Lua Programming Help Thread

i don't know if i should ask this here, but i will anyway:

i am getting ready to release my game now, but i want to know how to change the icons that are displayed on the psp when you make your game an eboot. Because right now it looks like it is luaplayer right now.

Zitat:

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Zitat von TacticalPinguin

Alright.

ANyways for you people having troubles with the number thingie, to get the number of items in a table use this:

blah = table.getn(nameoftablewit houtquotes)

blah will now be a number equal to the number of items in the table.

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Thank you so, so much. That helps more than you would ever imagine...

Zitat:

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Zitat von GuitarGod1134

omg i missed that lol thx

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lol, yea. i hate that like in your case it will detect the whole while loop when the error is really an if statement. With bigger code it is hard to find the error.

Does anyone know if I declare a variable as local, then put it through a if...then thing and change it's value will it still be local? for example

Code:

---

local x=4
if x==4 then
x=3
end

---

will x still be local?

And I need some way to save memory because I have a lot of images to load, and the program can't get through half of them

Zitat:

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Zitat von PSPhakkor

Does anyone know if I declare a variable as local, then put it through a if...then thing and change it's value will it still be local? for example

Code:

---

local x=4
if x==4 then
x=3
end

---

will x still be local?

And I need some way to save memory because I have a lot of images to load, and the program can't get through half of them

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Yes it will be local but will save you **** all memory in relative to images.

You need to load images that you need to use and unload the ones you don't.

Zitat:

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Zitat von yaustar

Yes it will be local but will save you **** all memory in relative to images.

You need to load images that you need to use and unload the ones you don't.

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That's pretty smart... Nice logic lol. The game actually runs pretty nicely now

whats the problem with this? o_O

Code:

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read = io.open("flash1:/registry/system.dreg","r")
read:seek("set", 0x2380)
line = read:read()
read:close()

---

error:attempt to index global "read" (a nil value)

:(

Zitat:

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Zitat von myschoo

whats the problem with this? o_O

Code:

---

read = io.open("flash1:/registry/system.dreg","r")
read:seek("set", 0x2380)
line = read:read()
read:close()

---

error:attempt to index global "read" (a nil value)

:(

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It couldn't open the file.

thats strange...i will have a look

edit:

this is xmODs src code of Pass Retriever:

Code:

---

file = io.open("system.dreg","r")
file:seek("set", 0x2de0)
line = file:read(4)
file:close()

---

and it works ...

I'm really just throwing this out there, but maybe either lua can't read from flash1, or the prefix isn't "flash1:\" maybe "f1:\" or something different

strange is he didnt even use prefix... o_O

edit. strange, i probably did a mistake, it works...

its like this:

("flash1:/registry/system.dreg","r")

Does anyone know how to completely end a program? I can't use "break" because then the psp starts running the code that's outside of the structure that I "broke" out of. Lua doesn't have a "main" function like C++, does it?

um not that i know of...PSPhakkor. there is a function called 'os.exit()' that does that, but its only usable in one of the modded luaplayers. cools' third mod, i think.

nah... thats System.Quit() ;) not os.exit()

can anyone answer my question before? i need to know how to change the pictures shown for a game when you see them in the game folder, actually seen on your psp.

i used the actual luaplayer, and put my game in it so that it would load my game, but when you go to look for it on your psp it will still show the luaplayer icons, and say luaplayer.

does anyone know how to change this? because many of you who have released games know i guess, and i need to do this. Any help is appreciated.
-= Double Post =-
and after reading my post, it sounds confusing, so i want to tell everyone that i am trying to make it a standalone eboot, instead of having my game loaded from lua player.

Zitat:

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Zitat von emericaska8r

can anyone answer my question before? i need to know how to change the pictures shown for a game when you see them in the game folder, actually seen on your psp.

i used the actual luaplayer, and put my game in it so that it would load my game, but when you go to look for it on your psp it will still show the luaplayer icons, and say luaplayer.

does anyone know how to change this? because many of you who have released games know i guess, and i need to do this. Any help is appreciated.
-= Double Post =-
and after reading my post, it sounds confusing, so i want to tell everyone that i am trying to make it a standalone eboot, instead of having my game loaded from lua player.

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You're supposed to be able to do that with a program called PSpbrew, but I found it so confusing so I just got one of my beta testers do do it for me:tup:

You can google a tutroial

Thanks, guys, for answering my question. I got it working

i have a quick question: is it possible to wrap text (on the psp screen) in lua, so i dont have to screen:fontPrint 6 times to fit my words in?

If so, what function is used? Thanks for your help!

@: parm289
I had the same problem with my lua app. and the only solution i found to be the easiest and fastest was to make a transparent png and write your text in a program like gimp or photoshop. Save it and then load it and then blitted to the screen if u want an example or any further help i would be glad to help you just send me a pm.

@: emericaska8r
Read Your PMs'

yeah, thats a good idea - i just used a lot of screen:fontPrints to do the job. doesnt look too snazzy, but it'll do the job for an faq page.

Im glad it helped

no problem, another noob question though:
i have a variable a, and the value of it constantly changes as the user presses the l and r buttons. i.e.:

Code:

---

if pad:l() then
a = a+1
end
if pad:r() then
a = a-1
end

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that's not the real code, but i think you will get the idea. Now, the value of this variable is going to be displayed on the screen for the duration of a "while true do" loop. However, i can't seem to print the variable's value to the screen. I tried this:

Code:

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screen:fontPrint(comic,0,0,a,white)
screen:flip()
screen.waitVblankStart(300)
end

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.....but it didn't work. How can i get the valua of a variable as a string, so i can print it to the screen? Thanks for your help.

im trying to make a platform game and cuz im a dumb**** i dont know how to start, like i need to be able to have a flat image just move along all the time as the player does the image stuff is easy for me just the code.....

@: parm289

Did you establish the value of your variable before your while true do loop

Some sample code and an error message would be a lot better to help you.
-= Double Post =-
@: Jomann

I believe your problem is scrolling, so you might want to look for some scrolling tutorials. I have the feeling scrolling has been covered in this thread before. If I find a link that can help you with the scrolling I'll post it later.

yes, i did establish the variable a, as a = 0. Here's some sample code:

Code:

---

while true do
  local pad = Controls.read()
  if pad:select() then
    faq()
  end
if pad:start( ) then
screen:clear( )
countForm( )
screen:fontPrint(comic,0,0,a,white)
screen.flip( )
screen.waitVblankStart(300)
end
  screen:blit(0, 0, bg2)
  screen:fontPrint(comic,115,20,"Welcome to Parm's Card Counting app.",white)
  screen:fontPrint(comic,130,40,"For help and FAQs, press Select.",white)
  screen:fontPrint(comic,138,60,"To start counting, press Start.",white)
  screen.flip()
end

---

Code:

---

function countForm()
a = 0
if pad:r( ) then
a = a+1
end
if pad:l( ) then
a = a-1
end
while true do
screen:print(a)
screen.flip( )
screen.waitVblankStart(300)
end
end

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However, running this code, i do not get an error message, just a blank (black) screen, with no text. I'm pretty sure this is because i need to somehow obtain the string (which is just a one or two digit number) from the variable a. I'm guessing it only takes a small portion of code to do this, but searched wikis and google, and found nothing....

Thanks for your almost-immediate replies :D

EDIT: I added the function countForm into this post, so you can check out the way i declared the variable.

How do I get it so it waits for one animation blit to be over untill it blits another image? I know i'm not supposed to do this but what else can I do.

Ex.

Code:

---

while true do
logo:advancedBlit(0,0,500,1)
screen:blit(0,0,screen)
screen:waitVblankStart()
screen.flip()
end

---

They load correctly, but they just go over eachother, and yes i know if I put screen:clear() between them it would clear the screen for the "screen" image but it won't show the animation.. In time that is..

Zitat:

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Zitat von Cheez Pirate

How do I get it so it waits for one animation blit to be over untill it blits another image? I know i'm not supposed to do this but what else can I do.

Ex.

Code:

---

while true do
logo:advancedBlit(0,0,500,1)
screen:blit(0,0,screen)
screen:waitVblankStart()
screen.flip()
end

---

They load correctly, but they just go over eachother, and yes i know if I put screen:clear() between them it would clear the screen for the "screen" image but it won't show the animation.. In time that is..

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try this: (not sure itll work however):

Code:

---

state = anim

while true do
if state == anim then
logo:advancedBlit(0,0,500,1)
state = other
end
if state == other then
screen:blit(0,0,screen)
end
screen:waitVblankStart()
screen.flip()
end

---

remember, animlib depends on states.

@: Cheez Pirate

If you want to create an animation I believe using a timer would be the best. If you are a total noob at timers try going to EvilMana for some tutorials.
-= Double Post =-
@: parm289

I have a feeling a should equal 1 when you declare the value but since im doing some really hard homework right now i dont really have time to look for some solutions... I'll be here tomorrow at 6:00 P.M. If you need some more help.

Wait... you should establish the value of "a" outside the while true do loop and outside your functions so you can access it trough the font print. Go and try it. Report what you get.

Ohh and one more thing. What are all those waitVblanks for???

dr gringo: i tried both of your solutions, but i did not get to test them because of another small problem...i cannot get the app to detect the start button when it's being pressed. there is no official error message returned by luaplayer, but at the main menu, the start button doesnt work.
heres the code that the error is located in:

Code:

---

while true do
  local pad = Controls.read()
  if pad:select() then
    faq()
  end
if Controls.read():start() then
screen:clear( )
countForm( )
screen:fontPrint(comic,0,0,a,white)
screen.flip( )
screen.waitVblankStart(300)
end
  screen:blit(0, 0, bg2)
  screen:fontPrint(comic,115,20,"Welcome to Parm's Card Counting app.",white)
  screen:fontPrint(comic,130,40,"For help and FAQs, press Select.",white)
  screen:fontPrint(comic,138,60,"To start counting, press Start.",white)
  screen.flip()
end

---

I'm sorry for being noobish, but this is my first lua app, so be patient. Thanks for your help.

EDIT: gringo: i'm guessing you downloaded the game package from my other thread, which is outdated...but anyway, the waitvblanks are for the loading and splash screens at the launch of the app.

whats the exact error and which line?

Yeah you have to be more specific if you want us to help you out