refactoring

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

@@ -0,0 +1,313 @@
+use crate::{
+    LngLat, LngLatBounds, TrackSegment, TrackSegmentIndex, Trackpoint, distance, for_each_window,
+    ramer_douglas_peucker, slope, speed, sum_options, time_diff,
+};
+
+#[derive(Default, Debug)]
+pub struct Statistics {
+    pub global: GlobalStatistics,
+    pub local: Vec<TrackpointStatistics>,
+}
+
+impl Statistics {
+    pub fn total_time(&self) -> Option<i32> {
+        self.global.total_time()
+    }
+
+    pub fn total_speed(&self) -> Option<f64> {
+        self.global.total_speed()
+    }
+
+    pub fn moving_speed(&self) -> Option<f64> {
+        self.global.moving_speed()
+    }
+
+    pub fn compute(trkseg: &TrackSegment) -> Self {
+        let mut stats = Self::default();
+        if trkseg.len() == 0 {
+            return stats;
+        }
+
+        let mut prev = &trkseg[0];
+        for cur in trkseg.iter() {
+            stats.accumulate(prev, cur);
+            prev = cur;
+        }
+
+        stats.compute_smoothed_speed(trkseg);
+        stats.compute_smoothed_elevation_segments(trkseg);
+        stats.compute_smoothed_slope(trkseg);
+
+        stats
+    }
+
+    fn accumulate(&mut self, prev: &Trackpoint, cur: &Trackpoint) {
+        self.accumulate_distance_and_time(prev, cur);
+        self.update_time_bounds(cur.time);
+        self.update_bounds(cur.coordinates);
+        self.local
+            .push(TrackpointStatistics::from_partial_stats(&self));
+    }
+
+    fn accumulate_distance_and_time(&mut self, prev: &Trackpoint, cur: &Trackpoint) {
+        let dist = distance(prev.coordinates, cur.coordinates);
+        let time = time_diff(&cur.time, &prev.time);
+
+        self.global.total_distance += dist;
+
+        if let Some(time) = time {
+            let speed = speed(dist, time);
+            if speed >= 0.5 && speed <= 1500.0 {
+                self.global.moving_distance = self
+                    .global
+                    .moving_distance
+                    .map_or(Some(dist), |d| Some(d + dist));
+                self.global.moving_time = self
+                    .global
+                    .moving_time
+                    .map_or(Some(time), |t| Some(t + time));
+            }
+        }
+    }
+
+    fn update_time_bounds(&mut self, time: Option<i64>) {
+        if let Some(time) = time {
+            if self.global.start_time.is_none() {
+                self.global.start_time = Some(time);
+            }
+            self.global.end_time = Some(time);
+        }
+    }
+
+    fn update_bounds(&mut self, coordinates: LngLat) {
+        self.global.bounds.extend(coordinates);
+    }
+
+    fn compute_smoothed_speed(&mut self, trkseg: &TrackSegment) {
+        for_each_window!(
+            trkseg,
+            trkseg.first_index(),
+            trkseg.last_index(),
+            Some(10000),
+            |i, j| time_diff(&trkseg[i].time, &trkseg[j].time),
+            |i, left, right| {
+                self.local[i.flat].speed =
+                    time_diff(&trkseg[right].time, &trkseg[left].time).map(|t| {
+                        speed(
+                            self.local[right.flat].total_distance
+                                - self.local[left.flat].total_distance,
+                            t,
+                        )
+                    });
+            },
+        );
+    }
+
+    fn compute_smoothed_elevation_segments(&mut self, trkseg: &TrackSegment) {
+        let simplified = self.get_elevation_extremas(trkseg);
+
+        for i in 0..(simplified.len() - 1) {
+            let start = simplified[i];
+            let end = simplified[i + 1];
+            let last = i + 1 == simplified.len() - 1;
+
+            self.compute_smoothed_elevation_gain(trkseg, start, end, last);
+
+            let segment_dist =
+                self.local[end.flat].total_distance - self.local[start.flat].total_distance;
+            let segment_ele = trkseg[end].ele - trkseg[start].ele;
+            let segment_slope = slope(segment_ele, segment_dist);
+            for k in start.flat..(end.flat + last as usize) {
+                self.local[k].slope_segment = SlopeSegment {
+                    slope: segment_slope,
+                    distance: segment_dist,
+                };
+            }
+        }
+    }
+
+    fn compute_smoothed_elevation_gain(
+        &mut self,
+        trkseg: &TrackSegment,
+        start: TrackSegmentIndex,
+        end: TrackSegmentIndex,
+        last: bool,
+    ) {
+        let mut cumul_ele = 0.0;
+        let mut current_left = start;
+        let mut current_right = Some(start);
+        let mut prev_smoothed_ele = trkseg[start].ele;
+
+        for_each_window!(
+            trkseg,
+            Some(start),
+            Some(end),
+            0.1,
+            |i, j| self.local[j.flat].total_distance - self.local[i.flat].total_distance,
+            |i, left, right| {
+                while current_left != left {
+                    cumul_ele -= trkseg[current_left].ele;
+                    current_left = trkseg.next_index(Some(current_left)).unwrap();
+                }
+                while let Some(current) = current_right {
+                    if current > right {
+                        break;
+                    }
+                    cumul_ele += trkseg[current].ele;
+                    current_right = trkseg.next_index(current_right);
+                }
+
+                let smoothed_ele = if i == start || i == end {
+                    trkseg[i].ele
+                } else {
+                    cumul_ele / (right.flat - left.flat + 1) as f64
+                };
+
+                let delta = smoothed_ele - prev_smoothed_ele;
+                if delta > 0.0 {
+                    self.global.elevation_gain += delta;
+                } else if delta < 0.0 {
+                    self.global.elevation_loss -= delta;
+                }
+
+                if i < end || last {
+                    self.local[i.flat].elevation_gain = self.global.elevation_gain;
+                    self.local[i.flat].elevation_loss = self.global.elevation_loss;
+                }
+
+                prev_smoothed_ele = smoothed_ele;
+            },
+        );
+    }
+
+    fn compute_smoothed_slope(&mut self, trkseg: &TrackSegment) {
+        for_each_window!(
+            trkseg,
+            trkseg.first_index(),
+            trkseg.last_index(),
+            0.05,
+            |i, j| self.local[j.flat].total_distance - self.local[i.flat].total_distance,
+            |i, left, right| {
+                let dist =
+                    self.local[right.flat].total_distance - self.local[left.flat].total_distance;
+                let ele = trkseg[right].ele - trkseg[left].ele;
+                self.local[i.flat].slope = slope(ele, dist);
+            },
+        );
+    }
+
+    fn get_elevation_extremas(&self, trkseg: &TrackSegment) -> Vec<TrackSegmentIndex> {
+        ramer_douglas_peucker(
+            trkseg,
+            &|idx| {
+                (
+                    self.local[idx.flat].total_distance * 1000.0,
+                    trkseg[idx].ele,
+                )
+            },
+            20.0,
+        )
+    }
+}
+
+#[derive(Default, Debug)]
+pub struct GlobalStatistics {
+    pub total_distance: f64,
+    pub moving_distance: Option<f64>,
+    pub moving_time: Option<i32>,
+    pub elevation_gain: f64,
+    pub elevation_loss: f64,
+    pub start_time: Option<i64>,
+    pub end_time: Option<i64>,
+    pub bounds: LngLatBounds,
+}
+
+impl GlobalStatistics {
+    pub fn total_time(&self) -> Option<i32> {
+        time_diff(&self.start_time, &self.end_time)
+    }
+
+    pub fn total_speed(&self) -> Option<f64> {
+        self.total_time().map(|t| speed(self.total_distance, t))
+    }
+
+    pub fn moving_speed(&self) -> Option<f64> {
+        self.moving_distance
+            .zip(self.moving_time)
+            .map(|(d, t)| speed(d, t))
+    }
+
+    pub fn merge(&mut self, other: &GlobalStatistics) {
+        self.total_distance += other.total_distance;
+        self.moving_distance = sum_options(self.moving_distance, other.moving_distance);
+        self.moving_time = sum_options(self.moving_time, other.moving_time);
+        self.elevation_gain += other.elevation_gain;
+        self.elevation_loss += other.elevation_loss;
+        self.bounds.merge(&other.bounds);
+    }
+}
+
+#[derive(Default, Debug)]
+pub struct TrackpointStatistics {
+    pub total_distance: f64,
+    pub moving_distance: Option<f64>,
+    pub total_time: Option<i32>,
+    pub moving_time: Option<i32>,
+    pub speed: Option<f64>,
+    pub elevation_gain: f64,
+    pub elevation_loss: f64,
+    pub slope: f64,
+    pub slope_segment: SlopeSegment,
+}
+
+impl TrackpointStatistics {
+    fn from_partial_stats(stats: &Statistics) -> Self {
+        Self {
+            total_distance: stats.global.total_distance,
+            moving_distance: stats.global.moving_distance,
+            total_time: stats.total_time(),
+            moving_time: stats.global.moving_time,
+            // stats below are computed later
+            speed: None,
+            elevation_gain: Default::default(),
+            elevation_loss: Default::default(),
+            slope: Default::default(),
+            slope_segment: Default::default(),
+        }
+    }
+}
+
+#[derive(Default, Debug)]
+pub struct SlopeSegment {
+    pub slope: f64,
+    pub distance: f64,
+}
+
+#[cfg(test)]
+mod tests {
+    use std::{fs::File, io::Read};
+
+    use crate::parse;
+
+    use super::*;
+
+    #[test]
+    fn test_compute_smoothed_speed() {
+        let mut f = File::open("data/with_time.gpx").unwrap();
+        let mut data = String::new();
+        let _ = f.read_to_string(&mut data);
+        let gpx = parse(data.as_bytes()).unwrap();
+
+        let trkseg = &gpx.trk[0].trkseg[0];
+        let stats = Statistics::compute(trkseg);
+        assert_eq!(stats.local.len(), trkseg.len());
+        for trkpt_stats in stats.local.iter() {
+            assert!(trkpt_stats.speed.is_some());
+            let speed = trkpt_stats.speed.unwrap();
+            assert_ne!(speed, f64::NAN);
+            assert!((speed - 20.0).abs() < 0.1);
+        }
+    }
+
+    // TODO more tests
+}