Channel setVolume. How it works?

unlying

Hello.
Plz, explain me how it works. I spend more then hour and still can't find what i'm doing wrong
Here is code:

music = Sound.new("mus/heal.wav") channel:setVolume(0.0) print(channel:getVolume()) channel = music:play(0, 1) print(channel:getVolume())

and sound plays. I have 0 and 1 in output.
How to set Volume to 0 forever?

hnim

@unlying: if you want to set volume to 0 (or other value) forever, why you dont change your own gfx files?
when you call music:play(), it returns new channel, so volume will back to 1. If you want to play sound/music with custom volume, you can write some util funtions

function play(snd, vol) local channel = snd:play() channe:setVolume(vol) --return channel end

unlying

It is weird. To set Volume everytime when i play sound. I used it in my first projects by Gideros. But it is really-really weird. After that i just don't care about sound volume.
It should be normal way to set volume for channel.

plamen

channel = music:play(0, 1) - this is the moment when channel is created.
you can set the volume or get the volume after it.

unlying

I don't think that it is ok. If we really should set volume everytime when we play any sound, then it should be changed.

atilim

@unlying When a new object is created (like SoundChannel), all of its properties are set to default values. And the default value of the volume of a SoundChannel object is 1.

For example alpha is a property of Sprite and its default value is 1:

sprite = Sprite.new() sprite:setAlpha(0) print(sprite:getAlpha()) --> prints 0 sprite = Sprite.new() print(sprite:getAlpha()) --> prints 1

And volume behaves exactly the same way.

ar2rsawseen

And it could be easily by passed

function Sound:setVolume(volume) self._volume = volume end   Sound._play = Sound.play   function Sound:play(...) local sound = self:_play(...) if self._volume then sound:setVolume(self._volume) end return sound end

Something similar to this is done in GiderosCodingEasy only there you can control the volume of whole app (all sounds and musics of an app )

unlying

In russian we spell it like "crutches"
It should be transparent way to set default values for these things.

asakharov

@atilim, Is it possible to add method setDefaultVolume(value) to Sound class? Or pass it to constructor, or play method.
And why do we need separation of Sound and Sound channel? To download music once and play over and over? (To save memory.)
It would be great to have a resource pool with lazy loading for music and other resources. Then you could get rid of classes like SoundChannel

OZApps

I guess what you are asking for is like a Master Volume, so if you set the volume to 0.2 then all sounds/music loaded and played thereafter should play at that volume. In the current scenario the only thing required would be to create a wrapper function that would set up the volume as required.

gmarinov

@unlying - there's volume control at the speaker already so simply make your sounds consistent if you don't want to do anything else. For a volume setting in your app, wrap sound:play to apply setVolume immediately. It's a great rabbit hole..

I actually like SoundChannel, especially with the events.

There's also the concept of sound layers (background, fx e.g. weapons, bonuses/pick-ups, music, UI). So maybe we can have the SoundChannel subscribe to event notifications for the "layer" it's on, to keep track of the global layer gain/volume, then it's a matter of wrapping setVolume() to apply that correction. I'm working on something similar, so I'll test this theory..

gmarinov

Here's what I ended up with.

Event.snd_layer_volume_change = "snd_slvc" -- any string   SoundLayer = Core.class(EventDispatcher) SoundLayer.name = "default" SoundLayer.vol = 1   function SoundLayer:setVolume(v) self.vol = v self:dispatchEvent(Event.new(Event.snd_layer_volume_change)) end function SoundLayer:getVolume() return self.vol end       SoundChannel.layer_ref = nil -- holds SoundLayer reference SoundChannel.vol = 1 -- full whack function SoundChannel:set_layer(l) -- l is a SoundLayer or NIL to detach if not l then if self.layer_ref then self.layer_ref:removeEventListener( Event.snd_layer_volume_change, self.on_layer_volume_change, self ) end end self.layer_ref = l if (self.layer_ref) then l:addEventListener( Event.snd_layer_volume_change, self.on_layer_volume_change, self) end end   function SoundChannel:on_layer_volume_change() self:set_volume_with_globalgain(self.vol) end   function SoundChannel:set_volume_with_globalgain(vol) -- sanity checks if not vol then return end self.vol = vol local global_vol = 1 if (self.layer_ref and self.layer_ref.vol) then global_vol = self.layer_ref:getVolume() end   vol = vol * global_vol if (vol < 0) then vol = 0 end if (vol > 1) then vol = 1 end   self:setVolume(vol); end