Lua Programming Help Thread

Music files like wav's can't be that big. It is better to use MOD format or IT, or anything which uses modules, rather than a waveform. Also, loading times are affected if you try and load like 5 5mb song wavs.
I would have thought though if you have to do it, maybe 2mb each. no longer than 30 seconds.

Zitat:

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Zitat von TeamOverload

Why are you having the vertical value increase when you press right? You should be increasing the x value

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Allright, changed it, but that didn't really change anything, the char image still does not move.


white = Color.new(255, 255, 255)
char = Image.load("char.png")
x = 150

screen:print(100, 100, "loading finished", white)
screen.flip()
screen.waitVblankStart(24 0)
screen:clear()

screen:blit(x, 50, char)
screen.flip()

pad = Controls.read()

if pad:right() then
x = x + 5
end

while true do
screen.waitVblankStart()
screen.flip()

end

Code:

---

white = Color.new(255, 255, 255)
char = Image.load("char.png")
x = 150

screenrint(100, 100, "loading finished", white)
screen.flip()
screen.waitVblankStart(24 0)
screen:clear()

screen:blit(x, 50, char)
screen.flip()

pad = Controls.read()

if pad:right() then
x = x + 5
end

while true do

pad = Controls.read()
screen:blit(x, 50, char)
screen.flip()

pad = Controls.read()

if pad:right() then
x = x + 5
end
screen.waitVblankStart()
screen.flip()

end

---

Try that m8!

Ha, it works, thanks a ton!

@ct-boy

If it stops at 90% it means there is something wrong between 90% and 100%. Just so you know for the future. I think people forget that, maybe im wrong. So anyway, Lua cant handle GIF's (yet), so change that in your code.

Zitat:

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Zitat von kozine

I am so stuck on these tile backgrounds. Its really annoying me also.

Code:

---

--Load images
tiles = Image.load("images/specialtiles.png")

-- the map
map1 = {
        "dkkkkkkkkfaaaaaaaaaaaaaaa",
        "ibgbgbbgbjaaaaaaaaaaaaaaa",
        "ibgbgbbgbjaaaaaaaaaaaaaaa",
        "ibgbgbbgbjaaaaaaaaaaaaaaa",
        "ibgbgbbgbjaaaaaaaaaaaaaaa",
        "ibgbgbbgbjaaaaaaaaaaaaaaa",
        "hlllllllleaaaaaaaacpaaaaa",
        "aaaaaaaaaaaaaaaaaanoaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaa"
}

function drawTile(tile, x, y)
        local tileX = math.mod(tile, 4)
        local tileY = math.floor(tile / 4)
        screen:blit(16 * x, 16 * y, tiles, 17 * tileX + 1, 17 * tileY + 1, 16, 16, false)
end

while true do

for y = 1, 17 do
                line = map1[y]
                for x = 1, 30 do
                        tile = string.byte(line, x) - string.byte("a")
                        drawTile(tile, x - 1, y - 1)
                end
        end

screen.flip()
end

---

Error:

error: game.lua:40: attempt to perform arithmetic on a nil value

Please help!

---

Cant help you if you dont tell me/us what line line 40 is :P . But anyway, the error means that something gets compared to something that hasnt got any value, so just check all the previous statements where that variable is involved in. Hope that its clear, otherwise you need to tell which line it is.

NVM it fixed. I had less tiles.

Zitat:

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Zitat von kozine

Ok try this:

Code:

---

--Load images
pica = Image.load("Path to image")
picb = Image.load("Path to image")

--Begin the main loop
while true do
pad = Controls.read()

screen:blit(0, 0, pica)

if pad:cross() then
screen:blit(0, 0, picb)
end

screen.flip()
end

---

That works for me!

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It didn't work the way I wanted it too. I'm tring to make a pinball game and I want the flappers to move

http://i27.photobucket.com/albums/c1...apperleft2.png http://i27.photobucket.com/albums/c1...apperleft1.png

With the code you gave me it overlaps on one another. Give it a try. I need that when one pic appears another disappears and viceversa. I would like the help. Thanks.

I dont think u replaces the 0's with the place u wanted it?

Yes I've changed the 0's but that does not change the overlapping.

--Load images
pica = Image.load("Path to image")
picb = Image.load("Path to image")

--Begin the main loop
while true do
pad = Controls.read()

screen:blit(0, 0, pica)

if pad:cross() then
screen:clear()
screen:blit(0, 0, picb)
end

screen.flip()
end

This works:

Code:

---

--Load images
bg = Image.load("bg.png")
pic = {}
pic[1] = Image.load("flapperleft1.png")
pic[2] = Image.load("flapperleft2.png")
imgpic=pic[1]

--Begin the main loop
while true do
screen:blit(0, 0, bg)
pad = Controls.read()

if pad:cross() then
imgpic=pic[2]
else
imgpic=pic[1]
end

screen:blit(0, 0, imgpic)
screen.flip()
end

---

Try it :icon_cool !
Also BG is the background, as i thought it would look neat...

Is there ANYBODY on this site that can help me make a two picture animation? at all?

Explain EXACTLY what you would like to do Greenskull.

when you press X, I want a dude to talk using two pictures, I want him to keep talking untill I press X again.

Something like(untested, just typed it up here):

Code:

---

frame1 = Image.load("bla.png")
frame2 = Image.load("bla2.png")

Animation = 0

while true do

pad = Controls.read()

if Animation = 0 then
screen:blit(x,y,frame1)
screen.flip()
screen.waitVblankStart()
end

if Animation = 1 then
screen:blit(x,y,frame1)
screen.flip()
screen.waitVblankStart(change depending on the delay needed)
screen:clear()
screen:blit(x,y,frame2)
screen.flip()
screen.waitVblankStart(again change for delay)
screen:clear()
end

if pad:cross() and Animation == 0 then
Animation = 1
end

if pad:cross() and Animation == 1 then
Animation = 0
end
end

---

I dunno if this works, as i say i just typed it up, but it should be along the lines of what you need.

As others have explained to you how animation works im not explaining that. To make the animation go untill you press X again just use a variable:

Code:

---

if pressed==true
play animantion
end

if pad:cross() and pressed==true then
pressed=false
end

---

easy as that... :icon_cool

I don't get why this doesn't work. I keep getting the "attempt to index field '?' ( a nil value)" error.

Code:

---

for i = 1,21 do
something[i] = {x = 25 + 10 * i, y = 480 - picture1:height(), pic = picture1}
end
while true do
screen:blit(something[i].x, something[i].y, something[i].pic)
end

---

please don't just tell me what's wrong, also tell me how to fix it. Thanks

You have to initiate something:

Code:

---

something = {}
for i = 1,21 do
something[i] = {x = 25 + 10 * i, y = 480 - picture1:height(), pic = picture1}
end
while true do
screen:blit(something[i].x, something[i].y, something[i].pic)
end

---

How do I make a function run only once? (while in the "While true do" loop)

Also, when I want make a function to print a random number between say, 1 and 30, it prints all of them! How do I make it print just one? ( or maybe, assign just one number between 1 and 30 to a variable...I have the problem that if a = math.random(1,30), a = 1 through 30)

so basically you want to make a random number once as a function in a while true do loop...

you cant. only way to do this would be to gen a random number when the program starts in use for this function... only way to do it to use the same number every time...

or...

function whiletruestart()
blah = math.random(1,30)
whiletrue(loop)
use blah somehow
end
end

I've made a UFA or... i should say, im learning lua through coding what i dont understand so i can learn how to use it... >>; but i've kinda run into an interesting ... bug?

When using Lua Player for Windows, everytime i run this code, the same colors and positions are used when the program starts... its kinda weird... even when using the math.random() function to generate "random" numbers...

is there a reliable random number function that doesnt seem to generate the same exact results each time... /cry

Code:

---

-- Demonstration No-User-App
-- Author: RanDom_ErrOr
-- Copyright 2006
-- No liscense with this product what so ever. Use at your own risk. I will accept no liability or responsibility if you **** something up.
color1 = Color.new(113, 113, 113 )
color2 = Color.new(61, 115, 169 )
color3 = Color.new(39, 75, 112)
color4 = Color.new(96,120,238)
color5 = Color.new(192,218,250)
color6 = Color.new(224,227,254)
screenwidth = 480
screenheight = 272
letter = "o"
organism = { }
organism[1] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[2] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[3] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[4] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[5] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[6] = { posx = math.random(1,480), posy = math.random(1,272) }
screen:print(100,240," User Free Application Demo_Author:RanDom_ErrOr", color3)

while true do

        x1 = organism[1].posx
        y1 = organism[1].posy
        screen:print(x1 , y1 , letter, color1)
        organism[1].posx = organism[1].posx + math.random(-3,3)
        organism[1].posy = organism[1].posy + math.random(-3,3)
       
        if organism[1].posx >= screenwidth  or organism[1].posx <= 0 then
                        organism[1].posx = math.random(1,480)
        end

        if organism[1].posy >= screenheight or organism[1].posy <= 0 then
                        organism[1].posy = math.random(1,272)
        end
        x2 = organism[2].posx
        y2 = organism[2].posy
        color = organism[1].color
        screen:print(x2 , y2 , letter, color2)
        organism[2].posx = organism[2].posx + math.random(-3,3)
        organism[2].posy = organism[2].posy + math.random(-3,3)

        if organism[2].posx >= screenwidth or organism[2].posx <= 0 then
                        organism[2].posx = math.random(1,480)
        end

        if organism[2].posy >= screenheight or organism[2].posy <= 0 then
                        organism[2].posy = math.random(1,272)
        end

        x3 = organism[3].posx
        y3 = organism[3].posy
        color = organism[3].color
        screen:print(x3 , y3 , letter, color3)
        organism[3].posx = organism[3].posx + math.random(-3,3)
        organism[3].posy = organism[3].posy + math.random(-3,3)

        if organism[3].posx >= screenwidth or organism[3].posx <= 0 then
                        organism[3].posx = math.random(1,480)
        end

        if organism[3].posy >= screenheight or organism[3].posy <= 0 then
                        organism[3].posy = math.random(1,272)
        end

        x4 = organism[4].posx
        y4 = organism[4].posy
        screen:print(x4 , y4 , letter, color4)
        organism[4].posx = organism[4].posx + math.random(-3,3)
        organism[4].posy = organism[4].posy + math.random(-3,3)

        if organism[4].posx >= screenwidth or organism[4].posx <= 0 then
                        organism[4].posx = math.random(1,480)
        end

        if organism[4].posy >= screenheight or organism[4].posy <= 0 then
                        organism[4].posy = math.random(1,272)
        end
        x5 = organism[5].posx
        y5 = organism[5].posy
        color = organism[4].color
        screen:print(x5 , y5 , letter, color5)
        organism[5].posx = organism[5].posx + math.random(-3,3)
        organism[5].posy = organism[5].posy + math.random(-3,3)

        if organism[5].posx >= screenwidth or organism[5].posx <= 0 then
                        organism[5].posx = math.random(1,480)
        end

        if organism[5].posy >= screenheight or organism[5].posy <= 0 then
                        organism[5].posy = math.random(1,272)
        end

        x6 = organism[6].posx
        y6 = organism[6].posy
        color = organism[6].color
        screen:print(x6 , y6 , letter, color6)
        organism[6].posx = organism[6].posx + math.random(-3,3)
        organism[6].posy = organism[6].posy + math.random(-3,3)

        if organism[6].posx >= screenwidth or organism[6].posx <= 0 then
                        organism[6].posx = math.random(1,480)
        end

        if organism[6].posy >= screenheight or organism[6].posy <= 0 then
                        organism[6].posy = math.random(1,272)
        end
        screen.flip()

end
while true do

screen.waitVblankStart()
end

---

also... unfortunately for the life of me i cant figure out how to compress this code down to a few lines in lua... if this was php i could do this like... real quick...

on tables is there anyway to dynamically create tables from the program? like using a variable inside on an array instead of just a number or text... is there a special delimiter used when doing this?

im guessing instead that you actually have to use a tableconstructor to use variables like i want to... great... or does that even work? i guess i'll have to try it and see if it will...

also is there a way to do a foreach table[?] do something like table[1]-[5] etc with less code than i've used...

whats funny is that this is the first program i've programmed in Lua, and its kind of restrained, not being able to easily (php is so easy with tables like blah[$vari] = { $blah2 = $blah, etc = $1234, $huh = $great}
)
basically i want code to easily increase the number of dudes >>; course, i could use the buttons, but i'd need an easy way to make new tables... (buttons and crap i can do, its just how to make the tables easier (with variables or with functions... w/e) )

thanks in advance... ^^

EDIT: optimized code a little, but still ugly and bloated... ><

Ok thats a lot so im just answering in parts and edit i guess lol.

Ok for a different "random" number each time you should make a seed. I dont know the exact command unfortunately, but its something like this: random.seed(ostime("%c"))

Ok sorry i have to do java programming for my study. One last thing:

Code:

---

organism = { }
organism[1] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[2] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[3] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[4] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[5] = { posx = math.random(1,480), posy = math.random(1,272) }
organism[6] = { posx = math.random(1,480), posy = math.random(1,272) }

---

could be shorter by using this:

Code:

---

organism = { }
for i=1,9 do
organism[i] = { posx = math.random(1,480), posy = math.random(1,272) }
end

---

Waaaaay shorter :D
Later!

Zitat:

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Zitat von Altair

@ct-boy

If it stops at 90% it means there is something wrong between 90% and 100%. Just so you know for the future. I think people forget that, maybe im wrong. So anyway, Lua cant handle GIF's (yet), so change that in your code.

---

thanks alot man! know I got my game to work fully but am not yet gonna release it!

am soo happy :humped: :humped: :Punk: :icon_smil

Zitat:

---

Zitat von kozine

--Load images
pica = Image.load("Path to image")
picb = Image.load("Path to image")

--Begin the main loop
while true do
pad = Controls.read()

screen:blit(0, 0, pica)

if pad:cross() then
screen:clear()
screen:blit(0, 0, picb)
end

screen.flip()
end

---

Ok now it's half done (pica) disappears when (picb) appears but then (picb) stays printed on the screen.

unfortunately man when trying to do organism[i] it makes it so i is the key / index... so it doesnt work... im actually looking for a way to use a variable(which will be a number) as an index... (so i dont have to hard code all this crap for each organism )

Zitat:

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Zitat von shadow-evillink

Ok now it's half done (pica) disappears when (picb) appears but then (picb) stays printed on the screen.

---

Once again this works:

Code:

---

--Load images
bg = Image.load("bg.png")
pic = {}
pic[1] = Image.load("flapperleft1.png")
pic[2] = Image.load("flapperleft2.png")
imgpic=pic[1]

--Begin the main loop
while true do
screen:blit(0, 0, bg)
pad = Controls.read()

if pad:cross() then
imgpic=pic[2]
else
imgpic=pic[1]
end

screen:blit(0, 0, imgpic)
screen.flip()
end

---

you just need a background know :D .

Zitat:

---

Zitat von ct-boy

thanks alot man! know I got my game to work fully but am not yet gonna release it!

am soo happy :humped: :humped: :Punk: :icon_smil

---

Care to state what your game is?

Zitat:

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Zitat von TeamOverload

Care to state what your game is?

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nope sry lol.

:Punk: :icon_smil ;) but I still need a little help from anyone my msn is [email protected]

Alright thats cool....ill be anxious to see it when it is released

Ok, let's say a = math.random(1, 20). Then i say, print (0,0, a), it prints every number 1, 2, 3, 4, 5, etc... through 20. I just want it to print a single random number

Zitat:

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Zitat von ro0kie42

Ok, let's say a = math.random(1, 20). Then i say, print (0,0, a), it prints every number 1, 2, 3, 4, 5, etc... through 20. I just want it to print a single random number

---

It looks like you have a = math.random(1, 20). in your loop. Put it before the loop, then it will only generate one number.

Zitat:

---

Zitat von PSPHax0r9

It looks like you have a = math.random(1, 20). in your loop. Put it before the loop, then it will only generate one number.

---

TIP:
Always put
math.randomseed(os.time() )
before a loop and a "math.random()" function!
This will stop you from gtting the same resualt
on startup of your code.

Zitat:

---

Zitat von c5cha7

TIP:
Always put
math.randomseed(os.time() )
before a loop and a "math.random()" function!
This will stop you from gtting the same resualt
on startup of your code.

---

Oh yea, I forgot to say all that. Thanks. That should help rookie.

yea, thats something improtant to know, i am going to use a random seed in BPPE

The math.random() part is outside the loop. The print part is inside the loop. If I put the print part outside the loop, it doesn't print. If i put the print part inside the loop, it prints all the numbers.

is there a way to end a SPECIFIC sound? rather than using voice:stop()?

Zitat:

---

Zitat von Greenskull

is there a way to end a SPECIFIC sound? rather than using voice:stop()?

---

yes....voice is a variable. So give each sound a different name and say voice1:stop...voice2:stop ...etc.

help!!!!!!! i am a new developer and i am using the tuts by pspmillionare and when i try to test my apps/games on my psp it always says error: no script file found.
does any1 know wat to do?
BTW- i am using luaplayer .16 on a 2.00 psp

Zitat:

---

Zitat von PSPHax0r9

yes....voice is a variable. So give each sound a different name and say voice1:stop...voice2:stop ...etc.

---

hmm I tried that but it said that "loop in gettable" thing....