melrōse musical expression player

package op import ( "bytes" "fmt" "github.com/emicklei/melrose/core" ) type TransposeMap struct { IndexOffsets []int2int // one-based Target core.Sequenceable } func NewTransposeMap(target core.Sequenceable, indices string) TransposeMap { return TransposeMap{ Target: target, IndexOffsets: parseIndexOffsets(indices), } } func (p TransposeMap) S() core.Sequence { return core.Sequence{Notes: p.Notes()} } func (p TransposeMap) Notes() [][]core.Note { source := p.Target.S().Notes target := [][]core.Note{} for _, entry := range p.IndexOffsets { 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.Pitched(entry.to)) } target = append(target, newGroup) } return target } // Storex is part of Storable func (p TransposeMap) Storex() string { var b bytes.Buffer fmt.Fprintf(&b, "transposemap('") for i, each := range p.IndexOffsets { if i > 0 { fmt.Fprintf(&b, ",") } fmt.Fprintf(&b, "%d:%d", each.from, each.to) } fmt.Fprintf(&b, "',%s", core.Storex(p.Target)) fmt.Fprintf(&b, ")") return b.String() } // Replaced is part of Replaceable func (p TransposeMap) Replaced(from, to core.Sequenceable) core.Sequenceable { if core.IsIdenticalTo(p, from) { return to } if core.IsIdenticalTo(p.Target, from) { return TransposeMap{Target: to, IndexOffsets: p.IndexOffsets} } if rep, ok := p.Target.(core.Replaceable); ok { return TransposeMap{Target: rep.Replaced(from, to), IndexOffsets: p.IndexOffsets} } return p }