melrōse musical expression player

package core import ( "bytes" "fmt" "io" "log" ) // https://en.wikipedia.org/wiki/Chord_(music) type Chord struct { start Note inversion int // Ground,Inversion1,Inversion2,Inversion3 interval int // Triad,Seventh,Sixth quality int // Major,Minor,Dominant,Augmented,Diminished,Suspended2,Suspended4 } func zeroChord() Chord { return Chord{start: N("C"), inversion: Ground, quality: Major, interval: Triad} } func (c Chord) Inspect(i Inspection) { i.Properties["sequence"] = c.S().String() } func (c Chord) WithInterval(i int) Chord { c.interval = i return c } func (c Chord) WithInversion(i int) Chord { c.inversion = i return c } func (c Chord) WithQuality(q int) Chord { c.quality = q return c } func (c Chord) WithVelocity(v int) Chord { c.start = c.start.WithVelocity(v) return c } func (c Chord) WithFraction(f float32, dotted bool) Chord { c.start = c.start.WithFraction(f, dotted) return c } func (c Chord) String() string { if c.start.IsRest() { return c.start.String() } var b bytes.Buffer fmt.Fprint(&b, c.start.String()) endsWithSlash := false emitSeparator := func() { if !endsWithSlash { io.WriteString(&b, "/") } endsWithSlash = false } if c.quality != Major { switch c.quality { case Minor: emitSeparator() io.WriteString(&b, "m") case Major: emitSeparator() io.WriteString(&b, "M") case Diminished: emitSeparator() io.WriteString(&b, "dim") case Augmented: emitSeparator() io.WriteString(&b, "aug") // OR + TODO case Suspended2: emitSeparator() io.WriteString(&b, "sus2") case Suspended4: emitSeparator() io.WriteString(&b, "sus4") } } if c.interval != Triad { switch c.interval { case Sixth: emitSeparator() io.WriteString(&b, "6") case Seventh: emitSeparator() io.WriteString(&b, "7") } } if c.inversion != Ground { switch c.inversion { case Inversion1: emitSeparator() io.WriteString(&b, "1") case Inversion2: emitSeparator() io.WriteString(&b, "2") case Inversion3: emitSeparator() io.WriteString(&b, "3") } } return b.String() } // Storex implements Storable func (c Chord) Storex() string { return fmt.Sprintf("chord('%s')", c.String()) } // S converts a Chord into a Sequence func (c Chord) S() Sequence { return Sequence{[][]Note{c.Notes()}} } // Replaced is part of Replaceable func (c Chord) Replaced(from, to Sequenceable) Sequenceable { if IsIdenticalTo(from, c) { return to } return c } // Notes returns the Note values for this chord. func (c Chord) Notes() []Note { notes := []Note{c.start} if c.start.IsRest() || c.start.IsPedalDown() || c.start.IsPedalUp() || c.start.IsPedalUpDown() { return notes } var semitones []int if c.interval == Triad { if c.quality == Augmented { semitones = []int{4, 8} } else if c.quality == Diminished { semitones = []int{3, 6} } else if c.quality == Major { semitones = []int{4, 7} } else if c.quality == Minor { semitones = []int{3, 7} } else if c.quality == Suspended2 { semitones = []int{2, 7} } else if c.quality == Suspended4 { semitones = []int{5, 7} } } if c.interval == Seventh { if c.quality == Augmented { semitones = []int{4, 8, 10} } else if c.quality == Diminished { semitones = []int{3, 6, 9} } else if c.quality == Minor { semitones = []int{3, 7, 10} } else if c.quality == Major { semitones = []int{4, 7, 11} } else if c.quality == Septiem { semitones = []int{4, 7, 10} } } for _, each := range semitones { next := c.start.Pitched(each) notes = append(notes, next) } // apply inversion if c.interval == Triad { if c.inversion == Inversion1 { notes = append(notes, notes[0].Octaved(1))[1:] } if c.inversion == Inversion2 { notes = append(notes, notes[0].Octaved(1))[1:] notes = append(notes, notes[0].Octaved(1))[1:] } // TODO handle inversion 3 } return notes } // C/D7/2 = C dominant 7, 2nd inversion func ParseChord(s string) (Chord, error) { return newFormatParser(s).parseChord() } func MustParseChord(s string) Chord { c, err := ParseChord(s) if err != nil { log.Fatal("ParseChord failed:", err) } return c }