Object
IMPORTANT: this class only exists if SDL_mixer is available! Your code should check "defined?(Rubygame::Music) != nil" to see if you can use this class, or be prepared to rescue from NameError.
Music holds a song, streamed from an audio file (see load for supported formats). There are two important differences between the Music and Sound classes:
Only one Music can be playing. If you try to play a second song, the first one will be stopped.
Music doesn't load the entire audio file, so it can begin quickly and doesn't use much memory. This is good, because music files are usually much longer than sound effects!
Music can play, pause/unpause, stop, rewind, jump_to another time, adjust volume, and fade_out (fade in by passing an option to play).
Music includes the Rubygame::NamedResource mixin module, which can perform autoloading of music on demand, among other things.
Searches each directory in Music.autoload_dirs for a file with the given filename. If it finds that file, loads it and returns a Music instance. If it doesn't find the file, returns nil.
See Rubygame::NamedResource for more information about this functionality.
# File lib/rubygame/music.rb, line 57 def autoload( filename ) path = find_file( filename ) if( path ) return load( path ) else return nil end end
# File lib/rubygame/music.rb, line 90 def current_music @current_music 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 music file could not be loaded. |
# File lib/rubygame/music.rb, line 76 def load( filename ) Rubygame.open_audio music = SDL::Mixer.LoadMUS( filename ) if( music.pointer.null? ) raise( Rubygame::SDLError, "Could not load Music file '%s': %s"% [filename, SDL.GetError()] ) end return new( music ) end
*NOTE*: Don't use this method. Use Music.load.
Raises NotImplementedError.
# File lib/rubygame/music.rb, line 108 def initialize( music=nil ) if( music.instance_of? SDL::Mixer::Music ) @struct = music @volume = 1 @repeats = 0 else raise( NotImplementedError, "Music.new is not implemented. "+ "Use Music.load to load a music file." ) end end
Fade out to silence over the given number of seconds. Once the music is silent, it is automatically stopped.
Returns |
The receiver (self). |
*NOTE*: If the music 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 music is currently stopped.
# File lib/rubygame/music.rb, line 340 def fade_out( fade_time ) if( fade_time < 0 ) raise ArgumentError, "fade time cannot be negative (got %.2f)"%fade_time end if current? result = SDL::Mixer.FadeOutMusic( (fade_time * 1000).to_i ) if( result < 0 ) raise Rubygame::SDLError, "Error fading out music: #{SDL.GetError()}" end end return self end
True if the Music 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/music.rb, line 362 def fading?( direction=:either ) return false unless current? case direction when :in SDL::Mixer.FadingMusic() == SDL::Mixer::FADING_IN when :out SDL::Mixer.FadingMusic() == SDL::Mixer::FADING_OUT else SDL::Mixer.FadingMusic() != SDL::Mixer::NO_FADING end end
Create a copy of the given Music instance. More efficient than using load to load the music 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/music.rb, line 139 def initialize_copy( other ) @struct = other.struct @volume = other.volume @repeats = other.repeats end
Jump to any time in the Music, in seconds since the beginning. If the Music was paused, it will still be paused again after the jump. Does nothing if the Music was stopped.
*NOTE*: Only works for OGG and MP3 formats! Other formats (e.g. WAV) will usually raise SDLError.
time |
the time to jump to, in seconds since the beginning of the song. (Numeric, required) |
May raise |
SDLError if something goes wrong, or if the music type does not support jumping. |
*CAUTION*: This method may be unreliable (and could even crash!) if you jump to a time after the end of the song. Unfortunately, SDL_Mixer does not provide a way to find the song's length, so Rubygame cannot warn you if you go off the end. Be careful!
# File lib/rubygame/music.rb, line 464 def jump_to( time ) if current? and not stopped? was_paused = paused? if( time < 0 ) raise Rubygame::SDLError, "cannot jump to negative time (got #{time})" end result = SDL::Mixer.SetMusicPosition( time.to_f ) if( result == -1) raise Rubygame::SDLError, "could not jump music: #{SDL.GetError()}" end SDL::Mixer.PauseMusic() if was_paused end return self end
Pause the Music. 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 music is not currently playing.
# File lib/rubygame/music.rb, line 268 def pause if current? SDL::Mixer.PauseMusic() end return self end
Play the Music, optionally fading in, repeating a certain number of times (or forever), and/or starting at a certain position in the song.
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 music the given number of times, or forever (or until stopped) if -1. Default: 0. (Integer, optional) |
:start_at |
Start playing the music at the given time in the song, in seconds. Default: 0. (Numeric, optional) *NOTE*: Non-zero start times only work for OGG and MP3 formats! Please refer to jump. |
Returns |
The receiver (self). |
May raise |
SDLError, if the audio device could not be opened, or if the music file could not be played, or if you used :start_at with an unsupported format. |
*NOTE*: Only one music can be playing at once. If any music is already playing (or paused), it will be stopped before playing the new music.
Example:
# Fade in over 2 seconds, play 4 times (1 + 3 repeats), # starting at 60 seconds since the beginning of the song. music.play( :fade_in => 2, :repeats => 3, :start_at => 60 );
# File lib/rubygame/music.rb, line 184 def play( options={} ) fade_in = (options[:fade_in] or 0) repeats = (options[:repeats] or 0) start_at = (options[:start_at] or 0) 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})" ) elsif( repeats > -1 ) # Adjust so repeats means the same as it does for Sound (repeats + 1).to_i else -1 end start_at = if( start_at < 0 ) raise( ArgumentError, ":start_at cannot be negative, (got %.2f)"%start_at ) else start_at.to_f end Rubygame.open_audio # Doing a little restart dance to please the SDL_mixer gods. SDL::Mixer.PlayMusic( @struct, 0 ) SDL::Mixer.HaltMusic() # Set music channel volume before we play SDL::Mixer.VolumeMusic( (SDL::Mixer::MAX_VOLUME * @volume).to_i ) @repeats = repeats result = SDL::Mixer.FadeInMusicPos( @struct, repeats, fade_in, start_at ) if( result == -1 ) raise Rubygame::SDLError, "Could not play Music: #{SDL.GetError()}" end self.class.__current_music = self return self end
Rewind the Music to the beginning. If the Music was paused, it will still be paused after the rewind. Does nothing if the Music is stopped.
# File lib/rubygame/music.rb, line 428 def rewind if current? and not stopped? was_paused = paused? SDL::Mixer.HaltMusic() result = SDL::Mixer.PlayMusic(@struct, @repeats) if( result == -1 ) raise Rubygame::SDLError, "Could not rewind music: #{SDL.GetError()}" end SDL::Mixer.PauseMusic() if was_paused end return self end
Stop the Music. Unlike pause, the music must be played again from the beginning, it cannot be resumed from it was stopped.
Returns |
The receiver (self). |
*NOTE*: Does nothing if the music is not currently playing or paused.
# File lib/rubygame/music.rb, line 311 def stop if current? SDL::Mixer.HaltMusic() end return self end
Unpause the Music, 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 music is not currently paused.
# File lib/rubygame/music.rb, line 284 def unpause if current? SDL::Mixer.ResumeMusic() end return self end
Return the volume level of the music. 0.0 is totally silent, 1.0 is full volume.
*NOTE*: Ignores fading in or out.
# File lib/rubygame/music.rb, line 382 def volume @volume end
Set the new volume level of the music. 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 music is fading in or out. Be sure to check fading? or rescue from SDLError when using this method.
May raise |
SDLError if the music is fading in or out. |
# File lib/rubygame/music.rb, line 398 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 current? if fading? raise Rubygame::SDLError, "cannot set Music volume while fading" else SDL::Mixer.VolumeMusic( (SDL::Mixer::MAX_VOLUME * new_vol).to_i ) end end @volume = new_vol end
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