derive_district_profile is now a thin wrapper over the shared
derive_at_metres_with_riparian core at survey-cell-centre world metres
— one derive core, two position sets. The batch pseudo-grid and the
true D-243 district grid were two coordinate systems sharing one bare
(i32,i32) type; the new SurveyCellPos newtype re-keys every batch
product (BodyWorldState.districts, Layer1Output.survey_basin_dirs) so
the compiler rejects cross-namespace passing.
Fixes two latent same-position divergences the T-1174 investigation
surfaced: three inconsistent latitude conventions collapse into the
core's single inverse mapping, and the region-climate baseline now
floor-divides true world metres instead of collapsing the whole body
onto region (0,0)'s baseline — batch climate becomes latitude/region
graded (D-245 direction: every changed believability metric increased).
Binding preservations per D-256(c): basin_direction rides a post-call
override with the true L1 D8 survey-cell aggregate (layer1's map
re-keyed to SurveyCellPos, identity lookup — a floor-divide lookup
against the pseudo-keyed map would have silently defaulted every cell
North); the riparian verdict comes from near_perennial_water_at, never
the empty-slice default (which would have flipped riverside
vegetation_class).
Quarter-skeleton morphology_zone now resolves at the settlement's
exact world position via derive_at_metres at work-item execution
(where TerrainAnalysisCache lives), replacing the survey-cell-centre
map lookup (D-256(d)); settlement_district_pos fixed to true-district
floor-division in passing (same doc/impl mismatch class). Second
pixel-vs-metre conflation fixed in aliveness_probe's anchor-walk math.
Window path byte-unchanged (window_derivation_golden 6/6 byte-
identical); derivation_harness golden untouched; believability golden
regenerated. Full lib + integration suites green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Promote the throwaway aliveness probe into a committed, repeatable believability
protocol — the instrument that found T-1080/T-1081/T-1082.
- atlas/believability.rs (new): BelievabilityReport (serde) + analyze() computing
CONTRAST (per-field min/max/distinct for moisture/elev/slope/ocean over all
districts; distinct morphology zones / vegetation classes / terrain materials)
and COHERENCE (water-renders-wet, drainage-monotonic, vegetation-present) — never
marginal per-tile counts (the lesson: that called a broken uniform world ALIVE).
evaluate_criteria() = advisory D-245 checks; cascade_for_body()/seed_to_u64()
loader shared by the bin and the harness. Unit tests prove the metric tells a
uniform world (fails) from a varied one (passes) + determinism.
- bin/aliveness_probe.rs: refactored to a thin CLI over the module — prints the
body-level report + advisory D-245 criteria, drops the naive per-tile verdict.
- tests/believability_harness.rs (+ golden): runs the real cascade for Arbour
(temperate/ocean) + Edict (frozen/ice), asserts determinism, golden-snapshots
the reports (regression — updates when T-1080/T-1082 land), advisory criteria
with BELIEVABILITY_STRICT=1 to fail on unmet D-245 criteria. Skips if committed
data absent. x86_64 golden (cascade has f32 warp paths).
Baseline @ believability-v1: Arbour 3/7, Edict 3/7 criteria pass — moisture
gradient, water-renders-wet, drainage all FAIL (T-1080/T-1082); Edict vegetation
0/64 (blank tundra — the frozen 'reads dead' case D-245 targets).
PNG layer maps (ticket item 3) deferred — explicitly optional; the contrast +
coherence metrics are the core enforcer.
clippy --all-targets -D warnings clean; 1575 lib tests + the harness pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>