melrōse musical expression player

package midi import ( "fmt" "time" "github.com/emicklei/melrose/core" "github.com/emicklei/melrose/midi/transport" "github.com/emicklei/melrose/notify" ) type midiEvent struct { echoString string which []int64 onoff int64 channel int velocity int64 device int out transport.MIDIOut mustHandle core.Condition } func (m midiEvent) NoteChangesDo(callback func(core.NoteChange)) { for _, each := range m.which { callback(core.NewNoteChange(m.onoff == noteOn, each, m.velocity)) } } func (m midiEvent) Handle(tim *core.Timeline, when time.Time) { // TODO not sure if the noteOn check is correct if m.mustHandle != nil && m.onoff == noteOn && !m.mustHandle() { return } status := m.onoff | int64(m.channel-1) for _, each := range m.which { if err := m.out.WriteShort(status, each, m.velocity); err != nil { notify.Errorf("failed to write MIDI data, error:%v", err) } } if m.echoString != "" { m.log(status, when) } } func (m midiEvent) log(status int64, when time.Time) { onoff := " on" if m.onoff == noteOff { onoff = "off" } fmt.Fprintf(notify.Console.StandardOut, "%s dev=%d ch=%d %s=%d nrs=%v vel=%d seq='%s'\n", when.Format("04:05.000"), m.device, m.channel, onoff, status, m.which, m.velocity, m.echoString) } func (m midiEvent) asNoteoff() midiEvent { m.onoff = noteOff return m } type restEvent struct { echoString string mustHandle core.Condition } func (r restEvent) NoteChangesDo(block func(core.NoteChange)) {} func (r restEvent) Handle(tim *core.Timeline, when time.Time) {}