Lua Programming Help Thread

[sony psp player]

Thanks man! How could i have forgotten this :Argh::Argh:

[wicked_fable]

I have a very simple question and hopefully it has a very simple answer: How do I know when music will stutter? Basically, I keep making things with music and sometimes the music works really well, like in a Pong game it runs super smoothly, but other times (mostly in menus) the music stutters and/or plays very slowly. I have made two different types of menus and both times this happens. One is where you press left and right and a different option will appear on screen and the other is the more standard one where all options are on screen and you just move a selector to the preferred choice. In both though, I always use something like

if pad:down () then
selector.y = selector.y + 38
end

or

selection = 0

function selector ()
if pad:left () and selection < 5 then
selection = selection + 1
end

For some reason I think that is the problem but I am not an experience doer so I may be completely off. An small example of a menu with music playing would be nice otherwise I would jsut like to know how to fix my menus and programs in general so that the music doesn't stutter all the time.

Thank you very much,
Daniel Chan

[homemister91]

Hey Daniel Chan,
What you could do use the System.setcpuspeed(300) or use the System.autoCpu().
BTW what type of music, mp3 ogg aac??

Homemister

[dan369]

Or you could just find the y position you need instead of adding
e.g

if pad:down() then
selected = selected + 1 
end

then have a IF for selected

 
if selected == 1 then
y = 36
end

This is a smother way then just add the play function for your music

[dan369]

Or you could just find the y position you need instead of adding
e.g

if pad:down() then
selected = selected + 1 
end

then have a IF for selected

 
if selected == 1 then
y = 36
end

This is a smother way then just add the play function for your music

[Nielkie]

The only reason music should be stuttering is due to the lack of resources. For some reason your "simple menu" is consuming a ton a CPU power, indicating there is probably something inherently wrong with your code/coding style/logic/understanding of your program's flow. Post your entire menu code.

P.S. @dan369: That would result in a huge amount of needless if statements, which is bad coding practise. Use tables:

selectionsY = {36,0,0,0,} --etc
y = selectionsY[selected]

A better way would be to create a neat little menu class. OO FTW.

[wicked_fable]

My music file type is .xm mostly(I took the EvilMana.com Tutorials seriously when they said LuaPlayer can't play MP3's so can it?) and maybe a few .mod files.

Okay, here is my whole menu code. I removed the music because it got very annoying when I tried playing it:

white = Color.new (255,255,255)
black = Color.new (0,0,0)
lime = Color.new (153,204,0)
plum = Color.new (153,51,102)
red = Color.new (255,0,0)
blue = Color.new (0,0,255)
orange = Color.new (255,102,0)

fontponglogo = Font.load ("Fonts/billo.ttf")
fonttagline = Font.load ("Fonts/BRADHITC.ttf")
fontpong = Font.load ("Fonts/billo.ttf")
fontluvtakes2 = Font.load ("Fonts/Complete in Him.ttf")
fontfrantic = Font.load ("Fonts/V5PRD.ttf")
fontmanic = Font.load ("Fonts/OCRAEXT.ttf")
fontdinosaur = Font.load ("Fonts/mizufalp.ttf")

fontponglogo:setPixelSizes (48,48)
fonttagline:setPixelSizes (20,20)
fontpong:setPixelSizes (0,36)
fontluvtakes2:setPixelSizes (0,36)
fontfrantic:setPixelSizes (0,36)
fontmanic:setPixelSizes (0,36)
fontdinosaur:setPixelSizes (0,30)

introbar = Image.createEmpty (480,55)
introbar:clear (plum)

selector = {y = 63,img = Image.createEmpty (480,38)}
selector.img:clear (plum)

background = Image.createEmpty (480,272)
background:clear (white)

number = 0

gamestate = "intro"

oldpad = Controls.read ()

function selection ()
if pad:cross () and selector.y == 63 then
dofile "pong.lua"
Music.stop ()
end

if pad:cross () and selector.y == 139 then
dofile "luvtakes2.lua"
Music.stop ()
end

if pad:cross () and selector.y == 177 then
dofile "frantic.lua"
Music.stop ()
end

if pad:cross () and selector.y == 215 then
dofile "manic.lua"
Music.stop ()
end

if pad:cross () and selector.y == 253 then
dofile "pongdinosaur.lua"
Music.stop ()
end

if pad:down () and selector.y < 215 then
selector.y = selector.y + 38
end

if pad:up () and selector.y > 63 then
selector.y = selector.y - 38
end
end 

function drawSelector ()
screen:blit (0,selector.y,selector.img)
end

function drawIntro ()
screen:blit (0,0,background)
screen:blit (0,180,introbar)
screen:fontPrint (fontponglogo,100,120,"pong.MODERN",black)
screen:fontPrint (fonttagline,8,150,"a step up from pong.CAVEMAN and pong.DINOSAUR",lime)
screen:fontPrint (fontmanic,120,220,"Press START",white)

if pad:start () then
gamestate = "menu"
end
end 

function drawMenu ()
screen:fontPrint (fontpong,190,90,"pong?",lime)
screen:fontPrint (fontluvtakes2,165,130,"l*v takes 2",red)
screen:fontPrint (fontfrantic,160,170,"frantic",blue)
screen:fontPrint (fontmanic,180,210,"manic",orange)
screen:fontPrint (fontdinosaur,110,240,"pong.DINOSAUR",black)
end

while true do
pad = Controls.read ()

screen:clear ()

if gamestate == "intro" then
drawIntro ()
end

if gamestate == "menu" then
selection ()
screen:blit (0,0,background)
drawSelector ()
drawMenu ()
end

screen.waitVblankStart ()
screen.flip ()

if pad:select () then
break
end

oldpad = pad
end

What is funny is that I left in the Music.stop () commands even though I already took out the music. Anything wrong with this? Originally I did it the second way that dan369 suggested as per the menu example at Evilmana.com's Music & Sound tutorial but then I reverted back to the 'adding' method.

[DimensionT]

Hey, guys. I hope this thread is still being read, because I'm completely stumped on what the issue might be with porting my game to 3.XX using LuaPlayerHM7.

I've put in a good 6 hours at least trying to figure this out. Honestly, it doesn't make any sense.

For some reason, my line of code for loading WAV sound effects work perfectly fine in 150 but not on 3.XX.

Here it is:

Move = Sound.load("Sounds/Move.wav", false)

Whenever it gets to that line, it gives me "error loading sound" and halts the program. So I downloaded a game I knew worked in 3.XX to check out what it did for sounds...

This is what it does:

kill5 = Sound.load("Data/Audio/DEDMAN5.WAV")

Why would this code work and not mine? I've tried taking out the ", false" parameter at the end, didn't work. I've tried using lowercase for the variable, caps for the files name and changing the directory... Nothing works. I've looked at his WAV sample, and it's the same exact bitrate and format as mine (352KB/s 22050Hz Mono).

I just don't get it. Everything else works fine. Images load and display, XM music plays, controls work fine.

If anyone knows what up, or if there's a different LuaPlayer/MOD that works on 3.XX, please let me know.

[thecobra]

Hey, guys. I hope this thread is still being read, because I'm completely stumped on what the issue might be with porting my game to 3.XX using LuaPlayerHM7.

I've put in a good 6 hours at least trying to figure this out. Honestly, it doesn't make any sense.

For some reason, my line of code for loading WAV sound effects work perfectly fine in 150 but not on 3.XX.

Here it is:

Move = Sound.load("Sounds/Move.wav", false)

Whenever it gets to that line, it gives me "error loading sound" and halts the program. So I downloaded a game I knew worked in 3.XX to check out what it did for sounds...

This is what it does:

kill5 = Sound.load("Data/Audio/DEDMAN5.WAV")

Why would this code work and not mine? I've tried taking out the ", false" parameter at the end, didn't work. I've tried using lowercase for the variable, caps for the files name and changing the directory... Nothing works. I've looked at his WAV sample, and it's the same exact bitrate and format as mine (352KB/s 22050Hz Mono).

I just don't get it. Everything else works fine. Images load and display, XM music plays, controls work fine.

If anyone knows what up, or if there's a different LuaPlayer/MOD that works on 3.XX, please let me know.

try and check if your directory exist with that same letters

and also check that your wav isn't to big as well

[DimensionT]

The directory is fine. It's copied over from the Game150 version, which works perfectly... And the sound is only 7KB, so there's no problem there.

I set up a new project with nothing but loading the sound and pressing X to play it. There's no problem with memory (as it's the only thing being loaded), and there's no conflict with anything else going on (as it's the only thing being processed)... But still, it gives me the same error everytime.

[homemister91]

I have added new wav loading functions for the next release to Fix the issue. Also it will alow for better paning and volume management of the wav.
Regards
Homemister

[DimensionT]

Holy crap... Good to know it's not my fault. It's been eating at me all day, lol.

Are you able to tell me how soon it will be released? It's not a pressing issue, I can keep working on 150 until then. Just curious :P.

[waywardson]

anyone know how to fill in a shape will color ...(not a rectangle) or shapes like triangles and stars.. but not just outlines filled in aswell? point me to a tutorial or show me please and thanks :P

[homemister91]

I should relese it with in the next week.
I have to finish some other things first.
Check the news on my site for what is already included in the next player

[Nielkie]

My music file type is .xm mostly(I took the EvilMana.com Tutorials seriously when they said LuaPlayer can't play MP3's so can it?) and maybe a few .mod files.

Okay, here is my whole menu code. I removed the music because it got very annoying when I tried playing it:

<SNIP>

What is funny is that I left in the Music.stop () commands even though I already took out the music. Anything wrong with this? Originally I did it the second way that dan369 suggested as per the menu example at Evilmana.com's Music & Sound tutorial but then I reverted back to the 'adding' method.

The problem is that fontprints are ridiculously CPU-intensive (rendering a font every frame is not a good idea). Fontprint to images first, or use bitmap fonts.

Also, your code is not very good. Aside from the obvious lack of indenting (learn to indent, else you will never cope with more complex code) You do know you can have if-statements within if-statements right? (MUCH neater)
Also, Elseifs
e.g:

if pad:cross() then
	if selector.y == 63 then
		dofile("pong.lua")
		Music.stop ()
	elseif selector.y == 139 then
		dofile("luvtakes2.lua")
		Music.stop ()
	elseif selector.y == 177 then
		dofile("frantic.lua")
		Music.stop ()
	elseif selector.y == 215 then
		dofile("manic.lua")
		Music.stop ()
	elseif selector.y == 253 then
		dofile("pongdinosaur.lua")
		Music.stop ()
	end
end

Also, use a selector value indicating which option is to be selected, and use a table like mentioned previously. You use too many magic numbers.

[dan369]

Could someone explain math.mod() and math.asin()

[joseph10444]

HELP!!!
is loadiing the background "background = image.load(*/background.png)" ?

and whatever text i print after that will go over the background right?

[dan369]

loading a image

file = Image.load("lok.png")

screen:blit(0,0,file)

after you've blitted the image print watever text u want :)

[waywardson]

loading a image

file = Image.load("lok.png")

screen:blit(0,0,file)

after you've blitted the image print watever text u want :)

^^^ and also if u want to print text to the image in the case above you would write:

file:print(10,10,"some text",Color.new(255,255,255))

[Nielkie]

Could someone explain math.mod() and math.asin()

asin: inverse sine (or arcsine) (sin ^ -1)
mod: returns modulus (remainder). Deprecated, so use the "modulo" operator instead: "%"
e.g: 20 % 3
= 2

more info:
http://www.lua.org/manual/5.1/manual.html#2.5.1
http://en.wikipedia.org/wiki/Modulo_operation
http://en.wikipedia.org/wiki/Inverse...etric_function
http://lua-users.org/wiki/MathLibraryTutorial

[joseph10444]

okay thanks

after i loaded it how can i make it appear on the screen?

[wicked_fable]

The problem is that fontprints are ridiculously CPU-intensive (rendering a font every frame is not a good idea). Fontprint to images first, or use bitmap fonts.

Also, your code is not very good. Aside from the obvious lack of indenting (learn to indent, else you will never cope with more complex code) You do know you can have if-statements within if-statements right? (MUCH neater)
Also, Elseifs
e.g:

if pad:cross() then
	if selector.y == 63 then
		dofile("pong.lua")
		Music.stop ()
	elseif selector.y == 139 then
		dofile("luvtakes2.lua")
		Music.stop ()
	elseif selector.y == 177 then
		dofile("frantic.lua")
		Music.stop ()
	elseif selector.y == 215 then
		dofile("manic.lua")
		Music.stop ()
	elseif selector.y == 253 then
		dofile("pongdinosaur.lua")
		Music.stop ()
	end
end

Also, use a selector value indicating which option is to be selected, and use a table like mentioned previously. You use too many magic numbers.

Thanks for the help! It isn't, though, that I don't know how to indent but I was never taught too. I have just been using Devsgen.com and Evilamana.com tutorials so far and I have yet to see any lessons on proper code organization. Also, that code was redone numerous times in order to figure out what was wrong so I am sorry for my lack of certain obvious things like using "elsifs"'s and such.

When you say fontprint to images first do you mean open up some sort of program like paint and write the font on there then save it? If so that would seem like a lot of work though.

[joseph10444]

oh NVM i found out how to get it to the screen...

but the problem is

once i do screen:clear() that means the background leaves for ever too!
how can i make the background stay no matter what?

[waywardson]

oh NVM i found out how to get it to the screen...

but the problem is

once i do screen:clear() that means the background leaves for ever too!
how can i make the background stay no matter what?

bg = Image.load("pic.png")

while true do
screen:clear()

screen:blit(0,0,bg)

screen.waitVblankStart()
screen.flip()
end

that will get u an image on the screen :P

[joseph10444]

yeah thanks
i found out its blit

but is there any way to keep the bg image even though i do

screen:clear()

[waywardson]

yeah thanks
i found out its blit

but is there any way to keep the bg image even though i do

screen:clear()

yeah write it just like i wrote above ur last post and it will stay there

[joseph10444]

OH YEAH right... i missed the while true do...
thanks so much

btw to everyone...
is this a good idea?? (my very first homebrew EVER - no past coding experience)

a tax calculator
calculates tax on the go by inputting amount and setting % multiplied and finally adding both for final price

for "on the go" situations like the one i had today at Winners.

please dont steal my idea and make an app like this just because you are better than me in lua/c

i really wanna try this
and noone made one yet :)

[andyauff]

OH YEAH right... i missed the while true do...
thanks so much

btw to everyone...
is this a good idea?? (my very first homebrew EVER - no past coding experience)

a tax calculator
calculates tax on the go by inputting amount and setting % multiplied and finally adding both for final price

for "on the go" situations like the one i had today at Winners.

please dont steal my idea and make an app like this just because you are better than me in lua/c

i really wanna try this
and noone made one yet :)

Yep sounds good. Good luck with it :).

[joseph10444]

cool thanks! :)
my first words of encouragement LOL

btw
im having some trouble at the very beginning..
impossible
but still

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


background = Image.load("images/background.jpg")

while true do
screen:clear()

screen:blit(0,0,background)

screen.waitVblankStart()
screen.flip()

screen:print(144, 74, "Welcome to Tax Calculator", black)
screen.flip()

while true do
screen.waitVblankStart()
end

my error shows up (in luaplayer.exe for pc)

error: script.lua:22: `end' expected (to close `while' at line 8) near `<eof>'

btw ive been always wondering whats eof?

[littlevish]

Alright, so I'm just making a simple game in Lua but my PNG images don't display correctly. They are supposed to fill the screen, but they only fill a portion of it and they are all green, when in reality the image is mostly black and white.

Any help?

I'm not sure what I'm doing wrong as this is all the code I used for the image:

screen:blit(0,0,startImg)
screen.flip()

It's not just one image that's doing it either.

I'm using the HM Mod. Could this be the problem? 3.90 M33