Someone suggested that it would be impossible to map the 12 tones
onto the white keys of a keyoard, and still get correct pitch bend
handling. Well, here's a solution:
The MIDI converter/driver:
This will have to make pitch bend available as a
separate control output from pitch. This does *not*
mean we have to apply pitch bend later, though!
Instead, we apply pitch bend to out PITCH output,
*and* then send pitch bend to the PITCHBEND output.
So, if you don't care for anything but continous
pitch, just ignore this feature.
As to pitch bend range, that is handled entirely
by the converter/driver; the bend output is in the
same units as the pitch output.
With NOTEPITCH:
NOTEPITCH is in 1.0/note
PITCHBEND is in 1.0/note
PITCHBEND = (midi_bend - 8192) * midi_range * (1.0/8192.0);
NOTEPITCH = midi_pitch + PITCHBEND;
Without NOTEPITCH:
PITCH is in (1/12)/note
PITCHBEND is in (1/12)/note
PITCHBEND = (midi_bend - 8192) * midi_range * (1.0/8192.0);
PITCH = midi_pitch + PITCHBEND;
PITCHBEND *= 1.0/12.0;
PITCH *= 1.0/12.0;
The keyboard remapper:
This one will have inputs for both pitch and pitch
bend controls, since it needs to be able to remove
the bend and then reapply it later. remap_lut[] is
simply a table that "returns" the desired pitch for
each key in the scale. (Obviously, you'll have to
add a conditional to ignore the black keys, if you
don't want to map them to anything.)
With NOTEPITCH:
int note = (int)(NOTEPITCH - PITCHBEND);
NOTEPITCH = remap_lut[note] + PITCHBEND;
Without NOTEPITCH:
int note = (int)((NOTEPITCH - PITCHBEND)*12.0);
NOTEPITCH = remap_lut[note] + PITCHBEND;
//David Olofson - Programmer, Composer, Open Source Advocate
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