95 lines
2.0 KiB
Go
95 lines
2.0 KiB
Go
// Package sdl implements an audio engine using libSDL2.
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package sdl
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import (
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"sync"
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"github.com/veandco/go-sdl2/mix"
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)
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// Engine is the SDL2 audio engine.
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type Engine struct {
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initFlags int
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// Keep track of which SDL channel numbers are ACTUALLY playing sound
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// effects right now, and watch for when the channels are finished.
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channelMu sync.RWMutex
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channelsPlaying map[int]*Track
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}
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// New initializes an SDL2 Mixer for the audio engine.
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//
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// Pass the SDL2 Mixer flags for its initialization. The flags are an OR'd
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// value made up of:
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//
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// mix.INIT_MP3
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// mix.INIT_OGG
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// mix.INIT_FLAC
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// mix.INIT_MOD
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func New(flags int) (*Engine, error) {
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return &Engine{
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initFlags: flags,
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channelsPlaying: map[int]*Track{},
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}, nil
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}
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// Setup initializes SDL2 Mixer.
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func (e *Engine) Setup() error {
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// Initialize SDL2 mixer.
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if err := mix.Init(e.initFlags); err != nil {
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return err
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}
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// Subscribe to sound effect channels finishing.
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mix.ChannelFinished(func(channel int) {
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_ = e.unsetPlaying(channel)
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})
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// Open the audio mixer.
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// the '2' is stereo (two channels), '1' would be mono.
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// 4096 is the chunk size.
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// https://www.libsdl.org/projects/SDL_mixer/docs/SDL_mixer_11.html
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return mix.OpenAudio(mix.DEFAULT_FREQUENCY, mix.DEFAULT_FORMAT, 2, 4096)
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}
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// Playing returns if either music or sounds are currently playing.
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func (e *Engine) Playing() bool {
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if mix.PlayingMusic() {
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return true
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}
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return mix.Playing(-1) > 0
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}
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// PlayingMusic returns if music is currently playing.
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func (e *Engine) PlayingMusic() bool {
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return mix.PlayingMusic()
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}
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// PlayingSound returns if sounds are playing.
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func (e *Engine) PlayingSound() bool {
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return mix.Playing(-1) > 0
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}
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// StopAll stops all music and sounds.
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func (e *Engine) StopAll() {
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e.StopMusic()
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e.StopSounds()
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}
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// StopMusic stops all music.
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func (e *Engine) StopMusic() {
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mix.HaltMusic()
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}
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// StopSounds stops all sounds.
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func (e *Engine) StopSounds() {
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mix.HaltChannel(-1)
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}
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// Teardown closes the SDL mixer.
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func (e *Engine) Teardown() error {
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mix.CloseAudio()
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mix.Quit()
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return nil
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}
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