melrōse musical expression player

package core import ( "errors" "fmt" "time" "github.com/emicklei/melrose/notify" ) type MIDINote struct { duration HasValue // faction number or number in milliseconds or time.Duration number HasValue velocity HasValue } // ToNote() is part of NoteConvertable func (m MIDINote) ToNote() (Note, error) { nr := Int(m.number) velocity := Int(m.velocity) // check for fraction i := getInt(m.duration, true) // do not warn if not integer if i == 1 || i == 2 || i == 4 || i == 8 || i == 16 || i == 32 { fraction := 1.0 / float32(i) return MIDItoNote(fraction, nr, velocity) } // use as time.Duration or milliseconds n, err := MIDItoNote(0.25, nr, velocity) if err != nil { return Rest4, err } // 0.25 will be discarded n.duration = Duration(m.duration) if n.duration < 0 { return Rest4, errors.New("MIDI duration cannot be < 0") } return n, nil } func (m MIDINote) S() Sequence { n, err := m.ToNote() if err != nil { notify.Console.Errorf("MIDI to sequence failed:%v", err) return EmptySequence } return n.S() } func NewMIDI(duration HasValue, number HasValue, velocity HasValue) MIDINote { return MIDINote{duration: duration, number: number, velocity: velocity} } func (m MIDINote) Storex() string { if s, ok := m.duration.(Storable); ok { return fmt.Sprintf("midi(%s,%v,%v)", s.Storex(), m.number, m.velocity) } return fmt.Sprintf("midi(%v,%v,%v)", m.duration, m.number, m.velocity) } func (m MIDINote) Inspect(i Inspection) { n, err := m.ToNote() if err != nil { i.Properties["error"] = err.Error() return } i.Properties["note"] = n.String() if d, ok := n.NonFractionBasedDuration(); ok { i.Properties["duration"] = d } else { wholeNoteDuration := WholeNoteDuration(i.Context.Control().BPM()) i.Properties["duration"] = time.Duration(float32(wholeNoteDuration) * n.DurationFactor()) } i.Properties["velocity"] = m.velocity } func IsBlackKey(nr int) bool { // https://www.inspiredacoustics.com/en/MIDI_note_numbers_and_center_frequencies i := (nr - 21) % 12 return i == 1 || i == 4 || i == 6 || i == 9 || i == 11 }