snow_rendering 0.2.7

Weather-to-rendering computation for driving safety apps — surface classification, particle parameters, visibility degradation. Pure Dart.

Changelog

0.2.7

• Precise surface vocabulary on the announcement seam. New RoadSurfaceAnnouncement + RoadSurfaceState.announcement extension: every surface except dry (which yields null — nothing to announce) provides a short spoken-style line (JA + EN) that leads with the precise JP-domestic surface term — ブラックアイスバーン for blackIce, 圧雪 for compactedSnow, シャーベット for slush — plus, for the snow-vocabulary surfaces, the authoritative JAF entry from japanese_snow_vocabulary (verbatim safeDrivingResponseJa for display surfaces; verbatim-relay binding). This is package-level capability for consumers composing warning surfaces; it does not itself speak or render anything.
• Certainty is graded, never asserted. The classifier's black-ice determinations are inferences (a feed flag or a dew-point heuristic), so composed lines say 凍結しているおそれ ("may be frozen"), mirroring JAF's own 可能性 phrasing — never flat certainty.
• Two black-ice variants, honest about visibility. The general RoadSurfaceState.blackIce.announcement is provenance-neutral: it is reachable from a feed ice flag during visible snowfall, where claiming the road "looks wet" would be false — so it carries neither a looks-wet spoken line NOR the JAF vocabulary entry (whose verbatim advisory itself opens with the looks-wet description). The separate top-level invisibleBlackIceAnnouncement carries both — the looks-merely-wet spoken fact and the verbatim JAF entry — and is intended ONLY for detection paths that imply invisibility (radiative frost, freezing rain). Additive, no breaking changes.

0.2.6

• Radiative-frost black ice on the in-drive surface classifier. RoadSurfaceState.fromCondition now recognises the no-precipitation, above-zero-ambient black-ice window (clear-sky radiative cooling freezing the road while the air still reads +1…+3 °C — the Akita pre-dawn bridge-deck hazard). Previously this case classified as dry / full grip, directly contradicting the pre-trip briefing's black-ice warning on the same morning. The classifier now calls navigation_safety_calibration's isRadiativeFrostBlackIce — the SAME function the pre-trip advisor uses, so the two surfaces cannot disagree about the radiative-frost black-ice determination when both are given the same temperature + humidity. (This is a scoped guarantee, not an absolute one: the surfaces can still differ on other hazard classes, and on any feed that omits humidity the in-drive branch abstains — see KNOWN_LIMITATIONS.md.) Humidity-gated and caution-add-only: needs the new WeatherCondition.humidityRH; absent humidity abstains (returns dry), so this never fabricates a hazard and never downgrades a colder classification. Backward-compatible — the new behaviour only activates when a driving_weather ^0.4.4 feed supplies humidity, so consumers on ^0.2.x adopt this with no change. Adds a direct dependency on navigation_safety_calibration ^0.1.3.
• Known scope (see KNOWN_LIMITATIONS.md): the in-drive classifier runs all-hours with no wind/time gate, and the primary live feeds (digitraffic, KUKSA) do not yet supply humidity — so this fix does not yet change the live in-drive screen for those feeds. It is a correct classifier that awaits a humidity-bearing live feed + a cry-wolf (wind/time) calibration pass.

0.2.5

• Non-breaking restore + honest correction of a mislabeled release. The 0.2.4 entry below was labeled "(no API change)", but 0.2.4 had in fact shipped a breaking public-API change relative to 0.2.3: it added the RecommendedResponse enum, exported it from the package, and added a required recommendedResponse parameter to the public const constructor of DrivingConditionAssessment. The required parameter broke any edge developer who constructs DrivingConditionAssessment directly (the 0.2.3 call sites no longer compiled).
• This release makes the recommendedResponse constructor parameter optional, defaulting to RecommendedResponse.proceed (the neutral, lowest-severity "conditions within normal driving tolerance" tier). Direct 0.2.3-style construction that omits recommendedResponse compiles again; 0.2.4 callers that pass recommendedResponse are unaffected. The field stays non-nullable, so consumers can always read a concrete tier.
• Documents the public API as it now stands: the RecommendedResponse enum, the recommendedResponse field on DrivingConditionAssessment (still part of equality/props), and the package export of recommended_response.dart are all supported public API. The DrivingConditionAssessment.fromCondition factory continues to classify and set recommendedResponse explicitly.

0.2.4

• docs: correct stale README install pin to current version (no API change). NOTE (see 0.2.5): this release was mislabeled — it also shipped a breaking API change (a required recommendedResponse ctor parameter + the RecommendedResponse enum + its export). 0.2.5 restores source compatibility.

0.2.3

• Republish from the embedded-target Dart 3.10.1 SDK (Flutter 3.38.3) to correct a stale ^3.11.0 SDK floor in the previously-published artifact. No source or behavior change; the source already declared sdk: ^3.10.0. Restores pub get for embedded/automotive Dart consumers on Dart 3.10.x.

0.2.2 — 2026-05-10 — Pana score recovery (Theme α P3)

• Trim pubspec description to within the pana 60–180 character target.
• Add minimal example/main.dart for pana documentation scoring.
• Apply dart format to clear any formatter findings.
• No SDK source changes; metadata + format pass only.

0.2.1 — 2026-05-10 — Refresh cascade-stale dependency constraint

• driving_weather: ^0.3.0 → ^0.4.0 (consumer-side refresh after driving_weather 0.4.0 release earlier the same day).
• No source changes; pubspec dep-constraint refresh only.

0.2.0

• Add DataBudget — stateful data-fetch budget tracker for snow- overlay render bandwidth management. Integrator-supplied DataMeterProvider interface; per-cycle bytes budget checked against DataBudgetConfig; broadcast budgetEvents stream emits BudgetWarning (75%) / BudgetExhausted (100%) / RenderFidelityDrop (in lock-step with Exhausted). Mirrors the GlanceBudgetTracker pattern from navigation_safety 0.9.0 (caution-add-only / severity-not-profile / driver-always-drives invariants enforced via debug-mode runtime asserts).
• Add DataBudgetConfig.forProfile(DriverProfile) factory — per- cohort tighter-direction defaults (4MB baseline / 3MB noviceUrban / 2MB ageingRural + foreignTouristSnowZone for bandwidth-margin). Per-cohort budgets are UNVERIFIED-magnitude design-default- hypothesis pending field-measurement validation; conservative-only (every cohort <= 4MB baseline). Per-population calibration deferred.
• Add tighten(int) — auto-tightening allowed at runtime; new budget must be <= active budget per caution-add-only invariant.
• Add relax(int, BudgetRelaxConfirmation) — auto-relax FORBIDDEN; loosening requires integrator-supplied affirmative confirmation token. Mirrors the cap-override-with-confirmation pattern from navigation_safety_core 0.10.0 #30 (driver-always-drives).
• Add BudgetResetReason enum + DataFetchEvent value object + sealed DataBudgetEvent hierarchy.
• Add navigation_safety_core: ^0.10.0 dependency for DriverProfile consumption.
• Add SAFETY_BOUNDARY.md (DataBudget invariants; cohort-tighter direction caveat; auto-relax-with-confirmation pattern; ASIL-QM advisory; severity-not-profile + driver-always-drives preserved).
• Add KNOWN_LIMITATIONS.md (per-cohort data-budget UNVERIFIED- magnitude flags + bandwidth-class assumptions).
• Public API additions are non-breaking; existing DrivingConditionAssessment / RoadSurfaceState / PrecipitationConfig / VisibilityDegradation contracts unchanged.

0.1.0

• Initial extraction from driving_conditions (SNGNav P1, D-SC22-2).
• RoadSurfaceState — six-state road surface classification with grip factors.
• PrecipitationConfig — particle configuration derived from weather conditions.
• VisibilityDegradation — opacity and blur parameters from visibility distance.
• DrivingConditionAssessment — combined assessment with advisory message.
• HysteresisFilter<T> — debounce filter for state oscillation at boundary conditions.