return nil end;function idM()return{{1,0,0,0},{0,1,0,0},{0,0,1,0},{0,0,0,1}}end;function mxM(j,q)ra=idM()for e=1,4 do for v=1,4 do sum=0;for i=1,4 do sum=sum+j[e\][i\]*q[i\][v\]end;ra[e\][v\]=sum end end;return ra end;function

mxapp(m,k,p,x)rx=m[1\][1\]*k+m[1\][2\]*p+m[1\][3\]*x+m[1\][4\]ry=m[2\][1\]*k+m[2\][2\]*p+m[2\][3\]*x+m[2\][4\]rz=m[3\][1\]*k+m[3\][2\]*p+m[3\][3\]*x+m[3\][4\]return rx,ry,rz end;function mRx(j)return{{1,0,0,0},{0,c(j),-s(j),0},{0,s(j),c(j),0},{0,0,0,1}}end;function mRy(j)return{{c(j),0,s(j),0},{0,1,0,0},{-s(j),0,c(j),0},{0,0,0,1}}end;function mRz(j)return{{c(j),-s(j),0,0},{s(j),c(j),0,0},{0,0,1,0},{0,0,0,1}}end;function mxT(k,p,x)return{{1,0,0,k},{0,1,0,p},{0,0,1,x},{0,0,0,1}}end;function cpT(y,z,A,tg,r,B,p)mxc=mxM(mxT(y,-z,A),mxM(mRz(-p),mxM(mRy(-B),mRx(-r))))Txr=tg.d*c(tg.az)*c(tg.el)tyr=tg.d*s(tg.az)*c(tg.el)tzt=tg.d*s(tg.el)Tx,Ty,Tz=mxapp(mxc,Txr,tyr,tzt)return Tx,-Ty,Tz end

https://redd.it/1k84z5n
@r_lua

Official Lua Mascot
https://redd.it/1k89y7q
@r_lua

I made a little rock paper scissors program inspired by a recent post

Idk why but seeing this post https://www.reddit.com/r/lua/s/eWJooyqrJZ
Just gave me an itch to remake it, anyway:

local moves = {
    rock = {rock = "Draw", paper = "Loss", scissors = "Win!"},
    paper = {rock = "Win!", paper = "Draw", scissors = "Loss"},
    scissors = {rock = "Loss", paper = "Win!", scissors = "Draw"}
}

local function GetRandMove(randNum)
    local n = 0
    local randNum = math.random(1, 3)
    for k, _ in pairs(moves) do
        n = n + 1
        if randNum == n then return k end
    end
end

local function sleep(n)
    local t = os.time() + n
    while os.time() < t do end
end

print([[

Time to Play:

--------
rock
paper
scissors
--------
]])

while true do
    print("\nYour Move: ")

    local PlayerInput = io.read()
    local BotMove = GetRandMove()
    
    print(BotMove, "\n")
    
    sleep(.2)

    print(moves[PlayerInput][BotMove])

    sleep(.4)

    ::playagain::

    print("\ntype y to play again or x to quit: \n")

    local playAgain = io.read()

    if playAgain == "x" then
        print("Goodbye!")
        break
    elseif playAgain == "y" then
        print("\nAlright!\n")
    else
        goto playagain
    end
end

https://redd.it/1k8gezl
@r_lua

Yo guys, I have a question about the book

Is the book still relevant? And do you think it's worth buying or should I focus on learning from the internet?

https://redd.it/1k8jpsx
@r_lua

I'm trying to make a nice TV weather app, to show the potential and validate my cross-platform framework.
https://redd.it/1k8t3z7
@r_lua

Is there ANY difference between these two Lua snippets?

Snippet 1:

local function f(x,y)
local y = y or 1 -- Note: "local" here.`
do_something(x,y)
end

Snippet 2:

local function f(x,y)
y = y or 1 -- Note: no "local" here.
do_something(x,y)
end

I know why this pattern is often used but is there any situation whatsoever where these two snippets do not behave identically? If Lua version matters, I am specifically interested in LuaJIT. Also, if it matters, let's assume x and y are simple Lua values. They are **not** objects and don't have metatables.

https://redd.it/1k93frj
@r_lua

Where can i learn luau?

I am a very early stage roblox game developer and I need to know where is the best option to learn luau. I have been on the same youtube, there are few lessons. I read the documentation - it is unclear. What do you suggest me to do? Maybe I'm writing to the wrong community, but I still need help.

https://redd.it/1k9bqjt
@r_lua

Can nested loop have different types of loops within?

for example

for initialization, min/max value, iteration --yes this is numeric for idc
do
--insert stuff for 1st loop
while (condition)
do
--insert stuff for 2nd loop
repeat
--insert stuff for 3rd loop
until (condition)
end
end

i was wondering if it's possible to do so, since in many instance, nested loops will use loops of the same type...

https://redd.it/1k9ci93
@r_lua

Lua by example?

I'm thinking of developing a Lua by example. Is this something the community would like to see?

https://redd.it/1k9qek4
@r_lua

Is there robllox noscript to face fuc?



https://redd.it/1kbd621
@r_lua

Advice

Hi. New here. And to Lua as a whole. I am currently learning Lua to embed it into C++ and possibly use it together with the C++ inline assembler for game development. However Lua is not a walk in the park. The basics of Lua are. And I am stuck there. The basics. Actually, outside of the basic input output, data type conversions (Tostring/tonumber), io.open()/ file:read() / file:close(), os.execute() and maybe "require", i cant say i understand much else.. Trust me i tried but this isnt as easy as promised.. Lua has a very special complexity surrounding it that you only discover after starting..

What advice do you have for a freshman college student like me learning Lua. I should add this is not a part of the program I am doing. Its just a personal interest. How did you master Lua or at least know enough of it to produce a game in it either in pure Lua or Lua embedded in C.

https://redd.it/1kbpn57
@r_lua