SDL::Mixer::Channels

Section: User Contributed Perl Documentation (3)
Updated: 2019-07-26
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NAME

SDL::Mixer::Channels -- SDL::Mixer channel functions and bindings  

CATEGORY

Mixer  

DESCRIPTION

 

METHODS

 

allocate_channels

 my $ret = SDL::Mixer::Channels::allocate_channels( $number_of_channels );

Dynamically change the number of channels managed by the mixer. If decreasing the number of channels, the upper channels are stopped. This function returns the new number of allocated channels.

Example

 use SDL::Mixer::Channels;
 
 printf("We got %d channels!\n", SDL::Mixer::Channels::allocate_channels( 8 ) );

 

volume

 my $prev_volume = SDL::Mixer::Channels::volume( $channel_number, $volume );

"volume" changes the volume of the channel specified in channel by the amount set in volume. The range of volume is from 0 to "MIX_MAX_VOLUME" which is 128. Passing "-1" to channel will change the volume of all channels. If the specified volume is "-1", it will just return the current volume.

Returns the previously set volume of the channel.  

play_channel

 my $channel_number = SDL::Mixer::Channels::play_channel( $channel, $chunk, $loops );

"play_channel" will play the specified "chunk" over the specified "channel". SDL_mixer will choose a channel for you if you pass "-1" for "channel".

The chunk will be looped "loops" times, the total number of times played will be "loops+1". Passing "-1" will loop the chunk infinitely.

Returns the channel the chunk will be played on, or "-1" on error.

Example:

 use SDL::Mixer;
 use SDL::Mixer::Channels;
 use SDL::Mixer::Samples;
 
 SDL::init(SDL_INIT_AUDIO);
 SDL::Mixer::open_audio( 44100, SDL::Constants::AUDIO_S16, 2, 4096 );
 
 my $chunk = SDL::Mixer::Samples::load_WAV('sample.wav');
 
 SDL::Mixer::Channels::play_channel( -1, $chunk, -1 );
 
 SDL::delay(1000);
 SDL::Mixer::close_audio();

 

play_channel_timed

 my $channel = SDL::Mixer::Channels::play_channel_timed( $channel, $chunk, $loops, $ticks );

Same as play_channel but you can specify the time it will play by $ticks.  

fade_in_channel

 my $channel = SDL::Mixer::Channels::fade_in_channel( $channel, $chunk, $loops, $ms );

Same as play_channel but you can specify the fade-in time by $ms.  

fade_in_channel_timed

 my $channel = SDL::Mixer::Channels::fade_in_channel_timed( $channel, $chunk, $loops, $ms, $ticks );

Same as fade_in_channel but you can specify the time how long the chunk will be played by $ticks.  

pause

 SDL::Mixer::Channels::pause( $channel );

Pauses the given channel or all by passing "-1".  

resume

 SDL::Mixer::Channels::resume( $channel );

Resumes the given channel or all by passing "-1".  

halt_channel

 SDL::Mixer::Channels::halt_channel( $channel );

Stops the given channel or all by passing "-1".  

expire_channel

 my $channels = SDL::Mixer::Channels::expire_channel( $channel, $ticks );

Stops the given channel (or "-1" for all) after the time specified by $ticks (in milliseconds).

Returns the number of affected channels.  

fade_out_channel

 my $fading_channels = SDL::Mixer::Channels::fade_out_channel( $which, $ms );

"fade_out_channel" fades out a channel specified in "which" with a duration specified in "ms" in milliseconds.

Returns the the number of channels that will be faded out.  

channel_finished

 SDL::Mixer::Channels::channel_finished( $callback );

Add your own callback when a channel has finished playing. "NULL" to disable callback. The callback may be called from the mixer's audio callback or it could be called as a result of halt_channel, etc. do not call "lock_audio" from this callback; you will either be inside the audio callback, or SDL_mixer will explicitly lock the audio before calling your callback.

Example 1:

 my $callback = sub{ printf("[channel_finished] callback called for channel %d\n", shift); };
 
 SDL::Mixer::Channels::channel_finished( $callback );

Example 2:

 sub callback
 {
     ...
 }
 
 SDL::Mixer::Channels::channel_finished( \&callback );

 

playing

 my $playing = SDL::Mixer::Channels::playing( $channel );

Returns 1 if the given channel is playing sound, otherwise 0. It doesn't check if the channel is paused.

Note: If you pass "-1" you will get the number of playing channels.  

paused

 my $paused = SDL::Mixer::Channels::paused( $channel );

Returns 1 if the given channel is paused, otherwise 0.

Note: If you pass "-1" you will get the number of paused channels.  

fading_channel

 my $fading_channel = SDL::Mixer::Channels::fading_channel( $channel );

Returns one of the following for the given channel:

MIX_NO_FADING
MIX_FADING_OUT
MIX_FADING_IN

Note: Never pass "-1" to this function!  

get_chunk

 my $chunk = SDL::Mixer::Channels::get_chunk( $channel );

"get_chunk" gets the most recent sample chunk played on channel. This chunk may be currently playing, or just the last used.

Note: Never pass "-1" to this function!  

AUTHORS

See ``AUTHORS'' in SDL.


 

Index

NAME
CATEGORY
DESCRIPTION
METHODS
allocate_channels
volume
play_channel
play_channel_timed
fade_in_channel
fade_in_channel_timed
pause
resume
halt_channel
expire_channel
fade_out_channel
channel_finished
playing
paused
fading_channel
get_chunk
AUTHORS
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