melrōse musical expression player

package midi import ( "sync" "time" "github.com/emicklei/melrose/core" "github.com/emicklei/melrose/notify" ) type KeyTrigger struct { mutex *sync.RWMutex playing bool ctx core.Context channel int note core.Note fun core.HasValue } func NewKeyTrigger(ctx core.Context, channel int, onNote core.Note, startStop core.HasValue) *KeyTrigger { return &KeyTrigger{ mutex: new(sync.RWMutex), ctx: ctx, channel: channel, note: onNote, fun: startStop} } // NoteOn is part of core.NoteListener func (t *KeyTrigger) NoteOn(channel int, n core.Note) { if notify.IsDebug() { notify.Debugf("keytrigger.NoteOn ch=%d note=%v", channel, n) } if channel != t.channel { return } if n.Name != t.note.Name { return } if n.Octave != t.note.Octave { return } val := t.fun.Value() if val == nil { return } t.mutex.Lock() defer t.mutex.Unlock() // both playable and evaluatable are allowed if play, ok := val.(core.Playable); ok { stopper, stoppable := val.(core.Stoppable) if stoppable { if t.playing { notify.Infof("%s -> stop(%s)", t.note.String(), core.Storex(t.fun)) stopper.Stop(t.ctx) t.playing = false } else { t.playing = true notify.Infof("%s -> play(%s)", t.note.String(), core.Storex(t.fun)) _ = play.Play(t.ctx, time.Now()) } return } // cannot stop _ = play.Play(t.ctx, time.Now()) return } // not playable, maybe evaluatable if eval, ok := val.(core.Evaluatable); ok { eval.Evaluate(t.ctx) } } // NoteOff is part of core.NoteListener func (t *KeyTrigger) NoteOff(channel int, n core.Note) { if notify.IsDebug() { notify.Debugf("keytrigger.NoteOff ch=%d note=%v", channel, n) } // key trigger is not interested in this } func (t *KeyTrigger) ControlChange(channel, number, value int) { if notify.IsDebug() { notify.Debugf("keytrigger.ControlChange %d %d %d", channel, number, value) } // key trigger is not interested in this }