progress

gpx-rs/src/utils.rs

@@ -0,0 +1,24 @@
+use std::f64::consts::PI;
+
+use crate::gpx::LngLat;
+
+static TO_RADIANS: f64 = PI / 180.0;
+static EARTH_RADIUS: f64 = 6371.0088;
+
+/// Computes the distance in kilometers between two coordinates using the Haversine formula
+pub fn distance(coord1: &LngLat, coord2: &LngLat) -> f64 {
+    let lat1 = coord1.lat * TO_RADIANS;
+    let lat2 = coord2.lat * TO_RADIANS;
+    let delta_lat = lat2 - lat1;
+    let delta_lng = (coord2.lng - coord1.lng) * TO_RADIANS;
+
+    let a =
+        (delta_lat / 2.0).sin().powi(2) + lat1.cos() * lat2.cos() * (delta_lng / 2.0).sin().powi(2);
+    let c = 2.0 * a.min(1.0).sqrt().asin();
+    EARTH_RADIUS * c
+}
+
+/// Computes the speed for a given distance in kilometers and a time in milliseconds
+pub fn speed(distance: f64, time: i64) -> f64 {
+    distance / (time as f64 / 3600_000.0)
+}