Lua Programming Help Thread

[Yongobongo]

white = Color.new(255,255,255)
red = Color.new(255,0,0)
blue = Color.new(0,0,255)
orange = Color.new(255, 102, 0)

background = Image.load("images/begin.jpg")

oldpad = Controls.read()
while true do
pad = Controls.read()
screen:clear()
screen:blit(0,0,begin)
if pad:cross() then
dofile("./game.lua")
end

screen.waitVblankStart()
screen.flip()
end

You need the right variable name :S

[Muhie]

OMFG xD

How the f*** did'nt I see that ? xD
Thx Yongobongo

[Highsight]

Thanks alot QuickJay! ^_^

[Muhie]

I've completed the game (almost :P ) , now I want a music file playing in the main-menu. I tried everything but it says : "cant open sound at ......... " or "error loading sound" . I tried both formats ( .xm & .wav ) , but it keeps giving me the same error :s

EDIT : I figured it out and i dont get any errors. But how does it come that I dont hear any sound of the song ??

[FaT3oYCG]

the first error you mentioned means an incorrect file path and the second is probably because you need to have a popper .wav file not just take an .mp3 for example and change the extension to .wav as this is still an mp3 file which cannot be played with sound:play()

and the answer to your edit

TURN THE VOLUME UP !!!!!!!!!!!!!

[Muhie]

the first error you mentioned means an incorrect file path and the second is probably because you need to have a popper .wav file not just take an .mp3 for example and change the extension to .wav as this is still an mp3 file which cannot be played with soundlay()

and the answer to your edit

TURN THE VOLUME UP !!!!!!!!!!!!!

Alright thx !

BTW : Lol, the volume was already turned up.

EDIT : Last question : The song lags when it starts to play , why ??

[FaT3oYCG]

it depends what your program is doing at the time it starts playing increasing the cpu speed will allow the song to play without lagging so either get the lua player with cpu speed functions or tell me what version you want and i will make you one with cpu functions and an example

[Xarro]

Simple request

how i can see if a file exists?

[FaT3oYCG]

Eelim i dont know if you will check this but i feel so stupid now that i know your problem and the result that you wanted this will let you check for a file

assert()

so to make a file check function

function file_check(file_path)
file = assert(io.open(file_path))
if file == nil then
screen:print(10, 10, "the file path was invalid")
else
screen:print(10, 10, "the file path was valid")
end
end

by using assert there is no need to actually open the file or close it so it should be much quicker

you can also return custom error messages using this command and create an error handler for your programs

- i dont have an example error handler but this is sort of how assert is used

if condition then
assert(test, "message")
end

this code means that if the condition is met then it will carry out the assert command so say if file == nil then you would use

if file == nil then
assert(file == nil, "this file is invalid")
end

if there is no message then the command can be used to check values and will return either false or nil so if the error or condition is false it wont be executed, but if it is nill it will assert the command given

- an example of this is the code used at the top of my post

that is the part of the code that is seen as the test

io.open(file_path)

in the top post no message was passed

the error messages come out the same was as if an error is returned in lua player with a black screen and a white error message

thanks

are you blind a quote from me - reference post 8177

[Nielkie]

Unfortunately, not everyone has the time to read through the entire thread. This results in many, many duplicate questions.

You may want to post snippets like that in the scripts/examples forum as well, as long as it hasn't already been posted there.

[Xarro]

oh sorry!

btw thx!

[FaT3oYCG]

just make sure you search the threads first a good way is to use the search button on the top of the main psp development section page or to find a phrase on the current page use ctrl & f and it will bring up a search box

[Muhie]

it depends what your program is doing at the time it starts playing increasing the cpu speed will allow the song to play without lagging so either get the lua player with cpu speed functions or tell me what version you want and i will make you one with cpu functions and an example

I was working on a Pong game and i finished it now.. it looks good (for a beginner xD ) but thx anway 4 ya help !

I'm now working on a Snake (or something like that) game which I hopefully release in a few days :)

Cheerz

[Xarro]

Hi, i have another problem, in luaplaer for windows (i don't tryed on psp yet) why when i use listDirectory the name and size are correctly and directory gotalways false? or are folder or are files i got always arent folder...

[Muhie]

I'm working on a game called Mario Road . Now I get an error ; "'then'" expected near '=' .

But I can't find where i made that mistake it should be here somewhere :

--Punten
if Player.x == star.x and Player.y == star.y then
score = score + 1
end
if Player.x == star.x and Player.y == star.y then
score = score + 1
end

if (Player.x > Enemy.x) and (Player.x < Enemy.x) and (Player.y > Enemy.y) and (Player.y < Enemy.y) then
dofile("./lose.lua")
end
if (Player.x > star.x) and (Player.x < star.x) and (Player.y > star.y) and (Player.y < star.y) then
score = score + 1

star.x = math.random
star.y = math.random
end

if score = 10 then
dofile("./index.lua")
end

Hope you guys can help me !

[Judas]

I'm working on a game called Mario Road . Now I get an error ; "'then'" expected near '=' .

But I can't find where i made that mistake it should be here somewhere :


Hope you guys can help me !

if score = 10 then

You forgot one. ;)

[FaT3oYCG]

--Punten
if Player.x == star.x and Player.y == star.y then
score = score + 1
end
if Player.x == star.x and Player.y == star.y then
score = score + 1
end

if (Player.x > Enemy.x) and (Player.x < Enemy.x) and (Player.y > Enemy.y) and (Player.y < Enemy.y) then
dofile("./lose.lua")
end
if (Player.x > star.x) and (Player.x < star.x) and (Player.y > star.y) and (Player.y < star.y) then
score = score + 1
end

star.x = math.random
star.y = math.random
end

if score = 10 then
dofile("./index.lua")
end

you missed an end so it wants you to replace the eqals with a then

also looking at your clisions they are slightly wrong

try this

if (Player.x + Player.width() > Enemy.x) and (Player.x < Enemy.x + Enemy.width()) and (Player.y + Player.height() > Enemy.y) and (Player.y < Enemy.y + Enemy.height()) then
dofile("./lose.lua")
end

and the same for the star

to save yourself time you could make a function that checks colisionsif you need some help with that then just ask

[Nielkie]

--Punten
if Player.x == star.x and Player.y == star.y then
score = score + 1
end
if Player.x == star.x and Player.y == star.y then
score = score + 1
end

if (Player.x > Enemy.x) and (Player.x < Enemy.x) and (Player.y > Enemy.y) and (Player.y < Enemy.y) then
dofile("./lose.lua")
end
if (Player.x > star.x) and (Player.x < star.x) and (Player.y > star.y) and (Player.y < star.y) then
score = score + 1
end

star.x = math.random
star.y = math.random
end

if score = 10 then
dofile("./index.lua")
end

you missed an end so it wants you to replace the eqals with a then

No, then there would be an extra end (In cases like this, indenting helps)

All you need to change:

if score == 10 then

[FaT3oYCG]

oh sorry didnt spot that one but his collisions wont work fully either

[Muhie]

Thx guys , you really helped me with this one ! :)

The game is now running pretty good, but I only got 1 level and I need at least 3 levels for a public release. I also need to make some graphical changes , I REALLY suck at photoshopping ,
Cuz I see a white 'box' around my sprite when he's moving xD --->

so if someone wants to help me out with that.. just PM me (or if you want to finish this project together with me, you can do the same ;) )

[Xsjado7]

if its a png, just delete the outside of him because png's use RGBA

[FaT3oYCG]

on photoshop either use the magic eraser - third option on the eraser tool or paint bucket the outside with with the alpha chanel which is underneath your two currnt selections and looks lie a white box with a red line through it diagonally top left to bottom right

hope that helps

[Muhie]

Thx Xsjado7 & FaT30YCG !
I'll give it a shot , hope it works ! :)

I love this thread .. you guys really help me out with every problem I have . Keep up the good work ! ;)
-= Double Post =-
Yaaayyy ! I got the game running without those stupid white boxes around my sprites , thanks to you guys !

The last thing that I want to add is some backgroundmusic , but it doesnt work for me , it keeps saying : error loading sound .
What the heck am I doing wrong ??

[Highsight]

For some reason, whenever I try to find out if a file on my listdirectory is a directory, it always returns false. (even when it is a directory)

Example:

files = System.listDirectory("Games")
for i=1, table.getn(files) do
	print(files[i].directory)
end

Everything returns false, regardless. Any idea why? (I am using the windows LUAPlayer, rather than the PSP LUAPlayer)

[yaustar]

'What' in that code you have given returns false? Is the function System.listDirectory returning false?

[Highsight]

files[i].directory (which is supposed to return true if the file is a directory)

[yaustar]

Considering it is LuaPlayer specific, it could just be a bug on the PC version. Try it on the PSP and post up the results.

[Highsight]

I wish I could, but I don't have a miniUSB on hand. XD Could someone else try it in my stead?

Edit: Nevermind, my dad had one on hand. It turns out it is just a Windows LUAPlayer error. Thanks anyway. ^_^

[bspdyz]

i just got a psp it has homebrew 3.7 something like that. i need to know all this stuff an got lots of dumb questions. first of all would converting this psp to homebrew cause the sound not to work, i bought it as is with no sound. if posible i would like to fix the sound. then i got questions about games on the memory stick , can that be done? i found lots of psp games to download , but can't get them to load up. thanks sorry for the dumb questions

[HaxxBlaster]

Just dropping by to show you guys some art i made in LUA.