Transposer

class Transposer : public MidiFilter {
public:
  Transposer(int);
  void filter(MIDI_msg*) const;
  virtual void apply(State*) const;
  virtual void unapply(State*) const;
};

Transposer(int t);

This creates a Transposer which transposes up (or down, if negative) by t halfsteps. t must be between +64 and -64, inclusive.

void filter(MIDI_msg* m)

This member function transposess m.

void apply(State* s)

This member function modifies s to the state it would be if the Transposer was applied, assuming it was not applied before.

void unapply(State* s)

This member function modifies s to the state it would be if the Transposer was not applied, assuming it was applied before.