Lua Programming Help Thread

[romulator]

And? It was the exact same thing... @[email protected]

I bet you $10 that if you tried your code in Luaplayer, it would give you an error.

[PSPJunkie_]

What? The,

screen:clear(Color.new(0, 0, 0))

I wasn't sure so I looked in the tut's on PSP-Programming for the syntax and that was it...

[SG57]

PSPJunkie_ - screen:clear( [Color] ). Without a parameter, its black. With, it requires a Color class (Color.new(r,g,b[,a])), so yours was correct. However, you have a typo... screenrint(200,100, <snip>)?

[TacticalPenguin]

Because they didn't check off "Disable smilies in text" so :p turned into a smiley face.

[ahrimanes]

sure ahrimanes, thanks.

will send wen be on pc

[radioactive_X]

How can I declare a table that doesn't have to be initialized all at once (it should be at runtime) and can be accessed like

table[1].arg1 = something
table[1].arg2 = something
table[2].arg1 = something
...

Because when I do it like

table = {arg1, arg2}

I get error "attempt to index filed '?' <a nil value>"
I don't want to do it like

table = {{arg1, arg2},{arg1, arg2},{arg1, arg2}...

because I don't know how long the table should be when it is created.
Basically I want to create something like a class that can just be filled with values latter.

Sorry if the answer is obvious. :)

[KleptoOne]

unlike c, everything in lua is declared at runtime. So once you declare a table, ie table = {} , then you can index it however you like, whenever you like.

[radioactive_X]

So

tab = {}

for i = 0, 50 do
	tab[i].arg1 = something
	tab[i].arg2 = somethingother
end

should work? Because it doesn't.
How would I make this work?

[KleptoOne]

each index has to be declared a table if you want to index it further, so

tab = {}

for i =1,50 do
tab[i] = {}
tab[i].arg1 = something
...ect...
end

That would work

[radioactive_X]

Thanks, while I was waiting for your reply I played with the code around and found that this works

tab = {}

for i = 1, 20 do
	tab[i] = {arg1 = 7, arg2 = 8}
end

Which is basically same as you said.

[PSPJunkie_]

PSPJunkie_ - screen:clear( [Color] ). Without a parameter, its black. With, it requires a Color class (Color.new(r,g,b[,a])), so yours was correct. However, you have a typo... screenrint(200,100, <snip>)?

It's good there was typo. That why it wasn't as easy as one idiot copying and pasting code. I was trying to help, too. Do people always have an aditude in here?

[Urameshi]

well sometimes TP does, and i never seen SG with one, but Youresam does, and that is because he's tired of answering the same question

[cruisx]

You know how you can move back and forth through pics in the psp XMB by pressing R and L. Well is their any way to do this in lua? like by pressing R u go to the next pick and pressing L u go back to the previous pic?

can someone pls help?

[KleptoOne]

do you want to use pics in your pic folder or have the user stash their pics into your lua folder? This is really simple to do, you might want to look for some tuts on file browsing and controls.

[cruisx]

do you want to use pics in your pic folder or have the user stash their pics into your lua folder? This is really simple to do, you might want to look for some tuts on file browsing and controls.

i want to use the pics in the lua folder, can someone help me with the code or possiably link me to some tuts so that i can do it =). Thx for the rply Kelp

[KleptoOne]

TP is cool. :Punk: Youresam, on the other hand.....

To be fair to Yoursam, there are a lot of repeated questions that get ask that are super simple to figure out if you stop to think about it for a moment. If really need help, then you should have some code posted showing that you at least made an attempt to figure the problem out. Plus with code, it's alot easier to determine what you are attempting to do.

[KleptoOne]

i want to use the pics in the lua folder, can someone help me with the code or possiably link me to some tuts so that i can do it =). Thx for the rply Kelp

check this out (system portion specifically)
http://wiki.ps2dev.org/psp:lua_player:functions#system

It would assume a certain level of familiarity with tables. If you can't figure out how to apply it, I know I have a simple file browser programmed somewhere that I'll post, I just have to find it.

[Bob Hoil]

Hey guys i was wondering if there are any tutorials on making a file browser. I need it for my project i am working on. I want to learn how to make one then make my own to go with what i need. It should end up being a lot different then the tutorial one though.

Thanks Bob Hoil

[Anti-QuickJay]

I don't think theirs a tutorial but check outs TacticalPenguin's file browser in the lua snippets thread.

[Bob Hoil]

Ok thanks a lot. I appreciate it a ton.

[TacticalPenguin]

NOEZ! That file browser is ancient and horribiblistical. I'll find the much more uberer one I made for my shell tomorrow just remind me and I'll show it to you. (im about ready to go to sleep so not now)
-= Double Post =-
Oh and here's a general idea for the concept of it:

--get the directory listing
blah = System.listDirectory("./pictures")
--remove the "." and ".." files
table.remove(blah,1)
table.remove(blah,1)
--get the number of pics
for i = 1, table.getn(blah) do
    if string.lower(string.sub(blah[i].name,-4)) == (".png" or ".jpg") then
        blah[i].ispic = true
    else
        blah[i].ispic = false
    end
end
_currentpic = 1
if pad:r() and not oldpad:r() then _currentpic = _currentpic + 1 elseif pad:l() and not oldpad:l() then _currentpic = _currentpic - 1 end
if _currentpic ~= _oldcurrentpic and blah[i].ispic then
_pic = Image.load("./pictures/"..blah[i].name)
elseif _currentpic ~= _oldcurrentpic then
_currentpic = _currentpic + (_oldcurrentpic - _currentpic)
end

etc then blit the image and just make it so when you press l/r it changes the image and checks that its an image. play with it and see what you can come up with.

[SG57]

TP - Have you considered using a OO approach to your programming? Nothing's wrong with what you currently do, but I highly recommend it (that doesnt mean much though, as ive yet to release anything decent using it (anything actually :P) but that will change soon).

[ahrimanes]

hi wy math.random is just giving me int values? is there way to get floats?

[emericaska8r]

i don't know, i was fiddling with it, but nothing :Cry:

you could use math.random for the integer part, then the decimal part, and then put them together, but that would be stupid

[ahrimanes]

i don't know, i was fiddling with it, but nothing :Cry:

you could use math.random for the integer part, then the decimal part, and then put them together, but that would be stupid

im doing this
a=0.5*100
random(a-10,a+10)
a=a/100
soo i got a random float

[Merick]

lol, it's easier to just do this:

var = math.random(100)+math.ran dom()

[LMelior]

function math.randfloat(low, high)
   x=math.random()*(high-low)+low
   return x
end

That might work.

[ahrimanes]

well the fact is that i have a fl value then ineed a range fl values and my original fl is the center thats wi do that ,now wiLL that function works for me ? im on_psp_far_from_pc so cant test

[Merick]

well if you take my version and just use a range in the first section like this:

var = math.random(-10, 10)+math.random()

you will get a float between -10 and 10

if you want to set the range based on your original value, then do it like this:

var = math.random( (orig-10), (orig+10) )+math.random()

[SG57]

To make it more portable, here's a function for what you want:

function randomFloatFromOrigin(center,range)
     return ( math.random( (center-range), (center+range) )+math.random() )
end

I believe that will work, however, i havent tested it.