Lua Programming Help Thread

[emericaska8r]

I have it to make the loading a little serious... else you wont reach to see anything.

But the problem is, there is NO error! I don't know why it says so.

why do people put loading screens if nothing is being loaded????????

[pspfreak9]

Hi, I need help with my highscore saving code. I have a file called scorefile in the same directory as this file is:


function saveHighscore()
file = io.open(scorefile, "w")
if file then
file:write(score[1].s1)
file:close()
end
end

function loadHighscore()
file = io.open(scorefile, "r")
if file then
oldhigh = file:read("*n")
file:close()
end
end


I have this code too:

if score[1].s1 > oldhigh then
saveHighscore()
end

I get the error:

Error: level1.lua:112: bad argument #1 to 'open' (string expected, got nil)

Thanks,
Nicko01

look at the bold underlined and italic print. It just says scorefile but did you tell it what scorefile is?? (extension)

[Nicko01]

Does it need one?
my actual file has no extension...
now its called "scorefile.stupidsavedata filethatididntknowwhattoc allit"...

no, it didnt work.

[eldiablov]

Cant you save it is a dat file or txt ? it should have some extension

[Nicko01]

I called it a .pie file.
is that bad?

.dat doesnt work either!!

it says "attempt to index global 'scorefile' (a nil value)

[pspfreak9]

Try this:
file = io.open(scorefile.txt, "w")

if that doest work try this:
scorefile = "scorefile.txt"
file = io.open(scorefile.txt, "w")

I'm not sure about the second one cuase in C U use characters i think this is how you do it in lua

[eldiablov]

Try txt and see what happens EDIT psp freak beat me to it

[Nicko01]

now its saying
bad argument #1 to 'open' (string expected, got nil)

[pspfreak9]

well is there anything in the file?? Since you have check to see..,.

[yaustar]

file = io.open("scorefile.txt", "w")

Note the quotation marks round the string scorefile.txt.

[pspfreak9]

oops ididnt see that

[Yongobongo]

What would i edit in the luaplayer source code to gain flash0 writing access?

[GuitarGod1134]

Is that possible? If so then you would probaly just have to look for flash0 refresences. But it might be the psp thats not allowing the flash0 access not luaplayer. But then again wasnt that xmb pic editor in lua?

[Grimfate126]

What would i edit in the luaplayer source code to gain flash0 writing access?

look at the PSPSDK samples for flash0 writing. and look at the luaplayer soruce to find out how to make your own functions. (you need to know atlest some C/C++)

[EminentJonFrost]

All right, I recently learned how to find the FPS of my game and it runs at 45 FPS at its fastest, and drops to a little less than 40 (about 37) when theres activity. (in my defense, theres quite a bit of activity. lol)

My question is: What are some 'rules of thumb', if any, to add some speed to your app/game?

[TacticalPenguin]

Optimization. If youd like you could post your code and I could look at it and show you some things you could do to optimize it.

[Grimfate126]

All right, I recently learned how to find the FPS of my game and it runs at 45 FPS at its fastest, and drops to a little less than 40 (about 37) when theres activity. (in my defense, theres quite a bit of activity. lol)

My question is: What are some 'rules of thumb', if any, to add some speed to your app/game?

just some off the top of my head:

1. avoid more than 1 "while" loop.
2. avoid too many copies of one thing. (use functions instead)
3. use function arguments as much as you can.

umm.. i forgot some others. post your code, as it might help.

[emericaska8r]

umm how exactly do you find the fps of your game?

[TacticalPenguin]

Its a function with a few variables and stuff. Yaustar's snippet examples have it.

[EminentJonFrost]

umm how exactly do you find the fps of your game?

look at my post somewhere in the latest posts in the lua snippets thread. i posted there an example of how to get the FPS to show.

i dont want to actually post my game code up. (but some of the beans are gonna drop later in my post anyway...) so far, i've been using functions, and i only have one 'while true' loop in my game script. however, i have a main menu which then goes to the actual game via 'dofile("./fileName.lua")'.

would that slow the game down? (i think dofile is essentially a function but with the function being in another file)

aside from the game's speed, i'll bet there is a way to shorten this script of my extras. its for scrolling text up and down in a certain area in the 'extras' part of my game.

--\\\\\\\\\\\\\\\\\\\\\\\\\\\
--Variable for scrolling list up and down
--///////////////////////////
scrollY = 30

--\\\\\\\\\\\\\\\\\\\\\\\\\\\
--Main loop
--///////////////////////////
while true do
	screen:clear(black)
	pad = Controls.read()

	if pad:start() then
		break
	end

	if pad:up() then
		if upPressed == false then
			scrollY = scrollY + 10
			if scrollY > 30 then
				scrollY = 30
			end
			upPressed = true
		end
	else
		upPressed = false
	end

	if pad:down() then
		if downPressed == false then
			scrollY = scrollY - 10
			if scrollY < -210 then
				scrollY = -210
			end
			downPressed = true
		end
	else
		downPressed = false
	end

	if a < 255 and b < 255 and c < 255 then
		a = a + 5
	elseif a == 255 and b < 255 and c < 255 then
		b = b + 5
	elseif  a > 1 and b == 255 and c < 255 then
		a = a - 5
	elseif a < 1 and b == 255 and c < 255 then
		c = c + 5
	elseif a < 1 and b > 1 and c == 255 then
		b = b - 5
	elseif a < 255 and b < 1 and c == 255 then
		a = a + 5
	elseif a == 255 and b < 1 and c > 1 then
		c = c - 5
	elseif a > 1 and b < 1 and c < 1 then
		a = a - 5
	end

	color = Color.new(a, b, c)
	lineimg:clear(color)

	screen:drawLine(1, 1, 479, 1, color)
	screen:drawLine(1, 1, 1, 272, color)
	screen:drawLine(1, 272, 479, 272, color)
	screen:drawLine(479, 1, 479, 272, color)

	screen:fillRect(8, 28, 443, 111, gray)
	screen:fillRect(9, 29, 441, 109, black)

	screen:print(10, 10, "EXTRAS", color)
	screen:print(80, 10, "Coder: EminentJonFrost", color)

	--this is where i DESPERATELY need to find a way to shorten the code. it MUST be possible!

	if scrollY == 30 then
		screen:print(10, scrollY, "", color)
	end
	if scrollY <= 30 and scrollY >= 20 then     
		screen:print(10, scrollY + 10, "", color)
	end
	if scrollY <= 30 and scrollY >= 10 then     
		screen:print(10, scrollY + 20, "", color)
	end
	if scrollY <= 30 and scrollY >= 0 then      
		screen:print(10, scrollY + 30, "", color)
	end
	if scrollY <= 30 and scrollY >= -10 then    
		screen:print(10, scrollY + 40, "", color)
	end
	if scrollY <= 30 and scrollY >= -20 then   
		screen:print(10, scrollY + 50, "", color)
	end
	if scrollY <= 30 and scrollY >= -30 then   
		screen:print(10, scrollY + 60, "", color)
	end
	if scrollY <= 30 and scrollY >= -40 then   
		screen:print(10, scrollY + 70, "", color)
	end
	if scrollY <= 30 and scrollY >= -50 then   
		screen:print(10, scrollY + 80, "", color)
	end
	if scrollY <= 30 and scrollY >= -60 then    
		screen:print(10, scrollY + 90, "", color)
	end
	if scrollY <= 30 and scrollY >= -70 then     
		screen:print(10, scrollY + 100, "", color)
	end
	if scrollY <= 10 and scrollY >= -90 then
		screen:print(10, scrollY + 120, "", color)
	end
	if scrollY <= -10 and scrollY >= -110 then
		screen:print(10, scrollY + 140, "", color)
	end
	if scrollY <= -20 and scrollY >= -120 then
		screen:print(10, scrollY + 150, "", color)
	end
	if scrollY <= - 30 and scrollY >= -130 then
		screen:print(10, scrollY + 160, "", color)
	end
	if scrollY <= -50 and scrollY >= -150 then
		screen:print(10, scrollY + 180, "", color)
	end
	if scrollY <= -60 and scrollY >= -160 then
		screen:print(10, scrollY + 190, "", color)
	end
	if scrollY <= -70 and scrollY >= -170 then
		screen:print(10, scrollY + 200, "", color)
	end
	if scrollY <= -80 and scrollY >= -180 then
		screen:print(10, scrollY + 210, "", color)
	end
	if scrollY <= -90 and scrollY >= -190 then
		screen:print(10, scrollY + 220, "", color)
	end
	if scrollY <= -100 and scrollY >= -200 then
		screen:print(10, scrollY + 230 , "", color)
	end
	if scrollY <= -110 and scrollY >= -210 then
		screen:print(10, scrollY + 240, "", color)
	end
	if scrollY <= -120 and scrollY >= -220 then
		screen:print(10, scrollY + 250, "", color)
	end
	if scrollY <= -140 and scrollY >= -240 then
		screen:print(10, scrollY + 270, "", color)
	end
	if scrollY <= -150 and scrollY >= -250 then
		screen:print(10, scrollY + 280, "", color)
	end
	if scrollY <= -160 and scrollY >= -260 then
		screen:print(10, scrollY + 290, "", color)
	end
	if scrollY <= -170 and scrollY >= -270 then
		screen:print(10, scrollY + 300, "", color)
	end
	if scrollY <= -180 and scrollY >= -280 then
		screen:print(10, scrollY + 310, "", color)
	end
	if scrollY <= -190 and scrollY >= -290 then
		screen:print(10, scrollY + 320, "", color)
	end
	if scrollY <= -210 and scrollY >= -310 then
		screen:print(10, scrollY + 340, "", color)
	end

	screen:print(10, 190, "Controls for Extras:", color)
	screen:print(10, 210, "Up to scroll up", color)
	screen:print(10, 220, "Down to scroll down", color)
	screen:print(10, 230, "Start to go back to menu", color)

	screen.flip()
	screen.waitVblankStart()
end

the code just seems so repetitive to me, it must be compressable. (<--that a word?)

[Yongobongo]

look at the PSPSDK samples for flash0 writing. and look at the luaplayer soruce to find out how to make your own functions. (you need to know atlest some C/C++)

Crappity crap I know nothing about C/C++ Help?
Also, would it be possible for me to make a function in luaplayer with the source to copy a file to flash0?

[SG57]

Hmmm... I actually may do that... Ill make an unofficial Lua Player vX.1 that will have flashing capabilities... I just got a Wii though, so Ill develope it in my spare spare time ;)

[Yongobongo]

Awesome :) I <3 wii...Not wee, wii

[GuitarGod1134]

Is the wii really good or is zelda basically the wii's finest and nothing else? if so then ill stick with project64 lol. Anyways what place can i got to to find lua player functions for the psp

[EminentJonFrost]

You can find lua functions here GG:
http://wiki.ps2dev.org/psp:lua_player

Back on my issue with FPS and code efficiency, I just discovered what a difference the CPU speed makes! (better late than never) i ran my game with IR Shell at cpu speed 222, and i got an FPS in the range of 37-44, then i put up the speed to 333 so i could listen to music while working, without problems. then the FPS shot past 60! at its best, it goes to a little past 70!

so just a note to other lua devs: merely putting up CPU speed should result in faster performance. i dont know why i find this out now 1 year and a quarter later...i guess i still fit in the 'noob' profile...lol

now i use cool's (aka Sphinx, Spirax) mod of luaplayer. it has a special function which allows to set the cpu speed. its mod 2 in the QJ downloads area just sos you know. ok, just thought i should post that up for future reference! :)

[Anti-QuickJay]

You can find lua functions here GG:
http://wiki.ps2dev.org/psp:lua_player

Back on my issue with FPS and code efficiency, I just discovered what a difference the CPU speed makes! (better late than never) i ran my game with IR Shell at cpu speed 222, and i got an FPS in the range of 37-44, then i put up the speed to 333 so i could listen to music while working, without problems. then the FPS shot past 60! at its best, it goes to a little past 70!

so just a note to other lua devs: merely putting up CPU speed should result in faster performance. i dont know why i find this out now 1 year and a quarter later...i guess i still fit in the 'noob' profile...lol

now i use cool's (aka Sphinx, Spirax) mod of luaplayer. it has a special function which allows to set the cpu speed. its mod 2 in the QJ downloads area just sos you know. ok, just thought i should post that up for future reference! :)

I hvae been using the CPU speed functions for awhile and they really give your game a boost.

[EminentJonFrost]

I hvae been using the CPU speed functions for awhile and they really give your game a boost.

no kidding! my game doubled in speed. but i also did some code optimization, which cut my script's size to roughly half. (again, i fit the noob profile well..lol) but im getting better! i guarantee my first GAME release will turn heads! (see how long i've been a member here? i know what most first releases look like, mine will not follow suit)

[SG57]

Funny... My game is doing swell at 222 (~60 FPS) and it just needs some enemies AI implemented for a complete side-scrolling beat em' up... But I have a Wii now... So all coding is in spare spare time...

[Grimfate126]

no kidding! my game doubled in speed. but i also did some code optimization, which cut my script's size to roughly half. (again, i fit the noob profile well..lol) but im getting better! i guarantee my first GAME release will turn heads! (see how long i've been a member here? i know what most first releases look like, mine will not follow suit)

just a warning. CPU does indeed give a good boost, but dont rely on it. i do all my C/C++/lua projects at 222 first, and if they are playable, then i up the CPU to 333.

using the CPu is good, but it wont do you good if you rely too much on it.

(just a warning)


@SG57, shouldnt studies be first, Programming 2nd, and Wii in your spare time? lol, jk.


P.S. IM GETTING A PS3 NEXT MOTH!

[TacticalPenguin]

Yea speeding up the cpu to run your game faster is a crutch. You need to optimize it to get it to run well without having to use 333mhz.