Lua Programming Help Thread

[rybarnes]

I started playing with Lua today, and decided to dive head first and attempt to make a game. The game will be a clone of an old arcade game called Tapper (has anyone heard of it?)

Basiclly, the game works like this: You are a bartender, and you have to keep the guests happy. You send drinks down the bar to the people who come in, and catch the empties they send back. If you miss an empty, or throw a full one to no body, you loose points.

I need to know how to randomly generate the guests that come in, how to get them out after they drink, and how to make them send back the drinks. That i feel is of the least importance right now.

More importantly, I was hoping someone had a collison and score keeping tutorial, because thats what I will really need help on. Thanks alot!

(...if anyone will want to hop on board and help make the game, your invited. [email protected])

[Altair]

To do something random you should first set the seed. Then just use the random number generator that comes with LUA.

collision is just checking if some x and y coords are the same.

With score keeping I assume you mean saving the score? if you search a bit you'll find its really not that hard. There are a lot of tuts that describe how to save something to a file. I know there's one at evilmana.com.

[Access_Denied]

I started playing with Lua today, and decided to dive head first and attempt to make a game. The game will be a clone of an old arcade game called Tapper (has anyone heard of it?)

Basiclly, the game works like this: You are a bartender, and you have to keep the guests happy. You send drinks down the bar to the people who come in, and catch the empties they send back. If you miss an empty, or throw a full one to no body, you loose points.

I need to know how to randomly generate the guests that come in, how to get them out after they drink, and how to make them send back the drinks. That i feel is of the least importance right now.

More importantly, I was hoping someone had a collison and score keeping tutorial, because thats what I will really need help on. Thanks alot!

(...if anyone will want to hop on board and help make the game, your invited. [email protected])

You can learn all of this from ProgramLua. There's a link in my signiture. Except for collisions. Got to evilmana.com for that.

[Bronx]

Yeah, or see my stickied list for lua snippets (it has animation and collision, which you most likely need ;))

[Aphonia]

Also, check out the code in Snake, which came with Lua. It has random generation and saving (single and multiple line). I couldn't understand saving at all until I looked at a real game's code.

For animation help, you could try Grimfate126's animation library:
http://forums.qj.net/f-psp-developme...y-2-68855.html

And take things slow. Make sure you understand and can demonstrate what you've learned before you continue to something else. If you rush yourself, you'll get discouraged and quit.

[myschoo]

can anyone help me with that battery part???

[cwirsing]

I need help
whenever i do this code i have to hold x to keep the file open and i want it to stay there right when i press x.

if pad:cross() and current == 1 then
dofile("nameentry.lua")
end

[Bronx]

dofile_state = 0

if pad:cross() then
dofile_state = 1
end

if dofile_state = 1 then
dofile("nameentry.lua")
end

That should work ;)

[cwirsing]

Thanks it finally works.

[Aphonia]

Cwirsing, you might understand it now, but if you don't:
You don't have to use dofile_state
You could use anything as the variable. The reason why your code didn't work right is because it was only active if 'pad:cross'. Since 'pad' isn't always 'cross', it would be inactive most of the time.

With Bronx's code, it (by 'it', I mean: dofile("nameentry.lua")) is only active if dofile_state equals 1. Every time you press cross, dofile_state becomes 1 (no matter what it used to be), and since there is no code to turn dofile_state into anything else, it'll stay like that, and dofile("nameentry.lua") will stay active.
If you add this:

if pad:circle() then
dofile_state = 0
end

Then every time 'pad' is 'circle', dofile_state will turn into 0, and dofile("nameentry.lua") will stop happening.

can anyone help me with that battery part???

I can't think of any, but if you can find a lua program that has that battery display code, look at the source, and do a search for the code you're confused about.

[myschoo]

ok thx ;)

[myschoo]

another question... is it possible to make eboot.pbp from LUA code???????

[Grimfate126]

another question... is it possible to make eboot.pbp from LUA code???????

yes, theres a guide somewhere. serach for it. BUT, the problem is, you can see the code half-way down the eboot.

[Aphonia]

I've never messed with making an eboot, but I think you can take an existing lua eboot, strip the game code from the middle, and replace it with your own.

[myschoo]

yes, theres a guide somewhere. serach for it. BUT, the problem is, you can see the code half-way down the eboot.

yeh i was searching, i will do again...:)

[ZereoX]

Hi im having probleme to proply blit my image by using table here is the table code but i get the following error attempt to compare number whit nil on line 55 whic is mark in the CODE][/CODE]

-- call player sprites as Tables

PlayerDir="right"
PlayerAnim = {}
PlayerAnim[1] = {} --standing right
PlayerAnim[1][1] = Image.load("Player/Stand/StandR-1.png")
PlayerAnim[1][2] = Image.load("Player/Stand/StandR-2.png")
PlayerAnim[1][3] = Image.load("Player/Stand/StandR-3.png")
PlayerAnim[1][4] = Image.load("Player/Stand/StandL-2.png")
PlayerAnim[1][5] = Image.load("Player/Stand/StandL-1.png")
PlayerAnim[2] = {} --standing left
PlayerAnim[2][1] = Image.load("Player/Stand/StandL-1.png")
PlayerAnim[2][2] = Image.load("Player/Stand/StandL-2.png")
PlayerAnim[2][3] = Image.load("Player/Stand/StandL-3.png")
PlayerAnim[2][4] = Image.load("Player/Stand/StandL-2.png")
PlayerAnim[2][5] = Image.load("Player/Stand/StandL-1.png")
PlayerAnim[3] = {} --running right
PlayerAnim[3][1] = Image.load("Player/Run/RunR-1.png")
PlayerAnim[3][2] = Image.load("Player/Run/RunR-2.png")
PlayerAnim[3][3] = Image.load("Player/Run/RunR-3.png")
PlayerAnim[3][4] = Image.load("Player/Run/RunR-4.png")
PlayerAnim[3][5] = Image.load("Player/Run/RunR-5.png")
PlayerAnim[4] = {} --running left
PlayerAnim[4][1] = Image.load("Player/Run/RunL-1.png")
PlayerAnim[4][2] = Image.load("Player/Run/RunL-2.png")
PlayerAnim[4][3] = Image.load("Player/Run/RunL-3.png")
PlayerAnim[4][4] = Image.load("Player/Run/RunL-4.png")
PlayerAnim[4][5] = Image.load("Player/Run/RunL-5.png")
while not Controls.read():start() do
pad= Controls.read()
if currimgstate > 5 then  <--------This is line 55 where i get the error
 currimgstate=1
else
 currimgstate=currimgstate+1
end 
if pad:right() then
 state=3 --running right
 PlayerDir="right"
elseif pad:left() then
 state=4 --running left
 PlayerDir="left"
else
 if PlayerDir=="right" then
 state=1 --standing still facing right
 elseif PlayerDir=="left" then
 state=2 --standing still facing left
 end
end
screen:blit(PlayerX, PlayerY, PlayerAnim[state][currimgstate])
end

[Grimfate126]

Hi im having probleme to proply blit my image by using table here is the table code but i get the following error attempt to compare number whit nil on line 55 whic is mark in the CODE][/CODE]

-- call player sprites as Tables

PlayerDir="right"
PlayerAnim = {}
PlayerAnim[1] = {} --standing right
PlayerAnim[1][1] = Image.load("Player/Stand/StandR-1.png")
PlayerAnim[1][2] = Image.load("Player/Stand/StandR-2.png")
PlayerAnim[1][3] = Image.load("Player/Stand/StandR-3.png")
PlayerAnim[1][4] = Image.load("Player/Stand/StandL-2.png")
PlayerAnim[1][5] = Image.load("Player/Stand/StandL-1.png")
PlayerAnim[2] = {} --standing left
PlayerAnim[2][1] = Image.load("Player/Stand/StandL-1.png")
PlayerAnim[2][2] = Image.load("Player/Stand/StandL-2.png")
PlayerAnim[2][3] = Image.load("Player/Stand/StandL-3.png")
PlayerAnim[2][4] = Image.load("Player/Stand/StandL-2.png")
PlayerAnim[2][5] = Image.load("Player/Stand/StandL-1.png")
PlayerAnim[3] = {} --running right
PlayerAnim[3][1] = Image.load("Player/Run/RunR-1.png")
PlayerAnim[3][2] = Image.load("Player/Run/RunR-2.png")
PlayerAnim[3][3] = Image.load("Player/Run/RunR-3.png")
PlayerAnim[3][4] = Image.load("Player/Run/RunR-4.png")
PlayerAnim[3][5] = Image.load("Player/Run/RunR-5.png")
PlayerAnim[4] = {} --running left
PlayerAnim[4][1] = Image.load("Player/Run/RunL-1.png")
PlayerAnim[4][2] = Image.load("Player/Run/RunL-2.png")
PlayerAnim[4][3] = Image.load("Player/Run/RunL-3.png")
PlayerAnim[4][4] = Image.load("Player/Run/RunL-4.png")
PlayerAnim[4][5] = Image.load("Player/Run/RunL-5.png")
while not Controls.read():start() do
pad= Controls.read()
if currimgstate > 5 then  <--------This is line 55 where i get the error
 currimgstate=1
else
 currimgstate=currimgstate+1
end 
if pad:right() then
 state=3 --running right
 PlayerDir="right"
elseif pad:left() then
 state=4 --running left
 PlayerDir="left"
else
 if PlayerDir=="right" then
 state=1 --standing still facing right
 elseif PlayerDir=="left" then
 state=2 --standing still facing left
 end
end
screen:blit(PlayerX, PlayerY, PlayerAnim[state][currimgstate])
end

have you declared currimgstate?

or, just use animation lib 1, since you dont have sprite sheets.

[-Marshall-]

..nvm ill come back later with a better question then pretty much asking you how to make an entire game lol >.<
-lost n00b porgrammer ;)

[Grimfate126]

..nvm ill come back later with a better question then pretty much asking you how to make an entire game lol >.<
-lost n00b porgrammer ;)

pool is probably not the best thing to start with. you need to calculate angles, hit powers, sin, cosin, tan, all that,

[TacticalPenguin]

Exactly, pool would requre more time doing calculations than it would to code it. I'm in geometry this year and it's freakin me out how long of a time people spend to demonstrate a simple geometric property.

[-Marshall-]

Exactly, pool would requre more time doing calculations than it would to code it. I'm in geometry this year and it's freakin me out how long of a time people spend to demonstrate a simple geometric property.

didtent think of that lol good pointbut im not shure what to start with? any ideas on something easy but cool :P lol becuse i thought pool would be easy but i was wrong
-= Double Post =-
ok ive got an idea what if i made a driveing game for the background say i had a track or something but how would i make it so if the car goes off track you lost per say?

[Access_Denied]

How would I use the analog stick to move? I've tried looking at other examples, but I couldn't figure it out.

[TacticalPenguin]

Ok, i just got done with my first lua thing ever, but it wont work......

*cries*

Could somebody take a look at the script for me and see whats wrong?
Its attached.
Edit: nvm, heres the code:

blue = Color.new(0, 0, 255)
screen:print(0, 0, "Loading: 30%", blue)
screen.flip()
screen.waitVblankStart(120)
screen:clear
screen:print(0, 0, "Loading: 70%", blue)
screen.flip()
screen.waitVblankStart(120)
screen:clear
screen:print(0,0, "Loading Complete", blue)
screen.flip
screen.waitVblankStart(120)
screen:clear
background = Image.load("background.jpg")
screen:print(0, 0, "Tux says hello!", blue)
screen.flip()
screen.waitVblankStart(240)
screen:clear
background = Image.load("background.jpg")
screen:print(0, 0, "Tux says goodbye!", blue)
screen.flip()
screen.waitVblankStart(180)
while true do
screen.waitVblankStart()
end

And the 7 extra kb is the picture that it loads, which is 480x272 in resolution and is named background.jpg

[-Marshall-]

thats what i have so far not much it works on the computer but not on my psp :S andi dont know how to set bounderies so it cant just drive off the track. and i need to create an ecceleration button insted of just useing the d-pad. and a brake button but for now i need to know hoto do too things bounderies and make it work on my psp???

track = Image.load("track.png")
car = Image.load("car.png")


screenwidth = 480 - player:width()
screenheight = 272 - player:width()

car = { }
car[1] = { x = 200, y = 50 }

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

for a = 0, 14 do
for b = 0,8 do
screen:blit(0,0,track)
end
end


screen:blit(car[1].x,car[1].y,car)

if pad:left() and car[1].x > 0 then
Player[1].x = car[1].x - 2
end

if pad:right() and car[1].x < screenwidth then
car[1].x = car[1].x + 2
end

if pad:up() and car[1].y > 0 then
car[1].y = car[1].y - 2
end

if pad:down() and car[1].y < screenheight then
car[1].y = car[1].y + 2
end

screen.waitVblankStart()
screen.flip()
end

[LMelior]

How would I use the analog stick to move? I've tried looking at other examples, but I couldn't figure it out.

It's pretty nice because since it returns an integer, you don't have to do an if statement (in the simplest case, at least).

player.x=player.x+math.floor(pad:analogX()/32)
player.y=player.y-math.floor(pad:analogY()/32)

You'll have to mess with the signs a bit to get it right, but that takes care of movement in almost all directions.


@ Tactical Penguin and iamcanadian:

Post errors.

[TacticalPenguin]

Post error? I can see my post fine......

[-Marshall-]

post error?? whats that and how do i fix it

[Grimfate126]

Post error? I can see my post fine......

ROFL!!! :ROFL: :ROFL: he means, post what error you get when you run the script.
-= Double Post =-

post error?? whats that and how do i fix it

same as above.

[TacticalPenguin]

Oh, ok. It says:

Error: index.lua :6: function arguments expected near 'scree'

Press start to restart

[-Marshall-]

oh haha i feel dumb now lol
heres the error:
Error: DRIVEING.LUA:4: Image.load Error loading image. lmao i think i can fix it now :P i read it before but i dident read the whole thing now i feel dumber :P