Debounce when the sound starts to keep from playing many copies of the
same sound layered on itself. Use AudioEngine's currentTime in seconds
plus some value in milliseconds to make sure the sound has a chance to
start before starting a second playback.
Self-resolving promise removes itself once it resolves. While it is on
a player the player may consider itself to not yet have the time to
actually start sound playback. While playback has not started, the
player can shortcut out of starting playback.
- Add GreenPlayer as SoundPlayer replacement
- Standalone playback separate from an AudioPlayer
- Each GreenPlayer has their own VolumeEffect for fading out
- play() while already isPlaying fades out the last copy
- stop() fades the sound out
- stopImmediate() hard stops the sound
