Lua Programming Help Thread

[SG57]

Simple logic ;)

[emericaska8r]

'local' means that only the function you called it in can access the variable.

thanks man

[psp11]

ok I wasnt sure if i should post this in this thread or not but here it is:

For school im doing a long term project on developing a program for the psp in c/c++.

I thought i had longer than i had so i cant learn the amount of info i need in time.

Basically is there a way that i can imbed a lua file in an eboot so that even if you open up the eboot you couldnt tell that its a lua file or w/e inside. This way i could just pretend its in c and i could make it better and get a better grade since im pretty good at lua

Well if your professor or whatever has seen anything on psp he may easily be able to spot it. But if he doesn't own a psp then he will not know whatsoever. But for a project like that you will most likely have to show him your sources so...

[joshparrisjosh]

I'm trying to learn to learn how to use functions in lua, but I get a bunch of errors when i try to transfer the value of a variable from a function back to a variable of the same name in the main loop.

sigh, I'm probably just not getting something. Does anyone know where I can learn how to use functions correctly? All of the newby tutorials I've come across have been too basic or un-indepth for what i am trying to do.

[GuitarGod1134]

www.evilmana.com

And heres something Im just gonna throw together that should work

function addition() 
variable = 2
bill = 3
check = variable + bill
end
while true do
addition()
screen:print(0,0,check,red)
screen.waitVblankStart()
screen.flip
end

You mean stuff like that doesnt work for you? If not then your probally doing something wrong check the tuts on evilmana for more info.

[the undead]

ok I wasnt sure if i should post this in this thread or not but here it is:

For school im doing a long term project on developing a program for the psp in c/c++.

I thought i had longer than i had so i cant learn the amount of info i need in time.

Basically is there a way that i can imbed a lua file in an eboot so that even if you open up the eboot you couldnt tell that its a lua file or w/e inside. This way i could just pretend its in c and i could make it better and get a better grade since im pretty good at lua

what if he ask's to see the source?

[EminentJonFrost]

I'm trying to learn to learn how to use functions in lua, but I get a bunch of errors when i try to transfer the value of a variable from a function back to a variable of the same name in the main loop.

sigh, I'm probably just not getting something. Does anyone know where I can learn how to use functions correctly? All of the newby tutorials I've come across have been too basic or un-indepth for what i am trying to do.

wait wait, lemme get this straight. you used the same .. word for a variable and a function?

like this?:

variable = something

(some code)

function variable()

if so, that wouldnt work, as you just found out.

if this has nothing to do with your problem, well then, the first thing you gotta know about getting help is that you post your code up and say what error luaplayer gives you. that way, people can .. well help you. :)

[joshparrisjosh]

Okay well here's my code, just promise not to make fun of me because of how bad it seems. :o

white = Color.new(255,255,255)
green = Color.new(0,255,0)

locke = 1
truewords = nil



function loopy(locke, truewords)


while locke > 0 do
screen:clear()
pad = Controls.read()

screenrint(0,0,"Pick a song", white)

if pad:up() then
screenrint(100,100,"turn it up",green)
if pad:up() and pad:cross() then
locke = 0
truewords = "turn it up"
end
end

if pad:down() then
screenrint(100,100,"the sharpest lives", green)
if pad:down() and pad:cross() then
locke = 0
truewords = "the sharpest lives"
end
end


screen.waitVblankStart()
screen.flip()
end

return truewords
return locke
end



while true do

screen:clear()
pad = Controls.read()

loopy(locke, truewords)

if locke > -1 then
screenrint(100,100,"press x to continue")
if pad:cross() then
locke = locke - 1
end
end

if locke == -1 then
screenrint(100,100,truewords,wh ite)
end


screen.waitVblankStart()
screen.flip()
end

[GuitarGod1134]

First off dont quote your code. Code your code . It stops the smileys and the space problem. Secondly whats the problem with your code?

EDIT: O AND [email protected]!!!!!!!!!!!!!!!! SWEEEEEEEEEEEETTTTTTTTTTT TTTTTTTTTT YAAAAAAAAAAA
400 pOSTS !!! YA

[joshparrisjosh]

the problem with my code is that without the "function loopy()" everything is gravy, but in its current state as posted... after the code executes to the point where it should blit the varible "truewords" it get the error that truewords is a nil value. This to me seems to point in the dirrection that my "function loopy()" isn't changing the value of truewords into a string as i would like it to.

Is this possible? I mean to change it to string through the use of a function?

[GuitarGod1134]

Very annoying all im trying to make is a simple screen saver app thing for me alone and lua player is being quite a fuc...... fucey... ya fucey. anyways I try to run this and i get an error a very common error that i see in almost all my homebrew games

error: script.lua:74: '=' expected near 'end'

And I go through this code over and over and i cant find anything wrong plz help.

Spoiler for Snow Simulator:

-- Snow Simulator By GuitarGod1134
-- just simulates a snow weather condition
--color
white = Color.new(255,255,255)
--pics
snow = Image.create(10,10)
snow:clear(white)
background = Image.load("background.png")
--x = width y = hieght
snowxy = {}
snowxy[1] = { x = 30, y = -300}
snowxy[2] = { x = 200, y = -300}
snowxy[3] = { x = 110, y = -300}
snowxy[4] = { x = 97, y = -300}
snowxy[5] = { x = 400, y = -300}
snowxy[6] = { x = 300, y = -390}
snowxy[7] = { x = 250, y = -300}
--is the snow falling
falling = "true"
--main loop
while true do
screen:clear()
--blit the background
screen:blit(0,0,background)
--blit the snow
snowy = "true"
if snowy == "true" then
screen:blit(snowxy[1].x, snowxy[1].y, snow)
screen:blit(snowxy[2].x, snowxy[2].y, snow)
screen:blit(snowxy[3].x, snowxy[3].y, snow)
screen:blit(snowxy[4].x, snowxy[4].y, snow)
screen:blit(snowxy[5].x, snowxy[5].y, snow)
screen:blit(snowxy[6].x, snowxy[6].y, snow)
screen:blit(snowxy[7].x, snowxy[7].y, snow)
end
--make the snow fall
if falling == "true" then
snowxy[1].y = snowxy[1].y + 2
snowxy[2].y = snowxy[2].y + 2
snowxy[3].y = snowxy[3].y + 2
snowxy[4].y = snowxy[4].y + 2
snowxy[5].y = snowxy[5].y + 2
snowxy[6].y = snowxy[6].y + 2
snowxy[7].y = snowxy[7].y + 2
end
--now we reset them back to true so they can
--fall down again
if snowxy[6].y == 272 then
falling = "false"
end
--all the snow flakes
--are reset back
--to thier original
--y coordinates
if falling == "false" then
backup = "true"
snowxy[1].y = -300
snowxy[2].y = -300
snowxy[3].y = -300
snowxy[4].y = -300
snowxy[5].y = -300
snowxy[6].y = -390
snowxy[7].y = -300
end
--once they reach the bottom
--falling is declared true again
--so that it makes the affect
--that the snow is always falling
if backup == "true" then
falling = "true"
end
screen.waitVblankStart()
screen.flip
end

[yaustar]

screen.flip

should be

screen.flip()

[TacticalPenguin]

Yea it says its expecting = because it expects you're declaring screen.flip as a variable because you forgot the function arguments.

[EminentJonFrost]

hey i was wondering, since screen.flip() has parantheses, can it be 'customized'? like how you can put a color in 'screen:clear()'? i'm having a hard time imagining whats possible to 'customize' about flipping the screen...but, i'm sure there is SOMEthing you can do with it...

[yaustar]

screen.flip doesn't take any arguements so no.

Ref: http://wiki.ps2dev.org/psp:lua_player:functions

[GuitarGod1134]

Ok thanks guys ill try that.

[Nicko01]

Hey, I can't figure out how to get the stupid analog to work.... I dont really understand the numbers. Can someone show me an example of analog in use to move a character on the screen?

Also, whenever i put music in my game, it lags it so much its unplayable.
How can I fix this?

Thanks a lot for your help.

[pspfreak9]

Analog:

   pad =  Controls.read(); 
   if math.abs(pad:analogX()) > 20 then 
      x = x + pad:analogX() / 64; 
   end 
   if math.abs(pad:analogY()) > 20 then 
      y = y + pad:analogY() / 64; 
   end 
   screen:print(x,y-5,"<|",w); 
   screen.waitVblankStart(); 
   screen.flip()

just replace

 screen:print(x,y-5,"<|",w);

with what ever you want to move like a pic. :)
Hope that answers your question.

As for music:
this should work:
boltsnd = Sound.load("music/comp.wav")
If it lags up your putting too many pics slowing it down and OR your song is too long/too much space, OR somethins wrong with your PSP.

[GuitarGod1134]

Actually pspfreak9 the correct way to load music is

yoursound = Sound.load("yoursound.wav ",false)

false is there so it doesnt loop over and over. If you want it to loop then use true.

[pspfreak9]

It works my way to and false is a default. :) But both ways work. ;)

[agashka]

I need help, I need to generate 9 numbers from 1 to 9 without 2 numbers to be the same.
How could i do that?

[the undead]

I need help, I need to generate 9 numbers from 1 to 9 without 2 numbers to be the same.
How could i do that?

use the math.random function

no.1 = math.random(1,9)
if no.1 == 1 then
no.2 = math.random(2,9)
else if no.1 == 2 then
no.2 = math.random(3,9)



Etc.

[agashka]

mmm if no.1 = 5 and no.4 = 5....

[the undead]

mmm if no.1 = 5 and no.4 = 5....

yup, smething like that, when i wrote mine i was being anoyed but you get the idea

[SG57]

Uh, too bad the_undead has given you faulty code...

number = {}

for i=1,9 do
     number[i] = math.random(1,9)
     for j=1,i do
          while number[i] == number[j] and i ~= j do -- 2 numbers are the same
               number[i] = math.random(1,9)
          end
     ebd
end

You might want to try that, or something similar to it compared to undead's ;)

[agashka]

thanks, actually here how i got it working;

alltoken = {1,2,3,4,5,6,7,8,9}
x = 9
gentable ={}
while x >=1 do
table.insert(gentable,tab le.remove(alltoken,math.r andom(table.getn(alltoken ))))
x = x-1 end


:)

[Freshmilk]

Guys, I've tried everything, and I'm stuck.

This maybe a weird question, but is there any way i could blit an image at an angle with having to make about 360 pictures of the same car facing in different directions?

Eg. this number 9 is my car

'9'

If i wanted to flip it veritcally, (or any other direction) it would look like this:

,6,

So, from the one image, how would i do this in lua?

[GuitarGod1134]

Did you search for some functions. THeres probaly one to blit an image at an angle.

Ok heres my questinos
I want to open a text file and print the whole file to the screen ie if the text file contains

aslkdfjaoidnfaoijdfoiajfo ;ia
dfiojasoifjaodijfoaijd;fi asjf

i want the psp to say that too. on all the lines. how would i do that?

[Freshmilk]

well, the only way you could do that is to blit all the text in a file to one line, unless you do it a line at a time, changing where it blits it every time...
Can't remember how you do it a line at a time though, but i know theres a way. :Cry:

And how would i do a search for functions?

[GuitarGod1134]

I just did a search
http://search.yahoo.com/search?ei=ut...ua%20functions
-= Double Post =-
Ok when I run my code it blits like the scale (not just the scale though its all the pics )but then it keeps flickering the menu and the scale over and over It wont stick with one pic.

Spoiler for GuitarHelpr:

--This is GuitarGod's NEW GUITARHELPER
--THe code is completely new 

--first we 
--define some colors
red = Color.new(255,0,0)
blue = Color.new(0,0,255)

--now we load all our pics
chords1 = Image.load("pics/chords1.png")
chords2 = Image.load("pics/chords2.png")
menu = Image.load("pics/menu.png")
pent = Image.load("pics/pentatonicminor.png")
scale = Image.load("pics/scale.png")
tuner = Image.load("pics/tuner.png")

--now that the pics are loaded we load our 
--sounds for the tuner

elow = Sound.load("sounds/elow.wav", false)
a = Sound.load("sounds/a.wav", false)
d = Sound.load("sounds/d.wav", false)
g = Sound.load("sounds/g.wav", false)
b = Sound.load("sounds/b.wav", false)
ehigh = Sound.load("sounds/ehigh.wav", false)

--menu variable
menublit = "true"

--selector for the menu
selector = 1

--and the main loop

while true do
--keep the screen refresed


--declare the buttons
pad = Controls.read()

if menublit == "true" then
screen:blit(0,0,menu)
end

--now we print our options
if menublit == "true" then
screen:print(180,80,"Pent Min Scale",red)
screen:print(180,90,"Scale",red)
screen:print(180,100,"Tuner",red)
screen:print(180,110,"Chord Chart 1",red)
screen:print(180,120,"Chord Chart 2",red)
screen:print(180,130,"Tab Reader",red)
end

--now for our menu selector
if pad:up() then
selector = selector - 1
end

if pad:down() then
selector = selector + 1
end

--now we print our selected options
if selector == 1 and menublit == "true" then
screen:print(180,80,"Pent Min Scale",blue)
end

if selector == 2 and menublit == "true" then
screen:print(180,90,"Scale",blue)
end

if selector == 3 and menublit == "true" then
screen:print(180,100,"Tuner",blue)
end

if selector == 4 and menublit == "true" then
screen:print(180,110,"Chord Chart 1", blue)
end

if Selector == 5 and menublit == "true" then 
screen:print(180,120,"Chord Chart  2", blue)
end

if selector == 6 and menublit == "true" then
screen:print(180,130,"Tab Reader",blue)
end


--now if it goes higher then the options
--its reset to the option on the opposite end

if selector == 7 then
selector = 1
end

if selector == 0 then
selector = 6
end

--now we have our selections
if pad:cross() and selector == 1 and menublit == "true" then
menublit = "false"
screen:clear()
screen:blit(0,0,pent)
end

if pad:cross() and selector == 2 and menublit == "true" then
menublit = "false"
screen:clear()
screen:blit(0,0,scale)
end

if pad:cross() and selector == 3 and menublit == "true" then
menublit = "false"
screen:clear()
screen:blit(0,0,tuner)
tunersel = "true"
end

if pad:cross() and selector == 4 and menublit == "true" then
menublit = "false"
screen:clear()
screen:blit(0,0,chords1)
end

if pad:cross() and selector == 5 and menublit == "true" then
menublit = "false"
screen:clear()
screen:blit(0,0,chords2)
end


--this should return us back
--to the menu
if pad:start() then
menublit = "true"
end


--now for our tuner
if tunersel == "true" and pad:cross() then
elow:play()
end

if tunersel == "true" and pad:circle() then
a:play()
end

if tunersel == "true" and pad:triangle() then
d:play()
end

if tunersel == "true" and pad:square() then
g:play()
end

if tunersel == "true" and pad:r() then
b:play()
end

if tunersel == "true" and pad:l() then
ehigh:play()
end

---all done
screen.waitVblankStart()
screen.flip()
end