VoicerMIDISocket
Extension
ExtensionDescription
VoicerMIDISocket makes it convenient to play a Voicer by MIDI keyboard.
There is a strict division of labor:
- Voicer handles all interaction with the server. It provides the programmatic interface to trigger and release notes (using frequency as the note ID), and manage "global controls" (e.g., a filter frequency that should always be the same across all notes).
- VoicerMIDISocket receives MIDI messages and uses Voicer's programmatic interface to play the notes. It also includes convenience methods to attach the Voicer's global controls to VoicerMIDIController responders.
MIDI note data are sent to the Voicer as follows:
- Note number
- Converted to frequency in Hz, and passed to the synth's
freqargument. The conversion is done by the socket's -midiToFreq function. If this function is not provided, then *defaultMidiToFreq is used. - Velocity
- Divided by 127 and passed to the synth's
gateargument. The SynthDef can convert this to an amplitude using Latch and some range mapping: e.g.,Latch.kr(gate, gate).linlin(0, 1, 0.1, 0.5).
The note data are also provided to an event pattern that supplies arbitrary arguments for each note. See -noteOnArgsPat.
Class Methods
.new
Create a new instance. Arguments are:
- chan
- The messages' source. See ddwMIDI_Guide: Identifying MIDI channels.
- lo
- The lowest MIDI note to which this socket will respond.
- hi
- The highest MIDI note to which this socket will respond.
- noteOnPat
- See -noteOnArgsPat.
- midi2Freq
- A custom function to translate MIDI note number into frequency. If not provided, the default function will be used; see *defaultMidiToFreq.
Returns:
The socket instance.
.defaultMidiToFreq
The default function to convert the incoming MIDI note number into frequency (Hz). During library initialization, this is assigned _.midicps. You may change this function at any time, and it will apply to any new VoicerMIDISockets created in the future. It does not retroactively alter existing sockets.
This function must be deterministic. Voicer will fail to release notes correctly if this function returns different frequencies for the same note number.
Instance Methods
.panic
Calls the target Voicer's panic method, shutting off all notes. Purely a convenience.
Member variables
.lowkey
The lowest MIDI note to which this socket will respond. With hikey, this variable supports keyboard splits by creating multiple VoicerMIDISockets on the same channel, with different key ranges.
.hikey
The highest MIDI note to which this socket will respond.
.transpose
A number of semitones to add to the note number, before converting to frequency. May be fractional, in which case it also serves as a tuning parameter.
.midiToFreq
A custom function to translate MIDI note number into frequency. See *defaultMidiToFreq.
.noteOnArgsPat
An event pattern (e.g., Pbind) providing additional argument values to the Voicer. The pattern can access note number and velocity by Pkey(\midinote) and Pkey(\velocity), respectively. All key-value pairs in the pattern's output events will be passed to the Voicer as note-onset synth arguments. Uses:
- Map note number or velocity onto Voicer synth parameters.
- Randomize, or otherwise algorithmically generate, parameter values per note. For example, each note could play at a random pan position.
.noteOnArgsEvent
An Event containing default values to provide to noteOnArgsPat.
Global controls
The following methods interface with global controls in the Voicer. Once a control is mapped globally, it makes sense to set its value using a physical continuous controller.
The connection between MIDI CC and global control is handled by VoicerMIDIController. You may use this class directly. In most cases, though, it's easier if the VoicerMIDISocket "owns" the controllers, so that (for instance) freeing the socket will also release the controllers.
.addControl
Adds a MIDI controller to this socket instance. Two possible cases:
- The voicer already has a global control under this name: The new MIDI controller will point to the existing global control. (In this case, the
valueandspecarguments are optional. If provided, they won't be used.) - The voicer does not have a global control for this name: The
addControlmethod will create the global control in the voicer for you, and attach the MIDI controller. This is provided for convenience.
Arguments:
| ccnum |
The controller number. See ddwMIDI_Guide: Controller_Numbers. |
| name |
The synth argument name (as a Symbol). |
| value |
If a new global control is being created (because none existed), this is the initial value. (If a global control already existed, this is ignored.) |
| spec |
If a new global control is being created (because none existed), this is the ControlSpec. (If a global control already existed, this is ignored.) |
| overrideChan |
By default (if this argument is not given), then MIDI controller will be created on the same MIDI channel as the socket. You may specify a different channel here -- for instance, if you have a full-size keyboard without many continuous controllers, and another device with several knobs, the socket can receive notes from the keyboard, and you can create controller mappings to the other device. |
Returns:
The socket instance (not the new MIDI controller object).
.removeControl
Disconnect and remove a VoicerMIDIController.
Arguments:
| control |
A way to identify the controller to remove. One of the following:
|
Returns:
The socket instance.
.searchControl
Look up a VoicerMIDIController (attached to this socket) by the parameter name.
Arguments:
| control |
A |
Returns:
The VoicerMIDIController instance.
.ccs
An Array, containing the VoicerMIDIControllers attached to this socket.
.searchControlNum
Look up a VoicerMIDIController (attached to this socket) by the controller number.
Arguments:
| control |
An integer or |
Returns:
The VoicerMIDIController instance.