Add separate Iron Coast mission, weapon and enemy mods with SD HD artwork and audio

examples/mods/ion_lance/generate_audio.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python3
+"""Reproduce local procedural weapon audio; WAV outputs are tracked with the package."""
+import math
+import struct
+import wave
+from pathlib import Path
+
+PACKAGE = "ion_lance"
+RATE = 22050
+
+def render(kind):
+    duration = 0.13 if kind == "fire" else 0.17
+    count = int(RATE * duration)
+    phase = 0.0
+    seed = 0xA7C51D3
+    samples = []
+    for n in range(count):
+        t = n / count
+        seed ^= (seed << 13) & 0xffffffff
+        seed ^= seed >> 17
+        seed ^= (seed << 5) & 0xffffffff
+        seed &= 0xffffffff
+        noise = (seed / 2147483648.0) - 1.0
+        if PACKAGE == "pulse_cannon":
+            frequency = (1350 * (1 - t) + 190) if kind == "fire" else 130
+            tone = math.sin(phase) * 0.64 + noise * 0.22
+        elif PACKAGE == "seeker_swarm":
+            frequency = 330 + 850 * t if kind == "fire" else 95
+            tone = noise * 0.48 + math.sin(phase) * 0.35
+        else:
+            frequency = 1850 + 680 * t if kind == "fire" else 680 * (1 - t) + 110
+            tone = math.sin(phase) * 0.52 + math.sin(phase * 1.997) * 0.2 + noise * 0.06
+        phase += 2 * math.pi * frequency / RATE
+        attack = min(1.0, n / (RATE * 0.003))
+        envelope = attack * (1 - t) ** (3 if kind == "impact" else 2)
+        samples.append(round(max(-1, min(1, tone * envelope)) * 21000))
+    return struct.pack("<" + "h" * len(samples), *samples)
+
+if __name__ == "__main__":
+    output = Path(__file__).resolve().parent / "audio"
+    output.mkdir(exist_ok=True)
+    for kind in ["fire", "impact"]:
+        with wave.open(str(output / (kind + ".wav")), "wb") as wav:
+            wav.setparams((1, 2, RATE, 0, "NONE", "not compressed"))
+            wav.writeframes(render(kind))
+        print(output / (kind + ".wav"))