Lua Programming Help Thread

[EminentJonFrost]

Okay, so I have just begun learning lua recently, and I am making a stupid app for practice/learning. I have this code:

--App by andyauff
--Version .02 of "Useless Music App", finished January   , 2007

--define colors---------------------------------------------------

white = Color.new (255,255,255)
blue = Color.new (0,0,255)
black = Color.new (0,0,0)
red = Color.new (255,0,0)
green = Color.new (0,255,0)
yellow = Color.new (255,255,0)
purple = Color.new (255,0,255)

--create the menu function----------------------------------------

function drawMenu()  

gamestate = "menu"
oldpad = Controls.read()
song = "mindwave"

selector = { image = Image.createEmpty (145,15), x = 147, y = 77}
selector.image:clear(yellow)

screen:clear(green)

pad = Controls.read()

screen:blit(selector.x,selector.y,selector.image)

screen:print(150,80,"Mindwave",blue)
screen:print(150,100,"Minute",blue)

--controls

if pad:up() and oldpad:up() ~= pad:up() then
selector.y = 77
song = "mindwave"
end

if pad:down() and oldpad:down() ~= pad:down() then
selector.y = 97
song = "minute"
end

if pad:cross() and oldpad:cross() ~= pad:cross() then
inGame()
end
screen.flip()
end

--create the game funtion------------------------------------------

function inGame()

gamestate = "start"

pad = Controls.read()

screen:clear(red)
screen:print(150,100,"To play song, press X.",green)
screen:print(150,120,"To pause song, press X again.",yellow)
screen:print(150,140,"Enjoy!",purple)

if pad:cross() and gamestate == "start" and song == "mindwave" then
Music.playFile("mindwave.mod", false)
gamestate = "playing"
end

if pad:cross() and gamestate == "start" and song == "minute" then
Music.playFile("minute.xm", false)
gamestate = "playing"
end

if pad:cross() and gamestate == "playing" then
Music.pause()
gamestate = "paused"
end

if pad:cross() and gamestate == "paused" then
Music.resume()
gamestate = "playing"
end

if pad:start() then
gamestate = "menu"
end
screen.flip()
end

--main loop---------------------------------------------------------

while true do

drawMenu()
oldpad = pad
end

First let me tell you what it is supposed to do- there is a start screen that is a menu with choices between 2 different songs to play. If you click (cross) on a song, it should go to a new screen that says "press x to play song, press x again to pause song, enjoy." The selected song should play once pressing cross, pause if cross is pressed again, and that's about it. I have many problems-the selector for the menu doesn't move, when I press X it sometimes plays music, sometimes it doesn't, and instead of pausing it stops it completely and starts back over when I press X again. Thanks for any help, I know this is confusing. Hopefully the code is at least sort of neat.

I believe this should work. :)
Its not very much different from yours, i believe you can figure out the differences and their effects.

--App by andyauff
--Version .02 of "Useless Music App", finished January   , 2007

--define colors---------------------------------------------------

white = Color.new (255,255,255)
blue = Color.new (0,0,255)
black = Color.new (0,0,0)
red = Color.new (255,0,0)
green = Color.new (0,255,0)
yellow = Color.new (255,255,0)
purple = Color.new (255,0,255)

oldpad = Controls.read()
song = "mindwave"

--create the menu function----------------------------------------

function drawMenu()  
	gamestate = "menu"

	selector = { image = Image.createEmpty (145,15), x = 147, y = 77}
	selector.image:clear(yellow)

	screen:clear(green)

	pad = Controls.read()

	screen:blit(selector.x,selector.y,selector.image)

	screen:print(150,80,"Mindwave",blue)
	screen:print(150,100,"Minute",blue)

	--controls

	if pad:up() and oldpad:up() ~= pad:up() then
		selector.y = 77
		song = "mindwave"
	end

	if pad:down() and oldpad:down() ~= pad:down() then
		selector.y = 97
		song = "minute"
	end

	screen.flip()
end

--create the game funtion------------------------------------------

function inGame()
	gamestate = "start"

	pad = Controls.read()

	screen:clear(red)
	screen:print(150,100,"To play song, press X.",green)
	screen:print(150,120,"To pause song, press X again.",yellow)
	screen:print(150,140,"Enjoy!",purple)

	if pad:cross() and oldpad:cross() ~= pad:cross() then
		if gamestate == "start" then
			if song == "mindwave" then
				Music.playFile("mindwave.mod", false)
			elseif song == "minute" then
				Music.playFile("minute.xm:, false)
			end
			gamestate = "playing"
		elseif gamestate == "playing" then
			Music.pause()
			gamestate = "paused"
		elseif gamestate == "paused" then
			Music.resume()
			gamestate = "playing"
		end
	end

	if pad:start() then
		gamestate = "menu"
	end

	screen.flip()
end

--main loop---------------------------------------------------------

while true do
	drawMenu()

	inGame()

	oldpad = pad
end

[andyauff]

Thanks a lot for the help, but unfortunately that didn't work either. It was flashing quickly between the menu and the instructions screen, and the music still starts over instead of pausing. Also, the selector still doesn't move. I think some of it may have to do with the main loop, it may be trying to run both functions at the same time? I'm new to lua but that sounds reasonable to me. Thanks a lot for the help, I'll see if I can mess around with it. And if you want to waste more time helping me, I can give you the eboot so you can run the script to test it. Just if you feel like it though. Thanks a lot for helping.

[altunozara]

omfg ive triedso harf to fix my game go go go! but noone will help!

[eyece]

Can somone anwser to my question please.Page 516 firstpost.

allot of people dont use the default vBulletin settings for posts per page.
get the post id.

[BlackShark]

I do :P whats the post id?

[altunozara]

hey guys u know when you say like when you clickm square do something
what would it be for the right d pad like wats it called when you right it...r?

[eyece]

buttonstate:left()

and i don't know what the post id is, i was asking zereox to get it for me.

[GuitarGod1134]

The psp buttons

pad = Controls.read()

pad:cross()

pad:square()

pad:triangle()

pad:circle()

--shoulder buttons
pad:r()
pad:l()

--d pad
pad:left()
pad:right()
pad:up()
pad:down()

Im pretty sure thats all right.

Now to use them its just if pad:down() then or however you want to use them.

[altunozara]

you might have heard of GO GO GO! i want to make an ai and ive tried to just do a test...and hmm heres my code can anyone tell me what ive done rong...it wont work

 
-- Loading music
Music.playFile ("ame002.it", true)
green=Color.new(0,255,0)
timer=Timer.new()
math.randomseed(os.time())
-- load graphics
tiles = Image.load("tiles.png")
figure = Image.load("figure.png")-- load graphics
tiles = Image.load("tiles.png")
figure = Image.load("figure.png")
-- the map
mapSource = {
 "mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm",
 "meaaaaaaaaaaaaaaaaaaaaaaaaaafm",
 "mdoooooooooooooooooooooooooobm",
 "mdoooooooooooooooooooooooooobm",
 "mdoooooooooooooooooooooooooobm",
 "mdoooooooooooooooooooooooooobm",
 "mdoooooooooooooooooooooooooobm",
 "mdoooooooooooooooooooooooooobm",
 "aiooooooooooooooooooooooooooja",
 "oooooooooooooooooooooooooooooo",
 "clooooooooooooooooooooooooookc",
 "mdoooooooooooooooooooooooooobm",
 "mdoooooooooooooooooooooooooobm",
 "mdoooooooooooooooooooooooooobm",
 "mdoooooooooooooooooooooooooobm",
 "mhccccccccccccccccccccccccccgm",
 "mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm",
}
 
-- offsreen image, where the map will be drawn
board = Image.createEmpty(480, 272)
 
-- draw one tile on the map
function drawTile(tile, x, y)
 tile = string.byte(tile, 1) - string.byte("a")
 local tileX = math.mod(tile, 4)
 local tileY = math.floor(tile / 4)
 board:blit(16 * x, 16 * y, tiles, 17 * tileX + 1, 17 * tileY + 1, 16, 16, false)
end 
 
-- copy the map source to an array for easier access and draw the offscreen board
map = {}
for y = 1, 17 do
 line = mapSource[y]
 map[y] = {}
 for x = 1, 30 do
  tile = string.sub(line, x, x)
  map[y][x] = tile
  drawTile(tile, x - 1, y - 1)
 end
end
 
-- current player position
playerX = 6
playerY = 14
-- current player 2 position
playerX = 15
playerY = 15
 
-- current player animation image
animation = 0
 
-- 1 = animation images increases, -1: decreases
animationDirection = 1
 
-- animation slowdown counter
animationSlowDown = 0
 
-- controls the movement speed. At speedStep == 0, the last
-- pad will be evaluated, other steps the pad movements are only
-- saved
speedStep = 0
 
-- last pad direction
dx = 0
dy = 0
 
-- current score
score = 0
 
-- text color
white = Color.new(255, 255, 255) 
gameover = Image.load("gameover.png")
-- text color
white = Color.new(255, 255, 255) 
gameover = Image.load("gameover.png")
while true do
timer:start()
if timer:time() > 10 then
 screen:blit(0,0,gameover,    true)
  end
 
-- read current pad
 pad = Controls.read()
 
 if pad:start() then
  -- exit to lowser, if started from there
  break
 end
 if speedStep == 0 then
  -- save old player position
  oldPlayerX = playerX
  oldPlayerY = playerY
  
  -- add last movement
  playerX = playerX + dx
  playerY = playerY + dy
  
  -- check new tile
  newTile = map[playerY][playerX]
  
  -- if the position is not allowed, restore old player position
  if newTile ~= "n" and newTile ~= "o" and newTile ~= "r" and newTile ~= "s" and newTile ~= "t" and newTile ~= "p" and newTile ~= "q" then
   playerX = oldPlayerX
   playerY = oldPlayerY
  end
  
  -- if it is a tile which can be eaten, eat it
  if newTile == "o" then score = score + 1 end
  if newTile == "o" then
   -- set background tile
   map[playerY][playerX] = "n"
 
   -- draw background tile
   drawTile("o", playerX - 1, playerY - 1)
  end
  
  -- reset last movement
  dx = 0
  dy = 0
 else
--Player movements
  
  if pad:up() then
   dy = -1
  elseif pad:down() then
   dy = 1
  elseif pad:left() then
   dx = -1
  elseif pad:right() then
   dx = 1
                elseif pad:cross() then
drawTile("o", playerX - 1, playerY - 1)
elseif pad:square() then
drawTile("r", playerX - 1, playerY - 1)
elseif pad:circle() then
drawTile("s", playerX - 1, playerY - 1)
elseif pad:triangle() then
drawTile("t", playerX - 1, playerY - 1)
elseif pad:l() then
drawTile("n", playerX - 1, playerY - 1)
elseif pad:r() then
dofile("battle land.lua")
  end
end
 
 -- update speed step counter
 speedStep = speedStep + 1
 if speedStep == 5 then
  speedStep = -1
 end
 
 -- blit board
 screen:blit(0, 0, board, 0, 0, board:width(), board:height(), false)
 
 -- blit current player animation image
 screen:blit((playerX - 1) * 16 - 4, (playerY - 1) * 16 - 4, figure, 1 + 25 * animation, 1, 24, 24)
 
 -- calculate next animation image
 animationSlowDown = animationSlowDown + 1
 if animationSlowDown == 3 then
  animationSlowDown = 0
  animation = animation + animationDirection
  if animation == 4 then
   animationDirection = -1
  elseif animation == 0 then
   animationDirection = 1
  end
 end
 
 -- print score
 screen:print(10, 260, "Score: " .. score, white)
        --print time
 screen:print(0,0,"Time:"..timer:time()/1000,green)
 -- wait for vertical sync and show new screen
 screen.waitVblankStart()
 screen:flip()
end
--** AI MOULD CREATION **--
--Mould 1 - figure
figuremould = {}
--figuremould.AI = math.random(1, 100)   To be done later
figuremould.run = true
figuremould.jog = false
figuremould.sprint = false
figuremould.x = 0
--**AI Mould Creation End**
--main loop
while true do
screen:clear()
screen:blit(0, 0, tiles)
--figure AI
if figuremould.x <= 480 then
figuremould.AI = math.random(1, 100)
if figuremould.AI == 75 or Easymould.AI == 100 then
figuremould.run = false
figuremould.jog = true
figuremould.sprint = false
end
if figuremould.AI == 99 then
figuremould.sprint = false
figuremould.run = true
figuremould.jog = false
end
if figuremould.AI == 2 then
figuremould.sprint = true
figuremould.run = false
figuremould.jog = false
end
if figuremould.run == true then
figuremould.x = figuremould.x + 2
end
if figuremould.jog == true then
figuremould.x = figuremould.x + 1
end
if figuremould.sprint == true then
figuremould.x = figuremould.x + 3
endend
--****ARTIFICIAL INTELLIGENCE**** END
figuremould.AI = math.random(1, 100)
if figuremould.AI == 75 or Easymould.AI == 100 then
figuremould.jog = true
if figuremould.run == true then
figuremould.x = figuremould.x + 2
end
if figuremould.jog == true then
figuremould.x = figuremould.x + 1
end
if figuremould.sprint == true then
figuremould.x = figuremould.x + 3
end
screen:blit(figuremould.x, 42, figure)

[GuitarGod1134]

Well before I look into the vast lines of code you have there what error are you getting?

[altunozara]

umm what do i do to check again..its njust flashing...so what do i dfo like...cmd then somethign or somehting like that

[eldiablov]

alright i tried doing math.random() but it just says unexpected symbol i dont understand :ARGH:

[yaustar]

no, thats what i tried, it didn't work, it just returns the "attempt to index field '?'" error,
i may have to have all the table parts set to false, kind of gay though, LUA-Player v0.21 should have implemented something like this:
if ~variable then
...
end

It works for me. What is your exact code?

[BlackShark]

alright i tried doing math.random() but it just says unexpected symbol i dont understand :ARGH:

I think you need to give it a range of numbers to go through...like math.random(1,20) that way, it will pick a number in between (and including) 1 through 20. hope this helps.

[PSPhakkor]

Quick question about modules:

How come the variables declared in my modules are not accessible outside of them(the module)? I thought Lua variables defaulted to global? Is there some exception with modules? and is there a way around this?


Smaller question: How do I output a new line to a file? I tried "/n" and nothing worked

[BlackShark]

Smaller question: How do I output a new line to a file? I tried "/n" and nothing worked

Im pretty interested in this as well!

[EminentJonFrost]

Quick question about modules:

How come the variables declared in my modules are not accessible outside of them(the module)? I thought Lua variables defaulted to global? Is there some exception with modules? and is there a way around this?


Smaller question: How do I output a new line to a file? I tried "/n" and nothing worked

your terminology is better than mine, so forgive me if i'm mistaken, but by 'modules' i'm assuming you mean something like a function or a loop.

anyways, no, lua variables do not always default to global. if you were just declaring a variable normally without loops or modules, it would be global, but if used like below, it would not be global.

--some simple function
function CustomNameHere(LocalVariableNameHereWhichIsOptional)
if LocalVariableNameHereWhichIsOptional == something then
DoSomething
end --end 'if'
end --end 'function'

"LocalVariableNameHereWhi chIsOptional" would not be global.

oh and "/n" is supposed to be "\n". lol. small mistakes...they suck dont they?

[PSPhakkor]

"/n" still doesn't work! It's supposed to be in quotes, right?

A module is a file of code that index.lua uses rather than putting all the code in one file. It's a lot more organised, but it doesn't matter if I can't get it working. I'll just have a disorganised program if I have to... No one will know when they play the game

[EminentJonFrost]

"/n" still doesn't work! It's supposed to be in quotes, right?

A module is a file of code that index.lua uses rather than putting all the code in one file. It's a lot more organised, but it doesn't matter if I can't get it working. I'll just have a disorganised program if I have to... No one will know when they play the game

(lol. i still dont get the modules, i'd have to see it.)

as for the newline, use the other diagonal line. you have "/" when its supposed to be "\".

and its used like this: file:write("\nText")

[yaustar]

There isn't a newline character for that function.

Don't assume variables will be declared global across files. It is poor practise and design. Parameter pass the values or objects needed to the functions that you call from other files.

[BlackShark]

I need some help with something....(obviously :P)

Alright, what i need help with is, I'm trying to make a Bar, a Vertical bar.
now this is easy to do normally, but i need it so that when L and R are pressed, the Bar, rises, until it hits 100, then it does something ( a charge shot)
then returns to 0, This is pretty easy to do, I can do that, the problem is the Bar goes Down, while charging, instead of up, I've tried using Negative numbers without luck, any Help?

[EminentJonFrost]

well blackshark, you know the drill! post the code soldier! j/k
or PM it if you want, though making a bar shouldnt be anything to hide...

[PSPhakkor]

(lol. i still dont get the modules, i'd have to see it.)

as for the newline, use the other diagonal line. you have "/" when its supposed to be "\".

and its used like this: file:write("\nText")

I'm sorry, I typed it wrongly in the post. my program has it going the right way, but it doesn't do anything. Here's the format I'm using: file:write(string1, "\n", string2)

If there's no newline character for that function, then how do I get new lines in my files?


As for modules, check out this tut. It's when a lua file connects to another lua file and uses it as code.

[TacticalPenguin]

Blackshark; easiest way is to use screen:fillRect but thats inefficient so ill show you somethin else:

barfill = 0
bar = Image.createEmpty(10,100)
bar:clear(colorofbar)
while true do
screen:clear()
pad = Controls.read()
if pad:l() then barfill = barfill + 0.2 end --or some other number
screen:blit(x,*the number you want to be the bottom of the bar*-barfill,bar,0,0,10,barfill)
if barfill > 100 then barfill = 100 end
if barfill == 100 and *buttontobepressedtoactivateattackispressed* then
*dotheattack*
barfill = 0
end
screen.waitVblankStart()
screen.flip()
end

[eyece]

It works for me. What is your exact code?

well, i never actualy tried using "~", i just assumed it would not work :P
did it work with tables though? i'd expect it not to, buts its what i need it for.

[ZereoX]

Sorry to ask again but what do I put where it say number dpiX/Y and what is ther original width and height or the normal print function lettering.

Font Font:setCharSize(number width, number height, number dpiX, number dpiY)

[yaustar]

well, i never actualy tried using "~", i just assumed it would not work :P
did it work with tables though? i'd expect it not to, buts its what i need it for.

Yes it did which is why I asked for the exact code.

I'm sorry, I typed it wrongly in the post. my program has it going the right way, but it doesn't do anything. Here's the format I'm using: file:write(string1, "\n", string2)

If there's no newline character for that function, then how do I get new lines in my files?


As for modules, check out this tut. It's when a lua file connects to another lua file and uses it as code.

Printing to the screen, the newline character doesn't work. 'Printing' to files, the newline character 'works' as intended.

As for your module question, it looks like the variable has to exist in the module to be used in the module.
-= Double Post =-
Did a bit of research. The "\n" does work for files BUT it uses the 'unix' version of newline which notepad does not recognise. Use notepad2, Crimson Editor, Notepad++ (basically any decent text editor) and you 'see' it.

[BlackShark]

Crimson Editor Rules!

[PSPhakkor]

Wow. Thanks for doing research for me!

So you're saying that if I use a different text editor, It will work? That's funny.

Unfortunately, I'm limited to LuaDevKit because I don't have my psp at the moment, and I can only test my programs on its tester thing. It's really handy.

However, I did realize that when I used "\n" (or whatever is the correct one, I can't remember!), it wasn't outputted to the file. Unfortunately, neither was the new line. I just got the two strings right next to each other. I hope the different editor will fix this.


Thanks again for your time

[BlackShark]

hehe ya, LuaDevKit is pretty handy for debugging