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set_volume_per_voice(3)         Allegro manual         set_volume_per_voice(3)

NAME
       set_volume_per_voice - Sets the volume of a voice. Allegro game
       programming library.

SYNOPSIS
       #include <allegro.h>

       void set_volume_per_voice(int scale);

DESCRIPTION
       By default, Allegro will play a centered sample at half volume on both
       the left and right channel. A sample panned to the far right or left
       will be played at maximum volume on that channel only. This is done so
       you can play a single panned sample without distortion. If you play
       multiple samples at full volume, the mixing process can result in
       clipping, a noticeable form of distortion. The more samples, the more
       likely clipping is to occur, and the more clipping, the worse the
       output will sound.

       If clipping is a problem - or if the output is too quiet - this
       function can be used to adjust the volume of each voice. You should
       first check that your speakers are at a reasonable volume, Allegro's
       global volume is at maximum (see set_volume() below), and any other
       mixers such as the Windows Volume Control are set reasonably. Once you
       are sure that Allegro's output level is unsuitable for your
       application, use this function to adjust it.

       Each time you increase the parameter by one, the volume of each voice
       will halve. For example, if you pass 4, you can play up to 16 centred
       samples at maximum volume without distortion.

       If you pass 0 to this function, each centred sample will play at the
       maximum volume possible without distortion, as will all samples played
       through a mono driver. Samples at the extreme left and right will
       distort if played at full volume. If you wish to play panned samples at
       full volume without distortion, you should pass 1 to this function.
       Note: this is different from the function's behaviour in WIPs 3.9.34,
       3.9.35 and 3.9.36. If you used this function under one of these WIPs,
       you will have to increase your parameter by one to get the same volume.

       Note: The default behaviour has changed as of Allegro 4.1.15. If you
       would like the behaviour of earlier versions of Allegro, pass -1 to
       this function. Allegro will choose a value dependent on the number of
       voices, so that if you reserve n voices, you can play up to n/2
       normalised samples with centre panning without risking distortion. The
       exception is when you have fewer than 8 voices, where the volume
       remains the same as for 8 voices. Here are the values, dependent on the
       number of voices:

          1-8 voices - set_volume_per_voice(2)
           16 voices - set_volume_per_voice(3)
           32 voices - set_volume_per_voice(4)
           64 voices - set_volume_per_voice(5)

       Of course this function does not override the volume you specify with
       play_sample() or voice_set_volume(). It simply alters the overall
       output of the program. If you play samples at lower volumes, or if they
       are not normalised, then you can play more of them without distortion.

       It is recommended that you hard-code the parameter into your program,
       rather than offering it to the user. The user can alter the volume with
       the configuration file instead, or you can provide for this with
       set_volume().

       To restore volume per voice to its default behaviour, pass 1.

SEE ALSO
       reserve_voices(3), set_volume(3), install_sound(3),
       detect_digi_driver(3), detect_midi_driver(3)

Allegro                          version 4.4.2         set_volume_per_voice(3)