melrōse musical expression player

package op import ( "bytes" "fmt" "io" "github.com/emicklei/melrose/core" ) func DecomposeSequence(s core.Sequence) core.Sequenceable { fractions := []int{} dynamics := []index2dynamic{} groups := [][]core.Note{} for i, eachGroup := range s.Notes { if len(eachGroup) == 1 { eachNote := eachGroup[0] f := int(1.0 / eachNote.Fraction()) fractions = append(fractions, f) s := core.VelocityToDynamic(eachNote.Velocity) if s != "" { dynamics = append(dynamics, index2dynamic{at: i + 1, dynamic: s}) // 1-based index } note := eachNote.WithoutDynamic().WithFraction(0.25, false) groups = append(groups, []core.Note{note}) } else { f := int(1.0 / eachGroup[0].Fraction()) // first will decide fractions = append(fractions, f) s := core.VelocityToDynamic(eachGroup[0].Velocity) // first will decide if s != "" { dynamics = append(dynamics, index2dynamic{at: i + 1, dynamic: s}) // 1-based index } group := groupWithoutDynamic(eachGroup) group = groupWithFraction(group, 0.25, false) groups = append(groups, group) } } fs := new(bytes.Buffer) io.WriteString(fs, "'") for i, each := range fractions { if i > 0 { io.WriteString(fs, " ") } fmt.Fprintf(fs, "%d", each) } io.WriteString(fs, "'") r := DynamicMap{ Target: []core.Sequenceable{FractionMap{ target: core.Sequence{Notes: groups}, fraction: core.On(fs), }}, IndexDynamics: dynamics, } return r } func groupWithoutDynamic(g []core.Note) (list []core.Note) { for _, each := range g { list = append(list, each.WithoutDynamic()) } return } func groupWithFraction(g []core.Note, fraction float32, dotted bool) (list []core.Note) { for _, each := range g { list = append(list, each.WithFraction(fraction, dotted)) } return }