85 lines
1.6 KiB
Go
85 lines
1.6 KiB
Go
package ebiten
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import (
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"io"
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"math"
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"github.com/hajimehoshi/ebiten/v2/audio"
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)
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type panStream struct {
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io.ReadSeeker
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pan float64 // -1: left; 0: center; 1: right
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}
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const (
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bitsPerByte = 8
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)
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func newPanStreamFromReader(src io.ReadSeeker) *panStream {
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return &panStream{
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ReadSeeker: src,
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pan: 0,
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}
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}
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func (s *panStream) Read(p []byte) (n int, err error) {
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n, err = s.ReadSeeker.Read(p)
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if err != nil {
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return
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}
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ls := math.Min(s.pan*-1+1, 1)
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rs := math.Min(s.pan+1, 1)
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for i := 0; i < len(p); i += 4 {
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lc := int16(float64(int16(p[i])|int16(p[i+1])<<bitsPerByte) * ls)
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rc := int16(float64(int16(p[i+2])|int16(p[i+3])<<bitsPerByte) * rs)
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p[i] = byte(lc)
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p[i+1] = byte(lc >> bitsPerByte)
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p[i+2] = byte(rc)
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p[i+3] = byte(rc >> bitsPerByte)
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}
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return
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}
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// SoundEffect represents an ebiten implementation of a sound effect
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type SoundEffect struct {
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player *audio.Player
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volumeScale float64
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panStream *panStream
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}
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// SetPan sets the audio pan, left is -1.0, center is 0.0, right is 1.0
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func (v *SoundEffect) SetPan(pan float64) {
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v.panStream.pan = pan
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}
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// SetVolume ets the volume
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func (v *SoundEffect) SetVolume(volume float64) {
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v.player.SetVolume(volume * v.volumeScale)
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}
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// IsPlaying returns a bool for whether or not the sound is currently playing
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func (v *SoundEffect) IsPlaying() bool {
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return v.player.IsPlaying()
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}
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// Play plays the sound effect
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func (v *SoundEffect) Play() {
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err := v.player.Rewind()
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if err != nil {
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panic(err)
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}
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v.player.Play()
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}
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// Stop stops the sound effect
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func (v *SoundEffect) Stop() {
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v.player.Pause()
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}
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