midipolyaftertouch
midipolyaftertouch — Gets a MIDI polyphonic aftertouch value.
Description
midipolyaftertouch is designed to simplify writing instruments that can be used interchangeably for either score or MIDI input, and to make it easier to adapt instruments originally written for score input to work with MIDI input.
In general, it should be possible to write instrument definitions that work identically with both scores and MIDI, including both MIDI files and real-time MIDI input, without using any conditional statements, and that take full advantage of MIDI voice messages.
Note that correlating Csound instruments with MIDI channel numbers is done using the massign opcode for real-time performance,. For file-driven performance, instrument numbers default to MIDI channel number + 1, but the defaults are overridden by any MIDI program change messages in the file.
Initialization
ilow (optional) -- optional low value after rescaling, defaults to 0.
ihigh (optional) -- optional high value after rescaling, defaults to 127.
Performance
xpolyaftertouch -- returns MIDI polyphonic aftertouch during MIDI activation, remains unchanged otherwise.
xcontrollervalue -- returns the value of the MIDI controller during MIDI activation, remains unchanged otherwise.
If the instrument was activated by MIDI input, the opcode overwrites the values of xpolyaftertouch and xcontrollervalue with the corresponding values from MIDI input. If the instrument was NOT activated by MIDI input, the values of xpolyaftertouch and xcontrollervalue remain unchanged.
This enables score p-fields to receive MIDI input data during MIDI activation, and score values otherwise.
![[Note]](images/note.png)
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Adapting a score-activated Csound instrument. |
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See the MIDI interop opcodes section for details on adapting score driven instruments for MIDI or vice-versa. |