Lua Programming Help Thread

[Mraellis]

any more ideas FaT3oYCG?

[michaelp]

Well, for every one of your "screenrint()" calls, you didn't include a 4th argument. I'm pretty sure you need to supply one, not sure.

[TurtlesPwn]

A fourth argument is not needed for screenrint, it will default to black.

[Mraellis]

it isn't needed but if you tell me what to change i can try it just to see.

[andyauff]

Thanks, TurtlesPwn.

[FaT3oYCG]

menuBackground=Image.load("fl.png")
screen:blit(0,0,menuBackground)

screen:print(30,30,"What Does Ds mean?")
screen:print(80,130,"Dualshock")
screen:print(300,130,"Duel screen")
screen:print(200,220,"Dual screens")

oldpad=Controls.read()

while true do

pad=Controls.read()

---------------------------
if pad:square() then
dofile("ni/wrong.lua")
end
if pad:circle() then
dofile("ni/wrong.lua")
end
if pad:triangle() then
dofile("ni/right.lua")
end
---------------------------

screen.flip() 
screen.waitVblankStart()

oldpad = pad

end

[Mraellis]

Bol**ks still didn't work, it doesn't seem to even be trying to load the 1.lua file anyway so it must be a kat.lua or its got something else elsewhere relating to it i haven't seen.

[IMIX]

Hello,
I'm just learning Lua, and I'm trying to get System.usbDiskModeActivat e() to work on my PSP-2000 slim cfw3.80M33-5.
I have LuaPlayer for cfw3.71M33 installed in my /game folder.
In the Lowser/index.lua if you hit the L trigger, its supposed to trigger USB mode, but all it does is freeze up the LuaPlayer, so I have to hit [home] to quit out of it.
The memory stick LED flickers a second after I hit L trigger, but just freezes.
I've tried this on a completely clean memory stick with no plugins installed and only LuaPlayer installed, and connected to two different PC's.
I've also tried this with the PSPhud 1.3 installed to see if it was hitting the cpu when it locked, but it didn't appear to be.

I suspect cfw3.80M33-5 has something to do with it.
I've been searching a while for something about this, but can't seem to find anything.
Is there a better LuaPlayer for the Slim cfw3.80M33-5 anywhere?
I'm a complete noob at this, so sorry if theres something obvious I've missed.
Any help or insight would be greatly appreciated.
Thanks.

[FaT3oYCG]

Hello,
I'm just learning Lua, and I'm trying to get System.usbDiskModeActivat e() to work on my PSP-2000 slim cfw3.80M33-5.
I have LuaPlayer for cfw3.71M33 installed in my /game folder.
In the Lowser/index.lua if you hit the L trigger, its supposed to trigger USB mode, but all it does is freeze up the LuaPlayer, so I have to hit [home] to quit out of it.
The memory stick LED flickers a second after I hit L trigger, but just freezes.
I've tried this on a completely clean memory stick with no plugins installed and only LuaPlayer installed, and connected to two different PC's.
I've also tried this with the PSPhud 1.3 installed to see if it was hitting the cpu when it locked, but it didn't appear to be.

I suspect cfw3.80M33-5 has something to do with it.
I've been searching a while for something about this, but can't seem to find anything.
Is there a better LuaPlayer for the Slim cfw3.80M33-5 anywhere?
I'm a complete noob at this, so sorry if theres something obvious I've missed.
Any help or insight would be greatly appreciated.
Thanks.

it just shows up as corrupted data on mine so you are further than me

and it probably wont work seen as in 3.80 there were some nid changes which mean that when it was made for 3.71 the nids are now different so do not relate to the same things

basically i cant get it to work at all and even if it does work like on yours i dbout any of the main functions will work - until a 3.80 version is made if there ever is

[IMIX]

That makes sense, I didn't think about the nid changes.
I guess i could try to contact Emeric0101 over at XtreamLua.com to see if there's any chance of a new LuaPlayer release for the new cfw..
I wish I knew enough to mess with that stuff myself.
are you saying that the 3.71 luaplayer wont even run for you?
I formatted and reset my flash1 in recovery after this last update,
dunno if that would make a difference for you or not.
Thanks for the quick reply!

[andyauff]

I just use Cool's Mod 4 built for 1.50. I use it in 3.80 M33-5 and the System.usbDiskModeActivat e() works perfectly.

[IMIX]

I just ran the 3.71-M33 LuaPlayer on eLoader 1.0, and System.usbDiskModeActivat e() works now!!!
I've tried running every other LuaPlayer I could find normally, even through eLoader, with no luck.
how'd you get Mod 4 for 1.50 running on your slim?

[andyauff]

Oh no, not on a slim, sorry. I misunderstood. My bad.

[IMIX]

ah, no problem.
got it working (or worked around).
thanks all!
:Jump:

[andyauff]

Good job! :)

[nUke_moose]

hi,

i wanted to create a tile engine, but i get "loop in gettable" in line 27, which is

screen:blit(x*picture:width()+1-picture:width(),y*picture:height()+1-picture:heigt(),picture)

the whole code:

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

tiles = {}
tiles[1] = Image.createEmpty(30,30)
tiles[1]:clear(white)

coord = {}

coord[1] = {}
coord[1].x1 = 1 
coord[1].x2 = 6
coord[1].y1 = 3
coord[1].y2 = 7

coord[2] = {}
coord[2].x1 = 8
coord[2].x2 = 11
coord[2].y1 = 2
coord[2].y2 = 8


function tile(x1,x2,y1,y2,picture)

for x = x1,x2 do
for y = y1,y2 do
screen:blit(x*picture:width()+1-picture:width(),y*picture:height()+1-picture:heigt(),picture)
end
end
end


while true do

screen:clear()

tile(coord[1].x1,coord[1].x2,coord[1].y1,coord[1].y2,tiles[1])
tile(coord[2].x1,coord[2].x2,coord[2].y1,coord[2].y2,tiles[1])

screen.flip()
screen.waitVblankStart()
end

i hope you can help me.....im still a noob and it took quite some time to come up with this oO

[TurtlesPwn]

You misspelled height:
screen:blit(x*picture:wid th()+1-picture:width(),y*picture :height()+1-picture:heigt(),picture)

[nUke_moose]

damn, i spent an hour just changing things in my script..

[SG57]

Not to be rude, but that's hilarious lol

this too --------------->

[nUke_moose]

yea, i know ;(...... and the tile engine sucks anyway,im going to make a new one today..... are there any lua tutorials "more advanced" than the ones on evilmana?

[TurtlesPwn]

Don't make a tile engine more complex than it is - it's just a table with a bunch of tables inside it and each entry (tile) has some properties.

[dan369]

i need i tiny bit of help!!!

I have a variable like this
enemy.health = 100
and another one for the player

i would like to know where to put this if statement

if enemy.health = 0 then
dofile("Story2.lua)
end

do i put it in the main loop or outside of it and also is that the correct if statement to use :?

[FaT3oYCG]

i need i tiny bit of help!!!

I have a variable like this
enemy.health = 100
and another one for the player

i would like to know where to put this if statement

if enemy.health = 0 then
dofile("Story2.lua)
end

do i put it in the main loop or outside of it and also is that the correct if statement to use :?

requires tables

player = { health = 100 }
enemy = { health = 100 }

while  true do

-- game stuff for shooting or whatever

if enemy.health == 0 then
dofile("story2.lua")
end

end -- end of while loop

my code was messed up although right i just edited it to give it popper line formatting

[andyauff]

Dang it. I had a great post all typed up and I lost it. Oh well; I'll try again.

Where you put the if statement depends on the complexity of your script and what you need the if statement to do. If the script is not very complex or the if statement is a big part of the game or application you are making, you can put it in the main loop. However, if you might need to only do the if statement under certain conditions, or if you would need to be able to have more control over the if statement, I would put it in a function outside of the main loop. Then, if need be, you can put that function inside of the main loop; you'll have more control over the if statement and all of your code.

Secondly, the if statement script you provided is incorrect.

if enemy.health = 0 then
dofile("Story2.lua)
end

It should be:

if enemy.health == 0 then
dofile("Story2.lua)
end

Here's why:

In lua, "=" and "==" have completely different meanings and uses. "=" is used to set a variable equal to something, such as in "red = Color.new(255,0,0)", or in "gamestate = 1". The symbol "==", however, is used to compare a variable to something, such as in your code, "if enemy.health == 0 then", or "if gamestate == 1 then".

I remember this difference in the way I say (or rather think) the names of the symbols. For "=" I think "equals", and for "==" I think "is equal to". This helps me keep them separated in my mind.

As for comparison symbols, there are others besides "==". In lua there are "<, >, <=, >=, and ~=. In order, these are "less than", "greater than", "less than or equal to", "greater than or equal to", and "not equal to". You can use these to compare variables to other variables or to numbers. For instance, "if enemy.health <= 0 then" would allow you to do the action even if the enemy has less than 0 health, as if he was "overkilled". Another example, "if gamestate ~= 1 then", would execute the code only if the variable gamestate is not equal to 1. For a final example, you can use these when using timers, such as in "if timer < 0 then", where timer is the variable connected to the timer in the script. The code would then only execute if the the timer has run below 0.

I hope this has helped you and others! I know you aren't the only one who didn't understand this concept; I see it being used incorrectly fairly often.

[dan369]

thanks i get it know

[andyauff]

No problem. :)

[michaelp]

And there was no second quote in the dofile.
You wrote:

dofile("Story2.lua)

when it should be:

dofile("Story2.lua")

[andyauff]

Ah, nice catch. Didn't see that.

[littlevish]

This may be a dumb question, but is there an easy way to restart my script? (Eg. Game Over! Press O to play a new game").

Or is the best thing to do just reset all the variables and things in a function.

[SG57]

littlevish - A typical 'restructure program flow or screw good practice' scenario.

Bad practice would be unloading all used resources then dofile("thisscript.lua"). One method of good practice would be creating a program that flows via 'game state's so restarting your script would be as easy as settingthe game state to the initial game state and initialize it. ('main menu' or 'intro' typically).