243 lines
6.6 KiB
Go
243 lines
6.6 KiB
Go
// Package audio 音频管理器：3D 衰减、声源上限、分类音量（场景/音频.md §2–§4）。
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//
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// 无音频文件阶段用程序化合成音（正弦/噪声包络）；播放后端为 beep + oto（Windows 纯 Go，
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// 基于 purego，无需 CGO）。
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package audio
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import (
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"math"
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"math/rand"
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"strings"
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"sync"
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"time"
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"github.com/ebitengine/oto/v3"
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"github.com/faiface/beep"
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"github.com/faiface/beep/effects"
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"github.com/faiface/beep/speaker"
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)
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// 声源上限（音频.md §3：同时播放 ≤64，超出按最远淘汰）。
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const (
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maxSources = 64
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defaultAtten = 16.0
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captionTTL = 3 * time.Second
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maxCaptions = 4
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)
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// 音量分类（音频.md §4）。
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type category uint8
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const (
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catSFX category = iota // 音效
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catMusic // 音乐
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catAmbient // 环境
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)
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// Manager 音频管理器（单例）。
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type Manager struct {
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mu sync.Mutex
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enabled bool
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ctx *oto.Context
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master float64
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vols [3]float64 // sfx / music / ambient
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sources []*source
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listener [3]float64 // 玩家位置
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listenerYaw float64 // 水平朝向（弧度，yaw=0 朝 -Z）
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events map[string]*resolvedEvent
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oggCache map[string]*beep.Buffer
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captions []Caption
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rng *rand.Rand
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}
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// source 一个正在播放的声源。
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type source struct {
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key string
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pos [3]float64 // 世界坐标
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dist float64 // 距玩家距离
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ctrl *beep.Ctrl
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cat category
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start time.Time
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}
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// New 创建音频管理器（找不到音频设备时降级为静默——服务器/CI 安全）。
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func New() *Manager {
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m := &Manager{master: 1.0, vols: [3]float64{1, 1, 1}, rng: rand.New(rand.NewSource(time.Now().UnixNano()))}
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const (
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sampleRate = 44100
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bufferSize = 100 * time.Millisecond
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)
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ctx, _, err := oto.NewContext(&oto.NewContextOptions{
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SampleRate: sampleRate,
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ChannelCount: 2,
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BufferSize: bufferSize,
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})
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if err != nil {
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return m // 无设备：静默模式
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}
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m.ctx = ctx
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m.enabled = true
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speaker.Init(sampleRate, int(sampleRate*0.1))
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return m
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}
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// SetListener 更新听者位置与朝向（每帧/tick；音频.md §3）。
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func (m *Manager) SetListener(x, y, z, yaw float64) {
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m.mu.Lock()
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m.listener = [3]float64{x, y, z}
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m.listenerYaw = yaw
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m.mu.Unlock()
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}
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// SetVolumes 设置分类音量（master × 分类）。
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func (m *Manager) SetVolumes(master, sfx, music, ambient float64) {
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m.mu.Lock()
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m.master, m.vols[catSFX], m.vols[catMusic], m.vols[catAmbient] = master, sfx, music, ambient
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m.mu.Unlock()
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}
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// Play 播放一个音效（3D 衰减，音频.md §3）：key 为音效键，pos 为声源世界坐标。
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func (m *Manager) Play(key string, x, y, z float64) {
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m.mu.Lock()
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defer m.mu.Unlock()
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dist := math.Sqrt((x-m.listener[0])*(x-m.listener[0]) + (y-m.listener[1])*(y-m.listener[1]) + (z-m.listener[2])*(z-m.listener[2]))
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if attenuation(dist, defaultAtten) <= 0 {
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return
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}
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m.pushCaption(key, m.subtitleOf(key))
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if !m.enabled {
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return
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}
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pk := m.pick(key, 0)
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params := PlayParams(key)
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atten := defaultAtten
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fileVol, filePitch := 1.0, 1.0
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var streamer beep.Streamer
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if pk.ok {
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streamer = pk.streamer
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fileVol, filePitch = pk.volume, pk.pitch
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if pk.atten > 0 {
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atten = pk.atten
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}
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} else {
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streamer = synthFor(key)
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}
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gain := params.Volume * fileVol * attenuation(dist, atten) * m.master * m.vols[catSFX]
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if gain <= 0.01 {
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return
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}
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if len(m.sources) >= maxSources {
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worst := -1
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worstDist := -1.0
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for i, s := range m.sources {
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if s.dist > worstDist {
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worstDist = s.dist
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worst = i
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}
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}
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if worst >= 0 {
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m.sources[worst].ctrl.Streamer = nil
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m.sources[worst].ctrl.Paused = true
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m.sources = append(m.sources[:worst], m.sources[worst+1:]...)
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}
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}
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streamer = pitchResample(params.Pitch*filePitch, streamer)
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pan := stereoPan(x-m.listener[0], y-m.listener[1], z-m.listener[2], m.listenerYaw)
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streamer = &panStreamer{Streamer: streamer, l: (1 - pan) / 2, r: (1 + pan) / 2}
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ctrl := &beep.Ctrl{Streamer: streamer, Paused: false}
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vol := &effects.Volume{Streamer: ctrl, Base: 2, Volume: math.Log2(gain)}
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speaker.Play(vol)
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m.sources = append(m.sources, &source{key: key, pos: [3]float64{x, y, z}, dist: dist, ctrl: ctrl, start: time.Now()})
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}
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// PlayParams 按事件后缀套 Java 调用点音量/音调（音频.md §6.1）。
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func PlayParams(key string) struct{ Volume, Pitch float64 } {
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switch {
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case strings.HasSuffix(key, ".hit"):
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return struct{ Volume, Pitch float64 }{0.25, 0.5}
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case strings.HasSuffix(key, ".break"), strings.HasSuffix(key, ".place"):
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return struct{ Volume, Pitch float64 }{1.0, 0.8}
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case strings.HasSuffix(key, ".step"):
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return struct{ Volume, Pitch float64 }{0.15, 1.0}
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case strings.Contains(key, ".ambient"), strings.Contains(key, ".hurt"), strings.Contains(key, ".death"):
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r1, r2 := rand.Float64(), rand.Float64()
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return struct{ Volume, Pitch float64 }{1.0, (r1-r2)*0.2 + 1}
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default:
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return struct{ Volume, Pitch float64 }{1.0, 1.0}
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}
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}
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// stereoPan 朝向左右平移：左负右正，听者自身 dist≈0 → 0（音频.md §3，非 HRTF）。
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func stereoPan(dx, dy, dz, yaw float64) float64 {
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dist := math.Sqrt(dx*dx + dy*dy + dz*dz)
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if dist < 0.01 {
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return 0
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}
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localX := dx*math.Cos(yaw) - dz*math.Sin(yaw)
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p := localX / dist
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if p < -1 {
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return -1
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}
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if p > 1 {
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return 1
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}
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return p
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}
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// panStreamer 按左右增益平衡立体声。
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type panStreamer struct {
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beep.Streamer
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l, r float64
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}
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func (p *panStreamer) Stream(samples [][2]float64) (n int, ok bool) {
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n, ok = p.Streamer.Stream(samples)
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for i := 0; i < n; i++ {
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samples[i][0] *= p.l
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samples[i][1] *= p.r
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}
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return
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}
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// attenuation 线性衰减，默认 16 格（音频.md §3）。
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func attenuation(dist, maxDist float64) float64 {
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if maxDist <= 0 {
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maxDist = defaultAtten
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}
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if dist >= maxDist {
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return 0
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}
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if dist <= 0 {
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return 1
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}
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return 1 - dist/maxDist
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}
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// Close 释放设备。
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func (m *Manager) Close() {
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m.mu.Lock()
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defer m.mu.Unlock()
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if m.ctx != nil {
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_ = m.ctx.Suspend()
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m.ctx = nil
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}
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m.enabled = false
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}
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// synthFor 按音效键生成占位波形（后续替换为真实音效文件）。
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func synthFor(key string) beep.Streamer {
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switch {
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case strings.Contains(key, ".break") || strings.Contains(key, ".hit"):
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return noiseBurst(0.12)
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case strings.Contains(key, ".step") || strings.Contains(key, ".place") ||
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strings.Contains(key, "swim") || strings.Contains(key, "splash"):
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return sineBurst(220, 0.06)
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case strings.Contains(key, "eat") || strings.Contains(key, "burp"):
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return noiseBurst(0.08)
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case strings.Contains(key, "hurt"):
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return sineBurst(180, 0.08)
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default:
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return sineBurst(440, 0.1)
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}
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}
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