initial commit

scripts/generate_samples.py

@@ -0,0 +1,83 @@
+"""Generate synthetic mechanical keyboard switch samples."""
+
+import math
+import struct
+import wave
+from pathlib import Path
+
+SAMPLE_RATE = 48000
+OUT_DIR = Path(__file__).resolve().parent.parent / "assets" / "samples"
+
+
+def write_wav(path: Path, samples: list[float]) -> None:
+    pcm = b"".join(
+        struct.pack("<h", max(-32768, min(32767, int(s * 32767)))) for s in samples
+    )
+    with wave.open(str(path), "w") as wf:
+        wf.setnchannels(1)
+        wf.setsampwidth(2)
+        wf.setframerate(SAMPLE_RATE)
+        wf.writeframes(pcm)
+
+
+def envelope(length: int, attack: float, decay: float) -> list[float]:
+    env = []
+    attack_samples = int(attack * SAMPLE_RATE)
+    decay_samples = int(decay * SAMPLE_RATE)
+    for i in range(length):
+        if i < attack_samples:
+            env.append(i / max(attack_samples, 1))
+        elif i < attack_samples + decay_samples:
+            t = (i - attack_samples) / max(decay_samples, 1)
+            env.append(1.0 - t)
+        else:
+            env.append(0.0)
+    return env
+
+
+def generate_click(
+    freq: float,
+    duration: float,
+    attack: float,
+    decay: float,
+    noise_mix: float = 0.0,
+    click_burst: bool = False,
+) -> list[float]:
+    length = int(duration * SAMPLE_RATE)
+    env = envelope(length, attack, decay)
+    out = []
+    for i in range(length):
+        t = i / SAMPLE_RATE
+        tone = math.sin(2 * math.pi * freq * t) * (0.7 if not click_burst else 0.4)
+        if click_burst and t < 0.008:
+            tone += math.sin(2 * math.pi * (freq * 2.8) * t) * 0.5
+        noise = 0.0
+        if noise_mix > 0:
+            noise = (((i * 1103515245 + 12345) & 0x7FFFFFFF) / 0x7FFFFFFF - 0.5) * noise_mix
+        out.append((tone + noise) * env[i])
+    peak = max(abs(s) for s in out) or 1.0
+    return [s / peak * 0.85 for s in out]
+
+
+def main() -> None:
+    OUT_DIR.mkdir(parents=True, exist_ok=True)
+
+    profiles = {
+        "cherry-mx-blue.wav": generate_click(
+            2800, 0.09, 0.001, 0.085, noise_mix=0.15, click_burst=True
+        ),
+        "cherry-mx-red.wav": generate_click(
+            1200, 0.05, 0.002, 0.045, noise_mix=0.08
+        ),
+        "cherry-mx-brown.wav": generate_click(
+            1800, 0.07, 0.002, 0.065, noise_mix=0.12, click_burst=True
+        ),
+    }
+
+    for name, samples in profiles.items():
+        write_wav(OUT_DIR / name, samples)
+        print(f"Wrote {OUT_DIR / name}")
+
+
+if __name__ == "__main__":
+    main()