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66 lines
2.3 KiB
66 lines
2.3 KiB
extends Node
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## 简易音效：用 AudioStreamWAV 程序合成 4 种音效。
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## 每次播放 new 一个 AudioStreamPlayer，结束后自动释放。
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## 之后要替换成 .wav 素材，把 _generate_xxx() 换成 load() 资源即可。
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const SAMPLE_RATE: int = 22050
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func play_hit() -> void:
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_play(_make_sin(880.0, 0.05, 0.4))
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func play_break() -> void:
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_play(_make_noise(0.18, 0.5))
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func play_lost() -> void:
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_play(_make_sweep(440.0, 110.0, 0.4, 0.5))
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func play_win() -> void:
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_play(_make_sweep(523.0, 1046.0, 0.5, 0.5))
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# ───────── 合成函数 ─────────
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func _make_sin(freq: float, duration: float, volume: float) -> AudioStreamWAV:
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return _build(duration, func(t: float, d: float) -> float:
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var env: float = 1.0 - t / d # 线性衰减
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return sin(TAU * freq * t) * volume * env
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)
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func _make_noise(duration: float, volume: float) -> AudioStreamWAV:
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return _build(duration, func(t: float, d: float) -> float:
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var env: float = 1.0 - t / d
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return randf_range(-volume, volume) * env
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)
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func _make_sweep(from_freq: float, to_freq: float, duration: float, volume: float) -> AudioStreamWAV:
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return _build(duration, func(t: float, d: float) -> float:
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var progress: float = t / d
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var f: float = lerp(from_freq, to_freq, progress)
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var env: float = (1.0 - progress) * (1.0 - progress) # 平方衰减
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return sin(TAU * f * t) * volume * env
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)
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# 构造一个 AudioStreamWAV；sample_fn(t, duration) 返回 [-1, 1] 的振幅
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func _build(duration: float, sample_fn: Callable) -> AudioStreamWAV:
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var sample_count: int = int(SAMPLE_RATE * duration)
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var data := PackedByteArray()
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data.resize(sample_count * 2) # 16-bit 单声道
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for i in range(sample_count):
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var t: float = float(i) / SAMPLE_RATE
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var s: float = clamp(sample_fn.call(t, duration), -1.0, 1.0)
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# 16-bit: 范围 [-32768, 32767]
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var sample_i: int = int(s * 32767.0)
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data[2 * i] = sample_i & 0xFF
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data[2 * i + 1] = (sample_i >> 8) & 0xFF
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var stream := AudioStreamWAV.new()
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stream.format = AudioStreamWAV.FORMAT_16_BITS
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stream.mix_rate = SAMPLE_RATE
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stream.stereo = false
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stream.data = data
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return stream
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func _play(stream: AudioStream) -> void:
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var player := AudioStreamPlayer.new()
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player.stream = stream
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add_child(player)
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player.play()
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player.finished.connect(player.queue_free)
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