examples/piano: Refactoring

This commit is contained in:
Hajime Hoshi 2018-01-08 22:18:19 +09:00
parent 8b2dfdb3e7
commit b30703eb00

View File

@ -49,12 +49,13 @@ var pcm = make([]float64, 4*sampleRate)
const baseFreq = 220
func init() {
const twoPiF = 2.0 * math.Pi * baseFreq
s := float64(sampleRate)
amp := []float64{1.0, 0.8, 0.6, 0.4, 0.2}
x := []float64{4.0, 2.0, 1.0, 0.5, 0.25}
for i := 0; i < len(pcm); i++ {
v := 0.0
twoPiF := 2.0 * math.Pi * baseFreq
for j := 0; j < len(amp); j++ {
a := amp[j] * math.Exp(-5*float64(i)/(x[j]*s))
v += a * math.Sin(float64(i)*twoPiF*float64(j+1)/s)