# audio.synth Pure-CPU audio synthesis. Every noise *First Light: Vagant* makes is computed here as interleaved f32 PCM in a `buffer`, then handed to `audio.encodePcm` / `asset.create("soundClip", …)`. No network, no credits, no failure mode. Author time only — `audio.recipes` and `audio.bake` are its consumers, and the game ships the baked clips, so a browser session synthesises nothing on the player's machine. Two conventions run through it: - every generator **adds** into a destination buffer, so layers compose; - a **loop-coherent** generator takes its frequency in cycles across the WHOLE buffer rather than in hertz, which is what makes a bed seamless end to end. ## What is in it - **Oscillators** — `sine` (table-driven), `addTone` (a gliding harmonic stack with vibrato), `addLoopPartial` (the loop-coherent form), `addPluck` (Karplus-Strong), `addNoise`. - **Envelopes** — `env` (breakpoints in seconds), `decayEnv` (attack plus an exponential tail), `mulEnv`. - **Filters** — `lowpass`, `highpass`, `lowpassSweep`, `bandpass` (a swept state-variable band), and the circular forms `lowpassCircular` / `bandpassCircular`, which converge the filter's state on the wrap point so its output is continuous ACROSS the loop join. - **Space and finishing** — `reverb` (four combs into two allpasses), `resample`, `gain`, `normalize`, `softClip`, `removeDc`, `fadeEdges`, `mix`, `addWrapped` (a tail that wraps round to the head of a loop). - **Measurement** — `peak`, `rms`, and `seamError`, which reports the step across a loop's join in the units the signal itself steps in: around 1 is seamless, a click reads in the tens.

# recipes Every noise *First Light: Betocsin* makes, written down as a recipe rather than recorded: a length, a sample rate, whether it loops, and a `build` that fills a mono f32 buffer. `game.audio.bake` turns these into the `.soundClip` assets under `game/audio/clips`. Nothing here runs at play time. ## The palette The tuning is the bell's. The tocsin is cast bronze with its prime at **G3**; the tower's night bed is the same G two octaves under it, and the whole score is that drone with a **third** in it — B flat while it is night, B natural once the sky pales. `bed_night` and `bed_dawn` are the same twenty seconds, the same drone and the same fifth, differing by that one semitone, so crossfading between them *is* the dawn. Everything is low, wet and far off. An estuary at four in the morning is a room with a mile of fog in it, so nothing is dry and nothing is bright until the bell itself is struck. ## The clips | | | |---|---| | `ui_move` `ui_confirm` `ui_back` `ui_pause` | the console: paper, brass and a struck note | | `stone_seat` | a course set down; pitched per course by the Sound component | | `perfect_chime` | bronze agreeing with the stone | | `offcut_fall` | the shear, the air, and a soft landing far below | | `tocsin_toll` | the fallen bell, once, from under the fog | | `hoist_creak` | hemp under load and a timber jib taking the weight | | `bell_peal` | the tocsin rung — three strikes, the sound the game is for | | `collapse` | stone leaving stone, then everything at once | | `amb_fog` | air over a mile of flat water, with slate and rigging in the top | | `bed_night` `bed_dawn` | the drone, minor third and major | ## Loops A loop is built to join to **itself**: held notes are a whole number of cycles across the buffer, noise beds are filtered circularly, and a struck note's tail is wrapped round to the head. Interior loop points are stored and read by nothing, so a bed that does not already join is a bed that clicks. `synth.seamError` measures the join in the units the signal steps in — around one is seamless. Owned by the sound & voice slice. The synthesis primitives are `deps/…/audio/synth`, installed from ZeroMind.