libs/game/audio (77 tests): WAV decoder (8/16/24/32-bit int, f32/f64,
total on malformed input), Ogg container with packet reassembly, sample
bank with on-demand decode + linear resample + LRU eviction and pinning so
a playing voice can't be evicted, and a 24-voice mixer with equal-power
pan, playback-rate pitch, click-free fades, priority+age voice stealing and
a limiter. Generation-tagged voice handles mean a stale handle cannot
retune a reused slot. The limiter test caught a real bug: peak was being
measured per-voice, but what clips is the SUM.
Emission is the point — sounds come from the engine observing gameplay,
not from script calls: Material/MaterialPair (order-independent, the softer
material names the sound), an impact curve mapping closing speed to
gain/pitch, and an AudioDirector with repeat-avoiding variant selection,
per-category volumes, per-pair cooldowns and a per-frame cap. A 200-contact
frame yields <=6 sounds and the cooldown map is proven not to leak.
Blocks now emit their own audio: car engine tracking revs, skid on lateral
slip, suspension thud on landing; character footsteps timed off the WALK
CYCLE rather than a timer, so feet and sound stay together when slowing;
jump/land scaled by fall speed; plane engine by throttle; lap and win
stings. RNG isolation proven: heavy audio work interleaved with world-rng
draws leaves the drawn sequence bit-identical to a silent run.
KNOWN GAP, reported rather than hidden: every Kenney audio pack is Ogg
Vorbis only (471 files, zero WAV), and the from-scratch Vorbis decoder is
NOT correct yet — setup header parses exactly, channels/rate/frame count
and envelope shape are right, but floor magnitudes come out ~75x low and
best correlation against an afconvert reference is 0.67. Two real bugs were
found and fixed en route (type-1 residue filled one codeword instead of the
partition; MDCT post-twiddle carried the pre-twiddle's 1/4 term). The
reference test is committed as #[ignore] with its measurements in the
message so it stays runnable. Ogg stays flagged unplayable in the asset
index; WAV and the --transcode path work today.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
