The landing card sells "35mm & 120 Film Grain — authentic grain structures plus halation bloom, tuned per stock rather than one global overlay", and the engine printed one field for everything: a width/1080 cell, one spread, no bleed. `shared/utils/grainShader.ts` (new, the web fork of the phone's src/utils/grainShader.ts) now carries the stock table — format, cell, spread, octave mix, halation, halo radius, halo tint — and `grainStockFor( recipe.baseFilter)` picks the one this recipe prints. FORMAT. 35mm cells are the 1.0 reference the knob was tuned at (classic-negative 1.15, B&W high contrast 1.25); the 120 emulsions sit at 0.55-0.72 and open their base octave (mix 0.55/0.30/0.15 -> 0.62/0.26/0.12), so the same knob prints a finer, smoother texture on the bigger negative. Measured on a flat 128 grey at a 3200px preview (cells 3.41px vs 1.63px), GRAIN 10, luma residual against a 17px box: 35mm CLASSIC NEGIPES r1 0.793 keeps 0.976 35mm CLASSIC CHRIPES r1 0.744 keeps 0.931 35mm B&W HIGH CONTRAST r1 0.812 keeps 1.002 120 PROVIPES r1 0.423 keeps 0.728 120 VELVIPES r1 0.313 keeps 0.672 120 ACRIPES r1 0.543 keeps 0.794 r1 is the lag-1 autocorrelation of the residual — how coarse the clumps are — and "keeps" is the residual sd after a 2x box downscale over the sd before, i.e. how much of its texture a print at half size holds on to. Every 35mm stock beats every 120 stock on both, and VELVIPES (0.55 cell) is finer than PROVIPES (0.62) inside 120, so the format is a look and not a label. Raw sd is NOT the measure: the knob drives one alpha for every stock, so a stock's amount follows its cell and mix rather than the order anyone assumed. HALATION. A new pass 6b thresholds the print (T0 0.62, T1 0.92), tints what is left the stock's halo colour — red, because red is the light the emulsion passes and the backing returns — blurs it at the stock's own radius and screens it back at `halation * grain/10 * 0.6`. Riding the GRAIN knob keeps today's contract: OFF is still a clean frame, the OFF/WEAK/STRONG chips still mean 0/3/6, and a sensor stock carries none at any amount. Measured R-B of the ring around a white block on black, GRAIN 6 minus GRAIN 0 (mean, and the ring's reddest pixel): CLASSIC NEGIPES 7.87 (peak 0 -> 14) VELVIPES 3.71 (0 -> 13) CLASSIC CHRIPES 2.91 (0 -> 10) PROVIPES 2.01 (0 -> 7) B&W HIGH CONTRAST 0.61 (0 -> 5) ACRIPES 0.24 (0 -> 3) LC STREETLIFE CLASSIC 0.09 (0 -> 0) which is the table's own halation column (0.45 > 0.30 > 0.25 > 0.18 > 0.15 > 0.12) in order: the colour negative halates hardest, the B&W emulsions barely, Acros — no colour layer to bleed — least of all, and the sensor not at all. The colour negative's own grade leaves its ring blue at GRAIN 0 (-5.96 there), so the statistic is the change and not the absolute channel; in a crop of the block the bloom itself is unmistakable at GRAIN 6 and 10 and absent at 0. GRAIN_SEED moves here from exportEngine.ts so the roll is still one per page load, and still shared by the preview, the compare copy and the file. Checked: tsc --noEmit clean; grain-stock-test 53 PASS / 0 FAIL; sims-test 31/0, fx-mono-test 15/0, grain-size-test 12/0, grain-analog-test 7/0, wm-font-test green. ponytail: halation rides the GRAIN knob instead of a control of its own, since the card promises no more than "tuned per stock". Add a HALATION chip when the phone grows one. ponytail: `grainCell`'s 1px floor is the aliasing guard, and it also hides the format ratio under a ~1600px preview. Nothing to add: the exported file is always wide enough, and the harness renders at 3200 to see it.
RecipesCam web — self-contained stack
A Docker-hosted web build of RecipesCam. Everything it needs is in this folder: move it to another machine, run two commands, and the app is up. It does not need the React Native project around it.
cp .env.example .env
docker compose up -d --build
# → http://localhost:8090
What runs where
| Service | Image | Role |
|---|---|---|
frontend |
nginx:1.27-alpine (built by frontend/Dockerfile) |
Static SPA + /api/ reverse proxy |
api |
node:22-slim (built by backend/Dockerfile) |
Accounts + saved recipes, SQLite on ./data |
frontend resolves api through Docker's embedded DNS and proxies /api/* to
it — that is why the API container is named api and why it is not published on
the host. Only ${WEB_PORT:-8090} is exposed.
Photos never leave the browser. The CanvasKit render pipeline (grade, frame, watermarks, JPEG encode) runs in the visitor's tab; the API only stores recipes as JSON.
Layout
docker-compose.yml the stack
.env.example WEB_PORT
data/ SQLite (created on first run, gitignored)
backend/ Fastify + better-sqlite3 API, own Dockerfile
frontend/ Vite + React + CanvasKit SPA, own Dockerfile + nginx.conf
shared/ vendored copies of the app's types + utils (see below)
src/engine/ skiaShim.ts (CanvasKit) + exportEngine.ts (render pipeline)
+ session.ts (localStorage/IndexedDB studio persistence)
Vendored files
frontend/shared/{types/index.ts,utils/*.ts} are byte-identical copies of
src/types/index.ts and ten src/utils/*.ts files from the React Native
project (@shopify/react-native-skia is aliased to src/engine/skiaShim.ts in
vite.config.ts + tsconfig.json, so those files compile unchanged):
cinemaShader colorUtils defaultRecipes exifWrite frameUtils jpegDpi
paramDefs recipeShare skiaImage toneShader.
The landing page needs no CDN: frontend/public/assets/fonts/*.woff2 are the
seven self-hosted faces behind the three font groups the Themes menu offers
(Plus Jakarta Sans / Inter / JetBrains Mono, Fraunces / Be Vietnam Pro /
Courier Prime, Be Vietnam Pro / Space Mono — all SIL OFL, pulled from Google
Fonts, vietnamese + latin + latin-ext subsets), and
frontend/public/assets/samples/s*.jpg are the six placeholder negatives the
film strip, preset tester and QR card show (swap them for real graded stills
whenever we have them). Its one foreign request is the QR image from
api.qrserver.com, which degrades to an empty slot offline.
When the app changes one of them, copy it back in — the renderer is only "parity" for as long as these stay in sync:
cd <repo>/docker/frontend/shared/utils
cp <repo>/src/utils/<name>.ts .
Operations
docker compose logs -f api # API log
docker compose restart api # after backend/src changes (rebuild: --build)
docker compose down # stop; ./data survives
Backup is the ./data folder — that is the whole database.
Checks
curl -s http://localhost:8090/api/health # {"ok":true}
curl -sI http://localhost:8090/ # 200, index.html
Then open the UI, drop a photo in, and confirm the preview shows the picture and
EXPORT downloads a JPEG that opens. The preview going solid black while the
export still reports a plausible size is the one failure mode worth knowing: it
means the CanvasKit GPU surfaces lost their shared GrDirectContext (see
frontend/src/engine/skiaShim.ts), and with no GPU the raster fallback renders
the same pipeline correctly, just slower.