Method read

common/audio.go:176–219

Read reads from all the currently playing entities and combines them into a single stream that is passed to the oto player.

(b []byte, players []*Player)

// Read reads from all the currently playing entities and combines them into a
// single stream that is passed to the oto player.
func (a *AudioSystem) read(b []byte, players []*Player) (int, error) {
	l := len(b)
	l &= mask

	if len(players) == 0 {
		copy(b, make([]byte, l))
		return l, nil
	}

	b16s := [][]int16{}
	for _, player := range players {
		buf, err := player.bufferToInt16(l)
		if err != nil {
			return 0, err
		}
		b16s = append(b16s, buf)
	}
	for i := 0; i < l/2; i++ {
		x := 0
		for _, b16 := range b16s {
			x += int(b16[i])
		}
		if x > (1<<15)-1 {
			x = (1 << 15) - 1
		}
		if x < -(1 << 15) {
			x = -(1 << 15)
		}
		b[2*i] = byte(x)
		b[2*i+1] = byte(x >> 8)
	}

	for _, player := range players {
		if player.eof() {
			if player.Repeat {
				player.Rewind()
			} else {
				player.Pause()
			}
		}
	}

	return l, nil
}

// Close closes the AudioSystem's loop. After this is called the AudioSystem
// can no longer play audio.