Analysis in docs/brouter-findings.md: how BRouter knows roads (.rd5
segments), routes and reaches low elevation gain (profile uphill/downhill
cost + kinematics), the three call surfaces, and an evaluation of two ideas
— fill GPS gaps along roads, and offline waypoint route planning. License is
MIT; the engine has no desktop-only deps, so it embeds on Android ART.
Stage 1 (embed + bridge, compiles into the apk; on-device route not yet run):
- vendored brouter-1.6.3-all.jar into the Android module (dexes cleanly) and
bundled the trekking/shortest profiles + lookups.dat as assets, copied to
files/brouter/profiles2 on launch
- MainActivity: a brouter_command.txt handler on the existing FileObserver
runs btools.router.RoutingEngine off the UI thread (recipe taken via javap
from ServerHandler) and returns the track as GPX
- Rust brouter_route command: same file bridge as GPS (request + command,
poll for the result), registered in the invoke handler
- frontend/js/router.js: BRouter.route(points, profile) -> GPX (parseRouteGPX)
- LICENSE-brouter (MIT notice) kept alongside the vendored engine
Segments (.rd5, ~13-23 MB per 5x5 tile) are delivered later (Stage 2, wired
download inside BalDav). IMPLEMENTATION_PLAN.md tracks the 5 stages.
The pure-JS @zxing/library locator is weak on real ЧЗ codes (decoded 1/4 of the
test photos with correct grayscale input; libdmtx and zxing-wasm read 3/4 — the
4th is physically undecodable). Symptom: scanner takes very long to even find a
code, 2 of 4 never read.
- Bundle zxing-wasm reader as an IIFE (frontend/lib/zxing-wasm.js, global
ZXingWASM) + zxing_reader.wasm; drop frontend/lib/zxing.js. Init fetches the
.wasm as an arrayBuffer and hands it over as wasmBinary (no streaming/MIME/CDN).
- ChZ.zxReady()/ChZ.decodeImageData() (chzn.js): decode an ImageData -> raw GS1
bytes (result.bytes keeps the GS separators) with tryHarder/tryRotate/tryInvert.
- Scanner (main.js) rewritten to a canvas loop: crop the central ROI, upscale to
540px, decode each frame — full-frame search was the slow/unreliable part.
Photo path decodes the picked image the same way.
Not yet verified on-device (WebView WASM instantiation); decoder logic validated
in a Node harness against the 4 sample photos.
- Native BarcodeDetector needs Google Play Services (fails "Barcode detection
service unavailable" on de-Googled ROMs). Replace it with a bundled, fully
offline ZXing decoder (frontend/lib/zxing.js, @zxing/library UMD): scanner uses
BrowserDatamatrixCodeReader (TRY_HARDER) for live camera and decodeFromImageUrl
for the photo fallback. No Google, codes never leave the device.
- Source badge "ЧЗ" (src-chzn) for products added via the scanner.
- tools/chzn_export.sh: adb push the exported session to the device Downloads so
BalDav's file picker can import it directly.
- ChZ module (frontend/js/chzn.js): import an anonymous session (exported from
the CRPT app with tools/chzn_export.sh) and keep it alive via /authorize/refresh
— /authorize/anonymous is Play Integrity-gated so BalDav can't mint its own.
GS1 code normalization (reconstruct the GS separator before AI 93), check ->
catalogData good_attrs КБЖУ parser (match by attr group + name prefix, since
producers name the fields differently), optional nutrition/info vitamins.
- chzn_http Rust command: browser UA + returns {status,body} so 204/401/427 drive
the session/refresh logic.
- Scanner modal (BarcodeDetector camera + photo/manual fallbacks) -> prefill the
new-product form; CAMERA permission; settings section to import/refresh session.
- tools/chzn_export.sh: pull + validate the anonymous session from a rooted device.
- leaflet-rotate plugin: map rotates by compass heading via deviceorientation
- Landscape detection: CSS viewport rotation when phone held sideways (gamma > 50)
- Bottom nav hidden in landscape mode
- GPS placeholder: pixel art overlay shown until GPS signal arrives
- invalidateSize() after map init to prevent black screen
GPS background recording:
- Batched writes (10s flush) in native service
- Polling lock prevents parallel processing
- Track by timestamp instead of line count
- Recovery idempotent via max DB timestamp
- Seq numbers on live recorded points
GPX export:
- Button in session detail
- SAF file picker on Android (ACTION_CREATE_DOCUMENT)
- GPS config in metadata (accuracy, minSpeed, minDist)
Charts:
- Pinch zoom enabled at creation (Hammer.js registers handlers)
- touch-action: pan-y blocks pinch in normal view (page scrolls)
- Fullscreen: CSS-only expand (no canvas manipulation)
- Downsampled to 500 points for smooth rendering
- Back gesture collapses fullscreen before closing modal
Build: --real flag finds first non-emulator device
