Using sound effects as _G.

Getting Started Newbie Questions
#1

Hi there,

Not sure if i’m committing a faux pas here, but I thought i’d check and ask for your opinion!

I’m currently using a bunch of sound effects for my game as _G. variables set in main.lua (i’m still using Director class by the way). The main reason is primarily because i’ve hit a problem with using 200 local variables upvalue error (something along these lines) so since these sound effects are used throughout my all my .lua files i thought of setting them as _G.

So, i’ve currently got a bunch of: _G.sound1=audio.loadSound(“assets/sound1.wav”) etc in my main.lua. And in my other .lua fles, i set a local soundEffect variable and play the sound using: local soundEffect=audio.play(_G.sound1); This means, at the end of these .lua files, i simply: audio.stop();soundEffect=nil;

Because i’m using globals here, how do i (or do i need to) remove these? Normally, if it was a local variable i’d also add: audio.dispose(sound1);sound1=nil.

Just wondering, would the following be better (so, still using _G. and inserted in main.lua):

  local function onSystem(event)   if event.type == "applicationStart" then      \_G.sound1 = audio.loadSound("assets/sound1.wav") etc...     elseif event.type == "applicationExit" then       audio.dispose(sound1); sound1 = nil;       Runtime:removeEventListener( "system", onSystem ) --note: do i also need to set this here?     end   end   Runtime:addEventListener( "system", onSystem )  

Would this approach be ok and do you see any issues with this?

Thanks for reading!

Cheers,

#2

An easy way to solve the 200 local variables problem is to put all your local variables into one table, i.e.

[lua]

local v = {}

v.score = 100

v.bullets = 3

v.onGround = false

v.grid = {}

[/lua]

This way you’re only using one of your 200 limit for as many variables, objects and tables as you want.

As for sounds, I also load them in main.lua so they can be used throughout the app, but again I put them in a table:

[lua]

_G.sounds = {}

sounds.beep = audio.loadSound(“beep.mp3”)    

sounds.hit = audio.loadSound(“hit.mp3”)

[/lua]

And then call them like this - I don’t bother assigning them to a local variable and disposing/nilling:

[lua]

audio.play(sounds.beep)

[/lua]

#3

Hi @Appvism,

For this, I think you should definitely read Rob’s recent tutorial on modulizing audio:

http://www.coronalabs.com/blog/2013/06/04/tutorial-handling-cross-scene-audio/

The core principle should work fine with Director too.

Take care,

Brent

#4

Thanks for the replies and feedback/info back!

Cheers,

#5

Hi there,

Just wanted to confirm, if i use something like local v={} to store my local variables, such as v.flagGameActive=false, on scene change can i simply use: v=nil rather than specifically using: v.flagGameActive=nil?

If i nil the table, would everything inside this get nil’ed as well?

This approach of using a table certainly helps in minimising the 200 upvalue error! Very useful!

Thanks

#6

An easy way to solve the 200 local variables problem is to put all your local variables into one table, i.e.

[lua]

local v = {}

v.score = 100

v.bullets = 3

v.onGround = false

v.grid = {}

[/lua]

This way you’re only using one of your 200 limit for as many variables, objects and tables as you want.

As for sounds, I also load them in main.lua so they can be used throughout the app, but again I put them in a table:

[lua]

_G.sounds = {}

sounds.beep = audio.loadSound(“beep.mp3”)    

sounds.hit = audio.loadSound(“hit.mp3”)

[/lua]

And then call them like this - I don’t bother assigning them to a local variable and disposing/nilling:

[lua]

audio.play(sounds.beep)

[/lua]

#7

Hi @Appvism,

For this, I think you should definitely read Rob’s recent tutorial on modulizing audio:

http://www.coronalabs.com/blog/2013/06/04/tutorial-handling-cross-scene-audio/

The core principle should work fine with Director too.

Take care,

Brent

#8

Thanks for the replies and feedback/info back!

Cheers,

#9

Hi there,

Just wanted to confirm, if i use something like local v={} to store my local variables, such as v.flagGameActive=false, on scene change can i simply use: v=nil rather than specifically using: v.flagGameActive=nil?

If i nil the table, would everything inside this get nil’ed as well?

This approach of using a table certainly helps in minimising the 200 upvalue error! Very useful!

Thanks