feat(simulation): canonical spatial scale ladder + body_radius_km (T-1077)
First phase of the D-243 re-scale. Adds server/src/atlas/scale.rs as the single source of truth for the metric containment ladder (voxel 1m -> chunk 64m -> block 128m -> quarter 512m -> district 2048m -> region 204.8km), the fixed integer addressing (ChunkPos -> DistrictPos -> RegionPos), and the elastic seam regions_per_equator(R). Compile-time const asserts enforce the nesting so the rungs cannot silently drift again — the structural fix for the Q-110 failure mode (three files, three different region sizes). Wires body_radius_km (D-204) through BodyParams + the reader: the single body-specific input to the elastic seam. No behavior change — foundation only. The rename/re-scale of the carrier (RegionProfile -> DistrictProfile) and on-demand district derivation follow. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
Claude Opus 4.8
@@ -1921,3 +1921,5 @@ INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, chang
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Q-110 resolved (2026-06-14) -> D-243. Scope item (1) ChunkPos->RegionPos is now defined: the D-243 absolute ladder is voxel(1m)->chunk(64m)->block(128m)->quarter(512m)->district(2km)->region(~205km), with a single elastic seam region<->planet (round(2*pi*R/204.8km) regions per body from body_radius_km). ChunkPos->district->region is fixed integer math; only region->heightmap-sample is body-specific.
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Prerequisite: T-1077 re-scales the code to this ladder (the current ~1km RegionProfile moves onto the 2km district; the region becomes the new 205km top hard block) — T-1046 now blocked by T-1077. Climate/weather lockdown + edge fuzz on the region is T-1078. Once T-1077 lands, T-1046 is the production wiring (proxy layers + Atlas surfacing) over a ladder whose scale is finally coherent.', NULL, '2026-06-14 19:22:14', '2026-06-14 19:22:14', '2026-06-14 19:22:14', NULL, '386fdc3725a511127d2254a36dd90c62', 2) ON CONFLICT(hash) DO NOTHING;
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INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FCF56EAJ55PHQ977SV866CFM', 'status', 'backlog', 'in_progress', NULL, '2026-06-14 19:40:42', '2026-06-14 19:40:42', '2026-06-14 19:40:42', NULL, 'e13782322e02f56c9e7ddb3b28c76d3a', 2) ON CONFLICT(hash) DO NOTHING;
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INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FCF56EAJ55PHQ977SV866CFM', 'status', 'in_progress', 'in_progress', NULL, '2026-06-14 19:51:10', '2026-06-14 19:51:10', '2026-06-14 19:51:10', NULL, '8e625a7b0faf0d348bc718e0f8b7d7f3', 2) ON CONFLICT(hash) DO NOTHING;
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@@ -2241,3 +2241,19 @@ INSERT INTO tickets (record_id, type, parent_record_id, title, description, stat
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||||
Q-110 resolved (2026-06-14) -> D-243. Scope item (1) ChunkPos->RegionPos is now defined: the D-243 absolute ladder is voxel(1m)->chunk(64m)->block(128m)->quarter(512m)->district(2km)->region(~205km), with a single elastic seam region<->planet (round(2*pi*R/204.8km) regions per body from body_radius_km). ChunkPos->district->region is fixed integer math; only region->heightmap-sample is body-specific.
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Prerequisite: T-1077 re-scales the code to this ladder (the current ~1km RegionProfile moves onto the 2km district; the region becomes the new 205km top hard block) — T-1046 now blocked by T-1077. Climate/weather lockdown + edge fuzz on the region is T-1078. Once T-1077 lands, T-1046 is the production wiring (proxy layers + Atlas surfacing) over a ladder whose scale is finally coherent.', 'backlog', 'high', NULL, 'server', 'D-239', '2026-06-12 10:40:58', '2026-06-14 19:22:14', NULL, 'c3379b82cb706bdf11174688e5d203e6', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
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INSERT INTO tickets (record_id, type, parent_record_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FCF56EAJ55PHQ977SV866CFM', 'task', '06FB0TNSRZXCHGS16BFHSSGSV4', 'Re-scale the cascade to the D-243 ladder + elastic-seam resampling (region 205km / district 2km)', 'Per D-243 (resolves Q-110). Make the code match the canonical ladder.
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1. Re-scale the terrain/climate carrier: the current ~1km RegionProfile (region_profile.rs, derive_all_regions 8-cells/region) moves to the DISTRICT (2km), aligning with D-239 §2''s climate district. Rename RegionProfile -> DistrictProfile (or equivalent); fix the contradictory scale assumptions Q-110 flagged (region_profile.rs:3-4 ~1km doc, cascade.rs:235-237 ''8 cells/region on 128x64'', chunk_context.rs:137-141 ''region=16 chunks'').
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2. Add the REGION tier = 100x100 districts = 204.8km (~205km) = the top hard block.
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3. Elastic seam region<->planet: round(2*pi*R/204.8km) regions per body from body_radius_km (D-204). ChunkPos -> district -> region is fixed integer math; region->heightmap-sample is the only body-specific function.
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4. Detail-scatter synthesis (D-243 §2): interpolate the coarse heightmap (~40-78km/px) + compose a simple multi-octave seed+position-keyed detail field (shaped by morphology/slope, continuous) atop the D-239 §4 domain warp — invented, not stored (D-227), plausible-at-a-glance.
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Blocks T-1046 (the tier can''t wire to production until its scale matches the ladder).', 'in_progress', 'high', NULL, 'server', 'D-243', '2026-06-14 19:21:18', '2026-06-14 19:40:42', NULL, '752fdfed97c7f7fe81747a8504dee793', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
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INSERT INTO tickets (record_id, type, parent_record_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FCF56EAJ55PHQ977SV866CFM', 'task', '06FB0TNSRZXCHGS16BFHSSGSV4', 'Re-scale the cascade to the D-243 ladder + elastic-seam resampling (region 205km / district 2km)', 'Per D-243 (resolves Q-110). Make the code match the canonical ladder.
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1. Re-scale the terrain/climate carrier: the current ~1km RegionProfile (region_profile.rs, derive_all_regions 8-cells/region) moves to the DISTRICT (2km), aligning with D-239 §2''s climate district. Rename RegionProfile -> DistrictProfile (or equivalent); fix the contradictory scale assumptions Q-110 flagged (region_profile.rs:3-4 ~1km doc, cascade.rs:235-237 ''8 cells/region on 128x64'', chunk_context.rs:137-141 ''region=16 chunks'').
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2. Add the REGION tier = 100x100 districts = 204.8km (~205km) = the top hard block.
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3. Elastic seam region<->planet: round(2*pi*R/204.8km) regions per body from body_radius_km (D-204). ChunkPos -> district -> region is fixed integer math; region->heightmap-sample is the only body-specific function.
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4. Detail-scatter synthesis (D-243 §2): interpolate the coarse heightmap (~40-78km/px) + compose a simple multi-octave seed+position-keyed detail field (shaped by morphology/slope, continuous) atop the D-239 §4 domain warp — invented, not stored (D-227), plausible-at-a-glance.
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Blocks T-1046 (the tier can''t wire to production until its scale matches the ladder).', 'in_progress', 'high', NULL, 'server', 'D-243', '2026-06-14 19:21:18', '2026-06-14 19:51:10', NULL, 'ecae1405c540fb403d3f1126ce5b4082', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
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@@ -16,9 +16,10 @@
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//!
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//! | Field | Source |
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//! |-------|--------|
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//! | `hydrosphere` | `bodies.hydrosphere` |
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//! | `atmosphere` | `bodies.atmosphere` |
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//! | `planet_class` | `bodies.planet_class` |
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//! | `hydrosphere` | `bodies.hydrosphere` |
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//! | `atmosphere` | `bodies.atmosphere` |
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//! | `planet_class` | `bodies.planet_class` |
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//! | `body_radius_km` | `bodies.body_radius_km` (D-204 — the D-243 elastic-seam input) |
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//!
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//! `tectonic_activity` is **not** in the current schema; `BodyParams.tectonic_activity`
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//! is left `None` so the derivation falls back to `planet_class` as documented
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@@ -91,26 +92,28 @@ impl BodyParamsReader {
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.lock()
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.map_err(|e| BodyParamsReadError::Db(format!("mutex poisoned: {e}")))?;
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// All three columns are nullable; row absence is what signals UnknownBody.
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// All columns are nullable; row absence is what signals UnknownBody.
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// `tectonic_activity` is absent from the current schema — leave that
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// BodyParams field None (derives from planet_class at derivation time).
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let result: rusqlite::Result<(
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Option<String>, // b.hydrosphere
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Option<String>, // b.atmosphere
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Option<String>, // b.planet_class
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Option<f64>, // b.body_radius_km (D-204 — the D-243 elastic seam input)
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)> = conn.query_row(
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"SELECT
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b.hydrosphere,
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b.atmosphere,
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b.planet_class
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b.planet_class,
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b.body_radius_km
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FROM bodies AS b
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WHERE b.body_id = ?1",
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[body_id],
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|row| Ok((row.get(0)?, row.get(1)?, row.get(2)?)),
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|row| Ok((row.get(0)?, row.get(1)?, row.get(2)?, row.get(3)?)),
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);
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match result {
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Ok((hydrosphere, atmosphere, planet_class)) => Ok(BodyParams {
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Ok((hydrosphere, atmosphere, planet_class, body_radius_km)) => Ok(BodyParams {
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hydrosphere,
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atmosphere,
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planet_class,
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@@ -120,6 +123,7 @@ impl BodyParamsReader {
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// not at the body level. Leave at struct defaults (0.0).
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region_latitude_deg: 0.0,
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elevation_km: 0.0,
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body_radius_km,
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}),
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Err(rusqlite::Error::QueryReturnedNoRows) => {
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Err(BodyParamsReadError::UnknownBody(body_id.to_string()))
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@@ -161,6 +165,7 @@ mod tests {
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hydrosphere: Option<&str>,
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atmosphere: Option<&str>,
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planet_class: Option<&str>,
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body_radius_km: Option<f64>,
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) -> PathBuf {
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let n = SEQ.fetch_add(1, Ordering::Relaxed);
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let path = std::env::temp_dir().join(format!("sr_bpr_{}_{n}.db", std::process::id()));
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@@ -171,15 +176,16 @@ mod tests {
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body_id TEXT PRIMARY KEY,
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hydrosphere TEXT,
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atmosphere TEXT,
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planet_class TEXT
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planet_class TEXT,
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body_radius_km REAL
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);",
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)
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.expect("create tables");
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conn.execute(
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"INSERT INTO bodies (body_id, hydrosphere, atmosphere, planet_class)
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VALUES (?1, ?2, ?3, ?4)",
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rusqlite::params![body_id, hydrosphere, atmosphere, planet_class],
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"INSERT INTO bodies (body_id, hydrosphere, atmosphere, planet_class, body_radius_km)
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VALUES (?1, ?2, ?3, ?4, ?5)",
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rusqlite::params![body_id, hydrosphere, atmosphere, planet_class, body_radius_km],
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)
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.expect("insert body");
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@@ -189,13 +195,20 @@ mod tests {
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#[test]
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fn reads_all_columns_present() {
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let db = make_test_db("GJ1c", Some("ocean"), Some("breathable"), Some("temperate"));
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let db = make_test_db(
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"GJ1c",
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Some("ocean"),
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Some("breathable"),
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Some("temperate"),
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Some(6371.0),
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);
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let reader = BodyParamsReader::open(&db).expect("open");
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let params = reader.read_body_params("GJ1c").expect("read");
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assert_eq!(params.hydrosphere.as_deref(), Some("ocean"));
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assert_eq!(params.atmosphere.as_deref(), Some("breathable"));
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assert_eq!(params.planet_class.as_deref(), Some("temperate"));
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assert_eq!(params.body_radius_km, Some(6371.0));
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// Per-region fields always start at 0.0 from the reader.
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assert_eq!(params.region_latitude_deg, 0.0);
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assert_eq!(params.elevation_km, 0.0);
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@@ -205,18 +218,19 @@ mod tests {
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#[test]
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fn handles_all_null_columns() {
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let db = make_test_db("GJ2b", None, None, None);
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let db = make_test_db("GJ2b", None, None, None, None);
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let reader = BodyParamsReader::open(&db).expect("open");
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let params = reader.read_body_params("GJ2b").expect("read");
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assert!(params.hydrosphere.is_none());
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assert!(params.atmosphere.is_none());
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assert!(params.planet_class.is_none());
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assert!(params.body_radius_km.is_none());
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}
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#[test]
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fn unknown_body_returns_error() {
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let db = make_test_db("GJ3c", None, None, None);
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let db = make_test_db("GJ3c", None, None, None, None);
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let reader = BodyParamsReader::open(&db).expect("open");
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let err = reader.read_body_params("ghost").expect_err("should fail");
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assert!(matches!(err, BodyParamsReadError::UnknownBody(_)));
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@@ -224,7 +238,7 @@ mod tests {
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#[test]
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fn read_is_deterministic() {
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let db = make_test_db("GJ4d", Some("ice"), Some("thin"), Some("frozen"));
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let db = make_test_db("GJ4d", Some("ice"), Some("thin"), Some("frozen"), Some(3389.5));
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let reader = BodyParamsReader::open(&db).expect("open");
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let p1 = reader.read_body_params("GJ4d").expect("first read");
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let p2 = reader.read_body_params("GJ4d").expect("second read");
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@@ -232,6 +246,8 @@ mod tests {
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assert_eq!(p1.hydrosphere, p2.hydrosphere);
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assert_eq!(p1.atmosphere, p2.atmosphere);
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assert_eq!(p1.planet_class, p2.planet_class);
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assert_eq!(p1.body_radius_km, p2.body_radius_km);
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assert_eq!(p1.body_radius_km, Some(3389.5));
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}
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#[test]
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@@ -250,11 +266,12 @@ mod tests {
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body_id TEXT PRIMARY KEY,
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hydrosphere TEXT,
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atmosphere TEXT,
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planet_class TEXT
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planet_class TEXT,
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body_radius_km REAL
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-- orbital_period_days, axial_tilt_deg, spectral_class, star_type
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-- deliberately absent to prove SELECT doesn't reference them
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);
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INSERT INTO bodies VALUES ('X', 'ocean', 'breathable', 'temperate');",
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INSERT INTO bodies VALUES ('X', 'ocean', 'breathable', 'temperate', 6371.0);",
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)
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.expect("setup");
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drop(conn);
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@@ -21,6 +21,7 @@ pub mod layer_proxy;
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pub mod plugin;
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pub mod region_profile;
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pub mod road_graph;
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pub mod scale;
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pub mod skeleton_gen;
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pub mod source_resolver;
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pub mod subbiome;
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@@ -152,6 +152,10 @@ pub struct BodyParams {
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pub region_latitude_deg: f64,
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/// Mean elevation of this region relative to sea level, in km. Used for lapse rate.
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pub elevation_km: f64,
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/// `bodies.body_radius_km` (D-204) — the body's radius in km. The single
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/// body-specific input to the D-243 elastic seam (`scale::regions_per_equator`).
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/// `None` if the body has no recorded radius.
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pub body_radius_km: Option<f64>,
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}
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// ---------------------------------------------------------------------------
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@@ -0,0 +1,147 @@
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//! Canonical spatial scale ladder (D-243) — **the single source of truth** for
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//! the metric containment hierarchy. Every cascade consumer references these
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//! constants and conversions; no module re-derives its own scale.
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//!
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//! This is the *structural* fix for the Q-110 failure mode — three files had
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//! three different "region" sizes (1 024 m, 624 km, "16 chunks") because the
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//! metres-per-scale lived as scattered magic numbers. With one canonical source
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//! a file physically cannot invent a scale that disagrees, and the `const`
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//! asserts below fail the build if the rungs ever stop nesting cleanly.
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//!
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//! ```text
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//! voxel 1 m → chunk 64 m → block 128 m → quarter 512 m → district 2 048 m
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//! → region ~205 km → (elastic seam) → planet
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//! ```
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//!
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//! Below the region everything is fixed integer math; only [`regions_per_equator`]
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//! (the planetary count) varies per body. See [D-243] for the full model.
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//!
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//! [D-243]: ../../../governance/decisions/architecture.md
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// ---------------------------------------------------------------------------
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// Edge lengths in metres (absolute, fixed — D-243)
|
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// ---------------------------------------------------------------------------
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/// Voxel edge — the tile (D-228 / D-220).
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pub const VOXEL_M: i32 = 1;
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/// Chunk edge — the stream / derive unit (D-222, D-239).
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pub const CHUNK_M: i32 = 64;
|
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/// Block edge — generator planning unit (D-222).
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pub const BLOCK_M: i32 = 128;
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/// Quarter edge — settlement footprint cell (D-222).
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pub const QUARTER_M: i32 = 512;
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/// District edge — urban division **and** the local terrain/climate carrier cell
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/// (D-222, D-239 §2, D-243). The fine carrier `ChunkContext`/voxels consume.
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pub const DISTRICT_M: i32 = 2_048;
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/// Region edge — the top hard block: planetary grid + climate/weather/season
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/// lockdown (D-243). 100 districts on a side.
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pub const REGION_M: i32 = 204_800;
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// ---------------------------------------------------------------------------
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// Linear nesting ratios (children per parent edge)
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// ---------------------------------------------------------------------------
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/// Voxels per chunk edge (64 m / 1 m). A chunk is 64×64 voxels.
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pub const VOXELS_PER_CHUNK: i32 = CHUNK_M / VOXEL_M;
|
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/// Chunks per district edge (2 048 m / 64 m = 32 = `1 << 5`).
|
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pub const CHUNKS_PER_DISTRICT: i32 = DISTRICT_M / CHUNK_M;
|
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/// `log2(CHUNKS_PER_DISTRICT)` — chunk→district is an arithmetic shift (floors
|
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/// toward −∞ for negative coords, the correct tiling behaviour).
|
||||
pub const CHUNK_DISTRICT_SHIFT: u32 = 5;
|
||||
/// Districts per region edge (204 800 m / 2 048 m = 100). Not a power of two,
|
||||
/// so region mapping uses division, not a shift.
|
||||
pub const DISTRICTS_PER_REGION: i32 = REGION_M / DISTRICT_M;
|
||||
|
||||
// Compile-time ladder invariants — the build fails if a rung stops nesting.
|
||||
const _: () = assert!(CHUNKS_PER_DISTRICT == 1 << CHUNK_DISTRICT_SHIFT);
|
||||
const _: () = assert!(CHUNKS_PER_DISTRICT * CHUNK_M == DISTRICT_M);
|
||||
const _: () = assert!(DISTRICTS_PER_REGION * DISTRICT_M == REGION_M);
|
||||
const _: () = assert!(DISTRICTS_PER_REGION == 100);
|
||||
|
||||
// ---------------------------------------------------------------------------
|
||||
// Grid positions + fixed integer addressing
|
||||
// ---------------------------------------------------------------------------
|
||||
|
||||
/// Position on the 64 m chunk grid (chunk-units, not metres). `BTreeMap` key (D-010).
|
||||
pub type ChunkPos = (i32, i32);
|
||||
/// Position on the 2 km district grid (district-units) — the terrain/climate carrier cell.
|
||||
pub type DistrictPos = (i32, i32);
|
||||
/// Position on the ~205 km region grid (region-units) — the top hard block.
|
||||
pub type RegionPos = (i32, i32);
|
||||
|
||||
/// The district covering a chunk. Arithmetic shift floors toward −∞ so the tiling
|
||||
/// is consistent across the origin (a chunk at −1 belongs to district −1, not 0).
|
||||
#[inline]
|
||||
pub fn chunk_to_district(c: ChunkPos) -> DistrictPos {
|
||||
(c.0 >> CHUNK_DISTRICT_SHIFT, c.1 >> CHUNK_DISTRICT_SHIFT)
|
||||
}
|
||||
|
||||
/// The region covering a district. Euclidean floor division matches the shift's
|
||||
/// flooring, so chunk→district→region tiling is seamless across the origin.
|
||||
#[inline]
|
||||
pub fn district_to_region(d: DistrictPos) -> RegionPos {
|
||||
(
|
||||
d.0.div_euclid(DISTRICTS_PER_REGION),
|
||||
d.1.div_euclid(DISTRICTS_PER_REGION),
|
||||
)
|
||||
}
|
||||
|
||||
/// The region covering a chunk (chunk → district → region).
|
||||
#[inline]
|
||||
pub fn chunk_to_region(c: ChunkPos) -> RegionPos {
|
||||
district_to_region(chunk_to_district(c))
|
||||
}
|
||||
|
||||
// ---------------------------------------------------------------------------
|
||||
// The elastic seam — region ↔ planet (the only per-body-floating quantity)
|
||||
// ---------------------------------------------------------------------------
|
||||
|
||||
/// Number of ~205 km regions around the body's equator: `round(2πR / REGION_M)`,
|
||||
/// minimum 1 (D-243). `R` is `bodies.body_radius_km` (D-204) — the single
|
||||
/// body-specific input in the whole scale chain. Pole-to-pole is half this.
|
||||
pub fn regions_per_equator(body_radius_km: f64) -> u32 {
|
||||
let circumference_m = 2.0 * std::f64::consts::PI * body_radius_km * 1000.0;
|
||||
((circumference_m / REGION_M as f64).round() as i64).max(1) as u32
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
mod tests {
|
||||
use super::*;
|
||||
|
||||
#[test]
|
||||
fn ladder_nests_cleanly() {
|
||||
assert_eq!(VOXELS_PER_CHUNK, 64);
|
||||
assert_eq!(CHUNKS_PER_DISTRICT, 32);
|
||||
assert_eq!(DISTRICTS_PER_REGION, 100);
|
||||
assert_eq!(CHUNK_M * CHUNKS_PER_DISTRICT, DISTRICT_M);
|
||||
assert_eq!(DISTRICT_M * DISTRICTS_PER_REGION, REGION_M);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn addressing_floors_across_origin() {
|
||||
// chunk → district (32 chunks/district)
|
||||
assert_eq!(chunk_to_district((0, 0)), (0, 0));
|
||||
assert_eq!(chunk_to_district((31, 31)), (0, 0));
|
||||
assert_eq!(chunk_to_district((32, 32)), (1, 1));
|
||||
assert_eq!(chunk_to_district((-1, -1)), (-1, -1)); // floors, not truncates
|
||||
assert_eq!(chunk_to_district((-32, -32)), (-1, -1));
|
||||
assert_eq!(chunk_to_district((-33, -33)), (-2, -2));
|
||||
// district → region (100 districts/region)
|
||||
assert_eq!(district_to_region((99, 0)), (0, 0));
|
||||
assert_eq!(district_to_region((100, 0)), (1, 0));
|
||||
assert_eq!(district_to_region((-1, 0)), (-1, 0));
|
||||
// chunk → region (3200 chunks/region)
|
||||
assert_eq!(chunk_to_region((3199, 0)), (0, 0));
|
||||
assert_eq!(chunk_to_region((3200, 0)), (1, 0));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn regions_per_equator_earth_and_moon() {
|
||||
// Earth (R≈6371 km): 2πR ≈ 40 030 km / 204.8 km ≈ 195.46 → 195.
|
||||
assert_eq!(regions_per_equator(6371.0), 195);
|
||||
// A small moon (R≈200 km): ≈ 1257 km / 204.8 ≈ 6.1 → 6.
|
||||
assert_eq!(regions_per_equator(200.0), 6);
|
||||
// Degenerate radius still yields at least one region.
|
||||
assert_eq!(regions_per_equator(0.0), 1);
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user