make packages for dart and npm

2026-04-16 17:48:43 +03:00
parent 9f2a03a979
commit 34dd9ee35a
21 changed files with 1292 additions and 56 deletions
@@ -0,0 +1,43 @@
+/**
+ * Utilities for Intaleq Map SDK.
+ */
+export class PolylineUtils {
+    /**
+     * Decodes a Google-encoded polyline string into an array of [lng, lat] coordinates.
+     * Note: MapLibre and GeoJSON use [lng, lat] while Google/Flutter use [lat, lng].
+     */
+    static decode(encoded: string): [number, number][] {
+        const points: [number, number][] = [];
+        let index = 0;
+        const len = encoded.length;
+        let lat = 0;
+        let lng = 0;
+
+        while (index < len) {
+            let b: number;
+            let shift = 0;
+            let result = 0;
+            do {
+                b = encoded.charCodeAt(index++) - 63;
+                result |= (b & 0x1f) << shift;
+                shift += 5;
+            } while (b >= 0x20);
+            const dlat = ((result & 1) !== 0 ? ~(result >> 1) : (result >> 1));
+            lat += dlat;
+
+            shift = 0;
+            result = 0;
+            do {
+                b = encoded.charCodeAt(index++) - 63;
+                result |= (b & 0x1f) << shift;
+                shift += 5;
+            } while (b >= 0x20);
+            const dlng = ((result & 1) !== 0 ? ~(result >> 1) : (result >> 1));
+            lng += dlng;
+
+            // MapLibre uses [lng, lat]
+            points.push([lng / 1E5, lat / 1E5]);
+        }
+        return points;
+    }
+}