From c260d293acbddbc1ca6c4c1ac933c396ed34a045 Mon Sep 17 00:00:00 2001
From: Masashi Katsumata <wf9a5m75@gmail.com>
Date: Sat, 7 Nov 2026 21:47:37 -0800
Subject: [PATCH 1/2] Interpolate the closing edge of geodesic polygons

ring(_:geodesic:) densified a geodesic ring with createInterpolatePoints, which only
interpolates between neighbouring points. Rings arrive open, so the
closing edge (last vertex -> first) stayed a straight chord in both fill
and outline (Boston -> London -> Iceland: the Iceland -> Boston edge).
Use ios-sdk-core's densifyGeodesicRing. geodesic=false is unchanged.

Requires the ios-sdk-core release that adds densifyGeodesicRing.
---
 .../polygon/MapKitPolygonOverlayRenderer.swift                 | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Sources/MapConductorForMapKit/polygon/MapKitPolygonOverlayRenderer.swift b/Sources/MapConductorForMapKit/polygon/MapKitPolygonOverlayRenderer.swift
index 65e4726..b8542e6 100644
--- a/Sources/MapConductorForMapKit/polygon/MapKitPolygonOverlayRenderer.swift
+++ b/Sources/MapConductorForMapKit/polygon/MapKitPolygonOverlayRenderer.swift
@@ -132,8 +132,9 @@ final class MapKitPolygonOverlayRenderer: AbstractPolygonOverlayRenderer<MKPolyg
     /// リングをコア共通の補間（geodesic は球面補間・非 geodesic は線形補間）で密度化して
     /// `CLLocationCoordinate2D` へ変換する。外周・穴の両方に同じ処理を通す。
     private func ring(_ points: [GeoPointProtocol], geodesic: Bool) -> [CLLocationCoordinate2D] {
+        // geodesic は閉じる辺（末尾 → 先頭）も大圏で補間する（塗りと輪郭が同じ MKPolygon）。
         let geoPoints: [GeoPointProtocol] = geodesic
-            ? WGS84Geodesic.createInterpolatePoints(points)
+            ? densifyGeodesicRing(points)
             : Planar.createInterpolatePoints(points)
         return geoPoints.map { CLLocationCoordinate2D(latitude: $0.latitude, longitude: $0.longitude) }
     }

From a195afa23c19a0766f2c6f31469daa0fc64b958b Mon Sep 17 00:00:00 2001
From: Masashi Katsumata <wf9a5m75@gmail.com>
Date: Sat, 7 Nov 2026 23:26:58 -0800
Subject: [PATCH 2/2] Densify the closing edge of non-geodesic polygons too

A geodesic=false ring went through Planar.createInterpolatePoints, which
only interpolates between neighbouring points, so the closing edge (last
vertex -> first) stayed one straight Web Mercator segment while the other
edges - and polylines with geodesic=false - follow linear lat/lng
interpolation. Use ios-sdk-core's densifyPolygonRing for both modes (it
replaces the unreleased densifyGeodesicRing).

Requires the ios-sdk-core release that adds densifyPolygonRing.
---
 .../polygon/MapKitPolygonOverlayRenderer.swift            | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/Sources/MapConductorForMapKit/polygon/MapKitPolygonOverlayRenderer.swift b/Sources/MapConductorForMapKit/polygon/MapKitPolygonOverlayRenderer.swift
index b8542e6..414d807 100644
--- a/Sources/MapConductorForMapKit/polygon/MapKitPolygonOverlayRenderer.swift
+++ b/Sources/MapConductorForMapKit/polygon/MapKitPolygonOverlayRenderer.swift
@@ -132,11 +132,9 @@ final class MapKitPolygonOverlayRenderer: AbstractPolygonOverlayRenderer<MKPolyg
     /// リングをコア共通の補間（geodesic は球面補間・非 geodesic は線形補間）で密度化して
     /// `CLLocationCoordinate2D` へ変換する。外周・穴の両方に同じ処理を通す。
     private func ring(_ points: [GeoPointProtocol], geodesic: Bool) -> [CLLocationCoordinate2D] {
-        // geodesic は閉じる辺（末尾 → 先頭）も大圏で補間する（塗りと輪郭が同じ MKPolygon）。
-        let geoPoints: [GeoPointProtocol] = geodesic
-            ? densifyGeodesicRing(points)
-            : Planar.createInterpolatePoints(points)
-        return geoPoints.map { CLLocationCoordinate2D(latitude: $0.latitude, longitude: $0.longitude) }
+        // 閉じる辺（末尾 → 先頭）も他の辺と同じく補間する（塗りと輪郭が同じ MKPolygon）。
+        // geodesic は大圏、geodesic=false は緯度経度の線形補間（ポリラインの false と同じ線）。
+        densifyPolygonRing(points, geodesic: geodesic).map { CLLocationCoordinate2D(latitude: $0.latitude, longitude: $0.longitude) }
     }
 }