progress

gpx-rs/engine/src/core/gpx/common.rs

@@ -10,7 +10,7 @@ pub struct LngLat {
     pub lat: f64,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
 pub struct LngLatBounds {
     pub sw: LngLat,
     pub ne: LngLat,

gpx-rs/engine/src/core/statistics/statistics.rs

@@ -41,6 +41,10 @@ impl Statistics {
         self.accumulate_distance_and_time(prev, cur);
         self.update_time_bounds(cur.time);
         self.update_bounds(cur.coordinates);
+        self.global.hr.add(cur.hr.map(f64::from));
+        self.global.cad.add(cur.cad.map(f64::from));
+        self.global.atemp.add(cur.atemp.map(f64::from));
+        self.global.power.add(cur.power.map(f64::from));
         self.local
             .push(TrackpointStatistics::from_partial_stats(self));
     }
@@ -207,17 +211,47 @@ impl Statistics {
     }
 }
 
+/// Average of an optional measure (heart rate, cadence...) over the trackpoints that have it.
+/// Keeps the sum so that averages can be merged.
+#[derive(Default, Debug, Clone, Copy, PartialEq)]
+pub struct Average {
+    pub sum: f64,
+    pub count: u32,
+}
+
+impl Average {
+    pub fn add(&mut self, value: Option<f64>) {
+        if let Some(value) = value {
+            self.sum += value;
+            self.count += 1;
+        }
+    }
+
+    pub fn merge(&mut self, other: &Average) {
+        self.sum += other.sum;
+        self.count += other.count;
+    }
+
+    pub fn avg(&self) -> Option<f64> {
+        (self.count > 0).then(|| self.sum / self.count as f64)
+    }
+}
+
 #[derive(Default, Debug)]
 pub struct GlobalStatistics {
     pub total_distance: f64,
     pub moving_distance: Option<f64>,
-    pub total_time: Option<i32>,
-    pub moving_time: Option<i32>,
+    pub total_time: Option<i64>,
+    pub moving_time: Option<i64>,
     pub elevation_gain: f64,
     pub elevation_loss: f64,
     pub start_time: Option<i64>,
     pub end_time: Option<i64>,
     pub bounds: LngLatBounds,
+    pub hr: Average,
+    pub cad: Average,
+    pub atemp: Average,
+    pub power: Average,
 }
 
 impl GlobalStatistics {
@@ -241,6 +275,10 @@ impl GlobalStatistics {
         self.start_time = min_options(self.start_time, other.start_time);
         self.end_time = max_options(self.end_time, other.end_time);
         self.bounds.merge(&other.bounds);
+        self.hr.merge(&other.hr);
+        self.cad.merge(&other.cad);
+        self.atemp.merge(&other.atemp);
+        self.power.merge(&other.power);
     }
 }
 
@@ -248,8 +286,8 @@ impl GlobalStatistics {
 pub struct TrackpointStatistics {
     pub total_distance: f64,
     pub moving_distance: Option<f64>,
-    pub total_time: Option<i32>,
-    pub moving_time: Option<i32>,
+    pub total_time: Option<i64>,
+    pub moving_time: Option<i64>,
     pub speed: Option<f64>,
     pub elevation_gain: f64,
     pub elevation_loss: f64,
@@ -417,4 +455,50 @@ mod tests {
         assert_eq!(cumul.total_time, Some(7_000));
         assert_eq!((a.bounds.ne.lng, a.bounds.ne.lat), (2.0, 3.0));
     }
+
+    #[test]
+    fn test_average() {
+        let mut average = Average::default();
+        assert_eq!(average.avg(), None);
+        average.add(None);
+        assert_eq!(average.avg(), None);
+        average.add(Some(100.0));
+        average.add(Some(110.0));
+        assert_eq!(average.avg(), Some(105.0));
+
+        let mut other = Average::default();
+        other.add(Some(130.0));
+        average.merge(&other);
+        assert_eq!(average.count, 3);
+        assert_eq!(average.avg(), Some(113.33333333333333));
+    }
+
+    #[test]
+    fn test_measures_of_the_trackpoints_are_averaged() {
+        for (path, measure) in [
+            ("data/with_hr.gpx", 0),
+            ("data/with_cad.gpx", 1),
+            ("data/with_temp.gpx", 2),
+            ("data/with_power_1.gpx", 3),
+        ] {
+            let data = std::fs::read(path).unwrap();
+            let gpx = parse(&data).unwrap();
+            let trkseg = &gpx.trk[0].trkseg[0];
+            let global = Statistics::compute(trkseg).global;
+            let values: Vec<f64> = trkseg
+                .iter()
+                .filter_map(|trkpt| match measure {
+                    0 => trkpt.hr.map(f64::from),
+                    1 => trkpt.cad.map(f64::from),
+                    2 => trkpt.atemp.map(f64::from),
+                    _ => trkpt.power.map(f64::from),
+                })
+                .collect();
+            let average = [global.hr, global.cad, global.atemp, global.power][measure];
+            assert!(!values.is_empty(), "{path}");
+            assert_eq!(average.count as usize, values.len(), "{path}");
+            let expected = values.iter().sum::<f64>() / values.len() as f64;
+            assert!((average.avg().unwrap() - expected).abs() < 1e-9, "{path}");
+        }
+    }
 }

gpx-rs/engine/src/core/utils.rs

@@ -18,12 +18,12 @@ pub fn distance(p1: LngLat, p2: LngLat) -> f64 {
     EARTH_RADIUS * c
 }
 
-pub fn time_diff(a: Option<i64>, b: Option<i64>) -> Option<i32> {
-    Some((a? - b?) as i32)
+pub fn time_diff(a: Option<i64>, b: Option<i64>) -> Option<i64> {
+    Some(a? - b?)
 }
 
 /// Computes the speed for a given distance in kilometers and a time in milliseconds
-pub fn speed(distance: f64, time: i32) -> f64 {
+pub fn speed(distance: f64, time: i64) -> f64 {
     distance / (time as f64 / 3_600_000.0)
 }
 
@@ -115,6 +115,19 @@ mod tests {
         LngLat { lng, lat }
     }
 
+    #[test]
+    fn test_time_diff_and_speed_with_long_durations() {
+        // 40 days in milliseconds, more than an i32 can hold
+        let forty_days = 40 * 24 * 3_600_000_i64;
+        assert!(forty_days > i64::from(i32::MAX));
+        assert_eq!(time_diff(Some(forty_days), Some(0)), Some(forty_days));
+        assert_eq!(time_diff(Some(0), Some(forty_days)), Some(-forty_days));
+        assert_eq!(time_diff(None, Some(1)), None);
+        assert_eq!(time_diff(Some(1), None), None);
+        // 1 km in one hour
+        assert!((speed(1.0, 3_600_000) - 1.0).abs() < 1e-12);
+    }
+
     #[test]
     fn test_distance() {
         assert_eq!(distance(p(4.0, 50.0), p(4.0, 50.0)), 0.0);

gpx-rs/engine/src/engine/derived/statistics_buffer.rs

@@ -1,21 +1,52 @@
-use crate::{GlobalStatistics, Statistics, sum_options};
+use crate::{GlobalStatistics, Statistics, TrackSegment, sum_options};
 
+/// Value of the timestamps of the trackpoints that have none.
+pub const NO_TIME: i64 = i64::MIN;
+
+/// Flattened statistics of the selected segments, one entry per trackpoint, in selection order.
+///
+/// The distance, time, moving and elevation values are cumulative over the whole selection (the
+/// second segment continues where the first one ended), so the statistics of any range of
+/// trackpoints are the difference between its two ends: see [`StatisticsBuffer::slice`].
+/// Times are in milliseconds, distances in kilometers, speeds in km/h. Missing times are
+/// [`NO_TIME`], missing measures are NaN.
 #[derive(Debug, Default)]
 pub struct StatisticsBuffer {
+    /// Statistics of the whole selection.
+    pub global: GlobalStatistics,
     pub total_distance: Vec<f64>,
     pub moving_distance: Vec<f64>,
-    pub total_time: Vec<i32>,
-    pub moving_time: Vec<i32>,
+    pub total_time: Vec<i64>,
+    pub moving_time: Vec<i64>,
     pub speed: Vec<f64>,
     pub elevation_gain: Vec<f64>,
     pub elevation_loss: Vec<f64>,
     pub slope: Vec<f64>,
     pub slope_segment_slope: Vec<f64>,
     pub slope_segment_distance: Vec<f64>,
+    pub lng: Vec<f64>,
+    pub lat: Vec<f64>,
+    pub ele: Vec<f64>,
+    /// Timestamps, in milliseconds since the epoch.
+    pub time: Vec<i64>,
+    pub hr: Vec<f64>,
+    pub cad: Vec<f64>,
+    pub atemp: Vec<f64>,
+    pub power: Vec<f64>,
 }
 
 impl StatisticsBuffer {
-    pub fn update(&mut self, stats: &[&Statistics]) {
+    pub fn len(&self) -> usize {
+        self.total_distance.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.total_distance.is_empty()
+    }
+
+    /// `selected`: the segments and their statistics, in order.
+    pub fn update(&mut self, selected: &[(&TrackSegment, &Statistics)]) {
+        self.global = GlobalStatistics::default();
         self.total_distance.clear();
         self.moving_distance.clear();
         self.total_time.clear();
@@ -26,10 +57,20 @@ impl StatisticsBuffer {
         self.slope.clear();
         self.slope_segment_slope.clear();
         self.slope_segment_distance.clear();
+        self.lng.clear();
+        self.lat.clear();
+        self.ele.clear();
+        self.time.clear();
+        self.hr.clear();
+        self.cad.clear();
+        self.atemp.clear();
+        self.power.clear();
 
-        let mut cumul_stats = GlobalStatistics::default();
-        for stats in stats {
-            for trkpt_stats in stats.local.iter() {
+        let optional = |value: Option<f64>| value.unwrap_or(f64::NAN);
+
+        for (segment, stats) in selected {
+            for (trkpt, trkpt_stats) in segment.iter().zip(stats.local.iter()) {
+                let cumul_stats = &self.global;
                 self.total_distance
                     .push(cumul_stats.total_distance + trkpt_stats.total_distance);
                 self.moving_distance.push(
@@ -53,10 +94,55 @@ impl StatisticsBuffer {
                     .push(trkpt_stats.slope_segment.slope);
                 self.slope_segment_distance
                     .push(trkpt_stats.slope_segment.distance);
+                self.lng.push(trkpt.coordinates.lng);
+                self.lat.push(trkpt.coordinates.lat);
+                self.ele.push(trkpt.ele);
+                self.time.push(trkpt.time.unwrap_or(NO_TIME));
+                self.hr.push(optional(trkpt.hr.map(f64::from)));
+                self.cad.push(optional(trkpt.cad.map(f64::from)));
+                self.atemp.push(optional(trkpt.atemp.map(f64::from)));
+                self.power.push(optional(trkpt.power.map(f64::from)));
             }
-            cumul_stats.merge(&stats.global);
+            self.global.merge(&stats.global);
         }
     }
+
+    /// Statistics of the trackpoints from `start` to `end` (both included) of the selection, for
+    /// example the part of an elevation profile the user dragged over. `None` if the range is
+    /// not inside the selection.
+    ///
+    /// It is done in constant time, from the cumulative values at both ends: the bounds and
+    /// the averages are the ones of the whole selection, they are not computed for the range.
+    pub fn slice(&self, start: usize, end: usize) -> Option<GlobalStatistics> {
+        if start > end || end >= self.len() {
+            return None;
+        }
+
+        let delta = |values: &[f64]| values[end] - values[start];
+        let delta_time = |values: &[i64]| values[end] - values[start];
+        let time = |i: usize| (self.time[i] != NO_TIME).then_some(self.time[i]);
+        Some(GlobalStatistics {
+            total_distance: delta(&self.total_distance),
+            moving_distance: self
+                .global
+                .moving_distance
+                .map(|_| delta(&self.moving_distance)),
+            total_time: self.global.total_time.map(|_| delta_time(&self.total_time)),
+            moving_time: self
+                .global
+                .moving_time
+                .map(|_| delta_time(&self.moving_time)),
+            elevation_gain: delta(&self.elevation_gain),
+            elevation_loss: delta(&self.elevation_loss),
+            start_time: time(start),
+            end_time: time(end),
+            bounds: self.global.bounds,
+            hr: self.global.hr,
+            cad: self.global.cad,
+            atemp: self.global.atemp,
+            power: self.global.power,
+        })
+    }
 }
 
 #[cfg(test)]
@@ -65,28 +151,16 @@ mod tests {
 
     use super::*;
 
-    fn stats(path: &str) -> Statistics {
+    fn computed(path: &str) -> (TrackSegment, Statistics) {
         let data = std::fs::read(path).unwrap();
         let file = parse(&data).unwrap();
-        Statistics::compute(&file.trk[0].trkseg[0])
+        let segment = file.trk[0].trkseg[0].clone();
+        let stats = Statistics::compute(&segment);
+        (segment, stats)
     }
 
-    #[test]
-    fn test_empty() {
-        let mut buffer = StatisticsBuffer::default();
-        buffer.update(&[]);
-        assert!(buffer.total_distance.is_empty());
-        assert!(buffer.speed.is_empty());
-    }
-
-    #[test]
-    fn test_single_segment_matches_local_stats() {
-        let s = stats("data/simple.gpx");
-        let mut buffer = StatisticsBuffer::default();
-        buffer.update(&[&s]);
-
-        let n = s.local.len();
-        for len in [
+    fn all_lengths(buffer: &StatisticsBuffer) -> Vec<usize> {
+        vec![
             buffer.total_distance.len(),
             buffer.moving_distance.len(),
             buffer.total_time.len(),
@@ -97,21 +171,76 @@ mod tests {
             buffer.slope.len(),
             buffer.slope_segment_slope.len(),
             buffer.slope_segment_distance.len(),
-        ] {
-            assert_eq!(len, n);
-        }
+            buffer.lng.len(),
+            buffer.lat.len(),
+            buffer.ele.len(),
+            buffer.time.len(),
+            buffer.hr.len(),
+            buffer.cad.len(),
+            buffer.atemp.len(),
+            buffer.power.len(),
+        ]
+    }
+
+    #[test]
+    fn test_empty() {
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[]);
+        assert!(buffer.is_empty());
+        assert!(buffer.speed.is_empty());
+        assert_eq!(buffer.global.total_distance, 0.0);
+        assert!(buffer.slice(0, 0).is_none());
+    }
+
+    #[test]
+    fn test_single_segment_matches_local_stats() {
+        let (segment, s) = computed("data/simple.gpx");
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s)]);
+
+        let n = s.local.len();
+        assert!(all_lengths(&buffer).iter().all(|len| *len == n));
+        assert_eq!(buffer.len(), n);
         for (i, local) in s.local.iter().enumerate() {
             assert_eq!(buffer.total_distance[i], local.total_distance);
             assert_eq!(buffer.slope[i], local.slope);
         }
+        // the trackpoints
+        for (i, trkpt) in segment.iter().enumerate() {
+            assert_eq!(buffer.lng[i], trkpt.coordinates.lng);
+            assert_eq!(buffer.lat[i], trkpt.coordinates.lat);
+            assert_eq!(buffer.ele[i], trkpt.ele);
+        }
+    }
+
+    #[test]
+    fn test_global_is_the_merge_of_the_segments() {
+        let (segment, s) = computed("data/simple.gpx");
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s), (&segment, &s)]);
+
+        let global = &buffer.global;
+        assert!((global.total_distance - 2.0 * s.global.total_distance).abs() < 1e-9);
+        assert!((global.elevation_gain - 2.0 * s.global.elevation_gain).abs() < 1e-9);
+        assert!((global.elevation_loss - 2.0 * s.global.elevation_loss).abs() < 1e-9);
+        // and it is the last cumulative value of the points
+        assert_eq!(
+            global.total_distance,
+            *buffer.total_distance.last().unwrap()
+        );
+
+        buffer.update(&[(&segment, &s)]);
+        assert_eq!(buffer.global.total_distance, s.global.total_distance);
+        buffer.update(&[]);
+        assert_eq!(buffer.global.total_distance, 0.0);
     }
 
     #[test]
     fn test_distances_accumulate_over_segments() {
-        let s = stats("data/simple.gpx");
+        let (segment, s) = computed("data/simple.gpx");
         let n = s.local.len();
         let mut buffer = StatisticsBuffer::default();
-        buffer.update(&[&s, &s]);
+        buffer.update(&[(&segment, &s), (&segment, &s)]);
 
         assert_eq!(buffer.total_distance.len(), 2 * n);
         // the second segment starts where the first one ended
@@ -123,27 +252,156 @@ mod tests {
 
     #[test]
     fn test_total_time_accumulates_over_segments() {
-        let s = stats("data/with_time.gpx");
+        let (segment, s) = computed("data/with_time.gpx");
         let n = s.local.len();
         let duration = s.global.total_time.unwrap();
         assert!(duration > 0);
         let mut buffer = StatisticsBuffer::default();
-        buffer.update(&[&s, &s]);
+        buffer.update(&[(&segment, &s), (&segment, &s)]);
 
         assert_eq!(buffer.total_time[n - 1], duration);
         assert_eq!(buffer.total_time[n], duration);
         assert_eq!(buffer.total_time[2 * n - 1], 2 * duration);
         assert!(buffer.total_time.windows(2).all(|w| w[0] <= w[1]));
+        assert!(buffer.time.iter().all(|t| *t != NO_TIME));
+    }
+
+    #[test]
+    fn test_missing_times_and_measures_are_nan() {
+        let (segment, s) = computed("data/simple.gpx");
+        assert!(segment.iter().all(|trkpt| trkpt.time.is_none()));
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s)]);
+        assert!(buffer.time.iter().all(|t| *t == NO_TIME));
+        assert!(buffer.hr.iter().all(|v| v.is_nan()));
+        assert_eq!(buffer.global.hr.count, 0);
+        assert_eq!(buffer.global.total_time, None);
     }
 
     #[test]
     fn test_update_replaces_previous_content() {
-        let s = stats("data/simple.gpx");
+        let (segment, s) = computed("data/simple.gpx");
         let mut buffer = StatisticsBuffer::default();
-        buffer.update(&[&s]);
-        buffer.update(&[&s]);
+        buffer.update(&[(&segment, &s)]);
+        buffer.update(&[(&segment, &s)]);
         assert_eq!(buffer.total_distance.len(), s.local.len());
+        assert!(all_lengths(&buffer).iter().all(|len| *len == s.local.len()));
         buffer.update(&[]);
         assert!(buffer.total_distance.is_empty());
+        assert!(all_lengths(&buffer).iter().all(|len| *len == 0));
+    }
+
+    #[test]
+    fn test_slice_of_the_whole_selection_is_the_global_statistics() {
+        let (segment, s) = computed("data/with_time.gpx");
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s), (&segment, &s)]);
+
+        let slice = buffer.slice(0, buffer.len() - 1).unwrap();
+        let global = &buffer.global;
+        assert!((slice.total_distance - global.total_distance).abs() < 1e-9);
+        assert!((slice.elevation_gain - global.elevation_gain).abs() < 1e-9);
+        assert!((slice.elevation_loss - global.elevation_loss).abs() < 1e-9);
+        assert_eq!(slice.total_time, global.total_time);
+        assert_eq!(slice.moving_time, global.moving_time);
+        assert_eq!(slice.start_time, global.start_time);
+        assert_eq!(slice.end_time, global.end_time);
+    }
+
+    #[test]
+    fn test_slice_of_a_range() {
+        let (segment, s) = computed("data/with_time.gpx");
+        let n = s.local.len();
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s)]);
+
+        let (start, end) = (n / 4, n / 2);
+        let slice = buffer.slice(start, end).unwrap();
+        assert!(
+            (slice.total_distance - (buffer.total_distance[end] - buffer.total_distance[start]))
+                .abs()
+                < 1e-12
+        );
+        assert_eq!(
+            slice.total_time,
+            Some(buffer.total_time[end] - buffer.total_time[start])
+        );
+        assert_eq!(
+            slice.moving_time,
+            Some(buffer.moving_time[end] - buffer.moving_time[start])
+        );
+        assert_eq!(slice.start_time, Some(buffer.time[start]));
+        assert_eq!(slice.end_time, Some(buffer.time[end]));
+        assert!(slice.total_distance < buffer.global.total_distance);
+        assert!(slice.total_speed().is_some());
+
+        // a single point has nothing between its ends
+        let point = buffer.slice(start, start).unwrap();
+        assert_eq!(point.total_distance, 0.0);
+        assert_eq!(point.total_time, Some(0));
+    }
+
+    #[test]
+    fn test_slice_keeps_the_bounds_and_averages_of_the_selection() {
+        let data = std::fs::read("data/with_hr.gpx").unwrap();
+        let file = parse(&data).unwrap();
+        let segment = file.trk[0].trkseg[0].clone();
+        let s = Statistics::compute(&segment);
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s)]);
+        assert!(buffer.global.hr.count > 0);
+
+        let slice = buffer.slice(1, 3).unwrap();
+        let (global, bounds) = (&buffer.global, &slice.bounds);
+        assert_eq!(slice.hr, global.hr);
+        assert_eq!(slice.cad, global.cad);
+        assert_eq!(slice.atemp, global.atemp);
+        assert_eq!(slice.power, global.power);
+        assert_eq!(
+            (bounds.sw.lng, bounds.sw.lat),
+            (global.bounds.sw.lng, global.bounds.sw.lat)
+        );
+        assert_eq!(
+            (bounds.ne.lng, bounds.ne.lat),
+            (global.bounds.ne.lng, global.bounds.ne.lat)
+        );
+    }
+
+    #[test]
+    fn test_durations_are_not_limited_to_24_days() {
+        // 30 days of recording, in milliseconds
+        let (segment, mut s) = computed("data/with_time.gpx");
+        let month = 30 * 24 * 3_600_000_i64;
+        s.global.total_time = Some(month);
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s), (&segment, &s)]);
+        assert_eq!(buffer.global.total_time, Some(2 * month));
+        assert!(2 * month > i64::from(i32::MAX));
+    }
+
+    #[test]
+    fn test_slice_across_segments() {
+        let (segment, s) = computed("data/simple.gpx");
+        let n = s.local.len();
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s), (&segment, &s)]);
+
+        // from the middle of the first segment to the middle of the second one
+        let slice = buffer.slice(n / 2, n + n / 2).unwrap();
+        let expected = buffer.total_distance[n + n / 2] - buffer.total_distance[n / 2];
+        assert!((slice.total_distance - expected).abs() < 1e-9);
+        assert_eq!(slice.total_time, None);
+    }
+
+    #[test]
+    fn test_slice_out_of_range() {
+        let (segment, s) = computed("data/simple.gpx");
+        let mut buffer = StatisticsBuffer::default();
+        buffer.update(&[(&segment, &s)]);
+        let n = buffer.len();
+        assert!(buffer.slice(0, n).is_none());
+        assert!(buffer.slice(n, n).is_none());
+        assert!(buffer.slice(5, 4).is_none());
+        assert!(buffer.slice(0, n - 1).is_some());
     }
 }

gpx-rs/engine/src/engine/derived/statistics_cache.rs

@@ -1,10 +1,13 @@
 use std::collections::{HashMap, HashSet, hash_map::Entry};
 
 use crate::{
-    File, GlobalStatistics, Selection, StackEntry, Statistics, Track, TrackSegment,
+    File, FileId, GlobalStatistics, Selection, StackEntry, Statistics, Track, TrackSegment,
     TrackSegmentRevisionId,
 };
 
+/// A segment and its statistics.
+pub type SelectedSegment<'a> = (&'a TrackSegment, &'a Statistics);
+
 #[derive(Debug, Default)]
 pub struct StatisticsCache {
     map: HashMap<TrackSegmentRevisionId, Statistics>,
@@ -34,19 +37,38 @@ impl StatisticsCache {
         }
     }
 
+    /// Statistics of the segments of the selection.
     pub fn get<'a>(
         &'a self,
-        state: Option<&StackEntry>,
+        state: Option<&'a StackEntry>,
         selection: &Selection,
     ) -> Vec<&'a Statistics> {
-        let mut stats = vec![];
+        self.selected(state, selection, &[])
+            .into_iter()
+            .map(|(_, stats)| stats)
+            .collect()
+    }
+
+    /// The segments of the selection with their statistics. The segments of several selected
+    /// files follow `order` (the files missing from it come last).
+    pub fn selected<'a>(
+        &'a self,
+        state: Option<&'a StackEntry>,
+        selection: &Selection,
+        order: &[FileId],
+    ) -> Vec<SelectedSegment<'a>> {
+        let mut selected = vec![];
         if let Some(state) = state {
             match selection {
                 Selection::Empty => (),
                 Selection::File { file_ids } => {
-                    for id in file_ids.iter() {
+                    let ordered = order
+                        .iter()
+                        .filter(|id| file_ids.contains(id))
+                        .chain(file_ids.iter().filter(|id| !order.contains(id)));
+                    for id in ordered {
                         if let Some(file) = state.get(id) {
-                            self.add_file_stats(file, &mut stats);
+                            self.add_file_stats(file, &mut selected);
                         }
                     }
                 }
@@ -54,7 +76,7 @@ impl StatisticsCache {
                     if let Some(file) = state.get(file_id) {
                         for trk in file.trk.iter() {
                             if trk_ids.contains(&trk.id) {
-                                self.add_track_stats(trk, &mut stats);
+                                self.add_track_stats(trk, &mut selected);
                             }
                         }
                     }
@@ -69,7 +91,7 @@ impl StatisticsCache {
                             if *trk_id == trk.id {
                                 for trkseg in trk.trkseg.iter() {
                                     if trkseg_ids.contains(&trkseg.id) {
-                                        self.add_segment_stats(trkseg, &mut stats);
+                                        self.add_segment_stats(trkseg, &mut selected);
                                     }
                                 }
                                 break;
@@ -79,7 +101,7 @@ impl StatisticsCache {
                 }
                 Selection::Waypoints { file_id } => {
                     if let Some(file) = state.get(file_id) {
-                        self.add_file_stats(file, &mut stats);
+                        self.add_file_stats(file, &mut selected);
                     }
                 }
                 Selection::Waypoint {
@@ -87,40 +109,44 @@ impl StatisticsCache {
                     wpt_ids: _,
                 } => {
                     if let Some(file) = state.get(file_id) {
-                        self.add_file_stats(file, &mut stats);
+                        self.add_file_stats(file, &mut selected);
                     }
                 }
             }
         }
-        stats
+        selected
     }
 
     /// Global statistics of a file: its segments merged, in order.
     pub fn file_global(&self, file: &File) -> GlobalStatistics {
-        let mut stats = vec![];
-        self.add_file_stats(file, &mut stats);
+        let mut selected = vec![];
+        self.add_file_stats(file, &mut selected);
         let mut global = GlobalStatistics::default();
-        for s in stats {
-            global.merge(&s.global);
+        for (_, stats) in selected {
+            global.merge(&stats.global);
         }
         global
     }
 
-    fn add_file_stats<'a>(&'a self, file: &File, stats: &mut Vec<&'a Statistics>) {
+    fn add_file_stats<'a>(&'a self, file: &'a File, selected: &mut Vec<SelectedSegment<'a>>) {
         for trk in file.trk.iter() {
-            self.add_track_stats(trk, stats);
+            self.add_track_stats(trk, selected);
         }
     }
 
-    fn add_track_stats<'a>(&'a self, trk: &Track, stats: &mut Vec<&'a Statistics>) {
+    fn add_track_stats<'a>(&'a self, trk: &'a Track, selected: &mut Vec<SelectedSegment<'a>>) {
         for trkseg in trk.trkseg.iter() {
-            self.add_segment_stats(trkseg, stats);
+            self.add_segment_stats(trkseg, selected);
         }
     }
 
-    fn add_segment_stats<'a>(&'a self, trkseg: &TrackSegment, stats: &mut Vec<&'a Statistics>) {
-        if let Some(s) = self.map.get(&trkseg.rev_id) {
-            stats.push(s);
+    fn add_segment_stats<'a>(
+        &'a self,
+        trkseg: &'a TrackSegment,
+        selected: &mut Vec<SelectedSegment<'a>>,
+    ) {
+        if let Some(stats) = self.map.get(&trkseg.rev_id) {
+            selected.push((trkseg, stats));
         }
     }
 }
@@ -241,4 +267,33 @@ mod tests {
         cache.update(None);
         assert!(cache.map.is_empty());
     }
+
+    #[test]
+    fn test_segments_of_several_files_follow_the_given_order() {
+        let (mut state, first) = state("data/simple.gpx");
+        let (other, second) = {
+            let data = std::fs::read("data/with_time.gpx").unwrap();
+            let file = Rc::new(parse(&data).unwrap());
+            (file.clone(), file)
+        };
+        state.insert(other.id, other);
+        let mut cache = StatisticsCache::default();
+        cache.update(Some(&state));
+        let selection = Selection::File {
+            file_ids: HashSet::from([first.id, second.id]),
+        };
+
+        let ids = |order: &[FileId]| -> Vec<_> {
+            cache
+                .selected(Some(&state), &selection, order)
+                .iter()
+                .map(|(segment, _)| segment.id)
+                .collect()
+        };
+        let (a, b) = (first.trk[0].trkseg[0].id, second.trk[0].trkseg[0].id);
+        assert_eq!(ids(&[first.id, second.id]), vec![a, b]);
+        assert_eq!(ids(&[second.id, first.id]), vec![b, a]);
+        // the files that are not in the order come last
+        assert_eq!(ids(&[second.id]), vec![b, a]);
+    }
 }

gpx-rs/engine/src/engine/engine.rs

@@ -144,7 +144,11 @@ impl Engine {
         self.coordinates_cache.update(current);
         self.structure_cache.update(current, self.diff.as_ref());
         self.statistics_buffer
-            .update(&self.statistics_cache.get(current, &self.selection));
+            .update(
+                &self
+                    .statistics_cache
+                    .selected(current, &self.selection, &self.order.0),
+            );
     }
 }
 

gpx-rs/wasm/src/lib.rs

@@ -14,7 +14,7 @@ use std::cell::RefCell;
 use wasm_bindgen::prelude::*;
 
 use gpx_engine::{self as engine, Action, Command, Engine, FileId, LngLat, LngLatBounds};
-use js_sys::{Array, Float64Array, Int32Array, Object, Reflect};
+use js_sys::{Array, BigInt64Array, Float64Array, Object, Reflect};
 
 #[wasm_bindgen]
 #[derive(Clone, Copy)]
@@ -133,14 +133,36 @@ macro_rules! stats_getter {
 
 stats_getter!(total_distance, Float64Array);
 stats_getter!(moving_distance, Float64Array);
-stats_getter!(total_time, Int32Array);
-stats_getter!(moving_time, Int32Array);
+// Durations since the start of the selection, in milliseconds.
+stats_getter!(total_time, BigInt64Array);
+stats_getter!(moving_time, BigInt64Array);
 stats_getter!(speed, Float64Array);
 stats_getter!(elevation_gain, Float64Array);
 stats_getter!(elevation_loss, Float64Array);
 stats_getter!(slope, Float64Array);
 stats_getter!(slope_segment_slope, Float64Array);
 stats_getter!(slope_segment_distance, Float64Array);
+stats_getter!(lng, Float64Array);
+stats_getter!(lat, Float64Array);
+stats_getter!(ele, Float64Array);
+
+/// Timestamps in milliseconds since the epoch (`NO_TIME`, the smallest i64, when missing).
+#[wasm_bindgen]
+pub fn timestamps() -> BigInt64Array {
+    with_stats(|s| unsafe { BigInt64Array::view(&s.time) })
+        .unwrap_or_else(|| BigInt64Array::new_with_length(0))
+}
+
+/// Value of the timestamps of the trackpoints that have none.
+#[wasm_bindgen]
+pub fn no_time() -> i64 {
+    engine::NO_TIME
+}
+
+stats_getter!(hr, Float64Array);
+stats_getter!(cad, Float64Array);
+stats_getter!(atemp, Float64Array);
+stats_getter!(power, Float64Array);
 
 // File commands
 
@@ -443,8 +465,11 @@ export interface FileStructure {
     /** Changes when the waypoints of the file change: refetch their coordinates. */
     waypointsRev: string;
 }
-/** Global statistics of a file (optional fields are absent when the file has no timestamps). */
-export interface FileStatistics {
+/**
+ * Global statistics of a file, of the selection, or of a part of it. The optional fields are
+ * absent when there is no data for them (no timestamps, no heart rate...).
+ */
+export interface GlobalStatistics {
     /** km */
     totalDistance: number;
     movingDistance?: number;
@@ -459,7 +484,12 @@ export interface FileStatistics {
     /** km/h */
     totalSpeed?: number;
     movingSpeed?: number;
-    /** Absent when the file has no trackpoints. */
+    /** Average and number of trackpoints having the measure. */
+    hr?: { avg: number; count: number };
+    cad?: { avg: number; count: number };
+    atemp?: { avg: number; count: number };
+    power?: { avg: number; count: number };
+    /** Absent when there are no trackpoints. */
     bounds?: { west: number; south: number; east: number; north: number };
 }
 export interface TrackNode {
@@ -494,8 +524,8 @@ extern "C" {
     pub type FilesUpdate;
     #[wasm_bindgen(typescript_type = "FileStructure | undefined")]
     pub type FileStructure;
-    #[wasm_bindgen(typescript_type = "FileStatistics | undefined")]
-    pub type FileStatistics;
+    #[wasm_bindgen(typescript_type = "GlobalStatistics | undefined")]
+    pub type GlobalStatistics;
     #[wasm_bindgen(typescript_type = "string[]")]
     pub type FileOrder;
 }
@@ -594,41 +624,75 @@ pub fn file_structure(file_id: &str) -> FileStructure {
     structure.unchecked_into()
 }
 
+fn statistics_object(stats: &engine::GlobalStatistics) -> GlobalStatistics {
+    let object = Object::new();
+    let optional = |key: &str, value: Option<f64>| {
+        if let Some(value) = value {
+            set(&object, key, value);
+        }
+    };
+    let seconds = |ms: Option<i64>| ms.map(|ms| ms as f64 / 1000.0);
+    let average = |key: &str, average: &engine::Average| {
+        if let Some(avg) = average.avg() {
+            let value = Object::new();
+            set(&value, "avg", avg);
+            set(&value, "count", f64::from(average.count));
+            set(&object, key, value);
+        }
+    };
+    set(&object, "totalDistance", stats.total_distance);
+    optional("movingDistance", stats.moving_distance);
+    optional("totalTime", seconds(stats.total_time));
+    optional("movingTime", seconds(stats.moving_time));
+    set(&object, "elevationGain", stats.elevation_gain);
+    set(&object, "elevationLoss", stats.elevation_loss);
+    optional("startTime", stats.start_time.map(|t| t as f64));
+    optional("endTime", stats.end_time.map(|t| t as f64));
+    optional("totalSpeed", stats.total_speed());
+    optional("movingSpeed", stats.moving_speed());
+    average("hr", &stats.hr);
+    average("cad", &stats.cad);
+    average("atemp", &stats.atemp);
+    average("power", &stats.power);
+    let (sw, ne) = (&stats.bounds.sw, &stats.bounds.ne);
+    if sw.lng <= ne.lng && sw.lat <= ne.lat {
+        let bounds = Object::new();
+        set(&bounds, "west", sw.lng);
+        set(&bounds, "south", sw.lat);
+        set(&bounds, "east", ne.lng);
+        set(&bounds, "north", ne.lat);
+        set(&object, "bounds", bounds);
+    }
+    object.unchecked_into()
+}
+
 /// Global statistics of a file, `undefined` if the id is unknown.
 #[wasm_bindgen]
-pub fn file_statistics(file_id: &str) -> FileStatistics {
-    let stats = uuid::Uuid::parse_str(file_id)
+pub fn file_statistics(file_id: &str) -> GlobalStatistics {
+    uuid::Uuid::parse_str(file_id)
         .ok()
         .and_then(|id| with_engine(|e| e.file_statistics(&FileId(id))).flatten())
-        .map_or(JsValue::UNDEFINED, |stats| {
-            let object = Object::new();
-            let optional = |key: &str, value: Option<f64>| {
-                if let Some(value) = value {
-                    set(&object, key, value);
-                }
-            };
-            set(&object, "totalDistance", stats.total_distance);
-            optional("movingDistance", stats.moving_distance);
-            optional("totalTime", stats.total_time.map(f64::from));
-            optional("movingTime", stats.moving_time.map(f64::from));
-            set(&object, "elevationGain", stats.elevation_gain);
-            set(&object, "elevationLoss", stats.elevation_loss);
-            optional("startTime", stats.start_time.map(|t| t as f64));
-            optional("endTime", stats.end_time.map(|t| t as f64));
-            optional("totalSpeed", stats.total_speed());
-            optional("movingSpeed", stats.moving_speed());
-            let (sw, ne) = (&stats.bounds.sw, &stats.bounds.ne);
-            if sw.lng <= ne.lng && sw.lat <= ne.lat {
-                let bounds = Object::new();
-                set(&bounds, "west", sw.lng);
-                set(&bounds, "south", sw.lat);
-                set(&bounds, "east", ne.lng);
-                set(&bounds, "north", ne.lat);
-                set(&object, "bounds", bounds);
-            }
-            object.into()
-        });
-    stats.unchecked_into()
+        .map_or(JsValue::UNDEFINED.unchecked_into(), |stats| {
+            statistics_object(&stats)
+        })
+}
+
+/// Global statistics of the whole selection (the arrays of the statistics buffers cover it).
+#[wasm_bindgen]
+pub fn selection_statistics() -> GlobalStatistics {
+    with_stats(|buffer| statistics_object(&buffer.global))
+        .unwrap_or_else(|| JsValue::UNDEFINED.unchecked_into())
+}
+
+/// Global statistics of the trackpoints from `start` to `end` (both included) of the selection,
+/// as indexed by the statistics buffers. `undefined` when the range is not in the selection.
+#[wasm_bindgen]
+pub fn slice_statistics(start: usize, end: usize) -> GlobalStatistics {
+    with_stats(|buffer| buffer.slice(start, end))
+        .flatten()
+        .map_or(JsValue::UNDEFINED.unchecked_into(), |stats| {
+            statistics_object(&stats)
+        })
 }
 
 fn uuids<T>(items: impl IntoIterator<Item = T>, uuid: impl Fn(T) -> uuid::Uuid) -> Array {

website/src/lib/components/GPXStatistics.svelte

@@ -6,8 +6,9 @@
     import { MoveDownRight, MoveUpRight, Ruler, Timer, Zap } from '@lucide/svelte';
 
     import { i18n } from '$lib/i18n.svelte';
-    import type { GPXGlobalStatistics, GPXStatisticsGroup } from 'gpx';
     import type { Readable } from 'svelte/store';
+    import type { SelectionStatistics } from '$lib/engine';
+    import type { SlicedStatistics } from '$lib/logic/selection-statistics';
     import { settings } from '$lib/logic/settings';
 
     const { velocityUnits } = settings;
@@ -16,18 +17,17 @@
     let panelWidth: number = $state(0);
 
     let {
-        gpxStatistics,
-        slicedGPXStatistics,
+        statistics: selectionStatistics,
+        slicedStatistics,
         orientation,
     }: {
-        gpxStatistics: Readable<GPXStatisticsGroup>;
-        slicedGPXStatistics: Readable<[GPXGlobalStatistics, number, number] | undefined>;
+        statistics: Readable<SelectionStatistics>;
+        slicedStatistics: Readable<SlicedStatistics | undefined>;
         orientation: 'horizontal' | 'vertical';
     } = $props();
 
-    let statistics = $derived(
-        $slicedGPXStatistics !== undefined ? $slicedGPXStatistics[0] : $gpxStatistics.global
-    );
+    // the highlighted part of the selection, or all of it
+    let statistics = $derived($slicedStatistics?.global ?? $selectionStatistics.global);
 </script>
 
 <Card.Root
@@ -46,15 +46,15 @@
             <Tooltip label={i18n._('quantities.distance')}>
                 <span class="flex flex-row items-center">
                     <Ruler size="16" class="mr-1" />
-                    <WithUnits value={statistics.distance.total} type="distance" />
+                    <WithUnits value={statistics.totalDistance} type="distance" />
                 </span>
             </Tooltip>
             <Tooltip label={i18n._('quantities.elevation_gain_loss')}>
                 <span class="flex flex-row items-center">
                     <MoveUpRight size="16" class="mr-1" />
-                    <WithUnits value={statistics.elevation.gain} type="elevation" />
+                    <WithUnits value={statistics.elevationGain} type="elevation" />
                     <MoveDownRight size="16" class="mx-1" />
-                    <WithUnits value={statistics.elevation.loss} type="elevation" />
+                    <WithUnits value={statistics.elevationLoss} type="elevation" />
                 </span>
             </Tooltip>
             {#if panelHeight > 120 || (orientation === 'horizontal' && panelWidth > 450)}
@@ -67,9 +67,13 @@
                 >
                     <span class="flex flex-row items-center">
                         <Zap size="16" class="mr-1" />
-                        <WithUnits value={statistics.speed.moving} type="speed" showUnits={false} />
+                        <WithUnits
+                            value={statistics.movingSpeed ?? 0}
+                            type="speed"
+                            showUnits={false}
+                        />
                         <span class="mx-1">/</span>
-                        <WithUnits value={statistics.speed.total} type="speed" />
+                        <WithUnits value={statistics.totalSpeed ?? 0} type="speed" />
                     </span>
                 </Tooltip>
             {/if}
@@ -81,9 +85,9 @@
                 >
                     <span class="flex flex-row items-center">
                         <Timer size="16" class="mr-1" />
-                        <WithUnits value={statistics.time.moving} type="time" />
+                        <WithUnits value={statistics.movingTime ?? 0} type="time" />
                         <span class="mx-1">/</span>
-                        <WithUnits value={statistics.time.total} type="time" />
+                        <WithUnits value={statistics.totalTime ?? 0} type="time" />
                     </span>
                 </Tooltip>
             {/if}

website/src/lib/components/elevation-profile/ElevationProfile.svelte

@@ -18,7 +18,9 @@
         Construction,
     } from '@lucide/svelte';
     import type { Readable, Writable } from 'svelte/store';
-    import type { Coordinates, GPXGlobalStatistics, GPXStatisticsGroup } from 'gpx';
+    import type { Coordinates } from 'gpx';
+    import type { SelectionStatistics } from '$lib/engine';
+    import type { SlicedStatistics } from '$lib/logic/selection-statistics';
     import { settings } from '$lib/logic/settings';
     import { i18n } from '$lib/i18n.svelte';
     import { ElevationProfile } from '$lib/components/elevation-profile/elevation-profile';
@@ -26,15 +28,15 @@
     const { velocityUnits } = settings;
 
     let {
-        gpxStatistics,
-        slicedGPXStatistics,
+        statistics,
+        slicedStatistics,
         hoveredPoint,
         additionalDatasets,
         elevationFill,
         showControls = true,
     }: {
-        gpxStatistics: Readable<GPXStatisticsGroup>;
-        slicedGPXStatistics: Writable<[GPXGlobalStatistics, number, number] | undefined>;
+        statistics: Readable<SelectionStatistics>;
+        slicedStatistics: Writable<SlicedStatistics | undefined>;
         hoveredPoint: Writable<Coordinates | null>;
         additionalDatasets: Writable<string[]>;
         elevationFill: Writable<'slope' | 'surface' | 'highway' | undefined>;
@@ -47,8 +49,8 @@
 
     onMount(() => {
         elevationProfile = new ElevationProfile(
-            gpxStatistics,
-            slicedGPXStatistics,
+            statistics,
+            slicedStatistics,
             hoveredPoint,
             additionalDatasets,
             elevationFill,

website/src/lib/components/elevation-profile/elevation-profile.ts

@@ -21,7 +21,9 @@ import Chart, {
     type TooltipItem,
 } from 'chart.js/auto';
 import { get, type Readable, type Writable } from 'svelte/store';
-import type { Coordinates, GPXGlobalStatistics, GPXStatisticsGroup } from 'gpx';
+import type { Coordinates } from 'gpx';
+import { NO_TIME, type SelectionStatistics } from '$lib/engine';
+import type { SlicedStatistics } from '$lib/logic/selection-statistics';
 import { mode } from 'mode-watcher';
 import { getHighwayColor, getSlopeColor, getSurfaceColor } from '$lib/assets/colors';
 
@@ -51,23 +53,23 @@ export class ElevationProfile {
     private _dragging = false;
     private _panning = false;
 
-    private _gpxStatistics: Readable<GPXStatisticsGroup>;
-    private _slicedGPXStatistics: Writable<[GPXGlobalStatistics, number, number] | undefined>;
+    private _statistics: Readable<SelectionStatistics>;
+    private _slicedStatistics: Writable<SlicedStatistics | undefined>;
     private _hoveredPoint: Writable<Coordinates | null>;
     private _additionalDatasets: Readable<string[]>;
     private _elevationFill: Readable<'slope' | 'surface' | 'highway' | undefined>;
 
     constructor(
-        gpxStatistics: Readable<GPXStatisticsGroup>,
-        slicedGPXStatistics: Writable<[GPXGlobalStatistics, number, number] | undefined>,
+        statistics: Readable<SelectionStatistics>,
+        slicedStatistics: Writable<SlicedStatistics | undefined>,
         hoveredPoint: Writable<Coordinates | null>,
         additionalDatasets: Readable<string[]>,
         elevationFill: Readable<'slope' | 'surface' | 'highway' | undefined>,
         canvas: HTMLCanvasElement,
         overlay: HTMLCanvasElement
     ) {
-        this._gpxStatistics = gpxStatistics;
-        this._slicedGPXStatistics = slicedGPXStatistics;
+        this._statistics = statistics;
+        this._slicedStatistics = slicedStatistics;
         this._hoveredPoint = hoveredPoint;
         this._additionalDatasets = additionalDatasets;
         this._elevationFill = elevationFill;
@@ -78,10 +80,10 @@ export class ElevationProfile {
             Chart.register(module.default);
             this.initialize();
 
-            this._gpxStatistics.subscribe(() => {
+            this._statistics.subscribe(() => {
                 this.updateData();
             });
-            this._slicedGPXStatistics.subscribe(() => {
+            this._slicedStatistics.subscribe(() => {
                 this.updateOverlay();
             });
             distanceUnits.subscribe(() => {
@@ -235,7 +237,7 @@ export class ElevationProfile {
                         modifierKey: 'shift',
                         onPanStart: () => {
                             this._panning = true;
-                            this._slicedGPXStatistics.set(undefined);
+                            this._slicedStatistics.set(undefined);
                             return true;
                         },
                         onPanComplete: () => {
@@ -260,7 +262,7 @@ export class ElevationProfile {
                                 return false;
                             }
 
-                            this._slicedGPXStatistics.set(undefined);
+                            this._slicedStatistics.set(undefined);
                         },
                     },
                     limits: {
@@ -361,14 +363,12 @@ export class ElevationProfile {
                     if (startIndex === undefined) {
                         startIndex = endIndex;
                     } else if (startIndex !== endIndex) {
-                        this._slicedGPXStatistics.set([
-                            get(this._gpxStatistics).sliced(
-                                Math.min(startIndex, endIndex),
-                                Math.max(startIndex, endIndex)
-                            ),
-                            Math.min(startIndex, endIndex),
-                            Math.max(startIndex, endIndex),
-                        ]);
+                        const start = Math.min(startIndex, endIndex);
+                        const end = Math.max(startIndex, endIndex);
+                        const global = get(this._statistics).slice(start, end);
+                        if (global) {
+                            this._slicedStatistics.set({ global, start, end });
+                        }
                     }
                 }
             }
@@ -379,7 +379,7 @@ export class ElevationProfile {
             this._canvas.style.cursor = '';
             endIndex = getIndex(evt);
             if (startIndex === endIndex) {
-                this._slicedGPXStatistics.set(undefined);
+                this._slicedStatistics.set(undefined);
             }
         };
         this._canvas.addEventListener('pointerdown', onMouseDown);
@@ -391,7 +391,7 @@ export class ElevationProfile {
         if (!this._chart) {
             return;
         }
-        const data = get(this._gpxStatistics);
+        const data = get(this._statistics);
         const units = {
             distance: get(distanceUnits),
             velocity: get(velocityUnits),
@@ -399,52 +399,49 @@ export class ElevationProfile {
         };
 
         const datasets: Array<Array<any>> = [[], [], [], [], [], []];
-        data.forEachTrackPoint((trkpt, distance, speed, slope, index) => {
+        const { global } = data;
+        for (let index = 0; index < data.length; index++) {
+            const x = getConvertedDistance(data.totalDistance[index], units.distance);
+            const ele = data.ele[index];
+            const timestamp = data.timestamps[index];
             datasets[0].push({
-                x: getConvertedDistance(distance, units.distance),
-                y: trkpt.ele ? getConvertedElevation(trkpt.ele, units.distance) : 0,
-                time: trkpt.time,
-                slope: slope,
-                extensions: trkpt.getExtensions(),
-                coordinates: trkpt.getCoordinates(),
-                index: index,
+                x,
+                y: ele ? getConvertedElevation(ele, units.distance) : 0,
+                time: timestamp === NO_TIME ? undefined : new Date(Number(timestamp)),
+                slope: {
+                    at: data.slope[index],
+                    segment: data.slopeSegmentSlope[index],
+                    length: data.slopeSegmentDistance[index],
+                },
+                // TODO the engine does not store the extensions (surface, highway...) yet
+                extensions: data.extensions[index] ?? {},
+                coordinates: { lat: data.lat[index], lon: data.lng[index] },
+                index,
             });
-            if (data.global.time.total > 0) {
+            if ((global.totalTime ?? 0) > 0) {
                 datasets[1].push({
-                    x: getConvertedDistance(distance, units.distance),
-                    y: getConvertedVelocity(speed, units.velocity, units.distance),
-                    index: index,
+                    x,
+                    y: getConvertedVelocity(data.speed[index], units.velocity, units.distance),
+                    index,
                 });
             }
-            if (data.global.hr.count > 0) {
-                datasets[2].push({
-                    x: getConvertedDistance(distance, units.distance),
-                    y: trkpt.getHeartRate(),
-                    index: index,
-                });
+            if (global.hr) {
+                datasets[2].push({ x, y: data.hr[index], index });
             }
-            if (data.global.cad.count > 0) {
-                datasets[3].push({
-                    x: getConvertedDistance(distance, units.distance),
-                    y: trkpt.getCadence(),
-                    index: index,
-                });
+            if (global.cad) {
+                datasets[3].push({ x, y: data.cad[index], index });
             }
-            if (data.global.atemp.count > 0) {
+            if (global.atemp) {
                 datasets[4].push({
-                    x: getConvertedDistance(distance, units.distance),
-                    y: getConvertedTemperature(trkpt.getTemperature(), units.temperature),
-                    index: index,
+                    x,
+                    y: getConvertedTemperature(data.atemp[index], units.temperature),
+                    index,
                 });
             }
-            if (data.global.power.count > 0) {
-                datasets[5].push({
-                    x: getConvertedDistance(distance, units.distance),
-                    y: trkpt.getPower(),
-                    index: index,
-                });
+            if (global.power) {
+                datasets[5].push({ x, y: data.power[index], index });
             }
-        });
+        }
 
         this._chart.data.datasets[0] = {
             label: i18n._('quantities.elevation'),
@@ -482,7 +479,7 @@ export class ElevationProfile {
 
         this._chart.options.scales!.x!['min'] = 0;
         this._chart.options.scales!.x!['max'] = getConvertedDistance(
-            data.global.distance.total,
+            global.totalDistance,
             units.distance
         );
 
@@ -563,10 +560,10 @@ export class ElevationProfile {
         this._overlay.style.width = `${this._overlay.width}px`;
         this._overlay.style.height = `${this._overlay.height}px`;
 
-        const slicedGPXStatistics = get(this._slicedGPXStatistics);
-        if (slicedGPXStatistics) {
-            let startIndex = slicedGPXStatistics[1];
-            let endIndex = slicedGPXStatistics[2];
+        const slicedStatistics = get(this._slicedStatistics);
+        if (slicedStatistics) {
+            let startIndex = slicedStatistics.start;
+            let endIndex = slicedStatistics.end;
 
             // Draw selection rectangle
             let selectionContext = this._overlay.getContext('2d');
@@ -575,14 +572,12 @@ export class ElevationProfile {
                 selectionContext.globalAlpha = mode.current === 'dark' ? 0.2 : 0.1;
                 selectionContext.clearRect(0, 0, this._overlay.width, this._overlay.height);
 
-                const gpxStatistics = get(this._gpxStatistics);
+                const statistics = get(this._statistics);
                 let startPixel = this._chart.scales.x.getPixelForValue(
-                    getConvertedDistance(
-                        gpxStatistics.getTrackPoint(startIndex)?.distance.total ?? 0
-                    )
+                    getConvertedDistance(statistics.totalDistance[startIndex] ?? 0)
                 );
                 let endPixel = this._chart.scales.x.getPixelForValue(
-                    getConvertedDistance(gpxStatistics.getTrackPoint(endIndex)?.distance.total ?? 0)
+                    getConvertedDistance(statistics.totalDistance[endIndex] ?? 0)
                 );
 
                 selectionContext.fillRect(

website/src/lib/components/embedding/Embedding.svelte

@@ -16,11 +16,13 @@
     import { setMode } from 'mode-watcher';
     import { settings } from '$lib/logic/settings';
     import { fileStateCollection } from '$lib/logic/file-state';
-    import { gpxStatistics, hoveredPoint, slicedGPXStatistics } from '$lib/logic/statistics';
     import { loadFile } from '$lib/logic/file-actions';
     import { selection } from '$lib/logic/selection';
     import { untrack } from 'svelte';
     import { isSelected, toggle } from '$lib/components/map/layer-control/utils';
+    import { engine } from '$lib/engine';
+    import { hoveredPoint } from '$lib/logic/statistics';
+    import { slicedStatistics } from '$lib/logic/selection-statistics';
 
     let {
         useHash = true,
@@ -31,6 +33,7 @@
     let additionalDatasets = writable<string[]>([]);
     let elevationFill = writable<'slope' | 'surface' | 'highway' | undefined>(undefined);
 
+    const { statistics } = engine;
     const {
         currentBasemap,
         selectedBasemapTree,
@@ -122,14 +125,14 @@
         style={options.elevation.show ? `height: ${options.elevation.height}px` : ''}
     >
         <GPXStatistics
-            {gpxStatistics}
-            {slicedGPXStatistics}
+            {statistics}
+            {slicedStatistics}
             orientation={options.elevation.show ? 'vertical' : 'horizontal'}
         />
         {#if options.elevation.show}
             <ElevationProfile
-                {gpxStatistics}
-                {slicedGPXStatistics}
+                {statistics}
+                {slicedStatistics}
                 {hoveredPoint}
                 {additionalDatasets}
                 {elevationFill}

website/src/lib/engine.ts

@@ -4,10 +4,10 @@ import { FileColorAllocator, normalizeColor } from '$lib/file-colors';
 import { setHidden, type Visibility } from '$lib/file-visibility';
 import { selectedElementIds, type FileTreeNode } from '$lib/selection-helpers';
 import type { Feature, FeatureCollection, LineString, Point } from 'geojson';
-import type { FileStatistics, FileStructure, Selection } from 'gpx-rs';
+import type { GlobalStatistics, FileStructure, Selection } from 'gpx-rs';
 
 export type {
-    FileStatistics,
+    GlobalStatistics,
     FileStructure,
     FilesUpdate,
     Selection,
@@ -63,7 +63,7 @@ export type FileState = {
     /** Color of the file: the one defined by its tracks if any, otherwise one from the palette. */
     color: string;
     /** Global statistics of the file. */
-    statistics: FileStatistics;
+    statistics: GlobalStatistics;
     /** One LineString feature per track segment, in file order. */
     segments: FeatureCollection<LineString, SegmentProperties>;
     /** One Point feature per waypoint, in file order. */
@@ -75,7 +75,85 @@ export type FileState = {
     visibility: Visibility;
 };
 
-const EMPTY_STATISTICS: FileStatistics = { totalDistance: 0, elevationGain: 0, elevationLoss: 0 };
+const EMPTY_STATISTICS: GlobalStatistics = { totalDistance: 0, elevationGain: 0, elevationLoss: 0 };
+
+/**
+ * Timestamp of the trackpoints that have none, in `SelectionStatistics.timestamps` (the smallest
+ * 64-bit integer, like `NO_TIME` in the engine).
+ */
+export const NO_TIME = -(2n ** 63n);
+
+/**
+ * The statistics of the selection: its global statistics, and the values at each of its
+ * trackpoints (all the selected segments, one after the other). The arrays are copies.
+ *
+ * Distances, times, moving values and elevation gain / loss are cumulative over the whole
+ * selection. Distances are in km, speeds in km/h, times in ms (timestamps since the epoch, as
+ * 64-bit integers), elevations in m and slopes in %. Missing timestamps are `NO_TIME`, missing
+ * measures are NaN.
+ */
+export type SelectionStatistics = {
+    global: GlobalStatistics;
+    /** Number of trackpoints. */
+    length: number;
+    totalDistance: Float64Array;
+    movingDistance: Float64Array;
+    /** Duration since the start of the selection, in ms. */
+    totalTime: BigInt64Array;
+    movingTime: BigInt64Array;
+    speed: Float64Array;
+    elevationGain: Float64Array;
+    elevationLoss: Float64Array;
+    /** Slope at the trackpoint. */
+    slope: Float64Array;
+    /** Slope and length (km) of the smoothed elevation segment the trackpoint belongs to. */
+    slopeSegmentSlope: Float64Array;
+    slopeSegmentDistance: Float64Array;
+    lng: Float64Array;
+    lat: Float64Array;
+    ele: Float64Array;
+    timestamps: BigInt64Array;
+    hr: Float64Array;
+    cad: Float64Array;
+    atemp: Float64Array;
+    power: Float64Array;
+    /**
+     * Extensions of the trackpoints (surface, highway...), or an empty array when they are not
+     * known. TODO the engine does not store them yet.
+     */
+    extensions: Record<string, string>[];
+    /**
+     * Global statistics of the trackpoints from `start` to `end` (both included), for example
+     * the part of the elevation profile that was dragged over. `undefined` if the range is not
+     * in the selection, or if the selection is not the current one anymore.
+     */
+    slice(start: number, end: number): GlobalStatistics | undefined;
+};
+
+const EMPTY_SELECTION_STATISTICS: SelectionStatistics = {
+    global: EMPTY_STATISTICS,
+    length: 0,
+    totalDistance: new Float64Array(),
+    movingDistance: new Float64Array(),
+    totalTime: new BigInt64Array(),
+    movingTime: new BigInt64Array(),
+    speed: new Float64Array(),
+    elevationGain: new Float64Array(),
+    elevationLoss: new Float64Array(),
+    slope: new Float64Array(),
+    slopeSegmentSlope: new Float64Array(),
+    slopeSegmentDistance: new Float64Array(),
+    lng: new Float64Array(),
+    lat: new Float64Array(),
+    ele: new Float64Array(),
+    timestamps: new BigInt64Array(),
+    hr: new Float64Array(),
+    cad: new Float64Array(),
+    atemp: new Float64Array(),
+    power: new Float64Array(),
+    extensions: [],
+    slice: () => undefined,
+};
 
 function toPositions(flat: Float64Array): [number, number][] {
     const positions: [number, number][] = new Array(flat.length / 2);
@@ -119,9 +197,14 @@ class Engine {
     private _visibility = new Map<string, Visibility>();
     private _files = writable<Map<string, Writable<FileState>>>(new Map());
     private _selection = writable<Selection>({ type: 'empty' });
+    private _statistics = writable<SelectionStatistics>(EMPTY_SELECTION_STATISTICS);
+    /** Identifies the statistics currently in the engine's buffers. */
+    private _statisticsVersion = 0;
 
     /** Ids of the files in display order. */
     readonly order: Readable<string[]> = { subscribe: this._order.subscribe };
+    /** Statistics of what is currently selected. */
+    readonly statistics: Readable<SelectionStatistics> = { subscribe: this._statistics.subscribe };
     /** What is currently selected. */
     readonly selection: Readable<Selection> = { subscribe: this._selection.subscribe };
     /**
@@ -365,6 +448,46 @@ class Engine {
                 }
             }
         }
+
+        // the statistics depend on the selection, on its order, and on the files
+        if (
+            update.selectionChanged ||
+            update.orderChanged ||
+            update.added.length + update.modified.length + update.removed.length > 0
+        ) {
+            this._statistics.set(this.readStatistics(wasm));
+        }
+    }
+
+    /** Copies the statistics buffers of the engine (they are overwritten by the next action). */
+    private readStatistics(wasm: Wasm): SelectionStatistics {
+        const version = ++this._statisticsVersion;
+        const totalDistance = wasm.total_distance().slice();
+        return {
+            global: wasm.selection_statistics() ?? EMPTY_STATISTICS,
+            length: totalDistance.length,
+            totalDistance,
+            movingDistance: wasm.moving_distance().slice(),
+            totalTime: wasm.total_time().slice(),
+            movingTime: wasm.moving_time().slice(),
+            speed: wasm.speed().slice(),
+            elevationGain: wasm.elevation_gain().slice(),
+            elevationLoss: wasm.elevation_loss().slice(),
+            slope: wasm.slope().slice(),
+            slopeSegmentSlope: wasm.slope_segment_slope().slice(),
+            slopeSegmentDistance: wasm.slope_segment_distance().slice(),
+            lng: wasm.lng().slice(),
+            lat: wasm.lat().slice(),
+            ele: wasm.ele().slice(),
+            timestamps: wasm.timestamps().slice(),
+            hr: wasm.hr().slice(),
+            cad: wasm.cad().slice(),
+            atemp: wasm.atemp().slice(),
+            power: wasm.power().slice(),
+            extensions: [],
+            slice: (start, end) =>
+                version === this._statisticsVersion ? wasm.slice_statistics(start, end) : undefined,
+        };
     }
 
     /** Reads the state of a file, reusing from `previous` what did not change. */

website/src/lib/logic/selection-statistics.ts

@@ -0,0 +1,16 @@
+import { writable } from 'svelte/store';
+import { engine, type GlobalStatistics } from '$lib/engine';
+
+/** The part of the selection that is highlighted in the elevation profile. */
+export type SlicedStatistics = {
+    /** Statistics of the part. */
+    global: GlobalStatistics;
+    /** Indices of its first and last trackpoints in the statistics of the selection. */
+    start: number;
+    end: number;
+};
+
+export const slicedStatistics = writable<SlicedStatistics | undefined>(undefined);
+
+// the indices only make sense for the selection they were made on
+engine.statistics.subscribe(() => slicedStatistics.set(undefined));

website/src/routes/[[language]]/+page.svelte

@@ -18,14 +18,37 @@
     } from '@lucide/svelte';
     import { i18n } from '$lib/i18n.svelte';
     import { getURLForLanguage } from '$lib/utils';
-    import { exampleGPXFile } from '$lib/assets/example';
     import { writable } from 'svelte/store';
     import Scissors from '$lib/components/toolbar/tools/scissors/Scissors.svelte';
     import { currentTool, Tool } from '$lib/components/toolbar/tools';
     import { onDestroy, onMount } from 'svelte';
 
-    let gpxStatistics = writable(exampleGPXFile.getStatistics());
-    let slicedGPXStatistics = writable(undefined);
+    // TODO the example comes from the previous implementation
+    let statistics = writable({
+        global: { totalDistance: 0, elevationGain: 0, elevationLoss: 0 },
+        length: 0,
+        totalDistance: new Float64Array(),
+        movingDistance: new Float64Array(),
+        totalTime: new BigInt64Array(),
+        movingTime: new BigInt64Array(),
+        speed: new Float64Array(),
+        elevationGain: new Float64Array(),
+        elevationLoss: new Float64Array(),
+        slope: new Float64Array(),
+        slopeSegmentSlope: new Float64Array(),
+        slopeSegmentDistance: new Float64Array(),
+        lng: new Float64Array(),
+        lat: new Float64Array(),
+        ele: new Float64Array(),
+        timestamps: new BigInt64Array(),
+        hr: new Float64Array(),
+        cad: new Float64Array(),
+        atemp: new Float64Array(),
+        power: new Float64Array(),
+        extensions: [],
+        slice: () => undefined,
+    });
+    let slicedStatistics = writable(undefined);
     let hoveredPoint = writable(null);
     let additionalDatasets = writable(['speed', 'atemp']);
     let elevationFill = writable(undefined);
@@ -138,18 +161,14 @@
                 >
                     <div class="grow">
                         <ElevationProfile
-                            {gpxStatistics}
-                            {slicedGPXStatistics}
+                            {statistics}
+                            {slicedStatistics}
                             {hoveredPoint}
                             {additionalDatasets}
                             {elevationFill}
                         />
                     </div>
-                    <GPXStatistics
-                        {gpxStatistics}
-                        {slicedGPXStatistics}
-                        orientation={'horizontal'}
-                    />
+                    <GPXStatistics {statistics} {slicedStatistics} orientation={'horizontal'} />
                 </div>
             </div>
             <div class="grid md:grid-rows-subgrid md:row-start-3 md:row-end-5 gap-4">

website/src/routes/[[language]]/app/+page.svelte

@@ -16,7 +16,9 @@
     import { loadFiles } from '$lib/logic/file-actions';
     import { onDestroy, onMount } from 'svelte';
     import { page } from '$app/state';
-    import { gpxStatistics, hoveredPoint, slicedGPXStatistics } from '$lib/logic/statistics';
+    import { hoveredPoint } from '$lib/logic/statistics';
+    import { slicedStatistics } from '$lib/logic/selection-statistics';
+    import { engine } from '$lib/engine';
     import { getURLForGoogleDriveFile } from '$lib/components/embedding/embedding';
     import { db } from '$lib/db';
     import { fileStateCollection } from '$lib/logic/file-state';
@@ -140,14 +142,14 @@
             style={$elevationProfile ? `height: ${$bottomPanelSize}px` : ''}
         >
             <GPXStatistics
-                {gpxStatistics}
-                {slicedGPXStatistics}
+                statistics={engine.statistics}
+                {slicedStatistics}
                 orientation={bottomPanelOrientation == 'horizontal' ? 'vertical' : 'horizontal'}
             />
             {#if $elevationProfile}
                 <ElevationProfile
-                    {gpxStatistics}
-                    {slicedGPXStatistics}
+                    statistics={engine.statistics}
+                    {slicedStatistics}
                     {hoveredPoint}
                     {additionalDatasets}
                     {elevationFill}