release 0.0.9

.gitignore

@@ -14,3 +14,4 @@ coverage/
 
 .idea/
 
+.DS_Store

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.0.9
+
+- Implements `length`, `along` [#153](https://github.com/dartclub/turf_dart/pull/153)
+- Documentation: Improves pub.dev scores by fixing bad links in Readme.md
+
 ## 0.0.8
 
 - Implements `transformRotate`, `rhumbDistance`, `rhumbDestination`, `centroid` [#147](https://github.com/dartclub/turf_dart/pull/147)
@@ -38,7 +43,8 @@
 
 ## 0.0.5
 
-- Implements *all* meta functions and`lineSegment`
+
+- Implements *all* meta functions and `lineSegment`
 - Adds a lot of documentation
 - Several bug and type fixes
 

README.md

@@ -1,7 +1,5 @@
 # turf.dart
 
-ℹ️ Looking for maintainers as a work student position in Germany: Write an email to [[email protected]](mailto:[email protected]) ℹ️
-
 [![pub package](https://img.shields.io/pub/v/turf.svg)](https://pub.dev/packages/turf)
 
 THIS PROJECT IS WORK IN PROCESS
@@ -80,7 +78,7 @@ Any new benchmarks must be named `*_benchmark.dart` and reside in the
 
 ### Measurement
 
-- [ ] along
+- [x] [along](https://github.com/dartclub/turf_dart/blob/main/lib/src/along.dart)
 - [x] [area](https://github.com/dartclub/turf_dart/blob/main/lib/src/area.dart)
 - [x] [bbox](https://github.com/dartclub/turf_dart/blob/main/lib/src/bbox.dart)
 - [x] [bboxPolygon](https://github.com/dartclub/turf_dart/blob/main/lib/src/bbox_polygon.dart)
@@ -91,7 +89,7 @@ Any new benchmarks must be named `*_benchmark.dart` and reside in the
 - [x] [destination](https://github.com/dartclub/turf_dart/blob/main/lib/src/destination.dart)
 - [x] [distance](https://github.com/dartclub/turf_dart/blob/main/lib/src/distance.dart)
 - [ ] envelope
-- [ ] length
+- [x] [length](https://github.com/dartclub/turf_dart/blob/main/lib/src/length.dart)
 - [x] [midpoint](https://github.com/dartclub/turf_dart/blob/main/lib/src/midpoint.dart)
 - [ ] pointOnFeature
 - [ ] polygonTangents
@@ -123,7 +121,7 @@ Any new benchmarks must be named `*_benchmark.dart` and reside in the
 - [ ] dissolve
 - [ ] intersect
 - [ ] lineOffset
-- [x] [polygonSmooth](ttps://github.com/dartclub/turf_dart/blob/main/lib/src/polygon_smooth.dart)
+- [x] [polygonSmooth](https://github.com/dartclub/turf_dart/blob/main/lib/src/polygon_smooth.dart)
 - [ ] simplify
 - [ ] tesselate
 - [x] [transformRotate](https://github.com/dartclub/turf_dart/blob/main/lib/src/transform_rotate.dart)
@@ -234,7 +232,7 @@ Any new benchmarks must be named `*_benchmark.dart` and reside in the
 - [x] [booleanCrosses](https://github.com/dartclub/turf_dart/blob/main/lib/src/booleans/boolean_crosses.dart)
 - [x] [booleanDisjoint](https://github.com/dartclub/turf_dart/blob/main/lib/src/booleans/boolean_disjoint.dart)
 - [x] [booleanEqual](https://github.com/dartclub/turf_dart/blob/main/lib/src/booleans/boolean_equal.dart)
-- [x] [booleanIntersects](https://github.com/dartclub/turf_dart/blob/main/lib/src/booleans/boolean_intersect.dart)
+- [x] [booleanIntersects](https://github.com/dartclub/turf_dart/blob/main/lib/src/booleans/boolean_intersects.dart)
 - [ ] booleanOverlap
 - [x] [booleanParallel](https://github.com/dartclub/turf_dart/blob/main/lib/src/booleans/boolean_parallel.dart)
 - [x] [booleanPointInPolygon](https://github.com/dartclub/turf_dart/blob/main/lib/src/booleans/boolean_point_in_polygon.dart)
@@ -252,4 +250,4 @@ Any new benchmarks must be named `*_benchmark.dart` and reside in the
 - [x] [radiansToLength](https://github.com/dartclub/turf_dart/blob/main/lib/src/helpers.dart)
 - [x] [radiansToDegrees](https://github.com/dartclub/turf_dart/blob/main/lib/src/helpers.dart)
 - [ ] toMercator
-- [ ] toWgs84
+- [ ] toWgs84

lib/along.dart

@@ -0,0 +1,3 @@
+library turf_along;
+
+export "src/along.dart";

lib/length.dart

@@ -0,0 +1,3 @@
+library turf_length;
+
+export "src/length.dart";

lib/src/along.dart

@@ -0,0 +1,54 @@
+import 'dart:math';
+
+import 'package:turf/bearing.dart';
+import 'package:turf/destination.dart';
+import 'package:turf/helpers.dart';
+import 'package:turf/length.dart';
+import 'package:turf/src/distance.dart' as measure_distance;
+import 'package:turf/src/invariant.dart';
+
+/// Takes a [line] and returns a [Point] at a specified [distance] along the line.
+///
+/// If [distance] is less than 0, it will count distance along the line from end
+///   to start of line. If negative [distance] overshoots the length of the line,
+///   the start point of the line is returned.
+/// If [distance] is larger than line length, the end point is returned
+/// If [line] have no geometry or coordinates, an Exception is thrown
+Feature<Point> along(Feature<LineString> line, num distance,
+    [Unit unit = Unit.kilometers]) {
+  // Get Coords
+  final coords = getCoords(line);
+  if (coords.isEmpty) {
+    throw Exception('line must contain at least one coordinate');
+  }
+  if (distance < 0) {
+    distance = max(0, length(line, unit) + distance);
+  }
+  num travelled = 0;
+  for (int i = 0; i < coords.length; i++) {
+    if (distance >= travelled && i == coords.length - 1) {
+      break;
+    }
+    if (travelled == distance) {
+      return Feature<Point>(geometry: Point(coordinates: coords[i]));
+    }
+    if (travelled > distance) {
+      final overshot = distance - travelled;
+      final direction = bearing(Point(coordinates: coords[i]),
+              Point(coordinates: coords[i - 1])) -
+          180;
+      final interpolated = destination(
+        Point(coordinates: coords[i]),
+        overshot,
+        direction,
+        unit,
+      );
+      return Feature<Point>(geometry: interpolated);
+    } else {
+      travelled += measure_distance.distance(Point(coordinates: coords[i]),
+          Point(coordinates: coords[i + 1]), unit);
+    }
+  }
+  return Feature<Point>(
+      geometry: Point(coordinates: coords[coords.length - 1]));
+}

lib/src/length.dart

@@ -0,0 +1,25 @@
+import 'package:turf/distance.dart';
+import 'package:turf/helpers.dart';
+import 'package:turf/line_segment.dart';
+
+/// Takes a [line] and measures its length in the specified [unit].
+num length(Feature<LineString> line, [Unit unit = Unit.kilometers]) {
+  return segmentReduce<num>(line, (
+        previousValue,
+        currentSegment,
+        initialValue,
+        featureIndex,
+        multiFeatureIndex,
+        geometryIndex,
+        segmentIndex,
+      ) {
+        final coords = currentSegment.geometry!.coordinates;
+        return previousValue! +
+            distance(
+              Point(coordinates: coords[0]),
+              Point(coordinates: coords[1]),
+              unit,
+            );
+      }, 0.0) ??
+      0.0;
+}

lib/src/nearest_point_on_line.dart

@@ -183,6 +183,13 @@ _NearestMulti? _nearestPointOnMultiLine(
 }
 
 /// Takes a [Point] and a [LineString] and calculates the closest Point on the [LineString].
+///
+/// The properties of returned [Point] will contain three values:
+/// * index: closest point was found on nth line part
+/// * dist: distance between [point] and the closest point on line
+/// * location: distance along the line between start and the closest point.
+///
+/// Example:
 /// ```dart
 /// var line = LineString(
 ///   coordinates: [

lib/turf.dart

@@ -1,5 +1,6 @@
 library turf;
 
+export 'src/along.dart';
 export 'src/area.dart';
 export 'src/bbox.dart';
 export 'src/bearing.dart';
@@ -9,6 +10,7 @@ export 'src/destination.dart';
 export 'src/distance.dart';
 export 'src/geojson.dart';
 export 'src/helpers.dart';
+export 'src/length.dart';
 export 'src/midpoint.dart';
 export 'src/nearest_point.dart';
 export 'src/polyline.dart';

pubspec.yaml

@@ -1,22 +1,23 @@
 name: turf
 description: A turf.js-like geospatial analysis library working with GeoJSON, written in pure Dart.
-version: 0.0.8
+version: 0.0.9
 environment:
-  sdk: ">=2.15.0 <4.0.0"
+  sdk: ">=2.17.0 <4.0.0"
 homepage: https://github.com/dartclub/turf_dart
 repository: https://github.com/dartclub/turf_dart
 
 dependencies:
   json_annotation: ^4.8.1
-  turf_equality: ^0.0.2
-  turf_pip: ^0.0.1+1
+
+  turf_equality: ^0.0.3
+  turf_pip: ^0.0.2
   rbush: ^1.1.0
-  sweepline_intersections: ^0.0.3+1
+  sweepline_intersections: ^0.0.4
 
 dev_dependencies:
-  lints: ^2.1.1
+  lints: ^3.0.0
   test: ^1.24.3
   json_serializable: ^6.7.0
   build_runner: ^2.4.5
-  analyzer: ^5.13.0
+  analyzer: ^6.4.0
   benchmark: ^0.3.0

test/components/along_test.dart

@@ -0,0 +1,98 @@
+import 'package:test/test.dart';
+import 'package:turf/along.dart';
+import 'package:turf/distance.dart';
+import 'package:turf/helpers.dart';
+import 'package:turf/length.dart';
+
+void main() {
+  test('along - negative distance should count backwards', () {
+    final viaToEndDistance =
+        distance(Point(coordinates: via), Point(coordinates: end), Unit.meters);
+    expect(viaToEndDistance.round(), equals(198));
+    final resolvedViaPoint = along(line, -1 * viaToEndDistance, Unit.meters);
+    expect(resolvedViaPoint.geometry, isNotNull);
+    expect(resolvedViaPoint.geometry!.coordinates, equals(via));
+  });
+  test('along - to start point', () {
+    final resolvedStartPoint = along(line, 0, Unit.meters);
+    expect(resolvedStartPoint.geometry, isNotNull);
+    expect(resolvedStartPoint.geometry!.coordinates, equals(start));
+  });
+  test('along - to point between start and via', () {
+    final startToViaDistance = distance(
+        Point(coordinates: start), Point(coordinates: via), Unit.meters);
+    expect(startToViaDistance.round(), equals(57));
+    final resolvedViaPoint = along(line, startToViaDistance / 2, Unit.meters);
+    expect(resolvedViaPoint.geometry, isNotNull);
+    expect(resolvedViaPoint.geometry!.coordinates.lat.toStringAsFixed(6),
+        equals('55.709028'));
+    expect(resolvedViaPoint.geometry!.coordinates.lng.toStringAsFixed(6),
+        equals('13.185096'));
+  });
+  test('along - to via point', () {
+    final startToViaDistance = distance(
+        Point(coordinates: start), Point(coordinates: via), Unit.meters);
+    expect(startToViaDistance.round(), equals(57));
+    final resolvedViaPoint = along(line, startToViaDistance, Unit.meters);
+    expect(resolvedViaPoint.geometry, isNotNull);
+    expect(resolvedViaPoint.geometry!.coordinates, equals(via));
+  });
+  test('along - to point between via and end', () {
+    final startToViaDistance = distance(
+        Point(coordinates: start), Point(coordinates: via), Unit.meters);
+    final viaToEndDistance =
+        distance(Point(coordinates: via), Point(coordinates: end), Unit.meters);
+    expect(startToViaDistance.round(), equals(57));
+    expect(viaToEndDistance.round(), equals(198));
+    final resolvedViaPoint =
+        along(line, startToViaDistance + viaToEndDistance / 2, Unit.meters);
+    expect(resolvedViaPoint.geometry, isNotNull);
+    expect(resolvedViaPoint.geometry!.coordinates.lat.toStringAsFixed(6),
+        equals('55.708330'));
+    expect(resolvedViaPoint.geometry!.coordinates.lng.toStringAsFixed(6),
+        equals('13.186555'));
+  });
+  test('along - to end point', () {
+    final len = length(line, Unit.meters);
+    expect(len.round(), equals(254));
+    final resolvedEndPoint = along(line, len, Unit.meters);
+    expect(resolvedEndPoint.geometry, isNotNull);
+    expect(resolvedEndPoint.geometry!.coordinates, equals(end));
+  });
+  test('along - to end point - default unit (km)', () {
+    final len = length(line);
+    expect((len * 1000).round(), equals(254));
+    final resolvedEndPoint = along(line, len);
+    expect(resolvedEndPoint.geometry, isNotNull);
+    expect(resolvedEndPoint.geometry!.coordinates, equals(end));
+  });
+  test('along - beyond end point', () {
+    final len = length(line, Unit.meters);
+    expect(len.round(), equals(254));
+    final resolvedEndPoint = along(line, len + 100, Unit.meters);
+    expect(resolvedEndPoint.geometry, isNotNull);
+    expect(resolvedEndPoint.geometry!.coordinates, equals(end));
+  });
+}
+
+final start = Position.named(
+  lat: 55.7090430186194,
+  lng: 13.184645393920405,
+);
+final via = Position.named(
+  lat: 55.70901279569489,
+  lng: 13.185546616182755,
+);
+final end = Position.named(
+  lat: 55.70764669578079,
+  lng: 13.187563637197076,
+);
+final line = Feature<LineString>(
+  geometry: LineString(
+    coordinates: [
+      start,
+      via,
+      end,
+    ],
+  ),
+);

test/components/length_test.dart

@@ -0,0 +1,36 @@
+import 'package:test/test.dart';
+import 'package:turf/helpers.dart';
+import 'package:turf/length.dart';
+
+void main() {
+  test('length - in meters', () {
+    final len = length(line, Unit.meters);
+    expect(len.round(), equals(254));
+  });
+  test('length - default unit (km)', () {
+    final len = length(line);
+    expect((len * 1000).round(), equals(254));
+  });
+}
+
+final start = Position.named(
+  lat: 55.7090430186194,
+  lng: 13.184645393920405,
+);
+final via = Position.named(
+  lat: 55.70901279569489,
+  lng: 13.185546616182755,
+);
+final end = Position.named(
+  lat: 55.70764669578079,
+  lng: 13.187563637197076,
+);
+final line = Feature<LineString>(
+  geometry: LineString(
+    coordinates: [
+      start,
+      via,
+      end,
+    ],
+  ),
+);