melrōse musical expression player

package core import ( "math" "time" ) func WholeNoteDuration(bpm float64) time.Duration { return time.Duration(int(math.Round(4*60*1000/bpm))) * time.Millisecond } func FractionToDurationParts(f float64) (fraction float32, dotted bool) { type duration struct { fraction float32 dotted bool actual float64 } durations := []duration{ {1.0, true, 1.5}, {1.0, false, 1.0}, {0.5, true, 0.75}, {0.5, false, 0.5}, {0.25, true, 0.375}, {0.25, false, 0.25}, {0.125, true, 0.1875}, {0.125, false, 0.125}, {0.0625, true, 0.09375}, {0.0625, false, 0.0625}, } hitDistance := 2.0 hit := durations[0] for _, each := range durations { if distance := abs64(each.actual - f); distance <= hitDistance { hit = each hitDistance = distance } } return hit.fraction, hit.dotted } func abs64(f float64) float64 { if f < 0 { return -f } return f }