Lua Programming Help Thread

[parm289]

as i said, there is no exact error message or line.....luaplayer just does not detect when the user presses start.

I.E. You're at the main menu and you press start to start the app. however, the script does not do anything, just as if you had not pressed start or the controls detection was not there. i think that this could be the placement of my code.

[myschoo]

edit. oops my bad

[LMelior]

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:

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

It works fine for me on Luaplayer Windows, so the problem is most likely in your function countForm() since I had to take that out to run the code. Also, why do you always read the controls again to check for the start button? You could have done the same thing that you do when you check for the select button. You should also realize that since you don't clear the screen in this loop except when start is pressed, anything you blit when you press start will stay there (it will probably be flashing).

[EminentJonFrost]

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) -- i see a problem right here
screen.flip( )
screen.waitVblankStart(300)
end
end

you only put "a" in the parantheses for screenrint(). you forgot coordinates and text color

[parm289]

http://www.sendspace.com/file/e16i9e

That is the link to the full package/app that i have so far. It's a preview of whats coming next, but mainly its for people to help and look at the code.
Eminent: i changed that a while ago, it was just one of my tests.

If you guys dont wanna d/l the whole package and just want to take a look at the countForm(), here it is:

function countForm()
if pad:r( ) then
a = a+1
end
if pad:l( ) then
a = a-1
end
screen:fontPrint(comic,0,0,a,white)
screen.flip( )
screen.waitVblankStart(300)
end

a has already been declared as a = 0.

again, thanks for your help.

[emericaska8r]

@: 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'

yea sorry i hadn't been on the computer in a while. i am going to try the PSpbrew first, and then if i don't get it i'll do that. thanks

[parm289]

My WIP's - Egyptian Ratscrew

Great card game....
just had to say that lol good luck with it

[emericaska8r]

Great card game....
just had to say that lol god luck with it

lol thanks. it hasn't been getting very much attention because of the super mario brothers game, but its coming along

oh, and @ Dr.Gringo, i got it working using the PSPbrew, but thanks anyway!

[parm289]

no problem, i'm looking forward to it (*cough*beta test*cough* lol)!

anyway, i finally got the start button to be detected. it was the placement of the actual function countForm() declaration....
However, i still need to find out how to obtain a variable's contents as a string. For example, if a = 0, and i want to print the value of a to the screen, i don't know how to get the "0" value. I'm guessing from xml, javascript, and html experience that its an escape function, but I could be wrong. Either way, i have no clue if escape functions are even present in lua. I googled for help on this, but couldnt find any.

Again, thanks for your help and sorry for so many questions...I just have to get this ironed out before i can move on to the rest of my app.

EDIT: Looking around a little more, i found this:

tostring(VAR) accepts any type of variable and converts it into a string

I tried this as:

aString = tostring(a)
screen:print(0,0,aString,white)
screen:flip()
screen.waitVblankStart(300)

...but i still got the same result: a blank screen. I'm pretty sure this is how to turn the variable into a string, and i think this is the way to use it. I'm going to try it like this:

tostring(a)
screen:print(0,0,aS,white)
screen:flip()
screen.waitVblankStart(300)

and i'll report back.

EDIT2: Nope, the second way still returns a blank screen....I'll look around to see if i can find some info on it.
EDIT3: Well, i finally got it to work, and sorry for the epic post. This is the code i used:

function countForm()
local a = 0
if pad:r( ) then
a = a+1
end
if pad:l( ) then
a = a-1
end
aString = tostring(a)
screen:fontPrint(comic,20,20,aString,white)
screen.flip( )
screen.waitVblankStart(300)
end

Just so people can see how it works....now im gonna try to pull this app off tonight....

[emericaska8r]

yes! i am releasing my game today! the download link is below.
any criticisms and suggestions will be appreciated.

http://www.sendspace.com/file/csasz4

[parm289]

hmmmm.....i've been trying to get triangle to exit, and i've looked around the net and found that on the newer luaplayers, the only way to exit to the xmb is by loading an invalid .png. if anyone has the link to it or knows where i can find it, can you please post it? thanks!

[PSPhakkor]

I need the same thing, so I used a mod of luaplayer released by cools:
http://forums.ps2dev.org/viewtopic.php?t=6858

the command is System.Quit()

(note the capitals,, as always)

[HeaD_ShOt]

bg = Image.load("space.png")
ufo = Image.load("ufo.png")
s1 = Image.load("satelite1.png ")
s2 = Image.load("satelite2.png ")
s3 = Image.load("satelite3.png ")
s4 = Image.load("satelite4.png ")

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

oldpad = Controls.read()
while true do
pad = Controls.read()
screen:clear()

screen:blit(0,0,bg)
screen:blit(0,0,ufo)
screenrint(120,140,"press x",white)

if pad:cross() then
break
end

if pad:left() then
screen:blit(180,128,s1)
screen.flip()
end

screen.waitVblankStart()
screen.flip()
oldpad = pad
end

i dont get it
when i press left
it doesnt display the pic

[parm289]

psphakkor: i saw that in my searches, but i figured that most people would not have the luaplayer .20 mod, so i would need to something else.
wait - if i compile my game using pspbrew with the System:Quit() command, will it work? I.E. if my game is in eboot form and i call System.Quit(), will it exit to the xmb, or does the script have to be running under the luaplayer mod?

[EminentJonFrost]

i dont get it
when i press left
it doesnt display the pic

take out the screen.flip(), you already have one at the bottom. you dont need another. lol

[emericaska8r]

psphakkor: i saw that in my searches, but i figured that most people would not have the luaplayer .20 mod, so i would need to something else.
wait - if i compile my game using pspbrew with the System:Quit() command, will it work? I.E. if my game is in eboot form and i call System.Quit(), will it exit to the xmb, or does the script have to be running under the luaplayer mod?

i think if you edited the eboot.pbp given from the luaplayer mod that it might work, i'm not sure
-= Double Post =-
anybody ever tried that?

[Anti-QuickJay]

System:Quit will need the LUA Player .20 Mod
I think only users who have this mod can use this function properly.

[SG57]

Head_shoT - AS suggested, remove the screen.flip(). That will display the picture, and right after that, it reaches another screen.flip, and basically 'turns off' what you just drew to the screen (the image). The reason it doesnt even flash is because the screen hasnt met a vertical sync to start displaying it...

[*Ollie*]

i made this thread: http://forums.qj.net/f-psp-developme...ken-91010.html but it doesn't seem to be getting a whole lot of attention. could someone from here take a look at it. i tried the first lua tutorial and i can't get it working... :Cry:

i just wanna create...

All help apreciated!

[eyece]

i made this thread: http://forums.qj.net/f-psp-developme...ken-91010.html but it doesn't seem to be getting a whole lot of attention. could someone from here take a look at it. i tried the first lua tutorial and i can't get it working...

i just wanna create...

All help apreciated!

theres a problem with your player, are you suing version 20? if so, redownload it and try the script again.

[*Ollie*]

theres a problem with your player, are you suing version 20? if so, redownload it and try the script again.

k will do and report back

Success! i can't believe it was that simple! thanks!

[HeaD_ShOt]

okay i have another question
when i am writing the path of a bullet
here is my attempt

Bullet = { x = 180, y = 128, img = bullet}

function moveBullet()
Bullet.x = Bullet.x - 5
end

i jsut want the bullet to move to the left side
with this i never get the bullet to show

[myschoo]

bullet = Image.load("bullet.png")

Bullet = { x = 180, y = 128, image = bullet }

function moveBullet()
Bullet.x = Bullet.x - 5 
end

try this

[EminentJonFrost]

okay i have another question
when i am writing the path of a bullet
here is my attempt

i jsut want the bullet to move to the left side
with this i never get the bullet to show

you merely forgot to blit it (or post that you did, if you did)

screen:blit(Bullet.x, Bullet.y, Bullet.image)

[myschoo]

eminent:

he can do that in while true do part cant he

[emericaska8r]

eminent:

he can do that in while true do part cant he

he just doesn't know if he does have that in his code or not. if he does already than not loading the image is the problem since both of those things aren't shown

[HeaD_ShOt]

that was it
how did i not notice that
thanks

<edit>
dumb errors
now i am having trouble wtih my AI

math.randomseed(os.time() )

Player = { x = 205, y = 120, img = earth}

Enemy = { x = 0, y = 120, img = ufo }

function chasePlayer()
stallchase = math.random(2)
if stallchase == 1 then
if Enemy.x > 205 then
Enemy.x = Enemy.x - 2
elseif Enemy.x < 205 then
Enemy.x = Enemy.x + 2
end
end
stallchase = math.random(2)
if stallchase == 1 then
if Enemy.y > 120 then
Enemy.y = Enemy.y - 2
elseif Enemy.y < Player.y then
Enemy.y = Enemy.y + 2
end
end
end

with teh error...

attempt to compare number with nil

[EminentJonFrost]

math.randomseed(os.time() )

Player = { x = 205, y = 120, img = earth}

Enemy = { x = 0, y = 120, img = ufo }

function chasePlayer()
stallchase = math.random(2)
if stallchase == 1 then
if Enemy.x > 205 then
Enemy.x = Enemy.x - 2
elseif Enemy.x < 205 then
Enemy.x = Enemy.x + 2
end
end
stallchase = math.random(2)
if stallchase == 1 then
if Enemy.y > 120 then
Enemy.y = Enemy.y - 2
elseif Enemy.y < Player.y then
Enemy.y = Enemy.y + 2
end
end
end

well for one, i believe math.random() requires two numbers. (a minimum and a maximum). also, you have two "if stallchase == 1"s, which is redundant.

math.randomseed(os.time() )

Player = { x = 205, y = 120, img = earth}

Enemy = { x = 0, y = 120, img = ufo }

function chasePlayer()
	stallchase = math.random(1,2)
	if stallchase == 1 then
		if Enemy.x > 205 then
			Enemy.x = Enemy.x - 2
		elseif Enemy.x < 205 then
			Enemy.x = Enemy.x + 2
		end

		if Enemy.y > 120 then
			Enemy.y = Enemy.y - 2
		elseif Enemy.y < Player.y then
			Enemy.y = Enemy.y + 2
		end
	end
end

...though it would be much more helpful if you said what line the error was, and pointed that line out. you might find the problem yourself...lol

[eyece]

without a line number, i can only assume the error occurred at the first:
if stallchase == 1 then

witch would mean your random() is a dud.

edit:
to slow :P

[HeaD_ShOt]

there is no line number for this error...