simplify tool

website/src/lib/components/WithUnits.svelte

@@ -13,6 +13,7 @@
 	export let value: number;
 	export let type: 'distance' | 'elevation' | 'speed' | 'temperature' | 'time';
 	export let showUnits: boolean = true;
+	export let decimals: number | undefined = undefined;
 
 	const { distanceUnits, velocityUnits, temperatureUnits } = settings;
 </script>
@@ -20,26 +21,27 @@
 <span class={$$props.class}>
 	{#if type === 'distance'}
 		{#if $distanceUnits === 'metric'}
-			{value.toFixed(2)} {showUnits ? $_('units.kilometers') : ''}
+			{value.toFixed(decimals ?? 2)} {showUnits ? $_('units.kilometers') : ''}
 		{:else}
-			{kilometersToMiles(value).toFixed(2)} {showUnits ? $_('units.miles') : ''}
+			{kilometersToMiles(value).toFixed(decimals ?? 2)} {showUnits ? $_('units.miles') : ''}
 		{/if}
 	{:else if type === 'elevation'}
 		{#if $distanceUnits === 'metric'}
-			{value.toFixed(0)} {showUnits ? $_('units.meters') : ''}
+			{value.toFixed(decimals ?? 0)} {showUnits ? $_('units.meters') : ''}
 		{:else}
-			{metersToFeet(value).toFixed(0)} {showUnits ? $_('units.feet') : ''}
+			{metersToFeet(value).toFixed(decimals ?? 0)} {showUnits ? $_('units.feet') : ''}
 		{/if}
 	{:else if type === 'speed'}
 		{#if $distanceUnits === 'metric'}
 			{#if $velocityUnits === 'speed'}
-				{value.toFixed(2)} {showUnits ? $_('units.kilometers_per_hour') : ''}
+				{value.toFixed(decimals ?? 2)} {showUnits ? $_('units.kilometers_per_hour') : ''}
 			{:else}
 				{secondsToHHMMSS(distancePerHourToSecondsPerDistance(value))}
 				{showUnits ? $_('units.minutes_per_kilometer') : ''}
 			{/if}
 		{:else if $velocityUnits === 'speed'}
-			{kilometersToMiles(value).toFixed(2)} {showUnits ? $_('units.miles_per_hour') : ''}
+			{kilometersToMiles(value).toFixed(decimals ?? 2)}
+			{showUnits ? $_('units.miles_per_hour') : ''}
 		{:else}
 			{secondsToHHMMSS(distancePerHourToSecondsPerDistance(kilometersToMiles(value)))}
 			{showUnits ? $_('units.minutes_per_mile') : ''}

website/src/lib/components/file-list/FileList.ts

@@ -1,8 +1,7 @@
-import { dbUtils, fileObservers } from "$lib/db";
+import { dbUtils } from "$lib/db";
 import { castDraft, freeze } from "immer";
 import { Track, TrackSegment, Waypoint } from "gpx";
 import { selection } from "./Selection";
-import { get } from "svelte/store";
 import { newGPXFile } from "$lib/stores";
 
 export enum ListLevel {
@@ -22,6 +21,7 @@ export abstract class ListItem {
     }
 
     abstract getId(): string | number;
+    abstract getFullId(): string;
     abstract getIdAtLevel(level: ListLevel): string | number | undefined;
     abstract getFileId(): string;
     abstract extend(id: string | number): ListItem;
@@ -36,6 +36,10 @@ export class ListRootItem extends ListItem {
         return 'root';
     }
 
+    getFullId(): string {
+        return 'root';
+    }
+
     getIdAtLevel(level: ListLevel): string | number | undefined {
         return undefined;
     }
@@ -61,6 +65,10 @@ export class ListFileItem extends ListItem {
         return this.fileId;
     }
 
+    getFullId(): string {
+        return this.fileId;
+    }
+
     getIdAtLevel(level: ListLevel): string | number | undefined {
         switch (level) {
             case ListLevel.ROOT:
@@ -97,6 +105,10 @@ export class ListTrackItem extends ListItem {
         return this.trackIndex;
     }
 
+    getFullId(): string {
+        return `${this.fileId}-track-${this.trackIndex}`;
+    }
+
     getIdAtLevel(level: ListLevel): string | number | undefined {
         switch (level) {
             case ListLevel.ROOT:
@@ -137,6 +149,10 @@ export class ListTrackSegmentItem extends ListItem {
         return this.segmentIndex;
     }
 
+    getFullId(): string {
+        return `${this.fileId}-track-${this.trackIndex}--${this.segmentIndex}`;
+    }
+
     getIdAtLevel(level: ListLevel): string | number | undefined {
         switch (level) {
             case ListLevel.ROOT:
@@ -179,6 +195,10 @@ export class ListWaypointsItem extends ListItem {
         return 'waypoints';
     }
 
+    getFullId(): string {
+        return `${this.fileId}-waypoints`;
+    }
+
     getIdAtLevel(level: ListLevel): string | number | undefined {
         switch (level) {
             case ListLevel.ROOT:
@@ -213,6 +233,10 @@ export class ListWaypointItem extends ListItem {
         return this.waypointIndex;
     }
 
+    getFullId(): string {
+        return `${this.fileId}-waypoint-${this.waypointIndex}`;
+    }
+
     getIdAtLevel(level: ListLevel): string | number | undefined {
         switch (level) {
             case ListLevel.ROOT:

website/src/lib/components/file-list/Selection.ts

@@ -200,11 +200,11 @@ export function selectAll() {
     });
 }
 
-export function applyToOrderedSelectedItemsFromFile(callback: (fileId: string, level: ListLevel | undefined, items: ListItem[]) => void, reverse: boolean = true) {
+export function applyToOrderedItemsFromFile(selectedItems: ListItem[], callback: (fileId: string, level: ListLevel | undefined, items: ListItem[]) => void, reverse: boolean = true) {
     get(settings.fileOrder).forEach((fileId) => {
         let level: ListLevel | undefined = undefined;
         let items: ListItem[] = [];
-        get(selection).forEach((item) => {
+        selectedItems.forEach((item) => {
             if (item.getFileId() === fileId) {
                 level = item.level;
                 if (item instanceof ListFileItem || item instanceof ListTrackItem || item instanceof ListTrackSegmentItem || item instanceof ListWaypointsItem || item instanceof ListWaypointItem) {
@@ -218,4 +218,8 @@ export function applyToOrderedSelectedItemsFromFile(callback: (fileId: string, l
             callback(fileId, level, items);
         }
     });
+}
+
+export function applyToOrderedSelectedItemsFromFile(callback: (fileId: string, level: ListLevel | undefined, items: ListItem[]) => void, reverse: boolean = true) {
+    applyToOrderedItemsFromFile(get(selection).getSelected(), callback, reverse);
 }

website/src/lib/components/toolbar/Toolbar.svelte

@@ -48,7 +48,7 @@
 			</ToolbarItem>
 			<ToolbarItem tool={Tool.REDUCE}>
 				<Filter slot="icon" size="18" />
-				<span slot="tooltip">{$_('toolbar.reduce_tooltip')}</span>
+				<span slot="tooltip">{$_('toolbar.reduce.tooltip')}</span>
 			</ToolbarItem>
 			<ToolbarItem tool={Tool.CLEAN}>
 				<SquareDashedMousePointer slot="icon" size="18" />

website/src/lib/components/toolbar/ToolbarItemMenu.svelte

@@ -7,6 +7,7 @@
 	import Waypoint from '$lib/components/toolbar/tools/Waypoint.svelte';
 	import Merge from '$lib/components/toolbar/tools/Merge.svelte';
 	import Clean from '$lib/components/toolbar/tools/Clean.svelte';
+	import Reduce from '$lib/components/toolbar/tools/Reduce.svelte';
 	import RoutingControlPopup from '$lib/components/toolbar/tools/routing/RoutingControlPopup.svelte';
 	import { onMount } from 'svelte';
 	import mapboxgl from 'mapbox-gl';
@@ -42,6 +43,8 @@
 						<Merge />
 					{:else if $currentTool === Tool.CLEAN}
 						<Clean />
+					{:else if $currentTool === Tool.REDUCE}
+						<Reduce />
 					{/if}
 				</Card.Content>
 			</Card.Root>

website/src/lib/components/toolbar/tools/Reduce.svelte

@@ -0,0 +1,173 @@
+<script lang="ts">
+	import { Label } from '$lib/components/ui/label/index.js';
+	import { Button } from '$lib/components/ui/button';
+	import { Slider } from '$lib/components/ui/slider';
+	import { selection } from '$lib/components/file-list/Selection';
+	import { ListItem, ListRootItem, ListTrackSegmentItem } from '$lib/components/file-list/FileList';
+	import Help from '$lib/components/Help.svelte';
+	import { Filter } from 'lucide-svelte';
+	import { _ } from 'svelte-i18n';
+	import WithUnits from '$lib/components/WithUnits.svelte';
+	import { ramerDouglasPeucker, type SimplifiedTrackPoint } from '$lib/simplify';
+	import { dbUtils, fileObservers } from '$lib/db';
+	import { map } from '$lib/stores';
+	import { onDestroy } from 'svelte';
+	import { TrackPoint } from 'gpx';
+	import { derived } from 'svelte/store';
+
+	let sliderValue = [50];
+	let maxPoints = 0;
+	let currentPoints = 0;
+
+	$: validSelection = $selection.hasAnyChildren(new ListRootItem(), true, ['waypoints']);
+
+	$: tolerance = 2 ** (sliderValue[0] / (100 / Math.log2(10000)));
+
+	let simplified = new Map<string, [ListItem, number, SimplifiedTrackPoint[]]>();
+	let unsubscribes = new Map<string, () => void>();
+
+	function update() {
+		maxPoints = 0;
+		currentPoints = 0;
+
+		let data: GeoJSON.FeatureCollection = {
+			type: 'FeatureCollection',
+			features: []
+		};
+
+		simplified.forEach(([item, maxPts, points], itemFullId) => {
+			maxPoints += maxPts;
+
+			let current = points.filter(
+				(point) => point.distance === undefined || point.distance >= tolerance
+			);
+			currentPoints += current.length;
+
+			data.features.push({
+				type: 'Feature',
+				geometry: {
+					type: 'LineString',
+					coordinates: current.map((point) => [
+						point.point.getLongitude(),
+						point.point.getLatitude()
+					])
+				},
+				properties: {}
+			});
+		});
+
+		if ($map) {
+			let source = $map.getSource('simplified');
+			if (source) {
+				source.setData(data);
+			} else {
+				$map.addSource('simplified', {
+					type: 'geojson',
+					data: data
+				});
+			}
+			if (!$map.getLayer('simplified')) {
+				$map.addLayer({
+					id: 'simplified',
+					type: 'line',
+					source: 'simplified',
+					paint: {
+						'line-color': 'white',
+						'line-width': 3
+					}
+				});
+			} else {
+				$map.moveLayer('simplified');
+			}
+		}
+	}
+
+	$: if ($fileObservers) {
+		unsubscribes.forEach((unsubscribe, fileId) => {
+			if (!$fileObservers.has(fileId)) {
+				unsubscribe();
+				unsubscribes.delete(fileId);
+			}
+		});
+		$fileObservers.forEach((fileStore, fileId) => {
+			if (!unsubscribes.has(fileId)) {
+				let unsubscribe = derived([fileStore, selection], ([fs, sel]) => [fs, sel]).subscribe(
+					([fs, sel]) => {
+						if (fs) {
+							fs.file.forEachSegment((segment, trackIndex, segmentIndex) => {
+								let segmentItem = new ListTrackSegmentItem(fileId, trackIndex, segmentIndex);
+								if (sel.hasAnyParent(segmentItem)) {
+									let statistics = fs.statistics.getStatisticsFor(segmentItem);
+									simplified.set(segmentItem.getFullId(), [
+										segmentItem,
+										statistics.local.points.length,
+										ramerDouglasPeucker(statistics.local.points, 1)
+									]);
+									update();
+								} else if (simplified.has(segmentItem.getFullId())) {
+									simplified.delete(segmentItem.getFullId());
+									update();
+								}
+							});
+						}
+					}
+				);
+				unsubscribes.set(fileId, unsubscribe);
+			}
+		});
+	}
+
+	$: if (tolerance) {
+		update();
+	}
+
+	onDestroy(() => {
+		if ($map) {
+			if ($map.getLayer('simplified')) {
+				$map.removeLayer('simplified');
+			}
+			if ($map.getSource('simplified')) {
+				$map.removeSource('simplified');
+			}
+		}
+	});
+
+	function reduce() {
+		let itemsAndPoints = new Map<ListItem, TrackPoint[]>();
+		simplified.forEach(([item, maxPts, points], itemFullId) => {
+			itemsAndPoints.set(
+				item,
+				points
+					.filter((point) => point.distance === undefined || point.distance >= tolerance)
+					.map((point) => point.point)
+			);
+		});
+		dbUtils.reduce(itemsAndPoints);
+	}
+</script>
+
+<div class="flex flex-col gap-3 max-w-80">
+	<div class="p-2">
+		<Slider bind:value={sliderValue} min={0} max={100} step={1} />
+	</div>
+	<Label class="flex flex-row justify-between">
+		<span>{$_('toolbar.reduce.tolerance')}</span>
+		<WithUnits value={tolerance / 1000} type="distance" decimals={3} />
+	</Label>
+	<Label class="flex flex-row justify-between">
+		<span>{$_('toolbar.reduce.number_of_points')}</span>
+		<span>{currentPoints}/{maxPoints}</span>
+	</Label>
+	<Button variant="outline" disabled={!validSelection} on:click={reduce}>
+		<Filter size="16" class="mr-1" />
+		{$_('toolbar.reduce.button')}
+	</Button>
+
+	<Help>
+		{#if validSelection}
+			{$_('toolbar.reduce.help')}
+		{:else}
+			{$_('toolbar.reduce.help_no_selection')}
+		{/if}
+	</Help>
+</div>

website/src/lib/components/toolbar/tools/routing/Simplify.ts

@@ -1,8 +1,5 @@
-import type { Coordinates, GPXFile, TrackPoint, TrackSegment } from "gpx";
-
-type SimplifiedTrackPoint = { point: TrackPoint, distance?: number };
-
-const earthRadius = 6371008.8;
+import { earthRadius, ramerDouglasPeucker } from "$lib/simplify";
+import type { GPXFile, TrackSegment } from "gpx";
 
 export function getZoomLevelForDistance(latitude: number, distance?: number): number {
     if (distance === undefined) {
@@ -49,96 +46,3 @@ function computeAnchorPoints(segment: TrackSegment) {
     segment._data.anchors = true;
 }
 
-export function ramerDouglasPeucker(points: readonly TrackPoint[], epsilon: number = 50, start: number = 0, end: number = points.length - 1): SimplifiedTrackPoint[] {
-    if (points.length == 0) {
-        return [];
-    } else if (points.length == 1) {
-        return [{
-            point: points[0]
-        }];
-    }
-
-    let simplified = [{
-        point: points[start]
-    }];
-    ramerDouglasPeuckerRecursive(points, epsilon, start, end, simplified);
-    simplified.push({
-        point: points[end]
-    });
-    return simplified;
-}
-
-function ramerDouglasPeuckerRecursive(points: readonly TrackPoint[], epsilon: number, start: number, end: number, simplified: SimplifiedTrackPoint[]) {
-    let largest = {
-        index: 0,
-        distance: 0
-    };
-
-    for (let i = start + 1; i < end; i++) {
-        let distance = crossarc(points[start].getCoordinates(), points[end].getCoordinates(), points[i].getCoordinates());
-        if (distance > largest.distance) {
-            largest.index = i;
-            largest.distance = distance;
-        }
-    }
-
-    if (largest.distance > epsilon) {
-        ramerDouglasPeuckerRecursive(points, epsilon, start, largest.index, simplified);
-        simplified.push({ point: points[largest.index], distance: largest.distance });
-        ramerDouglasPeuckerRecursive(points, epsilon, largest.index, end, simplified);
-    }
-}
-
-function crossarc(coord1: Coordinates, coord2: Coordinates, coord3: Coordinates): number {
-    // Calculates the shortest distance in meters 
-    // between an arc (defined by p1 and p2) and a third point, p3.
-    // Input lat1,lon1,lat2,lon2,lat3,lon3 in degrees.
-
-    const rad = Math.PI / 180;
-    const lat1 = coord1.lat * rad;
-    const lat2 = coord2.lat * rad;
-    const lat3 = coord3.lat * rad;
-
-    const lon1 = coord1.lon * rad;
-    const lon2 = coord2.lon * rad;
-    const lon3 = coord3.lon * rad;
-
-    // Prerequisites for the formulas
-    const bear12 = bearing(lat1, lon1, lat2, lon2);
-    const bear13 = bearing(lat1, lon1, lat3, lon3);
-    let dis13 = distance(lat1, lon1, lat3, lon3);
-
-    let diff = Math.abs(bear13 - bear12);
-    if (diff > Math.PI) {
-        diff = 2 * Math.PI - diff;
-    }
-
-    // Is relative bearing obtuse?
-    if (diff > (Math.PI / 2)) {
-        return dis13;
-    }
-
-    // Find the cross-track distance.
-    let dxt = Math.asin(Math.sin(dis13 / earthRadius) * Math.sin(bear13 - bear12)) * earthRadius;
-
-    // Is p4 beyond the arc?
-    let dis12 = distance(lat1, lon1, lat2, lon2);
-    let dis14 = Math.acos(Math.cos(dis13 / earthRadius) / Math.cos(dxt / earthRadius)) * earthRadius;
-    if (dis14 > dis12) {
-        return distance(lat2, lon2, lat3, lon3);
-    } else {
-        return Math.abs(dxt);
-    }
-}
-
-function distance(latA: number, lonA: number, latB: number, lonB: number): number {
-    // Finds the distance between two lat / lon points.
-    return Math.acos(Math.sin(latA) * Math.sin(latB) + Math.cos(latA) * Math.cos(latB) * Math.cos(lonB - lonA)) * earthRadius;
-}
-
-
-function bearing(latA: number, lonA: number, latB: number, lonB: number): number {
-    // Finds the bearing from one lat / lon point to another.
-    return Math.atan2(Math.sin(lonB - lonA) * Math.cos(latB),
-        Math.cos(latA) * Math.sin(latB) - Math.sin(latA) * Math.cos(latB) * Math.cos(lonB - lonA));
-}

website/src/lib/db.ts

@@ -5,7 +5,7 @@ import { writable, get, derived, type Readable, type Writable } from 'svelte/sto
 import { initTargetMapBounds, splitAs, updateTargetMapBounds } from './stores';
 import { mode } from 'mode-watcher';
 import { defaultBasemap, defaultBasemapTree, defaultOverlayTree, defaultOverlays } from './assets/layers';
-import { applyToOrderedSelectedItemsFromFile, selection } from '$lib/components/file-list/Selection';
+import { applyToOrderedItemsFromFile, applyToOrderedSelectedItemsFromFile, selection } from '$lib/components/file-list/Selection';
 import { ListFileItem, ListItem, ListTrackItem, ListLevel, ListTrackSegmentItem, ListWaypointItem, ListRootItem } from '$lib/components/file-list/FileList';
 import { updateAnchorPoints } from '$lib/components/toolbar/tools/routing/Simplify';
 import { SplitType } from '$lib/components/toolbar/tools/Scissors.svelte';
@@ -676,6 +676,31 @@ export const dbUtils = {
             });
         });
     },
+    reduce: (itemsAndPoints: Map<ListItem, TrackPoint[]>) => {
+        if (itemsAndPoints.size === 0) {
+            return;
+        }
+        applyGlobal((draft) => {
+            let allItems = Array.from(itemsAndPoints.keys());
+            applyToOrderedItemsFromFile(allItems, (fileId, level, items) => {
+                let file = original(draft)?.get(fileId);
+                if (file) {
+                    let newFile = file;
+                    for (let item of items) {
+                        if (item instanceof ListTrackSegmentItem) {
+                            let trackIndex = item.getTrackIndex();
+                            let segmentIndex = item.getSegmentIndex();
+                            let points = itemsAndPoints.get(item);
+                            if (points) {
+                                newFile = newFile.replaceTrackPoints(trackIndex, segmentIndex, 0, file.trk[trackIndex].trkseg[segmentIndex].getNumberOfTrackPoints() - 1, points);
+                            }
+                        }
+                    }
+                    draft.set(newFile._data.id, freeze(newFile));
+                }
+            });
+        });
+    },
     deleteSelection: () => {
         if (get(selection).size === 0) {
             return;

website/src/lib/simplify.ts

@@ -0,0 +1,99 @@
+import type { Coordinates, TrackPoint } from "gpx";
+
+export type SimplifiedTrackPoint = { point: TrackPoint, distance?: number };
+
+export const earthRadius = 6371008.8;
+
+export function ramerDouglasPeucker(points: readonly TrackPoint[], epsilon: number = 50, start: number = 0, end: number = points.length - 1): SimplifiedTrackPoint[] {
+    if (points.length == 0) {
+        return [];
+    } else if (points.length == 1) {
+        return [{
+            point: points[0]
+        }];
+    }
+
+    let simplified = [{
+        point: points[start]
+    }];
+    ramerDouglasPeuckerRecursive(points, epsilon, start, end, simplified);
+    simplified.push({
+        point: points[end]
+    });
+    return simplified;
+}
+
+function ramerDouglasPeuckerRecursive(points: readonly TrackPoint[], epsilon: number, start: number, end: number, simplified: SimplifiedTrackPoint[]) {
+    let largest = {
+        index: 0,
+        distance: 0
+    };
+
+    for (let i = start + 1; i < end; i++) {
+        let distance = crossarc(points[start].getCoordinates(), points[end].getCoordinates(), points[i].getCoordinates());
+        if (distance > largest.distance) {
+            largest.index = i;
+            largest.distance = distance;
+        }
+    }
+
+    if (largest.distance > epsilon && largest.index != 0) {
+        ramerDouglasPeuckerRecursive(points, epsilon, start, largest.index, simplified);
+        simplified.push({ point: points[largest.index], distance: largest.distance });
+        ramerDouglasPeuckerRecursive(points, epsilon, largest.index, end, simplified);
+    }
+}
+
+function crossarc(coord1: Coordinates, coord2: Coordinates, coord3: Coordinates): number {
+    // Calculates the shortest distance in meters 
+    // between an arc (defined by p1 and p2) and a third point, p3.
+    // Input lat1,lon1,lat2,lon2,lat3,lon3 in degrees.
+
+    const rad = Math.PI / 180;
+    const lat1 = coord1.lat * rad;
+    const lat2 = coord2.lat * rad;
+    const lat3 = coord3.lat * rad;
+
+    const lon1 = coord1.lon * rad;
+    const lon2 = coord2.lon * rad;
+    const lon3 = coord3.lon * rad;
+
+    // Prerequisites for the formulas
+    const bear12 = bearing(lat1, lon1, lat2, lon2);
+    const bear13 = bearing(lat1, lon1, lat3, lon3);
+    let dis13 = distance(lat1, lon1, lat3, lon3);
+
+    let diff = Math.abs(bear13 - bear12);
+    if (diff > Math.PI) {
+        diff = 2 * Math.PI - diff;
+    }
+
+    // Is relative bearing obtuse?
+    if (diff > (Math.PI / 2)) {
+        return dis13;
+    }
+
+    // Find the cross-track distance.
+    let dxt = Math.asin(Math.sin(dis13 / earthRadius) * Math.sin(bear13 - bear12)) * earthRadius;
+
+    // Is p4 beyond the arc?
+    let dis12 = distance(lat1, lon1, lat2, lon2);
+    let dis14 = Math.acos(Math.cos(dis13 / earthRadius) / Math.cos(dxt / earthRadius)) * earthRadius;
+    if (dis14 > dis12) {
+        return distance(lat2, lon2, lat3, lon3);
+    } else {
+        return Math.abs(dxt);
+    }
+}
+
+function distance(latA: number, lonA: number, latB: number, lonB: number): number {
+    // Finds the distance between two lat / lon points.
+    return Math.acos(Math.sin(latA) * Math.sin(latB) + Math.cos(latA) * Math.cos(latB) * Math.cos(lonB - lonA)) * earthRadius;
+}
+
+
+function bearing(latA: number, lonA: number, latB: number, lonB: number): number {
+    // Finds the bearing from one lat / lon point to another.
+    return Math.atan2(Math.sin(lonB - lonA) * Math.cos(latB),
+        Math.cos(latA) * Math.sin(latB) - Math.sin(latA) * Math.cos(latB) * Math.cos(lonB - lonA));
+}

website/src/locales/en.json

@@ -60,8 +60,8 @@
                 "button": "Round trip",
                 "tooltip": "Return to the starting point by the same route"
             },
-            "help_no_file": "Select a file element to use the routing tool, or create a new file from the menu",
-            "help_multiple_files": "Select a single file element to use the routing tool",
+            "help_no_file": "Select a file item to use the routing tool, or create a new file from the menu",
+            "help_multiple_files": "Select a single file item to use the routing tool",
             "help": "Click on the map to add a new anchor point, or drag existing ones to change the route",
             "activities": {
                 "bike": "Bike",
@@ -114,7 +114,7 @@
             "tooltip": "Crop or split traces",
             "crop": "Crop",
             "split_as": "Split the trace into",
-            "help_invalid_selection": "Select a file element to crop or split",
+            "help_invalid_selection": "Select a file item to crop or split",
             "help": "Use the slider to crop the trace, or click on the map to split it at the selected point"
         },
         "time_tooltip": "Manage time and speed data",
@@ -122,15 +122,22 @@
             "merge_traces": "Connect the traces",
             "merge_contents": "Merge the contents and keep the traces disconnected",
             "merge_selection": "Merge selection",
-            "tooltip": "Merge file elements together",
-            "help_merge_traces": "Connecting the selected traces will result in a single file containing a single continuous trace",
+            "tooltip": "Merge file items together",
+            "help_merge_traces": "Connecting the selected traces will create a single file containing a single continuous trace",
             "help_cannot_merge_traces": "Your selection needs to contain several traces to connect them",
-            "help_merge_contents": "Merging the contents of the selected file elements will group all the contents inside the first file element",
-            "help_cannot_merge_contents": "Your selection needs to contain several file elements to merge their contents"
+            "help_merge_contents": "Merging the contents of the selected file items will group all the contents inside the first file item",
+            "help_cannot_merge_contents": "Your selection needs to contain several file items to merge their contents"
         },
         "extract_tooltip": "Extract inner tracks or segments",
         "waypoint_tooltip": "Create and edit points of interest",
-        "reduce_tooltip": "Reduce the number of GPS points",
+        "reduce": {
+            "tooltip": "Reduce the number of GPS points",
+            "tolerance": "Tolerance",
+            "number_of_points": "Number of GPS points",
+            "button": "Reduce",
+            "help": "Use the slider to choose the number of GPS points to keep",
+            "help_no_selection": "Select a file item to reduce the number of its GPS points"
+        },
         "clean": {
             "tooltip": "Clean GPS points and points of interest with a rectangle selection",
             "delete_trackpoints": "Delete GPS points",
@@ -139,7 +146,7 @@
             "delete_outside": "Delete outside selection",
             "button": "Delete",
             "help": "Select a rectangle area on the map to remove GPS points and points of interest",
-            "help_no_selection": "Select a file element to use the tool"
+            "help_no_selection": "Select a file item to clean GPS points and points of interest"
         },
         "style_tooltip": "Change the style of the trace"
     },