Object
IMPORTANT: this class only exists if SDL_mixer is available! Your code should check "defined?(Rubygame::Sound) != nil" to see if you can use this class, or be prepared to rescue from NameError.
Sound holds a sound effect, loaded from an audio file (see load for supported formats).
Sound can play, pause/unpause, stop, adjust volume, and fade_out (you can fade in by passing an option to play).
Sound can create duplicates (with dup or clone) in a memory-efficient way -- the new Sound instance refers back to the same audio data, so having 100 duplicates of a sound uses only slightly more memory than having the first sound. Duplicates can different volume levels, too!
Sound includes the Rubygame::NamedResource mixin module, which can perform autoloading of sounds on demand, among other things.
Searches each directory in Sound.autoload_dirs for a file with the given filename. If it finds that file, loads it and returns a Sound instance. If it doesn't find the file, returns nil.
See Rubygame::NamedResource for more information about this functionality.
# File lib/rubygame/sound.rb, line 54 def autoload( filename ) path = find_file( filename ) if( path ) return load( path ) else return nil end end
Load the given audio file. Supported file formats are WAVE, MOD, MIDI, OGG, and MP3.
filename |
Full or relative path to the file. (String, required) |
Returns |
|
May raise |
SDLError, if the sound file could not be loaded. |
# File lib/rubygame/sound.rb, line 73 def load( filename ) Rubygame.open_audio sound = SDL::Mixer.LoadWAV( filename ) if( sound.pointer.null? ) raise( Rubygame::SDLError, "Could not load Sound file '%s': %s"% [filename, SDL.GetError()] ) end return new( sound ) end
*NOTE*: Don't use this method. Use Sound.load.
Raises NotImplementedError.
# File lib/rubygame/sound.rb, line 96 def initialize( sound=nil ) if( sound.instance_of? SDL::Mixer::Chunk ) @struct = sound @volume = 1 @channel = -1 else raise( NotImplementedError, "Sound.new is not implemented. "+ "Use Sound.load to load a sound file." ) end end
Fade out to silence over the given number of seconds. Once the sound is silent, it is automatically stopped.
Returns |
The receiver (self). |
*NOTE*: If the sound is currently paused, the fade will start, but you won't be able to hear it happening unless you unpause during the fade.
Does nothing if the sound is currently stopped.
# File lib/rubygame/sound.rb, line 346 def fade_out( fade_time ) if( fade_time < 0 ) raise ArgumentError, "fade time cannot be negative (got %.2f)"%fade_time end if channel_active? SDL::Mixer.FadeOutChannel( @channel, (fade_time * 1000).to_i ) end return self end
True if the Sound is currently fading in or out. See also play and fade_out.
direction |
Check if it is fading :in, :out, or :either. (Symbol, required) |
# File lib/rubygame/sound.rb, line 365 def fading?( direction=:either ) return false unless channel_active? case direction when :in SDL::Mixer.FadingChannel( @channel ) == SDL::Mixer::FADING_IN when :out SDL::Mixer.FadingChannel( @channel ) == SDL::Mixer::FADING_OUT else SDL::Mixer.FadingChannel( @channel ) != SDL::Mixer::NO_FADING end end
Create a copy of the given Sound instance. More efficient than using load to load the sound file again.
other |
|
Returns |
*NOTE*: clone and dup do slightly different things; clone will copy the 'frozen' state of the object, while dup will create a fresh, un-frozen object.
# File lib/rubygame/sound.rb, line 127 def initialize_copy( other ) @struct = other.struct @volume = other.volume @channel = -1 end
Pause the Sound. Unlike stop, it can be unpaused later to resume from where it was paused. See also unpause and paused?.
Returns |
The receiver (self). |
*NOTE*: Does nothing if the sound is not currently playing.
# File lib/rubygame/sound.rb, line 274 def pause if channel_active? SDL::Mixer.Pause( @channel ) end return self end
Play the Sound, optionally fading in, repeating a certain number of times (or forever), and/or stopping automatically after a certain time.
options |
Hash of options, listed below. (Hash, required) |
:fade_in |
Fade in from silence over the given number of seconds. Default: 0. (Numeric, optional) |
:repeats |
Repeat the sound the given number of times, or forever (or until stopped) if -1. Default: 0. (Integer, optional) |
:stop_after |
Automatically stop playing after playing for the given number of seconds. Use nil to disable this behavior. (Numeric or nil, optional) |
Returns |
The receiver (self). |
May raise |
SDLError, if the audio device could not be opened, or if the sound file could not be played. |
*NOTE*: If the sound is already playing (or paused), it will be stopped and played again from the beginning.
Example:
# Fade in over 2 seconds, play 4 times (1 + 3 repeats), # but stop playing after 5 seconds. sound.play( :fade_in => 2, :repeats => 3, :stop_after => 5 );
# File lib/rubygame/sound.rb, line 168 def play( options={} ) fade_in = (options[:fade_in] or 0) repeats = (options[:repeats] or 0) stop_after = (options[:stop_after] or nil) fade_in = if( fade_in < 0 ) raise ArgumentError, ":fade_in cannot be negative (got %.2f)"%fade_in elsif( fade_in < 0.05 ) # Work-around for a bug with SDL_mixer not working with small # non-zero fade-ins 0 else (fade_in * 1000).to_i end repeats = if( repeats < -1 ) raise( ArgumentError, ":repeats cannot be negative, except -1 (got #{repeats})" ) else repeats end stop_after = if( stop_after.nil? ) -1 elsif( stop_after < 0 ) raise( ArgumentError, ":stop_after cannot be negative, (got %.2f)"%stop_after ) else (stop_after * 1000).to_i end Rubygame.open_audio # If it's already playing on a channel, stop it first. if channel_active? SDL::Mixer.HaltChannel( @channel ) end # Find first available channel @channel = SDL::Mixer.GroupAvailable(-1) if @channel == -1 # No channels were available, so make one more than there are now. # (Mix_AllocateChannels(-1) returns the current number of channels) SDL::Mixer.AllocateChannels( SDL::Mixer.AllocateChannels(-1) + 1 ) # Try again @channel = SDL::Mixer.GroupAvailable(-1) end # Set sound channel volume before we play SDL::Mixer.Volume( @channel, (SDL::Mixer::MAX_VOLUME * @volume).to_i ) result = if( fade_in <= 0 ) # Play sound without fading in SDL::Mixer.PlayChannelTimed( @channel, @struct, repeats, stop_after ) else # Play sound with fading in SDL::Mixer.FadeInChannelTimed( @channel, @struct, repeats, fade_in, stop_after ) end if( result == -1 ) raise Rubygame::SDLError, "Could not play Sound: #{SDL.GetError()}" end return self end
Stop the Sound. Unlike pause, the sound must be played again from the beginning, it cannot be resumed from it was stopped.
Returns |
The receiver (self). |
*NOTE*: Does nothing if the sound is not currently playing or paused.
# File lib/rubygame/sound.rb, line 317 def stop if channel_active? SDL::Mixer.HaltChannel( @channel ) end return self end
Unpause the Sound, if it is currently paused. Resumes from where it was paused. See also pause and paused?.
Returns |
The receiver (self). |
*NOTE*: Does nothing if the sound is not currently paused.
# File lib/rubygame/sound.rb, line 290 def unpause if channel_active? SDL::Mixer.Resume( @channel ) end return self end
Return the volume level of the sound. 0.0 is totally silent, 1.0 is full volume.
*NOTE*: Ignores fading in or out.
# File lib/rubygame/sound.rb, line 385 def volume @volume end
Set the new volume level of the sound. 0.0 is totally silent, 1.0 is full volume. The new volume will be clamped to this range if it is too small or too large.
Volume cannot be set while the sound is fading in or out. Be sure to check fading? or rescue from SDLError when using this method.
May raise |
SDLError if the sound is fading in or out. |
# File lib/rubygame/sound.rb, line 401 def volume=( new_vol ) # Clamp it to valid range new_vol = if new_vol < 0.0; 0.0 elsif new_vol > 1.0; 1.0 else; new_vol end if channel_active? if fading? raise Rubygame::SDLError, "cannot set Sound volume while fading" else SDL::Mixer.Volume( @channel, (SDL::Mixer::MAX_VOLUME * new_vol).to_i ) end end @volume = new_vol end
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