sparser data transfers

wasm/src/queries/statistics.rs

@@ -26,8 +26,6 @@ stats_getter!(total_distance, 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);
@@ -49,14 +47,6 @@ optional_stats_getter!(moving_distance, Float64Array);
 optional_stats_getter!(total_time, BigInt64Array);
 optional_stats_getter!(moving_time, BigInt64Array);
 optional_stats_getter!(speed, Float64Array);
-// Timestamps in milliseconds since the epoch (`NO_TIME`, the smallest i64, when missing).
-optional_stats_getter!(timestamps, BigInt64Array);
-
-/// Value of the timestamps of the trackpoints that have none.
-#[wasm_bindgen]
-pub fn no_time() -> i64 {
-    gpx_engine::NO_TIME
-}
 
 optional_stats_getter!(hr, Float64Array);
 optional_stats_getter!(cad, Float64Array);
@@ -96,6 +86,19 @@ categories_getters!(highway_starts, highway_values, highways);
 categories_getters!(sac_scale_starts, sac_scale_values, sac_scales);
 categories_getters!(mtb_scale_starts, mtb_scale_values, mtb_scales);
 
+// The smoothed elevation segments of the selection, over which the slope is averaged, as
+// intervals of trackpoints: `slope_segment_starts` holds the index of the first trackpoint of each
+// segment, and `slope_segment_slopes` its slope (%). Their length is in `selection_point`.
+stats_getter!(slope_segment_starts, Uint32Array);
+stats_getter!(slope_segment_slopes, Float64Array);
+
+/// What the buffers do not hold for each trackpoint of the selection, for the one at `index`
+/// (numbered as in the buffers), `undefined` if there is none.
+#[wasm_bindgen]
+pub fn selection_point(index: usize) -> SelectionPoint {
+    optional_js(with_engine(|e| api::selection_point(e, index)).flatten()).unchecked_into()
+}
+
 /// For each trackpoint of the selection (numbered as in the statistics), the highest tolerance
 /// (m) of `reduce` that keeps it: infinite for the ends of the segments.
 #[wasm_bindgen]

wasm/src/tests.rs

@@ -4,7 +4,7 @@
 
 #![allow(clippy::needless_borrows_for_generic_args)]
 
-use js_sys::{Array, BigInt64Array, Float64Array, Object, Reflect};
+use js_sys::{Array, Float64Array, Object, Reflect};
 use wasm_bindgen::prelude::*;
 use wasm_bindgen_test::*;
 
@@ -144,7 +144,10 @@ fn test_loaded_file_has_statistics_and_coordinates() {
     assert_eq!(crate::queries::statistics::lng().length(), n);
     assert_eq!(crate::queries::statistics::ele().length(), n);
     // no timestamps in this file
-    assert!(crate::queries::statistics::timestamps().is_none());
+    let point = crate::queries::statistics::selection_point(0);
+    assert!(get(&point, "slopeSegmentDistance").as_f64().is_some());
+    assert!(get(&point, "time").is_undefined());
+    assert!(crate::queries::statistics::selection_point(n as usize).is_undefined());
 
     let structure = crate::queries::files::file_structure(&id);
     let segment = get(
@@ -165,8 +168,8 @@ fn test_loaded_file_has_statistics_and_coordinates() {
 #[wasm_bindgen_test]
 fn test_timestamps_and_categories() {
     started_with(&[(WITH_TIME, "time")]);
-    let times: BigInt64Array = crate::queries::statistics::timestamps().unwrap();
-    assert!(times.length() > 0);
+    let point = crate::queries::statistics::selection_point(0);
+    assert!(get(&point, "time").as_f64().unwrap() > 0.0);
     assert!(crate::queries::statistics::total_time().is_some());
 
     started_with(&[(WITH_SURFACE, "surface")]);
@@ -179,6 +182,14 @@ fn test_timestamps_and_categories() {
         crate::queries::statistics::surface_starts().length(),
         values.len() as u32
     );
+    // the name of the surface of a trackpoint that has one
+    let starts = crate::queries::statistics::surface_starts().to_vec();
+    let known = values.iter().position(|v| *v > 0).unwrap();
+    let point = crate::queries::statistics::selection_point(starts[known] as usize);
+    assert_eq!(
+        get(&point, "surface").as_string(),
+        Some(surfaces[values[known] as usize - 1].clone())
+    );
 }
 
 #[wasm_bindgen_test]

wasm/src/ts.rs

@@ -64,6 +64,21 @@ export interface TrackpointDetails {
     /** ms since epoch */
     time?: number;
 }
+/**
+ * A trackpoint of the selection: what the statistics buffers do not hold for each trackpoint.
+ * Absent fields are unknown.
+ */
+export interface SelectionPoint {
+    /** ms since epoch */
+    time?: number;
+    /** Slope (%) and length (km) of the smoothed elevation segment of the trackpoint. */
+    slopeSegmentSlope?: number;
+    slopeSegmentDistance?: number;
+    surface?: string;
+    highway?: string;
+    sacScale?: string;
+    mtbScale?: string;
+}
 /** What was copied or cut, to be pasted: the kind of the elements and their ids. */
 export interface Clipboard {
     type: 'files' | 'tracks' | 'segments' | 'waypoints';
@@ -161,6 +176,8 @@ extern "C" {
     pub type WaypointDetails;
     #[wasm_bindgen(typescript_type = "TrackpointDetails | undefined")]
     pub type TrackpointDetails;
+    #[wasm_bindgen(typescript_type = "SelectionPoint | undefined")]
+    pub type SelectionPoint;
     #[wasm_bindgen(typescript_type = "MoveTarget")]
     pub type MoveTarget;