not good but not bad

mapOutput.js

@@ -24,6 +24,48 @@ function municipalityNameFromRoot(root, center, fields, seed, ordinal = 0) {
   return `${value}${municipalitySuffixForCenter(center, fields, seed, ordinal)}`;
 }
 
+function buildPrefectureRegions(prefectureRegionId, sea, fields, seed, usedNames, nameDebug) {
+  if (!prefectureRegionId) return [];
+  const byId = new Map();
+  for (let i = 0; i < prefectureRegionId.length; i++) {
+    const id = prefectureRegionId[i];
+    if (sea[i] || id < 0) continue;
+    if (!byId.has(id)) byId.set(id, { id, area: 0, sx: 0, sy: 0, cells: [] });
+    const row = byId.get(id);
+    const x = i % MAP_W;
+    const y = Math.floor(i / MAP_W);
+    row.area++;
+    row.sx += x;
+    row.sy += y;
+    row.cells.push(i);
+  }
+  const regions = [];
+  for (const row of [...byId.values()].sort((a, b) => a.id - b.id)) {
+    const cx = row.sx / Math.max(1, row.area);
+    const cy = row.sy / Math.max(1, row.area);
+    let bestI = row.cells[0];
+    let bestScore = -INF;
+    for (const i of row.cells) {
+      const x = i % MAP_W;
+      const y = Math.floor(i / MAP_W);
+      const score =
+        (fields.populationDensity?.[i] || 0) * 1.6 +
+        (fields.plain?.[i] || 0) * 0.28 +
+        (fields.basinField?.[i] || 0) * 0.22 +
+        (fields.coastalLowland?.[i] || 0) * 0.16 -
+        (fields.slope?.[i] || 0) * 0.36 -
+        (fields.ridgeField?.[i] || 0) * 0.30 -
+        Math.hypot(x - cx, y - cy) * 0.08;
+      if (score > bestScore) { bestScore = score; bestI = i; }
+    }
+    const x = bestI % MAP_W;
+    const y = Math.floor(bestI / MAP_W);
+    regions.push({ id: row.id, x, y, area: row.area, kind: row.id === 0 ? "Current Prefecture" : "Prefecture", labelPriorityBase: 900 + Math.sqrt(row.area) });
+  }
+  return attachIdsAndNames(regions, "prefecture", seed + 41000, null, fields, usedNames, nameDebug)
+    .map((region, index) => ({ ...region, featureId: region.id, id: regions[index].id, labelName: region.name }));
+}
+
 export function finishMapOutput({
   seed,
   options,
@@ -65,10 +107,7 @@ export function finishMapOutput({
     smallStreams,
     prefectureMask,
     prefectureBorder,
-    prefectureRegionId,
-    regionalDebug,
     terrainDebug,
-    regionalPrefectureBorders,
   } = terrain;
 
   const {
@@ -115,6 +154,12 @@ export function finishMapOutput({
     adminId,
     adminBorders,
     adminDebug,
+    prefectureRegionId,
+    municipalityToPrefectureId,
+    regionalPrefectureBorders: adminRegionalPrefectureBorders,
+    regionalDebug,
+    naturalCompartmentId,
+    naturalCompartments,
   } = admin;
 
   let villages = inputVillages;
@@ -206,6 +251,8 @@ export function finishMapOutput({
     if (best) {
       center.representativeFeatureId = best.id;
       center.representativeFeatureName = best.name;
+      center.canonicalSettlementId = best.id;
+      center.canonicalSettlementName = best.name;
       center.municipalityRootName = best.name;
     } else {
       center.municipalityRootName = center.generatedMunicipalityName;
@@ -215,12 +262,12 @@ export function finishMapOutput({
   for (const [index, center] of adminCenters.entries()) {
     center.adminNumericId = index;
     center.municipalityId = index;
-    let candidate = municipalityNameFromRoot(center.municipalityRootName || center.generatedMunicipalityName || center.name, center, nameFields, seed, index);
+    let candidate = center.canonicalSettlementName || municipalityNameFromRoot(center.municipalityRootName || center.generatedMunicipalityName || center.name, center, nameFields, seed, index);
     const generated = municipalityNameFromRoot(center.generatedMunicipalityName || center.name, center, nameFields, seed + 177, index);
-    if (usedAdminNames.has(candidate) && Array.from(generated).length >= 2 && !usedAdminNames.has(generated)) {
+    if (!center.canonicalSettlementName && usedAdminNames.has(candidate) && Array.from(generated).length >= 2 && !usedAdminNames.has(generated)) {
       candidate = generated;
     }
-    if (usedAdminNames.has(candidate)) {
+    if (!center.canonicalSettlementName && usedAdminNames.has(candidate)) {
       const suffix = municipalitySuffixForCenter(center, nameFields, seed + 313, index);
       const base = String(center.generatedMunicipalityName || center.municipalityRootName || center.name || `自治${index + 1}`).replace(/[市町村区]$/u, "");
       candidate = `${base}${index + 1}${suffix}`;
@@ -231,6 +278,12 @@ export function finishMapOutput({
     usedAdminNames.add(center.name);
   }
   nameDebug.maxDerivedPerBase = 0;
+  const prefectureRegions = buildPrefectureRegions(prefectureRegionId, sea, nameFields, seed, usedNames, nameDebug);
+  const regionalPrefectureBorders = adminRegionalPrefectureBorders || [];
+  if (regionalDebug) {
+    regionalDebug.finalRegionalPrefectureBorderCount = regionalPrefectureBorders.length;
+    regionalDebug.regionalPrefectureBordersRebuiltFromFinalId = true;
+  }
 
   outputProgress("final package");
   const entitiesForNames = [
@@ -260,6 +313,8 @@ export function finishMapOutput({
     humanRegionMask,
     prefectureBorder,
     prefectureRegionId,
+    municipalityToPrefectureId,
+    prefectureRegions,
     regionalDebug,
     terrainDebug,
     regionalPrefectureBorders,
@@ -289,6 +344,8 @@ export function finishMapOutput({
     alluvialFanField,
     deltaField,
     naturalBarrierScore,
+    naturalCompartmentId,
+    naturalCompartments,
     villages,
     ports,
     crossings,