melrōse musical expression player

package op import ( "bytes" "fmt" "github.com/emicklei/melrose/core" ) type VelocityMap struct { Target core.Sequenceable IndexVelocities []int2int // one-based } func NewVelocityMap(target core.Sequenceable, indices string) VelocityMap { return VelocityMap{ Target: target, IndexVelocities: parseIndexOffsets(indices), } } func (v VelocityMap) S() core.Sequence { return core.Sequence{Notes: v.Notes()} } func (v VelocityMap) Notes() [][]core.Note { source := v.Target.S().Notes target := [][]core.Note{} for _, entry := range v.IndexVelocities { if entry.from <= 0 || entry.from > len(source) { // invalid offset, skip continue } eachGroup := source[entry.from-1] // from is one-based if entry.to == 0 { // no offset, use as is target = append(target, eachGroup) continue } newGroup := []core.Note{} for _, eachNote := range eachGroup { newGroup = append(newGroup, eachNote.WithVelocity(entry.to)) } target = append(target, newGroup) } return target } func (v VelocityMap) Storex() string { s, ok := v.Target.(core.Storable) if !ok { return "" } var b bytes.Buffer fmt.Fprintf(&b, "velocitymap('") for i, each := range v.IndexVelocities { if i > 0 { fmt.Fprintf(&b, ",") } fmt.Fprintf(&b, "%d:%d", each.from, each.to) } fmt.Fprintf(&b, "',%s", s.Storex()) fmt.Fprintf(&b, ")") return b.String() } // Replaced is part of Replaceable func (v VelocityMap) Replaced(from, to core.Sequenceable) core.Sequenceable { if core.IsIdenticalTo(v, from) { return to } if core.IsIdenticalTo(v.Target, from) { return OctaveMap{Target: to, IndexOffsets: v.IndexVelocities} } if rep, ok := v.Target.(core.Replaceable); ok { return VelocityMap{Target: rep.Replaced(from, to), IndexVelocities: v.IndexVelocities} } return v }