Lua Programming Help Thread

Zitat:

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//here load your map make sure it larger than 272 in length
map = Image.load("map.png")

//here you load player
player = Image.load("player.png")

//here you have player x and y value
Px=220
Py=250

//here you have the current postion in the map
mapx = 480
mapy = 272

while true do
pad = Controls.read()

//here we clean up the screen so we could prepare to blit the new map postion
screen:clear()

//here we blit the map from were we are in the map picture
screen:blit(0, 0, map, [maplx, maply, 480, 272], [alpha = true])

//here we blit the player
screen:blit(px, py, player)

//here we check if the player x postion is greated than 270 so if it is then we will change the new position of the map
if pad:left() and Px > 270 then
mapx = mapx + 1
end
end

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this is just a example of a scrolling map so it may have some error due to the fact i was doing it in a rush so modifi it as you like

Zitat:

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Zitat von TurtlesPwn

Code:

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-- This will stop any currently playing song
-- Load and play a random one from PSP/MUSIC/ folder
function PlayRandomSong()
        -- get the files and folders in our music folder
        mp3List = System.listDirectory("ms0:/PSP/MUSIC/")

        --remove all non-mp3 items in the folder
        i = 1
        while i <= table.getn(mp3List) do
                if string.lower(string.sub(mp3List[i].name, -4)) ~= ".mp3" then
                        table.remove(mp3List, i)
                else
                        i = i + 1
                end
        end

        if table.getn(mp3List) > 0 then        --if there is atleast 1 song to play
                Mp3me.Stop()
                Mp3me.load(mp3List[math.random(1,table.getn(mp3List))].name) --load a random mp3 from the list
                Mp3me.play()
        end
end

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fixed it up a bit, changed how it does the loop to avoid not knowing how lua does it compared to C etc

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thanks for this, it is greatly appreciated, ill mention both you and sg in my credits!!!:Jump:


--edit--
im having trouble, i am using a lua script from bumper harvest, and i add this under the functions, and it does not seem to load, i have tried adding it to many different places, but no luck, if you have a fix for this it would be nice

Zitat:

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Zitat von ifiwere1337

thanks for this, it is greatly appreciated, ill mention both you and sg in my credits!!!:Jump:


--edit--
im having trouble, i am using a lua script from bumper harvest, and i add this under the functions, and it does not seem to load, i have tried adding it to many different places, but no luck, if you have a fix for this it would be nice

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i think that where it says the math.random bit you need it in a math.floor so that is is an actual number with no decimals

edit:

i just tested it and that isn't the problem, make sure its above while true do and use the correct name with the same case for all of the words

e.g. if it is Word dont use word

Zitat:

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Zitat von FaT3oYCG

i think that where it says the math.random bit you need it in a math.floor so that is is an actual number with no decimals

edit:

i just tested it and that isn't the problem, make sure its above while true do and use the correct name with the same case for all of the words

e.g. if it is Word dont use word

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im not sure what you mean, could you elaborate?

Zitat:

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Zitat von ifiwere1337

im not sure what you mean, could you elaborate?

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it wasnt what i origionally thought but make sure it is like this when you use it

PlayRandomSong()

and not like this

playrandomsong()

Zitat:

---

Zitat von TurtlesPwn

Code:

---

-- This will stop any currently playing song
-- Load and play a random one from PSP/MUSIC/ folder
function PlayRandomSong()
    -- get the files and folders in our music folder
    mp3List = System.listDirectory("ms0:/PSP/MUSIC/")

    --remove all non-mp3 items in the folder
    i = 1
    while i <= table.getn(mp3List) do
        if string.lower(string.sub(mp3List[i].name, -4)) ~= ".mp3" then
            table.remove(mp3List, i)
        else
            i = i + 1
        end
    end

    if table.getn(mp3List) > 0 then    --if there is atleast 1 song to play
        Mp3me.Stop()
        Mp3me.load(mp3List[math.random(1,table.getn(mp3List))].name) --load a random mp3 from the list
        Mp3me.play()
    end
end

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fixed it up a bit, changed how it does the loop to avoid not knowing how lua does it compared to C etc

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I didn't know Lua had a tolower or toupper string member. Neat :) And ya thx for the fix up, I expected no less ;)

Zitat:

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Zitat von FaT3oYCG

it wasnt what i origionally thought but make sure it is like this when you use it

PlayRandomSong()

and not like this

playrandomsong()

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okay i changed playrandomsong() to PlayRandomSong(), and it still wont work, i dont know why, but it is getting really annoying trying to fix this

ifiwere1337 - Post your usage, and keep in mind how bumper harvest's program flow is (it might have nested inifinite loops, etc. keeping it from running)

Zitat:

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Zitat von SG57

ifiwere1337 - Post your usage, and keep in mind how bumper harvest's program flow is (it might have nested inifinite loops, etc. keeping it from running)

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kk just a minute
code removed due to length

ifiwere1337... I didn't say post the entire source, I said post the usage of it. And strangely enough you aren't even using it. I highly suggest you learn a little more before you do stuff like this, it makes alot of people's head aches less frequent when that happens. I made you a function, you have yet to actually call it / use it.

Zitat:

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Zitat von ifiwere1337

kk just a minute

i didnt know what parts to add so i put them all

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Umm, you need to call it from somewhere...

EDIT: Beaten.

Zitat:

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Zitat von SG57

ifiwere1337... I didn't say post the entire source, I said post the usage of it. And strangely enough you aren't even using it. I highly suggest you learn a little more before you do stuff like this, it makes alot of people's head aches less frequent when that happens. I made you a function, you have yet to actually call it / use it.

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ah damnit, lol sorry a newb mistake, ill try and fix it, sorry for the waste of time, im only learning


---edit---

now i have a prob, i added a line to call the function PlayRandonSong() and all i get is an error on lua player, what i am wondering is if i need to put anything in the parentheses or not?

Paste the error... seems like common sense when something goes wrong doesn't it? ;)

Zitat:

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Zitat von SG57

Paste the error... seems like common sense when something goes wrong doesn't it? ;)

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oops sorry on the lua player screen it says this

Zitat:

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Error: index.lua:24 : attempt to call field 'stop' (a nil value)

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Zitat:

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Zitat von ifiwere1337

oops sorry on the lua player screen it says this

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i think it is the way you put it like when you put "stop" is should be "Stop" or something.

but i dont know because im new to this. i only started learning today but i had to register to see these threads, which are very helpful by the way thank you qj'ers.

have fun

wolfy

Zitat:

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Zitat von Lone_Wolf_O_o

i think it is the way you put it like when you put "stop" is should be "Stop" or something.

but i dont know because im new to this. i only started learning today but i had to register to see these threads, which are very helpful by the way thank you qj'ers.

have fun

wolfy

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never thought to check that, i seen stop, but didnt think Stop

--edit--
no it is Stop, but i took the media engine off and ill try that


--edit--

nope its not the media engine thats stopping it

hmm ok then maybe it is this bit

Code:

---

        Mp3me.Stop()
        Mp3me.load(mp3List[math.random(1,table.getn(mp3List))].name) --load a random mp3 from the list
        Mp3me.play()

---

maybe you cant stop it before loading or playing it

Zitat:

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Zitat von Lone_Wolf_O_o

hmm ok then maybe it is this bit

Code:

---

        Mp3me.Stop()
        Mp3me.load(mp3List[math.random(1,table.getn(mp3List))].name) --load a random mp3 from the list
        Mp3me.play()

---

maybe you cant stop it before loading or playing it

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okay that got rid of that error, but now i have a new error

Zitat:

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Error: index.lua : 25: can't open sound file ms0/PSP/GAME/Bumper Harvest-pegglemod/Led Zepplin - Led Zeppelin - Rock and Roll.mp3.

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the problem is that the player thinks that the song is in the game folder, and i want it to recognize it in the PSP/MUSIC folder.

any help?

Code:

---

mp3List = System.listDirectory("ms0:/PSP/MUSIC/")

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i think that should be

Code:

---

System.currentDirectory("ms0:/PSP/MUSIC/")
mp3List = System.listDirectory()

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because i have just looked at a file browser example and that is what it was like
-= Double Post =-
wait i just looked at another one and that is fine so i dont think its that

but it says its a problem loading.

wouldn't that just load the song file from the current directory ?

couldn't you just add a bit on

Code:

---

Mp3me.load(ms0:/PSP/MUSIC/mp3List[math.random(1,table.getn(mp3List))].name) --load a random mp3 from the list

---

Zitat:

---

Zitat von Lone_Wolf_O_o

Code:

---

mp3List = System.listDirectory("ms0:/PSP/MUSIC/")

---

i think that should be

Code:

---

System.currentDirectory("ms0:/PSP/MUSIC/")
mp3List = System.listDirectory()

---

because i have just looked at a file browser example and that is what it was like
-= Double Post =-
wait i just looked at another one and that is fine so i dont think its that

but it says its a problem loading.

wouldn't that just load the song file from the current directory ?

couldn't you just add a bit on

Code:

---

Mp3me.load(ms0:/PSP/MUSIC/mp3List[math.random(1,table.getn(mp3List))].name) --load a random mp3 from the list

---

---

OMG NOW IT WORKS, the only problem is that it is choppy, but the framerate of the game stays the same

--edit--

thanks all who helped, i will add you to my credits

also if anyone can help me with a problem, i want to load a config file, called config.cfg

say i want redballscore=20
i put

config 1
12
config 2
123
config ...
1337
redballscore
20

in the config file, and under redball score i put redballscore=config line8
or something similar, is this possible with lua?

Zitat:

---

Zitat von ifiwere1337

OMG NOW IT WORKS, the only problem is that it is choppy, but the framerate of the game stays the same

--edit--

thanks all who helped, i will add you to my credits

also if anyone can help me with a problem, i want to load a config file, called config.cfg

say i want redballscore=20
i put

config 1
12
config 2
123
config ...
1337
redballscore
20

in the config file, and under redball score i put redballscore=config line8
or something similar, is this possible with lua?

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open the file and read a line 8 times the 8th one willbe the score if im correct?

i dont know how you open a file but isnt the read command file:read() or something so like

line1 = file:read()
line... = file:read()
line7 = file:read()
score = file:read()

Zitat:

---

Zitat von ifiwere1337

OMG NOW IT WORKS, the only problem is that it is choppy, but the framerate of the game stays the same

--edit--

thanks all who helped, i will add you to my credits

also if anyone can help me with a problem, i want to load a config file, called config.cfg

say i want redballscore=20
i put

config 1
12
config 2
123
config ...
1337
redballscore
20

in the config file, and under redball score i put redballscore=config line8
or something similar, is this possible with lua?

---

Yes, yes it is. I'm not going to tell you how because you start figuring things out for yourself instead of asking here for everything. Even beginners know how to help themselves.

Useful links:
http://lua-users.org/wiki/IoLibraryTutorial
http://lua-users.org/wiki/StringLibraryTutorial

Zitat:

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Zitat von Nielkie

Yes, yes it is. I'm not going to tell you how because you start figuring things out for yourself instead of asking here for everything. Even beginners know how to help themselves.

Useful links:
http://lua-users.org/wiki/IoLibraryTutorial
http://lua-users.org/wiki/StringLibraryTutorial

---

i thank you for your help and links, you deserve a cookie

http://pixiestixkidspix.files.wordpr...e-bite-web.jpg

You're stealing my shtick...

Zitat:

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Zitat von SG57

You're stealing my shtick...

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lol you get that cookie too
-= Double Post =-
one last question for now, is there any lua apps/games that use a config file, if so can i get a link, i just want to know how to implement it, i have an idea of how

config.lua:
somesettingvariable = lolhi
someothersettingvariable = lolhiagain
blahblahblah

script.lua:
dofile("config.lua")
blah
blah
blah
part to rewrite the config file for changing settings
blah
blah
blah

Zitat:

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Zitat von TurtlesPwn

config.lua:
somesettingvariable = lolhi
someothersettingvariable = lolhiagain
blahblahblah

script.lua:
dofile("config.lua")
blah
blah
blah
part to rewrite the config file for changing settings
blah
blah
blah

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okay thanks, i didnt know if that was the way to do it, i didnt really understand the links from above

Zitat:

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Zitat von ifiwere1337

okay thanks, i didnt know if that was the way to do it, i didnt really understand the links from above

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Using dofiles is generally considered bad coding (Especially using them for config files). I would recommend against doing it the way TurtlesPwn suggests. Rather you should make your own function that searches and reads specific values.

Zitat:

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Zitat von Nielkie

Using dofiles is generally considered bad coding (Especially using them for config files). I would recommend against doing it the way TurtlesPwn suggests. Rather you should make your own function that searches and reads specific values.

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oh,


ok then, im not really worried about bad coding right now, im just gonna release a beta version soon, and that is no problem at the moment, maybe later ill remove it

Dofiling to load other parts of the script in certain actions or circumstances is considered bad coding. However, using it for configuration files or organizing your code (i.e. stuffforonepartoftheprogr am.lua, stuffforanotherpartofthep rogram.lua each file declaring functions and variables for its part) is fine - if it is not, please explain what bad effects it causes.

Because config files usually mean you load and save to them in-game and if you try to save to a file loaded in memory (dofile'd), it'll corrupt it (don't use a lua text editor to edit itself ;))

as i said thanks for these pages but i think i need to learn lua a little better before i can understand this.

when i have i should be able to make the game that i want to. I will be back around here when i have learned it better and understand it more. evilmana is very useful too, so i think i will use that to learn more.

cya soon if i need help i hope i can come here. thanks very much wolfy

Zitat:

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Zitat von Lone_Wolf_O_o

as i said thanks for these pages but i think i need to learn lua a little better before i can understand this.

when i have i should be able to make the game that i want to. I will be back around here when i have learned it better and understand it more. evilmana is very useful too, so i think i will use that to learn more.

cya soon if i need help i hope i can come here. thanks very much wolfy

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hey you sound pretty good already from what i have seen on your posts you helped someone ? so you must be alright at lua even though one or two things that you said were wrong on the whole you were correct, hope to see you here again soon when you have learned more as you said, what game did you want to make ? if you dont want to say its ok

one other thing while im posting that was strange i got like a 5 month ban for flaming maxy_psp but i went online earlier today and it was lifted wtf oh well atleast i can post again

thanks

[email protected]

Zitat:

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Zitat von SG57

Because config files usually mean you load and save to them in-game and if you try to save to a file loaded in memory (dofile'd), it'll corrupt it (don't use a lua text editor to edit itself ;))

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okay, if i made the config file, but not alow editing in game, would that be acceptable?

Zitat:

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Zitat von ifiwere1337

okay, if i made the config file, but not alow editing in game, would that be acceptable?

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it is fine to dofile a config file it wont corrupt it, but the variables in memory wont change when you save it unless you dofile it again

Configuration files are loaded and edited in-game for options saving or highscore saving or whatever. True you can do a 'dofile' to that file and have your variable, but it doesn't write to the file any new value you assign to it. You must manually do this and editing a lua script thta you're 'dofile'ing in code will corrupt that lua script, once again try using a lua text editor to edit itself and you'll see my point.

If you mean to load and save values, use file:open and read the file line by line then parse each line saying if it finds an equal sign, assign whatever is after that to your variable(s) that need it.

If you mean to simply load values that you don't intend to adjust or save after changing, just use a lua script and dofile it.

"saying if it finds an equal sign, assign whatever is after that to your variable(s) that need it."
or loadstring it.....

Code:

---

for line in file:lines() do
assert(loadstring(line))
end

---

loadstring is a bit slow but for loading a small config file it is fine

Zitat:

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Zitat von TurtlesPwn

"saying if it finds an equal sign, assign whatever is after that to your variable(s) that need it."
or loadstring it.....

Code:

---

for line in file:lines() do
assert(loadstring(line))
end

---

loadstring is a bit slow but for loading a small config file it is fine

---

Well, looping through a file with loadstring is essentially a dofile.

Yes, I know. But then when you call file:close() you can then open it back up to edit it.

Code:

---

loaded = 0

while true do

if loaded == 0 then
dofile("./config.cfg")
started = 1
end

if pad:cross() then -- you obviously wouldnt do it on a button press but its an example
config_file = io.open("./config.cfg", "w")
config_file:write("data")
config_file:close()
loaded = 0
end

end

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