NAME
MIDI::RtController::Filter::Math - Math based RtController filters
VERSION
version 0.0302
SYNOPSIS
use curry;
use MIDI::RtController ();
use MIDI::RtController::Filter::Math ();
my $rtc = MIDI::RtController->new(
input => 'keyboard',
output => 'usb',
);
my $filter = MIDI::RtController::Filter::Math->new(rtc => $rtc);
$filter->control(1); # CC#01 = mod-wheel
$filter->channel(0);
$rtc->add_filter('stair_step', note_on => $filter->curry::stair_step);
$rtc->run;DESCRIPTION
MIDI::RtController::Filter::Math is the collection of Math based MIDI::RtController filters.
ATTRIBUTES
rtc
$rtc = $filter->rtc;The required MIDI::RtController instance provided in the constructor.
channel
$channel = $filter->channel;
$filter->channel($number);The current MIDI channel (0-15, drums=9).
Default: 0
value
$value = $filter->value;
$filter->value($number);Return or set the MIDI event value. This is a generic setting that can be used by filters to set or retrieve state. This often a whole number between 0 and 127, but can take any number.
Default: undef
trigger
$trigger = $filter->trigger;
$filter->trigger($number);Return or set the trigger. This is a generic setting that can be used by filters to set or retrieve state. This often a whole number between 0 and 127, but can take any number.
Default: undef
delay
$delay = $filter->delay;
$filter->delay($number);The current delay time.
Default: 0.1 seconds
feedback
$feedback = $filter->feedback;
$filter->feedback($number);The amount of feedback.
Default: 3
up
$up = $filter->up;
$filter->up($number);The upward movement steps.
Default: 2
down
$down = $filter->down;
$filter->down($number);The downward movement steps.
Default: -1
METHODS
All filter methods must accept the object, a MIDI device name, a delta-time, and a MIDI event ARRAY reference, like:
sub stair_step ($self, $device, $delta, $event) {
my ($event_type, $chan, $note, $value) = $event->@*;
...
return $boolean;
}A filter also must return a boolean value. This tells MIDI::RtController to continue processing other known filters or not.
stair_step
Notes are played from the event note, in up-down, stair-step fashion.
If trigger or value is set, the filter checks those against the MIDI event note or value, respectively, to see if the filter should be applied.
SEE ALSO
The eg/*.pl program(s) in this distribution
MIDI::RtController::Filter::Tonal
MIDI::RtController::Filter::Drums
MIDI::RtController::Filter::CC
AUTHOR
Gene Boggs <gene.boggs@gmail.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2025 by Gene Boggs.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.