Merge remote-tracking branch 'refs/remotes/origin/main'

frontend/src/lib/gps.ts

@@ -0,0 +1,62 @@
+export type Coordinates = {
+    latitude: number
+    longitude: number
+}
+
+function geolocation_to_simple_coords(coordinates: GeolocationCoordinates): Coordinates {
+    return { latitude: coordinates.latitude, longitude: coordinates.longitude }
+}
+
+export function get_coords(): Promise<{ coords: Coordinates | null, error: string | null }> {
+    return new Promise((resolve) => {
+        if (!navigator.geolocation) {
+            resolve({ coords: null, error: "Geolocation is not supported by your browser" })
+            return
+        }
+
+        const error_callback = (gps_error: GeolocationPositionError) => {
+            console.log(gps_error)
+            resolve({
+                coords: null,
+                error: `Unable to retrieve your location: (${gps_error.message})`
+            })
+            return
+        }
+
+        const success_callback = (gps_position: GeolocationPosition) => {
+            resolve({
+                coords: geolocation_to_simple_coords(gps_position.coords),
+                error: null
+            })
+            return
+        }
+
+        navigator.geolocation.getCurrentPosition(success_callback, error_callback)
+    })
+}
+
+function distance_between_coords(
+    lhs: Coordinates,
+    rhs: Coordinates
+): number {
+    const R = 6371000; // earth radius in meters
+    const to_rad = (deg: number) => (deg * Math.PI) / 180;
+
+    const d_lat = to_rad(rhs.latitude - lhs.latitude);
+    const d_lon = to_rad(rhs.longitude - lhs.longitude);
+
+    const a =
+        Math.sin(d_lat / 2) ** 2 +
+        Math.cos(to_rad(lhs.latitude)) *
+        Math.cos(to_rad(rhs.latitude)) *
+        Math.sin(d_lon / 2) ** 2;
+
+    const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+
+    return R * c; // distance in meters
+}
+
+export function is_within_range(my_coords: Coordinates, target_coords: Coordinates, max_range: number): boolean {
+    const distance = distance_between_coords(my_coords, target_coords)
+    return distance <= max_range
+}

frontend/src/routes/zesty/gps/+page.svelte

@@ -0,0 +1,17 @@
+<script lang="ts">
+    import { onMount } from "svelte"
+    import { get_coords, is_within_range, type Coordinates } from "$lib/gps"
+
+    let lido_schenna_coords: Coordinates = { latitude: 46.6769043, longitude: 11.1851585 }
+
+    onMount(async () => {
+        let { coords, error } = await get_coords()
+        console.log(coords)
+        if (error != null) {
+            return console.log(error)
+        }
+        if (coords == null) return
+
+        console.log(is_within_range(coords, lido_schenna_coords, 103))
+    })
+</script>