70 lines
1.9 KiB
Go
70 lines
1.9 KiB
Go
package beep
|
|
|
|
// Mixer allows for dynamic mixing of arbitrary number of Streamers. Mixer automatically removes
|
|
// drained Streamers. Mixer's stream never drains, when empty, Mixer streams silence.
|
|
type Mixer struct {
|
|
streamers []Streamer
|
|
}
|
|
|
|
// Len returns the number of Streamers currently playing in the Mixer.
|
|
func (m *Mixer) Len() int {
|
|
return len(m.streamers)
|
|
}
|
|
|
|
// Add adds Streamers to the Mixer.
|
|
func (m *Mixer) Add(s ...Streamer) {
|
|
m.streamers = append(m.streamers, s...)
|
|
}
|
|
|
|
// Clear removes all Streamers from the mixer.
|
|
func (m *Mixer) Clear() {
|
|
m.streamers = m.streamers[:0]
|
|
}
|
|
|
|
// Stream streams all Streamers currently in the Mixer mixed together. This method always returns
|
|
// len(samples), true. If there are no Streamers available, this methods streams silence.
|
|
func (m *Mixer) Stream(samples [][2]float64) (n int, ok bool) {
|
|
var tmp [512][2]float64
|
|
|
|
for len(samples) > 0 {
|
|
toStream := len(tmp)
|
|
if toStream > len(samples) {
|
|
toStream = len(samples)
|
|
}
|
|
|
|
// clear the samples
|
|
for i := range samples[:toStream] {
|
|
samples[i] = [2]float64{}
|
|
}
|
|
|
|
for si := 0; si < len(m.streamers); si++ {
|
|
// mix the stream
|
|
sn, sok := m.streamers[si].Stream(tmp[:toStream])
|
|
for i := range tmp[:sn] {
|
|
samples[i][0] += tmp[i][0]
|
|
samples[i][1] += tmp[i][1]
|
|
}
|
|
if !sok {
|
|
// remove drained streamer
|
|
sj := len(m.streamers) - 1
|
|
m.streamers[si], m.streamers[sj] = m.streamers[sj], m.streamers[si]
|
|
m.streamers = m.streamers[:sj]
|
|
si--
|
|
}
|
|
}
|
|
|
|
samples = samples[toStream:]
|
|
n += toStream
|
|
}
|
|
|
|
return n, true
|
|
}
|
|
|
|
// Err always returns nil for Mixer.
|
|
//
|
|
// There are two reasons. The first one is that erroring Streamers are immediately drained and
|
|
// removed from the Mixer. The second one is that one Streamer shouldn't break the whole Mixer and
|
|
// you should handle the errors right where they can happen.
|
|
func (m *Mixer) Err() error {
|
|
return nil
|
|
}
|