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Interpolate the closing edge of polygons, geodesic or not #14

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Merged
wf9a5m75 merged 2 commits into from
Nov 8, 2026
Merged

Interpolate the closing edge of polygons, geodesic or not #14

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f0cf8dd
Interpolate the closing edge of geodesic polygons
wf9a5m75 Nov 8, 2026
aa471a3
Densify non-geodesic polygon rings, closing edge included
wf9a5m75 Nov 8, 2026
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36 changes: 21 additions & 15 deletions src/main/java/com/mapconductor/tomtom/polygon/TomTomPolygonOverlayRenderer.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -3,13 +3,13 @@ package com.mapconductor.tomtom.polygon
import androidx.compose.ui.graphics.toArgb
import com.mapconductor.core.features.GeoPoint
import com.mapconductor.core.features.GeoPointInterface
import com.mapconductor.core.geometry.densifyPolygonRing
import com.mapconductor.core.polygon.AbstractPolygonOverlayRenderer
import com.mapconductor.core.polygon.PolygonEntityInterface
import com.mapconductor.core.polygon.PolygonState
import com.mapconductor.core.polygon.bridgeHolesIntoSingleRing
import com.mapconductor.core.polygon.unionHoles
import com.mapconductor.core.projection.Earth
import com.mapconductor.core.spherical.WGS84Geodesic
import com.mapconductor.tomtom.TomTomActualPolygon
import com.mapconductor.tomtom.TomTomMapViewHolder
import com.mapconductor.tomtom.toTomTomGeoPoint
Expand Down Expand Up @@ -42,13 +42,7 @@ class TomTomPolygonOverlayRenderer(
points: List<GeoPointInterface>,
geodesic: Boolean,
): List<TomTomGeoPoint> {
// 非 geodesic は補間せず生の頂点を使う（HERE と同じ）。geodesic のみ補間する。
val geoPoints =
if (geodesic) {
WGS84Geodesic.createInterpolatePoints(points, maxSegmentLength = maxSegmentLengthMeters())
} else {
points
}
val geoPoints = densify(points, geodesic)
var ring = geoPoints.map { GeoPoint.from(it).toTomTomGeoPoint() }
// 末尾の重複始点を除く（開いたリング）。
if (ring.size >= 2 && ring.first() == ring.last()) {
Expand Down Expand Up @@ -78,16 +72,28 @@ class TomTomPolygonOverlayRenderer(
points: List<GeoPointInterface>,
geodesic: Boolean,
): List<GeoPointInterface> {
val geoPoints =
if (geodesic) {
WGS84Geodesic.createInterpolatePoints(points, maxSegmentLength = maxSegmentLengthMeters())
} else {
points
}
val ring = geoPoints.map { GeoPoint.from(it) }
val ring = densify(points, geodesic).map { GeoPoint.from(it) }
return if (ring.size >= 2 && ring.first() == ring.last()) ring.dropLast(1) else ring
}

/**
* 閉じる辺（末尾 → 先頭）も含めてリングを密度化する（塗りと輪郭が同じネイティブポリゴン）。
* 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）。
*
* 線形補間は [MAX_GEODESIC_SEGMENT_METERS] 刻みと粗くする。世界マスク級のリングを 10 km 刻みで
* 補間すると過密になり TomTom の描画が失敗する（以前はこのため false を補間していなかった）。
* 緯度経度の直線は 200 km 刻みでもメルカトル上の曲がりを十分に表せる。
*/
private fun densify(
points: List<GeoPointInterface>,
geodesic: Boolean,
): List<GeoPointInterface> =
densifyPolygonRing(
points,
geodesic,
maxSegmentLength = if (geodesic) maxSegmentLengthMeters() else MAX_GEODESIC_SEGMENT_METERS,
)

private fun maxSegmentLengthMeters(): Double {
val zoom = holder.map.cameraPosition.zoom
val metersPerPixel = Earth.CIRCUMFERENCE_METERS / (256.0 * 2.0.pow(zoom))
Expand Down
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