feat: add GeoUtils.fastDistance and draft AnnotationPlacer (2c3265e3) · Commits · e / os / Murena Maps

cardinal-android/app/src/main/java/earth/maps/cardinal/data/GeoUtils.kt

+27 −10

Original line number	Original line	Diff line number	Diff line
	@@ -30,12 +30,11 @@ import kotlin.math.sqrt
	*/		*/
	object GeoUtils {		object GeoUtils {

			private const val EARTH_RADIUS_METERS = 6371000.0
	private const val METERS_TO_KILOMETERS = 1000.0		private const val METERS_TO_KILOMETERS = 1000.0
	private const val METERS_TO_MILES = 1609.34		private const val METERS_TO_MILES = 1609.34
	private const val METERS_TO_FEET = 3.28084		private const val METERS_TO_FEET = 3.28084

	private const val SHORT_DISTANCE_THRESHOLD_METERS = 200.0

	/**		/**
	* Formats a distance in meters to a human-readable string based on the unit preference.		* Formats a distance in meters to a human-readable string based on the unit preference.
	*		*
	@@ -112,10 +111,31 @@ object GeoUtils {
	val a = sin(deltaLat / 2).pow(2) + cos(lat1) * cos(lat2) * sin(deltaLon / 2).pow(2)		val a = sin(deltaLat / 2).pow(2) + cos(lat1) * cos(lat2) * sin(deltaLon / 2).pow(2)
	val c = 2 * atan2(sqrt(a), sqrt(1 - a))		val c = 2 * atan2(sqrt(a), sqrt(1 - a))

	// Earth's radius in meters		return EARTH_RADIUS_METERS * c
	val earthRadius = 6371000.0		}

	return earthRadius * c		/**
			* Calculates the distance between two points using a locally cartesian approximation.
			* This is faster than haversine for short distances but less accurate for long distances.
			* Uses the mean of the two latitudes for the longitude scaling factor.
			*
			* @param latLng1 First point
			* @param latLng2 Second point
			* @return Distance in meters
			*/
			fun fastDistance(latLng1: LatLng, latLng2: LatLng): Double {
			// Calculate mean latitude for longitude scaling
			val meanLat = (latLng1.latitude + latLng2.latitude) / 2.0
			val meanLatRad = Math.toRadians(meanLat)

			// Convert latitude and longitude differences to meters
			val latDiff = (latLng2.latitude - latLng1.latitude) * Math.toRadians(EARTH_RADIUS_METERS)
			val lonDiff = (latLng2.longitude - latLng1.longitude) * Math.toRadians(
			EARTH_RADIUS_METERS * cos(meanLatRad)
			)

			// Calculate cartesian distance
			return sqrt(latDiff * latDiff + lonDiff * lonDiff)
	}		}

	/**		/**
	@@ -126,13 +146,10 @@ object GeoUtils {
	* @return A BoundingBox representing the area around the center point		* @return A BoundingBox representing the area around the center point
	*/		*/
	fun createBoundingBoxAroundPoint(center: LatLng, radiusMeters: Double): BoundingBox {		fun createBoundingBoxAroundPoint(center: LatLng, radiusMeters: Double): BoundingBox {
	// Earth's radius in meters
	val earthRadius = 6371000.0

	// Calculate the approximate delta in degrees for the given radius		// Calculate the approximate delta in degrees for the given radius
	val latDelta = Math.toDegrees(radiusMeters / earthRadius)		val latDelta = Math.toDegrees(radiusMeters / EARTH_RADIUS_METERS)
	val lonDelta =		val lonDelta =
	Math.toDegrees(radiusMeters / (earthRadius * cos(Math.toRadians(center.latitude))))		Math.toDegrees(radiusMeters / (EARTH_RADIUS_METERS * cos(Math.toRadians(center.latitude))))

	// Create the bounding box with north, south, east, west boundaries		// Create the bounding box with north, south, east, west boundaries
	return BoundingBox(		return BoundingBox(

cardinal-android/app/src/main/java/earth/maps/cardinal/data/LatLng.kt

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -25,4 +25,8 @@ data class LatLng(
	fun distanceTo(other: LatLng): Double {		fun distanceTo(other: LatLng): Double {
	return GeoUtils.haversineDistance(this, other)		return GeoUtils.haversineDistance(this, other)
	}		}

			fun fastDistanceTo(other: LatLng): Double {
			return GeoUtils.fastDistance(this, other)
			}
	}		}
			No newline at end of file

cardinal-android/app/src/main/java/earth/maps/cardinal/routing/RoutingOptions.kt

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -36,6 +36,7 @@ abstract class RoutingOptions {
	val gson = GsonBuilder().setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)		val gson = GsonBuilder().setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
	.create()		.create()
	val wrapper = object {		val wrapper = object {
			val alternates = 5
	val costing_options = mapOf(costingType to this@RoutingOptions)		val costing_options = mapOf(costingType to this@RoutingOptions)
	}		}
	return gson.toJson(wrapper)		return gson.toJson(wrapper)

cardinal-android/app/src/main/java/earth/maps/cardinal/ui/util/AnnotationPlacer.kt

0 → 100644

+12 −0

Original line number	Original line	Diff line number	Diff line
			package earth.maps.cardinal.ui.util

			import earth.maps.cardinal.data.LatLng
			import uniffi.ferrostar.GeographicCoordinate
			import javax.inject.Inject

			class AnnotationPlacer @Inject constructor() {

			fun placeAnnotations(routes: List<List<LatLng>>): List<LatLng> {
			return emptyList()
			}
			}

cardinal-android/app/src/test/java/earth/maps/cardinal/data/GeoUtilsTest.kt

+60 −0

Original line number	Original line	Diff line number	Diff line
	@@ -124,4 +124,64 @@ class GeoUtilsTest {
	assertEquals(center.longitude + lonDelta, boundingBox.east, 0.01)		assertEquals(center.longitude + lonDelta, boundingBox.east, 0.01)
	assertEquals(center.longitude - lonDelta, boundingBox.west, 0.01)		assertEquals(center.longitude - lonDelta, boundingBox.west, 0.01)
	}		}

			@Test
			fun fastDistance_samePoint() {
			val latLng1 = LatLng(37.7749, -122.4194) // San Francisco
			val latLng2 = LatLng(37.7749, -122.4194) // Same point
			val expectedDistance = 0.0
			val actualDistance = GeoUtils.fastDistance(latLng1, latLng2)
			assertEquals(expectedDistance, actualDistance, 0.01)
			}

			@Test
			fun fastDistance_shortDistance_equals_haversine() {
			// Short distance between two nearby points in San Francisco
			val point1 = LatLng(37.7749, -122.4194)
			val point2 = LatLng(37.7750, -122.4195) // About 14m apart
			val expectedDistance = GeoUtils.haversineDistance(point1, point2)
			val actualDistance = GeoUtils.fastDistance(point1, point2)
			assertEquals(expectedDistance, actualDistance, 0.01)
			}


			@Test
			fun fastDistance_shortDistance() {
			// Short distance between two nearby points in San Francisco
			val point1 = LatLng(37.7749, -122.4194)
			val point2 = LatLng(37.7750, -122.4195) // About 14m apart
			val expectedDistance = 14.173617226379271
			val actualDistance = GeoUtils.fastDistance(point1, point2)
			assertEquals(expectedDistance, actualDistance, 0.01)
			}

			@Test
			fun fastDistance_mediumDistance() {
			// Distance between San Francisco and Oakland (across the bay)
			val sf = LatLng(37.7749, -122.4194)
			val oakland = LatLng(37.8044, -122.2711)
			val expectedDistance = 13438.14841287118
			val actualDistance = GeoUtils.fastDistance(sf, oakland)
			assertEquals(expectedDistance, actualDistance, 0.01)
			}

			@Test
			fun fastDistance_longDistance() {
			// Distance between New York City and Los Angeles
			val nyc = LatLng(40.7128, -74.0060)
			val la = LatLng(34.0522, -118.2437)
			val expectedDistance = 3978193.533035539
			val actualDistance = GeoUtils.fastDistance(nyc, la)
			assertEquals(expectedDistance, actualDistance, 0.01)
			}

			@Test
			fun fastDistance_highLatitude() {
			// Test at high latitude (near Arctic Circle)
			val point1 = LatLng(66.5, 0.0)
			val point2 = LatLng(66.6, 0.1)
			val expectedDistance = 11967.60736579976
			val actualDistance = GeoUtils.fastDistance(point1, point2)
			assertEquals(expectedDistance, actualDistance, 0.01)
			}
	}		}