Lua Programming Help Thread

[yaustar]

That still won't work. The problem is that when you press R, it will trigger the functionality inside the R keypress every frame that R is pressed down for which is why it is flashing the images and changing number so quickly since it is extremely difficult to press and release a button within a 2 frames (1/30 th of a second).

You have to check the difference between a key press, a key release and when a key is being held down.

Clue: There is an unused variable there which can be used to help with this.

[GuitarGod1134]

Well according to head 54us I dont have to test it because it still wont work. Omg head54us what is this a mystery or something lol. Hm..... Is it oldpad?... or maybe randomnr is being used wrong? Do I have to create a new variable or is this variable already in there somewhere? Also I present to you another problem.

if Bullet[1].x + Bullet[1].y == Alien[1].x = Alien[1].y then
bla
end
--would that work right as my collision detection for a dude shooting an alien and the bullet hitting the alien or am i dont something wrong cause i blanked out on the collision detection i had it right (i thought) but it didnt look right. anyone have any examples?

or is it

if Bullet[1].x == Alien[1].x and Bullet[1].y == Alien[1].y then
bla
end

[the unique warrior]

I think the second one and just try the code I gave you :) please ?

[GuitarGod1134]

ok give me a sec
EDIT: Well this is a mystery still to all of us because no it still does not work. If you dont believe me you can run it yourself just ask me for the pics. But it gives me the same problem while i hold down R it keeps changing the value and bliting the random pics.

[the unique warrior]

hmmm ... odd ....
I have no more idea's xD I never had

[EminentJonFrost]

well...i saw right off the bat a few things that could've been shortened (i already did it). as for the problem with the R button, i dont know. But, dont people normally also put something like "pad ~= oldpad"? you dont have that anywhere in this script...maybe thats it. i cant say for sure, i dont use that technique to get around holding-button-down glitches. hope this helps.

-- *******Lua Rock Paper Scissors***********
-- Script written by GuitarGod1241 or GuitarGod1134 or GuitarGod1124
-- DUE TO POPULAR DEMAND WE NOW HAVE SINGLE PLAYER!!!

--variables
rock = Image.load("rock.png")
scissors = Image.load("scissors.png" )
paper = Image.load("paper.png")
battlefield = Image.load("field.png")
green = Color.new(0, 255, 0)

--delcare old pad to prevent hold down button bug
oldpad = Controls.read()

-- main loop starts here
while true do
 pad = Controls.read()
 for a = 0, 14 do
  for b = 0,8 do
   screen:blit(32 * a, 32 * b, battlefield)

   -- variable that decides the win
   player1 = 0 
   computer = 0
   -- variable added < TUW: if random nr was used 
   randomnr = 0
   --prevents the same random numbers on each program run
   math.randomseed(os.time() )

   --x=width y=height
   -- this is player 1
   screenrint(140, 0, "Let the Battle Begin!", green)
   screenrint(0,20, "Player 1 Select your Weapon" ,green)

   if pad:left() then
    screen:blit(0, 40, rock)
    player1 = player1 + 3
   end

   if pad:up() then
    screen:blit(0, 40, paper)
    player1 = player1 + 4
   end

   if pad:down() then
    screen:blit(0, 40, scissors)
    player1 = player1 + 5
   end

   -- now the psp's turn
   screenrint(250, 20, "PSP Select your Weapon" ,green)

   if pad:r() then
    if randomnr == 0 then
     computer = math.random(3,5)
    end
   end


   if computer == 3 then
    screen:blit(390, 40, rock)
    randomnr = 1
   end

   if computer == 4 then
    screen:blit(390, 40, paper)
    randomnr = 1
   end

   if computer == 5 then
    screen:blit(390, 40, scissors)
    randomnr = 1
   end

   --now time to compare -- shortened this by alot

   if player1 == computer then
    screenrint(150, 150, "YOU BOTH LOST OMG" ,green)
    randomnr = 0
   end

   -- these are if player1 wins -- shortened
   if player1 > computer then
    screenrint(150, 150, "Player 1 is the winner!", green)
    randomnr = 0
   end

   -- these are if psp wins -- ...and this too

   if player1 < computer then
    screenrint(150, 150, "PSP is the winner!", green)
    randomnr = 0
   end

  end
 end

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

[Anti-QuickJay]

[edit]

[GuitarGod1134]

hi im having some problems again not on lua RPS but (well im still having problems on that ) but this is something else. I want to make The charactor have a musket. Demons are coming at him and as you know muskets have one shot so he must reload. I want to make it so that he shoots then a timer starts and he can only shoot again once that timer reachers a certain number. i know i would have to start the timer once the bullet is fired but then how would i make it so he cant shoot anymore until the timer is at a certain time?

[gameo]

I have a problem about getting my first game to work, lol.

Well, i just call it "Simple Pong, Nothing Else."

Here:

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

screen:print(136, 136, "Loading LUA Pong...", white)
screen.flip()

background = Image.load("Background.png")

bat1 = Image.load("Bat1.png")

bat2 = Image.load("Bat2.png")

screen.waitVblankStart(60)

while true do
screen:blit(40, 240, bat1, true)
screen:blit(440, 240, bat2, true)

pad = Controls.read()

if pad:down() then
bat1.y = bat1.y -2
end

if pad:up() then
bat1.y = bat1.y +2
end

if pad:cross() then
bat2.y = bat2.y -2
end

if pad:triangle() then
bat2.y = bat2.y +2
end

screen:clear()
screen:print(136, 136, "Simple Pong, nothing else.", white)
screen.waitVblankStart()
screen.flip()
end

It's something with the controls, it always says "loop in gettable" Or "ERROR: funtion expected near "If".

[EminentJonFrost]

doesnt seem like anything is wrong there, gameo. is that the whole script? cause there's no (user-made) function.

pspgamer81, does the screen go black when you leave horizontally or vertically?

edit - oh and GG, try here. http://wiki.ps2dev.org/psp:lua_player:functions
theres a part called Millisecond Timer. that should help

[gameo]

Ok what it says is:

[CODE]Error: index.lua:25 loop in gettable

Press start to restart[CODE]

I think its weird...

IT HAPPENS ONLY WHEN I PRESS THE CONTROLS.

It loads just fine.

[EminentJonFrost]

*hands slaps forehead*
where are the arrays for 'bat1' and 'bat2'? i'll bet thats the problem.
you gotta do this:

bat1 = { x = some#, y = some#)

for bats 1 and 2. you never announced the bats as objects (or variables, whatever), only as photos.

yep...that should do it. :)

[gameo]

Okey, let me just understand this right:

1: Do i put that line like yours just as it is, or should i edit it in a way?

2: Should i put it before or after the game loop.

3: It says something with an unexpected symbol blablabla.

Sry im such a n00b... everyone have to start from somewhere..

[EminentJonFrost]

try this:

bat1 = { x = 200, y = 100 }
bat2 = { x = 100, y = 200 }

copy and paste that anywhere above "while true do". and, no worrys, its true everyone had their own special beginnings. lol

EDIT - wait! the names of the pics and the arrays cannot be the same! change the name of all the pics, something small, like add another "1" to its name, just to differentiate it from the array.

[gameo]

I'm almost getting sorry for making you waste your time on me.

Érror: index.lua:19 bad argument #2 to `blit´ (Image expected, got table)

Press ******blablabla.

[EminentJonFrost]

I'm almost getting sorry for making you waste your time on me.

Érror: index.lua:19 bad argument #2 to `blit´ (Image expected, got table)

Press ******blablabla.

lol
nah...i feel sorry for both of us for not being able to pinpoint the problem even though i've been over this for a while now...
i said how to fix in my previous post. :)

[gameo]

Well... my father always says: "It's not the machines fault, only the humans."

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

screen:print(136, 136, "Loading LUA Pong...", white)
screen.flip()

background = Image.load("Background.png")

bat1 = Image.load("Bat1.png")

bat2 = Image.load("Bat2.png")

bat1 = { x = 200, y = 100 }
bat2 = { x = 100, y = 200 }

screen.waitVblankStart(60)

while true do

screen:blit(40, 240, bat1, true)
screen:blit(440, 240, bat2, true)

pad = Controls.read()

if pad:down() then
bat1.y = bat1.y -2
end

if pad:up() then
bat1.y = bat1.y +2
end

if pad:cross() then
bat2.y = bat2.y -2
end

if pad:triangle() then
bat2.y = bat2.y +2
end

screen:clear()
screen:print(136, 136, "Simple Pong, nothing else.", white)
screen.waitVblankStart()
screen.flip()
end

[EminentJonFrost]

but...humans built the machines...
lets not think on it. we'll hurt ourselves. lol

Well... my father always says: "It's not the machines fault, only the humans."

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

screen:print(136, 136, "Loading LUA Pong...", white)
screen.flip()

background = Image.load("Background.png")

bat11 = Image.load("Bat1.png")

bat21 = Image.load("Bat2.png")

bat1 = { x = 200, y = 100 }
bat2 = { x = 100, y = 200 }

screen.waitVblankStart(60)

while true do

screen:blit(bat1.x, bat1.y, bat11, true)
screen:blit(bat2.x, bat2.y, bat21, true)

pad = Controls.read()

if pad:down() then
bat1.y = bat1.y -2
end

if pad:up() then
bat1.y = bat1.y +2
end

if pad:cross() then
bat2.y = bat2.y -2
end

if pad:triangle() then
bat2.y = bat2.y +2
end

screen:clear()
screen:print(136, 136, "Simple Pong, nothing else.", white)
screen.waitVblankStart()
screen.flip()
end

[gameo]

So will it work? Because the error still shows.

Érror: index.lua:19 bad argument #2 to `blit´ (Image expected, got table)

[EminentJonFrost]

copy and paste what i did, or rather, so you learn quicker, type all the changes i made yourself. its all there, just compare the one you posted to the one i did. and yes, it should work.

[gameo]

It works, but the Bat's doesent show up.

[EminentJonFrost]

thats easily fixed. move "screen:clear()" to just below "while true do".

putting it at the bottom of the loop clears the screen after everything else happens. its pretty logical really.
i'll explain something to you:
reading from top to bottom what you wrote is what your script does (obviously). think of it this way, Luaplayer is a person reading a script and acts on what he reads. "while true do" - "end" is a loop, so its like the reader keeps on reading the same thing over and over. in your script, you told luaplayer to blit an image, then if a button is pressed change the location of it (in reality, the image wont actually move until luaplayer goes back to the image blitting and updates the coordinate values, therefore moving the image. all this happens in the blink of an eye.) and then, after all the trouble of blitting and changing values, you clear the screen. get it?

[GuitarGod1134]

What text editor do you guys use for programming in lua? I have been using ConTEXT but it feels pretty much like notepad and it doesnt highlight any of my statements or anything do any of you use a different text editor and is there one disigned for lua?
EDIT: i found this if any of u havent already seen it
http://lua-users.org/wiki/LuaEditorSupport
it has alot of editors and how they support lua im using luaedit right now but dont trust luaedit with error checking because it says red = Color.new(255, 0, 0) is bad.

[EminentJonFrost]

i just use normal notepad. i dont need another editor since this one works fine.

[yaustar]

Notepad++.

[TacticalPenguin]

I use notepad because im too lazy to dl something else

[Anti-QuickJay]

It turns black when i go vertically.

[EminentJonFrost]

It turns black when i go vertically.

very interesting...i dont see anything wrong with it so far...this is genuine problem.
it'll test my abilities...:)

EDIT-
ok, the problem is: that the values of 'areax' and 'areay' can exceed values that are tested in the large "if" list you have.

take this code cut from your script as an example:

if player.y < 2 then
if areay < 1 then 
areay = areay + 1

if the player were to keep going in a direction, as you said was the problem and i am demonstrating, theres nothing to stop (i'm using the code above) 'areay''s value from going up past 1. and if you were to look below in your loop, all your 'if' statements would not have any affect if 'areay''s value reaches 2 or more, therefore presenting you with your problem. see?
you basically either have to:
1. limit the potential values of 'areax' and 'areay'
-or-
2. "un-limit" the restricted 'if' statements.

wow...reading this over, i think i made it sound complicated. lol

[Anti-QuickJay]

K, I got it, Thanks!

[c5cha7]

Is there any tutorials for lua's wifi capability's?
(sorry but its an old addition to lua that i never noticed )