melrōse musical expression player

package core import ( "bytes" "fmt" "time" "github.com/emicklei/melrose/notify" ) type Track struct { Title string Channel int Content map[int]Sequenceable // bar -> musical object } func NewTrack(title string, channel int) *Track { return &Track{ Title: title, Channel: channel, Content: map[int]Sequenceable{}, } } func (t *Track) Play(ctx Context, now time.Time) time.Time { bpm := ctx.Control().BPM() biab := ctx.Control().BIAB() whole := WholeNoteDuration(bpm) var endingAt time.Time for bars, each := range t.Content { cs := NewChannelSelector(each, On(t.Channel)) offset := int64((bars-1)*biab) * whole.Nanoseconds() / 4 when := now.Add(time.Duration(time.Duration(offset))) if notify.IsDebug() { notify.Debugf("core.track title=%s channel=%d bar=%d, biab=%d, bpm=%.2f time=%s", t.Title, t.Channel, bars, biab, bpm, when.Format("04:05.000")) } endingAt = ctx.Device().Play(NoCondition, cs, bpm, when) } return endingAt } func (t *Track) Inspect(i Inspection) { i.Properties["channel"] = t.Channel i.Properties["pieces"] = len(t.Content) } // Add adds a SequenceOnTrack func (t *Track) Add(seq SequenceOnTrack) { b := Int(seq.Bar) t.Content[b] = seq.Target } // Storex implements Storable func (t *Track) Storex() string { var buf bytes.Buffer fmt.Fprintf(&buf, "track('%s',%d", t.Title, t.Channel) for k, v := range t.Content { fmt.Fprint(&buf, ",") sont := NewSequenceOnTrack(On(k), v) // TODO fmt.Fprint(&buf, sont.Storex()) } fmt.Fprintf(&buf, ")") return buf.String() } type SequenceOnTrack struct { Bar HasValue Target Sequenceable } func NewSequenceOnTrack(bar HasValue, seq Sequenceable) SequenceOnTrack { return SequenceOnTrack{Bar: bar, Target: seq} } func (s SequenceOnTrack) S() Sequence { return s.Target.S() } // Storex implements Storable func (s SequenceOnTrack) Storex() string { if st, ok := s.Target.(Storable); ok { return fmt.Sprintf("onbar(%v,%s)", s.Bar, st.Storex()) } return "" } type MultiTrack struct { Tracks []HasValue } // Storex implements Storable func (m MultiTrack) Storex() string { var buf bytes.Buffer fmt.Fprintf(&buf, "multitrack(") for i, each := range m.Tracks { if i > 0 { fmt.Fprintf(&buf, ",") } if t, ok := each.(Storable); ok { fmt.Fprintf(&buf, "%s", t.Storex()) } else { fmt.Fprintf(&buf, "%v", each) } } fmt.Fprintf(&buf, ")") return buf.String() } // Play is part of Playable func (m MultiTrack) Play(ctx Context, at time.Time) error { // because all tracks must be synchronized, we first stop the beatmaster // then schedule all tracks // then start the beatmaster again. ctx.Control().Stop() for _, each := range m.Tracks { if track, ok := each.Value().(*Track); ok { for bar, seq := range track.Content { ch := NewChannelSelector(seq, On(track.Channel)) ctx.Control().Plan(int64(bar-1), ch) } } else { // TODO notify.NewErrorf("not a track:%v", each) } } ctx.Control().Start() return nil }