feat: Improve accuracy of polyline click, and refactor variable naming and eliminate duplicate functions in core module.

.claude/settings.local.json

@@ -15,7 +15,8 @@
       "Bash(find:*)",
       "Bash(for:*)",
       "WebFetch(domain:github.com)",
-      "Bash(grep:*)"
+      "Bash(grep:*)",
+      "Bash(rm:*)"
     ],
     "deny": [],
     "ask": []

example-app/src/main/java/com/mapconductor/example/MainActivity.kt

@@ -12,7 +12,7 @@ class MainActivity : ComponentActivity() {
 
         setContent {
             DemoAppScreen(
-//                initPage = "marker-animation",
+//                initPage = "polyline-click",
                 initPage = "startup",
             )
         }

example-app/src/main/java/com/mapconductor/example/pages/circle/CirclePageViewModel.kt

@@ -15,8 +15,8 @@ import com.mapconductor.core.map.MapCameraPositionImpl
 import com.mapconductor.core.map.MapViewState
 import com.mapconductor.core.marker.DefaultIcon
 import com.mapconductor.core.marker.MarkerState
+import com.mapconductor.core.spherical.WGS84Geodesic.computeDistanceBetween
 import com.mapconductor.core.spherical.calculatePositionAtDistance
-import com.mapconductor.core.spherical.haversineDistance
 import com.mapconductor.example.toast.ToastMessage
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -119,7 +119,7 @@ class CirclePageViewModelImpl :
         get() = _edgeMarker.value
 
     override val radiusMeters by derivedStateOf {
-        haversineDistance(circleCenter, _edgeMarker.value.position)
+        computeDistanceBetween(circleCenter, _edgeMarker.value.position)
     }
 
     override val circleState: CircleState

example-app/src/main/java/com/mapconductor/example/pages/map/visibleregion/VisibleRegionMapComponent.kt

@@ -53,6 +53,7 @@ import com.mapconductor.core.map.OnMapLoadedHandler
 import com.mapconductor.core.marker.ColorDefaultIcon
 import com.mapconductor.core.marker.Marker
 import com.mapconductor.core.marker.MarkerState
+import com.mapconductor.core.spherical.WGS84Geodesic.computeDistanceBetween
 import com.mapconductor.example.MapViewContainer
 import android.annotation.SuppressLint
 import android.content.ClipData
@@ -471,14 +472,14 @@ private fun createVisibleRegionInfo(visibleRegion: com.mapconductor.core.map.Vis
     }
 
     val widthKm =
-        calculateDistance(
-            bounds.southWest!!.latitude, bounds.southWest!!.longitude,
-            bounds.southWest!!.latitude, bounds.northEast!!.longitude,
+        computeDistanceBetween(
+            bounds.southWest!!,
+            GeoPointImpl(bounds.southWest!!.latitude, bounds.northEast!!.longitude),
         )
     val heightKm =
-        calculateDistance(
-            bounds.southWest!!.latitude, bounds.southWest!!.longitude,
-            bounds.northEast!!.latitude, bounds.southWest!!.longitude,
+        computeDistanceBetween(
+            bounds.southWest!!,
+            GeoPointImpl(bounds.northEast!!.latitude, bounds.southWest!!.longitude),
         )
 
     return VisibleRegionInfo(
@@ -489,20 +490,3 @@ private fun createVisibleRegionInfo(visibleRegion: com.mapconductor.core.map.Vis
         heightKm = heightKm,
     )
 }
-
-private fun calculateDistance(
-    lat1: Double,
-    lon1: Double,
-    lat2: Double,
-    lon2: Double,
-): Double {
-    val earthRadius = 6371.0
-    val dLat = Math.toRadians(lat2 - lat1)
-    val dLon = Math.toRadians(lon2 - lon1)
-    val a =
-        kotlin.math.sin(dLat / 2) * kotlin.math.sin(dLat / 2) +
-            kotlin.math.cos(Math.toRadians(lat1)) * kotlin.math.cos(Math.toRadians(lat2)) *
-            kotlin.math.sin(dLon / 2) * kotlin.math.sin(dLon / 2)
-    val c = 2 * kotlin.math.atan2(kotlin.math.sqrt(a), kotlin.math.sqrt(1 - a))
-    return earthRadius * c
-}

example-app/src/main/java/com/mapconductor/example/pages/map/visibleregion/VisibleRegionViewModel.kt

@@ -3,9 +3,11 @@ package com.mapconductor.example.pages.map.visibleregion
 import androidx.compose.runtime.State
 import androidx.compose.runtime.mutableStateOf
 import androidx.lifecycle.ViewModel
+import com.mapconductor.core.features.GeoPointImpl
 import com.mapconductor.core.map.MapCameraPosition
 import com.mapconductor.core.map.MapViewState
 import com.mapconductor.core.map.VisibleRegion
+import com.mapconductor.core.spherical.WGS84Geodesic.computeDistanceBetween
 
 interface VisibleRegionViewModel {
     val mapViewState: State<MapViewState<*>?>
@@ -110,14 +112,14 @@ class VisibleRegionViewModelImpl :
         val centerString = "Center: (${String.format("%.6f", centerLat)}, ${String.format("%.6f", centerLng)})"
 
         val widthKm =
-            calculateDistance(
-                bounds.southWest!!.latitude, bounds.southWest!!.longitude,
-                bounds.southWest!!.latitude, bounds.northEast!!.longitude,
+            computeDistanceBetween(
+                bounds.southWest!!,
+                GeoPointImpl(bounds.southWest!!.latitude, bounds.northEast!!.longitude),
             )
         val heightKm =
-            calculateDistance(
-                bounds.southWest!!.latitude, bounds.southWest!!.longitude,
-                bounds.northEast!!.latitude, bounds.southWest!!.longitude,
+            computeDistanceBetween(
+                bounds.southWest!!,
+                GeoPointImpl(bounds.northEast!!.latitude, bounds.southWest!!.longitude),
             )
 
         return VisibleRegionInfo(
@@ -128,21 +130,4 @@ class VisibleRegionViewModelImpl :
             heightKm = heightKm,
         )
     }
-
-    private fun calculateDistance(
-        lat1: Double,
-        lon1: Double,
-        lat2: Double,
-        lon2: Double,
-    ): Double {
-        val earthRadius = 6371.0 // Earth's radius in kilometers
-        val dLat = Math.toRadians(lat2 - lat1)
-        val dLon = Math.toRadians(lon2 - lon1)
-        val a =
-            kotlin.math.sin(dLat / 2) * kotlin.math.sin(dLat / 2) +
-                kotlin.math.cos(Math.toRadians(lat1)) * kotlin.math.cos(Math.toRadians(lat2)) *
-                kotlin.math.sin(dLon / 2) * kotlin.math.sin(dLon / 2)
-        val c = 2 * kotlin.math.atan2(kotlin.math.sqrt(a), kotlin.math.sqrt(1 - a))
-        return earthRadius * c
-    }
 }

example-app/src/main/java/com/mapconductor/example/pages/map/visibleregion/ZoomCalibrationPage.kt

@@ -36,12 +36,9 @@ import com.mapconductor.arcgis.ArcGISMapView
 import com.mapconductor.arcgis.rememberArcGISMapViewState
 import com.mapconductor.core.features.GeoPointImpl
 import com.mapconductor.core.map.MapCameraPositionImpl
+import com.mapconductor.core.spherical.WGS84Geodesic.computeDistanceBetween
 import com.mapconductor.googlemaps.GoogleMapsView
 import com.mapconductor.googlemaps.rememberGoogleMapViewState
-import kotlin.math.atan2
-import kotlin.math.cos
-import kotlin.math.sin
-import kotlin.math.sqrt
 import android.annotation.SuppressLint
 
 @SuppressLint("DefaultLocale")
@@ -583,14 +580,14 @@ private fun createVisibleRegionInfo(visibleRegion: com.mapconductor.core.map.Vis
     }
 
     val widthKm =
-        calculateDistance(
-            bounds.southWest!!.latitude, bounds.southWest!!.longitude,
-            bounds.southWest!!.latitude, bounds.northEast!!.longitude,
+        computeDistanceBetween(
+            bounds.southWest!!,
+            GeoPointImpl(bounds.southWest!!.latitude, bounds.northEast!!.longitude),
         )
     val heightKm =
-        calculateDistance(
-            bounds.southWest!!.latitude, bounds.southWest!!.longitude,
-            bounds.northEast!!.latitude, bounds.southWest!!.longitude,
+        computeDistanceBetween(
+            bounds.southWest!!,
+            GeoPointImpl(bounds.northEast!!.latitude, bounds.southWest!!.longitude),
         )
 
     return VisibleRegionInfo(
@@ -601,20 +598,3 @@ private fun createVisibleRegionInfo(visibleRegion: com.mapconductor.core.map.Vis
         heightKm = heightKm,
     )
 }
-
-private fun calculateDistance(
-    lat1: Double,
-    lon1: Double,
-    lat2: Double,
-    lon2: Double,
-): Double {
-    val earthRadius = 6371.0
-    val dLat = Math.toRadians(lat2 - lat1)
-    val dLon = Math.toRadians(lon2 - lon1)
-    val a =
-        sin(dLat / 2) * sin(dLat / 2) +
-            cos(Math.toRadians(lat1)) * cos(Math.toRadians(lat2)) *
-            sin(dLon / 2) * sin(dLon / 2)
-    val c = 2 * atan2(sqrt(a), sqrt(1 - a))
-    return earthRadius * c
-}

example-app/src/main/java/com/mapconductor/example/pages/polyline/click/PolylineClickMapComponent.kt

@@ -2,6 +2,7 @@ package com.mapconductor.example.pages.polyline
 
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import com.mapconductor.core.map.MapViewState
 import com.mapconductor.core.marker.Marker
 import com.mapconductor.core.marker.MarkerState
@@ -26,6 +27,13 @@ fun PolylineClickMapComponent(
         ) {
             // Polyline
             Polyline(polylineState)
+            Polyline(
+                polylineState.copy(
+                    id = "${polylineState.id}-straight",
+                    geodesic = false,
+                    strokeColor = Color.Blue,
+                ),
+            )
 
             // Waypoint markers
             markers.forEach { marker ->

example-app/src/main/java/com/mapconductor/example/pages/polyline/click/PolylineClickMapPage.kt

@@ -44,7 +44,7 @@ fun PolylineClickMapPage(onToggleSidebar: () -> Unit = {}) {
                         end = paddingValues.calculateEndPadding(LayoutDirection.Ltr) + 16.dp,
                     ),
         ) {
-            Text("Tap on the curved polyline")
+            Text("Tap on the curved polyline. A marker would be placed on the tapped polyline.")
         }
     }
 }

example-app/src/main/java/com/mapconductor/example/pages/polyline/click/PolylineClickPageViewModel.kt

@@ -7,7 +7,7 @@ import androidx.lifecycle.ViewModel
 import com.mapconductor.core.features.GeoPointImpl
 import com.mapconductor.core.map.MapCameraPositionImpl
 import com.mapconductor.core.map.MapViewState
-import com.mapconductor.core.marker.MarkerAnimation
+import com.mapconductor.core.marker.DefaultIcon
 import com.mapconductor.core.marker.MarkerState
 import com.mapconductor.core.polyline.PolylineEvent
 import com.mapconductor.core.polyline.PolylineState
@@ -65,6 +65,7 @@ class PolylineClickPageViewModelImpl :
     override val mapViewState: StateFlow<MapViewState<*>?> = _mapViewState.asStateFlow()
 
     override fun onMapViewChanged(state: MapViewState<*>) {
+        _markers.value = emptyList<MarkerState>()
         mapViewState.value?.cameraPosition?.value?.let {
             state.moveCameraTo(it)
         }
@@ -75,7 +76,10 @@ class PolylineClickPageViewModelImpl :
         _markers.value = _markers.value +
             MarkerState(
                 position = clicked.clicked,
-                animation = MarkerAnimation.Drop,
+                icon =
+                    DefaultIcon(
+                        fillColor = clicked.state.strokeColor,
+                    ),
             )
     }
 

gradle/libs.versions.toml

@@ -34,6 +34,7 @@ ktLint = "13.1.0"
 uiToolingPreviewAndroid = "1.9.1"
 uiToolingPreview = "1.9.1"
 uiTooling = "1.9.1"
+geographiclib = "2.1"
 
 [libraries]
 # Android 基本
@@ -84,6 +85,8 @@ androidx-compose-ui-tooling-preview-android = { group = "androidx.compose.ui", n
 androidx-compose-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview", version.ref = "uiToolingPreview" }
 androidx-compose-ui-tooling = { group = "androidx.compose.ui", name = "ui-tooling", version.ref = "uiTooling" }
 
+net-sf-geographiclib = { group = "net.sf.geographiclib", name="GeographicLib-Java", version.ref="geographiclib"}
+
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
 kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }

mapconductor-core/build.gradle.kts

@@ -66,6 +66,7 @@ dependencies {
     implementation(libs.androidx.ui.tooling.preview)
     implementation(platform(libs.androidx.compose.bom))
     implementation(libs.androidx.foundation)
+    implementation(libs.net.sf.geographiclib)
 
     // Core dependencies - use api to avoid version conflicts
     api(libs.androidx.core.ktx)