### Run Turf.js Helpers Examples

Source: https://github.com/dartclub/turf_dart/blob/main/test/examples/helpers/README.md

Execute the example code to see the output of the turf_dart helper functions.

```bash
dart test/examples/helpers/helpers_example.dart
```

--------------------------------

### Install Dependencies

Source: https://github.com/dartclub/turf_dart/blob/main/CONTRIBUTING.md

Navigate to the project's folder and install its dependencies using Dart Pub.

```bash
dart pub get
```

--------------------------------

### Install Turf Package

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Run this command in your terminal to install the turf package after adding it to pubspec.yaml.

```bash
dart pub add turf
```

--------------------------------

### Create a LineString Instance

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Example of creating a LineString with multiple coordinate points.

```dart
var line = LineString(coordinates: [
  Position(0, 0),
  Position(5, 5),
  Position(10, 10),
]);
```

--------------------------------

### Example Usage of Turf.dart Library

Source: https://github.com/dartclub/turf_dart/blob/main/CONTRIBUTING.md

Demonstrates how to import and use the Turf.dart library for geometric operations, specifically using segmentReduce with a Polygon.

```dart
import 'package:turf/helpers.dart';
import 'package:turf/src/line_segment.dart';

  Feature<Polygon> poly = Feature<Polygon>(
    geometry: Polygon(coordinates: [
      [
        Position(0, 0), 
        Position(2, 2),
        Position(0, 1),
        Position(0, 0),
      ],
      [
        Position(0, 0),
        Position(1, 1),
        Position(0, 1),
        Position(0, 0),
      ],
    ]),
  );

var total = segmentReduce<int>(poly, (previousValue,
        currentSegment,
        initialValue,
        featureIndex,
        multiFeatureIndex,
        geometryIndex,
        segmentIndex) {
      if (previousValue != null) {
        previousValue++;
      }
      return previousValue;
    }, 0, combineNestedGeometries: false);
// total.length ==  6

```

--------------------------------

### Create a Simple Polygon Instance

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Example of creating a Polygon with a single outer ring.

```dart
// Simple polygon
var poly = Polygon(coordinates: [
  [
    Position(0, 0),
    Position(10, 0),
    Position(10, 10),
    Position(0, 10),
    Position(0, 0)
  ]
]);
```

--------------------------------

### Run Output Generator

Source: https://github.com/dartclub/turf_dart/blob/main/test/examples/point_on_feature/README.md

Run this command to regenerate the output GeoJSON files for the examples.

```bash
dart test/examples/point_on_feature/generate_outputs.dart
```

--------------------------------

### Create a Feature Instance

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Example of creating a Feature with Point geometry, properties, ID, and bounding box. Access its components using dot notation.

```dart
var feature = Feature<Point>(
  geometry: Point(coordinates: Position(10, 45)),
  properties: {
    'name': 'My Location',
    'population': 10000,
    'elevation': 1000.5,
  },
  id: 'loc-001',
  bbox: BBox.named(lng1: 10, lat1: 45, lng2: 10, lat2: 45),
);

// Access
print(feature.geometry?.coordinates);  // Position(10, 45)
print(feature.properties?['name']);    // 'My Location'
print(feature.id);                     // 'loc-001'
```

--------------------------------

### Create a FeatureCollection Instance

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Example of creating a FeatureCollection with two Point Features. It includes a bounding box encompassing all features.

```dart
var collection = FeatureCollection(
  features: [
    Feature<Point>(
      geometry: Point(coordinates: Position(0, 0)),
      properties: {'id': 1},
    ),
    Feature<Point>(
      geometry: Point(coordinates: Position(1, 1)),
      properties: {'id': 2},
    ),
  ],
  bbox: BBox.named(lng1: 0, lat1: 0, lng2: 1, lat2: 1),
);
```

--------------------------------

### Polygon Segment Reduction Example

Source: https://github.com/dartclub/turf_dart/blob/main/README.md

Demonstrates how to use segmentReduce to process segments of a GeoJSON Polygon. Ensure the turf and geotypes libraries are imported.

```dart
import 'package:turf/helpers.dart';
import 'package:turf/src/line_segment.dart';

Feature<Polygon> poly = Feature<Polygon>(
  geometry: Polygon(coordinates: [
    [
      Position(0, 0), 
      Position(2, 2), 
      Position(0, 1), 
      Position(0, 0),
    ],
    [
      Position(0, 0), 
      Position(1, 1), 
      Position(0, 1), 
      Position(0, 0),
    ],
  ]),
);

void main() {
  var total = segmentReduce<int>(
    poly,
    (previousValue, currentSegment, initialValue, featureIndex,
        multiFeatureIndex, geometryIndex, segmentIndex) {
      if (previousValue != null) {
        previousValue++;
      }
      return previousValue;
    },
    0,
    combineNestedGeometries: false,
  );
  print(total);
  // total ==  6
}
```

--------------------------------

### Create a Polygon Instance with a Hole

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Example of creating a Polygon with an outer ring and an inner hole.

```dart
// Polygon with hole
var polyWithHole = Polygon(coordinates: [
  [  // Outer ring
    Position(0, 0),
    Position(10, 0),
    Position(10, 10),
    Position(0, 10),
    Position(0, 0)
  ],
  [  // Hole
    Position(2, 2),
    Position(4, 2),
    Position(4, 4),
    Position(2, 4),
    Position(2, 2)
  ]
]);
```

--------------------------------

### Create and Access BBox Instance

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Example of creating a BBox using the named constructor and accessing its coordinates via array or named properties. The format is [minLng, minLat, maxLng, maxLat].

```dart
var bbox = BBox.named(
  lng1: -10.5,
  lat1: 45.2,
  lng2: 20.3,
  lat2: 55.8,
);

// Array access
var minLng = bbox[0];   // -10.5
var minLat = bbox[1];   // 45.2
var maxLng = bbox[2];   // 20.3
var maxLat = bbox[3];   // 55.8

// Named access
var west = bbox.lng1;   // -10.5
var south = bbox.lat1;  // 45.2
```

--------------------------------

### Navigate to Destination

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/03-geometry-operations.md

Calculates the destination point given a starting point, distance, bearing, and unit.

```dart
var currentLocation = Point(coordinates: Position(-75.343, 39.984));
var distance = 100;
var bearing = 45;  // northeast

var newLocation = destination(currentLocation, distance, bearing, Unit.kilometers);
```

--------------------------------

### Turf.js Dart Installation in pubspec.yaml

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/00-index.md

Specifies the Turf.js package dependency in your Dart project's pubspec.yaml file. Ensure you use a compatible version.

```yaml
dependencies:
  turf: ^0.0.12
```

--------------------------------

### lineSliceAlong

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/06-line-operations.md

Extracts a section of a line based on distance from the start. It takes a start distance and a stop distance along the line and returns the corresponding segment. The unit of distance can be specified.

```APIDOC
## lineSliceAlong

### Description
Extracts a section of a line based on distance from the start. It takes a start distance and a stop distance along the line and returns the corresponding segment. The unit of distance can be specified.

### Parameters
#### Path Parameters
- **startDist** (num) - Required - Start distance along line
- **stopDist** (num) - Required - Stop distance along line
- **line** (Feature<LineString>) - Required - LineString to slice
#### Query Parameters
- **unit** (Unit) - Optional - Unit of distance (default: kilometers)

### Returns
`Feature<LineString>` — Sliced line segment

### Example
```dart
var line = Feature<LineString>(
  geometry: LineString(coordinates: [
    Position(0, 0),
    Position(5, 5),
    Position(10, 10),
  ]),
);

// Extract 2-8 km of the line
var sliced = lineSliceAlong(2, 8, line, unit: Unit.kilometers);
```
```

--------------------------------

### Navigate by Distance and Bearing

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Calculate a destination point given a starting point, distance, and bearing using the `destination` function. Specify the unit for distance.

```dart
import 'package:turf/destination.dart';

var start = Point(coordinates: Position(0, 0));
var distance = 100;
var bearing = 45;  // Northeast

var destination = destination(start, distance, bearing, Unit.kilometers);
print(destination.coordinates);
```

--------------------------------

### Handle Common Turf.js Errors

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Illustrates how to catch specific errors like invalid units, null/missing geometries, and invalid coordinate data. Provides examples for common exception scenarios.

```dart
// Invalid unit
try {
  radiansToLength(1.0, Unit.hectares);  // Invalid unit
} on Exception catch (e) {
  print('$e');  // Exception: Unit.hectares units is invalid
}

// Null/missing geometry
try {
  var geom = getGeom(featureCollection);  // FeatureCollection not allowed
} on Exception catch (e) {
  print('$e');  // Cannot retrieve single Geometry from FeatureCollection
}

// Invalid coordinates
try {
  var line = LineString(coordinates: [Position(0, 0)]);  // Need ≥2 coords
} on Exception catch (e) {
  print('$e');
}
```

--------------------------------

### destination

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/03-geometry-operations.md

Calculates a destination point given a starting point, distance, and bearing. Supports various units for distance.

```APIDOC
## destination

### Description
Calculates a destination point given distance and bearing from an origin.

### Method
```dart
Point destination(
  Point origin,
  num distance,
  num bearing,
  [Unit unit = Unit.kilometers]
)
```

### Parameters
#### Path Parameters
- **origin** (Point) - Required - Starting point
- **distance** (num) - Required - Distance to travel
- **bearing** (num) - Required - Direction in degrees (0° = north, 90° = east)
- **unit** (Unit) - Optional - Unit of distance (kilometers, miles, meters, etc.)

### Returns
`Point` — Destination point

### Example
```dart
var startPoint = Point(coordinates: Position(-75.343, 39.984));
var distance = 50;
var bearing = 90;  // due east

var endPoint = destination(startPoint, distance, bearing, Unit.miles);
// Result: Point ~50 miles east of starting point
```
```

--------------------------------

### Calculate Initial Bearing Between Points

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/02-distance-bearing.md

Use the `bearing` function to determine the initial compass direction from a starting `Point` to an ending `Point`. The result is in degrees (0-360).

```dart
var point1 = Point(coordinates: Position(-75.343, 39.984));
var point2 = Point(coordinates: Position(-75.543, 39.123));

var initialBearing = bearing(point1, point2);        // ~215.5° (southwest)
var finalBearing = bearing(point1, point2, calcFinal: true);  // ~211.2°
```

--------------------------------

### Calculate Destination Point

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/03-geometry-operations.md

Calculates a destination point given a starting point, distance, and bearing. Supports various units for distance.

```dart
var startPoint = Point(coordinates: Position(-75.343, 39.984));
var distance = 50;
var bearing = 90;  // due east

var endPoint = destination(startPoint, distance, bearing, Unit.miles);
// Result: Point ~50 miles east of starting point
```

--------------------------------

### calculateFinalBearing

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/02-distance-bearing.md

Calculates the final bearing (reverse direction) from one point to another. This is equivalent to calling `bearing(start, end, calcFinal: true)`.

```APIDOC
## calculateFinalBearing

### Description
Calculates the final bearing (reverse direction) from one point to another.

### Method
```dart
num calculateFinalBearing(Point start, Point end)
```

### Parameters
#### Path Parameters
- **start** (Point) - Required - Starting point
- **end** (Point) - Required - Destination point

### Returns
`num` — Final bearing in degrees 0-360

### Example
```dart
var finalBearing = calculateFinalBearing(
  Point(coordinates: Position(-75.343, 39.984)),
  Point(coordinates: Position(-75.543, 39.123))
);
```
```

--------------------------------

### along

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/06-line-operations.md

Finds a point at a specific distance along a given line. This function is useful for determining a location on a path based on a measured distance from its start. The unit of distance can be specified.

```APIDOC
## along

### Description
Finds a point at a specific distance along a given line. This function is useful for determining a location on a path based on a measured distance from its start. The unit of distance can be specified.

### Parameters
#### Path Parameters
- **line** (Feature<LineString>) - Required - LineString to traverse
- **distance** (num) - Required - Distance along line
#### Query Parameters
- **unit** (Unit) - Optional - Unit of distance (default: kilometers)

### Returns
`Feature<Point>` — Point at specified distance

### Example
```dart
var line = Feature<LineString>(
  geometry: LineString(coordinates: [
    Position(0, 0),
    Position(5, 5),
    Position(10, 10),
  ]),
);

// Find point 2 km along the line
var point = along(line, 2, unit: Unit.kilometers);
```
```

--------------------------------

### Measure Route Properties

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Calculates various properties of a route represented as a LineString, including its total length, bounding box, start point, and end point.

```dart
var route = Feature<LineString>(geometry: ...);

var routeLength = length(route, unit: Unit.kilometers);
var routeBounds = envelope(route);
var startPoint = route.geometry?.coordinates.first;
var endPoint = route.geometry?.coordinates.last;

print('Route: ${routeLength.toStringAsFixed(2)} km');
```

--------------------------------

### Get Bounding Box of a Geometry

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Calculate the minimum bounding box (axis-aligned) for a given geometry using the `bbox` function. The result contains the coordinates of the bounding box.

```dart
import 'package:turf/bbox.dart';

var polygon = Polygon(coordinates: [[...]]);
var boundingBox = bbox(polygon);

print('Bounds: ${boundingBox.lng1}, ${boundingBox.lat1}, '
      '${boundingBox.lng2}, ${boundingBox.lat2}');
```

--------------------------------

### Run Benchmarks

Source: https://github.com/dartclub/turf_dart/blob/main/CONTRIBUTING.md

Execute all benchmarks for the Turf.dart project using the Dart benchmark runner.

```bash
dart pub run benchmark
```

--------------------------------

### Import All Turf Modules

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Import all available types and functions from the turf library at once.

```dart
import 'package:turf/turf.dart';
```

--------------------------------

### Run Visualization Generator

Source: https://github.com/dartclub/turf_dart/blob/main/test/examples/point_on_feature/README.md

Run this command to generate the combined visualization GeoJSON file.

```bash
dart test/examples/point_on_feature/generate_visualization.dart
```

--------------------------------

### Turf.dart Module Structure

Source: https://github.com/dartclub/turf_dart/blob/main/CONTRIBUTING.md

Illustrates the directory structure for modules within the Turf.dart project, including public API, implementation, benchmarks, and tests.

```text
TURF_DART/lib/<MODULE NAME>.dart // public facing API, exports the implementation
         │   │
         │   └───src/<MODULE NAME>.dart // the implementation
         │ 
         └───benchmark/<MODULE NAME>_benchmark.dart
         │
         └───test/components/<MODULE NAME>_test.dart // all the related tests

```

--------------------------------

### Clone Turf.dart Repository

Source: https://github.com/dartclub/turf_dart/blob/main/CONTRIBUTING.md

Clone the Turf.dart repository to your local machine using Git.

```bash
git clone git@github.com:dartclub/turf_dart.git
```

--------------------------------

### Rhumb Line Bearing Calculation

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/02-distance-bearing.md

Calculates the bearing along a rhumb line between a start and end point. Can optionally calculate the final bearing.

```dart
num rhumbBearing(Point start, Point end, {bool calcFinal = false})
```

```dart
var bearing = rhumbBearing(
  Point(coordinates: Position(-75.343, 39.984)),
  Point(coordinates: Position(-75.543, 39.123))
);
```

--------------------------------

### Create and Access Position Instances

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Demonstrates creating Position objects with and without altitude, and accessing their coordinates.

```dart
var pos1 = Position(10.5, 45.2);
var pos2 = Position.named(lng: 10.5, lat: 45.2);
var pos3 = Position(10.5, 45.2, 1000);  // With altitude

print(pos1.lng);  // 10.5
print(pos1.lat);  // 45.2
print(pos1[0]);   // 10.5
```

--------------------------------

### Create and Use Typed Features

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Demonstrates how to create typed and untyped features, and how to safely access their geometries using null-aware checks.

```dart
// Typed feature
Feature<Point> pointFeature = Feature<Point>(
  geometry: Point(coordinates: Position(10, 45)),
);

// Untyped feature
Feature untypedFeature = Feature(
  geometry: Point(coordinates: Position(10, 45)),
);

// Null-safe geometry
var geom = pointFeature.geometry;  // Point?
if (geom is Point) {
  print(geom.coordinates);  // Guaranteed Point
}
```

--------------------------------

### Bounding Box Operations

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Shows how to create a BBox, check if a point is within it, and convert a BBox into a Polygon.

```dart
var bbox = BBox.named(lng1: -10, lat1: 0, lng2: 10, lat2: 20);

// Check if point is in bbox
var point = Position(5, 10);
bool inBbox = (bbox[0]! <= point[0]! && 
               bbox[1]! <= point[1]! && 
               bbox[2]! >= point[0]! && 
               bbox[3]! >= point[1]!)
;

// Create polygon from bbox
var polygon = Polygon(coordinates: [[
  Position(bbox[0]!, bbox[1]!),
  Position(bbox[2]!, bbox[1]!),
  Position(bbox[2]!, bbox[3]!),
  Position(bbox[0]!, bbox[3]!),
  Position(bbox[0]!, bbox[1]!),
]]);
```

--------------------------------

### Importing Turf.js Modules in Dart

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/00-index.md

Demonstrates how to import specific modules or all of Turf.js for use in your Dart project. This allows for selective importing to reduce bundle size or importing all functions at once for convenience.

```dart
import 'package:turf/helpers.dart';              // Units, conversions
import 'package:turf/distance.dart';             // distance(), bearing() 
import 'package:turf/area.dart';                 // area() 
import 'package:turf/bbox.dart';                 // bbox() 
import 'package:turf/circle.dart';               // circle() 
import 'package:turf/centroid.dart';             // centroid() 
import 'package:turf/boolean.dart';              // All boolean operations 
import 'package:turf/meta.dart';                 // coordEach, featureEach, etc. 
import 'package:turf/line_segment.dart';         // segmentEach, lineSegment() 
import 'package:turf/simplify.dart';             // simplify() 
import 'package:turf/line_slice.dart';           // lineSlice() 
import 'package:turf/nearest_point_on_line.dart';// nearestPointOnLine() 
import 'package:turf/line_intersect.dart';       // lineIntersect() 
import 'package:turf/polyline.dart';             // encode/decode polylines 
import 'package:turf/flatten.dart';              // flatten() 
import 'package:turf/explode.dart';              // explode() 
import 'package:turf/flip.dart';                 // flip() 

// Or import all at once:
import 'package:turf/turf.dart';
```

--------------------------------

### Slice a Line Between Two Points

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Extracts a segment of a LineString that falls between two specified points. Creates a new LineString from the start to end points.

```dart
import 'package:turf/line_slice.dart';

var line = Feature<LineString>(
  geometry: LineString(coordinates: [
    Position(0, 0),
    Position(5, 5),
    Position(10, 10),
    Position(15, 15),
  ]),
);

var sliced = lineSlice(
  Position(2, 2),
  Position(12, 12),
  line,
);
```

--------------------------------

### Import Specific Turf Modules

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Import only the specific spatial analysis functions and types you need from the turf library.

```dart
// All types and helpers
import 'package:turf/helpers.dart';

// Spatial analysis functions (choose what you need)
import 'package:turf/distance.dart';      // distance, bearing
import 'package:turf/area.dart';          // area calculation
import 'package:turf/bbox.dart';          // bounding box
import 'package:turf/destination.dart';   // navigate by bearing
import 'package:turf/circle.dart';        // buffer zones
import 'package:turf/boolean.dart';       // point-in-polygon, overlaps, etc.
import 'package:turf/meta.dart';          // iterate coordinates/features
import 'package:turf/line_slice.dart';    // slice lines
import 'package:turf/simplify.dart';      // simplify geometry
```

--------------------------------

### Handle Exceptions with Try-Catch

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Demonstrates the use of try-catch blocks to gracefully handle potential exceptions during geospatial operations. Catches and prints any exceptions that occur.

```dart
try {
  var result = distance(point1, point2);
} on Exception catch (e) {
  print('Error: $e');
}
```

--------------------------------

### Create a Buffer Zone (Circle)

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Generate a circular buffer zone around a center point using the `circle` function. Specify the radius and unit. This can be used with `booleanPointInPolygon` to check containment.

```dart
import 'package:turf/circle.dart';

var center = Point(coordinates: Position(10, 45));
var bufferZone = circle(center, 5, unit: Unit.kilometers);
// Creates 5 km circular buffer

// Check if point is in buffer
if (booleanPointInPolygon(testPoint, bufferZone.geometry!)) {
  print('Within buffer zone!');
}
```

--------------------------------

### Create Geometries (Point, LineString, Polygon)

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Instantiate basic geospatial geometries like Point, LineString, and Polygon. Polygons can include holes.

```dart
// Point
var point = Point(coordinates: Position(10, 45));

// LineString
var line = LineString(coordinates: [
  Position(0, 0),
  Position(5, 5),
  Position(10, 10),
]);

// Polygon (with hole)
var polygon = Polygon(coordinates: [
  [  // Outer ring (counterclockwise)
    Position(0, 0),
    Position(10, 0),
    Position(10, 10),
    Position(0, 10),
    Position(0, 0)
  ],
  [  // Hole (clockwise)
    Position(2, 2),
    Position(4, 2),
    Position(4, 4),
    Position(2, 4),
    Position(2, 2)
  ]
]);
```

--------------------------------

### Slice a LineString by distance

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/06-line-operations.md

Extracts a section of a line based on start and stop distances along its length. Supports different units for distance measurement. The function returns the sliced line segment.

```dart
var line = Feature<LineString>(
  geometry: LineString(coordinates: [
    Position(0, 0),
    Position(5, 5),
    Position(10, 10),
  ]),
);

// Extract 2-8 km of the line
var sliced = lineSliceAlong(2, 8, line, unit: Unit.kilometers);
```

--------------------------------

### Find Features Matching Area Criteria

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/05-iteration-reduction.md

Filters a `FeatureCollection` to find features that meet a specific area criterion. This example iterates through features using `featureEach` and adds matching features to a new list.

```dart
var matchingFeatures = <Feature>[];
featureEach(featureCollection, (feature, _) {
  if (feature.properties?['area'] as num? ?? 0 > 1000) {
    matchingFeatures.add(feature);
  }
});
```

--------------------------------

### Spatial Index Search with Turf.js Dart

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Demonstrates how to create a grid over a region of interest and query features within each grid cell using spatial intersection checks. This is useful for optimizing searches in large geospatial datasets.

```dart
var roi = BBox.named(lng1: 0, lat1: 0, lng2: 100, lat2: 100);
var grid = squareGrid(roi, 10, unit: Unit.kilometers);

grid.features.forEach((cell) {
  var cellBounds = bbox(cell);
  var featuresInCell = features.where((f) {
    var fBounds = bbox(f);
    // Check if bounds overlap
    return booleanIntersects(cell, f);
  }).toList();
  
  print('Cell has ${featuresInCell.length} features');
});
```

--------------------------------

### Convert Closed LineString to Polygon

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/07-coordinate-manipulation.md

Converts a closed LineString feature into a Polygon feature. The linestring must start and end at the same coordinate to form a valid ring. Properties can be optionally passed to the resulting polygon feature.

```dart
var ring = Feature<LineString>(
  geometry: LineString(coordinates: [
    Position(0, 0),
    Position(5, 0),
    Position(5, 5),
    Position(0, 5),
    Position(0, 0)
  ]),
);

var polygon = lineToPolygon(ring, properties: {'area': 'test'});
// Polygon with single outer ring
```

--------------------------------

### Get a Point on a Feature

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

This function finds a point that is guaranteed to be inside a given GeoJSON geometry or feature. It's useful for tasks like labeling or testing point containment within polygons, lines, or points.

```dart
import 'package:turf/helpers.dart';
import 'package:turf/point_on_feature.dart';

var polygon = Polygon(coordinates: [[
  Position(0, 0),
  Position(10, 0),
  Position(10, 10),
  Position(0, 10),
  Position(0, 0)
]]);

var insidePoint = pointOnFeature(polygon);
// Feature<Point> with coordinates inside the polygon
// Guaranteed that booleanPointInPolygon(insidePoint.geometry?.coordinates, polygon) == true
```

--------------------------------

### Calculate Distance Between Two Points

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/00-index.md

Demonstrates how to calculate the distance between two points using the `distance` function. Ensure the `turf/helpers.dart` library is imported.

```dart
import 'package:turf/helpers.dart';

void main() {
  var berlin = Point(coordinates: Position(13.4, 52.52));
  var paris = Point(coordinates: Position(2.35, 48.85));
  
  var dist = distance(berlin, paris, Unit.kilometers);
  print('Distance: $dist km');  // ~877 km
}
```

--------------------------------

### lineSlice

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/06-line-operations.md

Extracts a section of a line between two specified points. The function finds the closest points on the line to the provided start and stop points and returns the segment between them. It preserves the original feature properties and returns an empty line if the slice is invalid.

```APIDOC
## lineSlice

### Description
Extracts a section of a line between two points. The function finds the closest points on the line to the provided start and stop points and returns the segment between them. It preserves the original feature properties and returns an empty line if the slice is invalid.

### Parameters
#### Path Parameters
- **start** (Position) - Required - Starting point [longitude, latitude]
- **stop** (Position) - Required - Ending point [longitude, latitude]
- **line** (Feature<LineString>) - Required - LineString to slice

### Returns
`Feature<LineString>` — Sliced line segment

### Example
```dart
var line = Feature<LineString>(
  geometry: LineString(coordinates: [
    Position(0, 0),
    Position(5, 5),
    Position(10, 10),
  ]),
);

var sliced = lineSlice(
  Position(1, 1),
  Position(9, 9),
  line,
);
// Returns line from ~(1,1) to ~(9,9)
```
```

--------------------------------

### simplify

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/06-line-operations.md

Simplifies a LineString using the Ramer-Douglas-Peucker algorithm. It reduces the number of vertices in a line while preserving its general shape, based on a specified tolerance. An option to use only RDP for highest quality is available.

```APIDOC
## simplify

### Description
Simplifies a LineString using the Ramer-Douglas-Peucker algorithm. It reduces the number of vertices in a line while preserving its general shape, based on a specified tolerance. An option to use only RDP for highest quality is available.

### Parameters
#### Path Parameters
- **points** (Feature<LineString>) - Required - LineString to simplify
#### Query Parameters
- **tolerance** (double) - Optional - Simplification tolerance (higher = more simplified) (default: 1)
- **highestQuality** (bool) - Optional - If true, uses only RDP; if false, combines radial distance and RDP (default: false)

### Returns
`Feature<LineString>` — Simplified line

### Example
```dart
var complexLine = Feature<LineString>(
  geometry: LineString(coordinates: [
    Position(0, 0),
    Position(0.1, 0.1),
    Position(0.2, 0.2),
    Position(5, 5),
    Position(5.1, 5.1),
    Position(5.2, 5.2),
    Position(10, 10),
  ]),
);

var simplified = simplify(complexLine, tolerance: 0.5);
// Removes near-duplicate vertices, keeps key turning points
```
```

--------------------------------

### Create Features (Geometry + Properties)

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Create a Feature object by combining a geometry with arbitrary properties and an optional ID. Access geometry and properties using dot or bracket notation.

```dart
var feature = Feature<Point>(
  geometry: Point(coordinates: Position(10, 45)),
  properties: {
    'name': 'Berlin',
    'population': 3645000,
    'country': 'Germany',
  },
  id: 'berlin-01',
);

// Access
print(feature.geometry?.coordinates);
print(feature.properties?['name']);
```

--------------------------------

### Slice a LineString between two points

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/06-line-operations.md

Extracts a section of a line between two specified points. The function uses the closest points on the line to the provided start and stop points. It preserves original feature properties and returns an empty line if the slice is invalid.

```dart
var line = Feature<LineString>(
  geometry: LineString(coordinates: [
    Position(0, 0),
    Position(5, 5),
    Position(10, 10),
  ]),
);

var sliced = lineSlice(
  Position(1, 1),
  Position(9, 9),
  line,
);
// Returns line from ~(1,1) to ~(9,9)
```

--------------------------------

### Create Labels for Polygons

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Finds a guaranteed interior point for a given polygon, which is suitable for placing labels. This ensures the label point is within the polygon's boundaries.

```dart
var polygon = Feature<Polygon>(
  geometry: Polygon(coordinates: [
    [Position(0, 0), Position(10, 0), Position(10, 10), Position(0, 10), Position(0, 0)]
  ]),
  properties: {'name': 'Region A'}
);

// Find guaranteed interior point for label placement
var labelPoint = pointOnFeature(polygon);
```

--------------------------------

### Generate Point Grid

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Creates a grid of points within a specified bounding box. Use this to sample locations or define points for further spatial processing. The cellSize determines the spacing between points.

```dart
FeatureCollection<Point> pointGrid(
  BBox bbox,
  num cellSize,
  {Unit unit = Unit.kilometers}
)
```

```dart
var bbox = BBox.named(lng1: -10, lat1: 0, lng2: 10, lat2: 20);
var grid = pointGrid(bbox, 5, unit: Unit.kilometers);
// Creates grid of points 5 km apart within bbox
```

--------------------------------

### Run Component Tests

Source: https://github.com/dartclub/turf_dart/blob/main/CONTRIBUTING.md

Execute tests for a specific component within the Turf.dart project using the Dart test runner.

```bash
dart test test/components/XXX.dart
```

--------------------------------

### Create Buffer Zone

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/03-geometry-operations.md

Creates a circular buffer zone around a given point with a specified radius and unit.

```dart
var point = Point(coordinates: Position(10, 45));
var bufferZone = circle(point, 5, unit: Unit.kilometers);
// Creates 5 km buffer around point
```

--------------------------------

### Reuse Bounding Box (BBox)

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Optimizes performance by reusing a cached bounding box instead of recomputing it. Use `recompute: false` when the bbox is already known.

```dart
// Don't recompute bbox if already cached
var box = bbox(geometry, recompute: false);
```

--------------------------------

### pointGrid

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Generates a grid of points within a bounding box. This function is useful for creating sample points for spatial analysis or data distribution visualization.

```APIDOC
## pointGrid

### Description
Generates a grid of points within a bounding box.

### Method
```dart
FeatureCollection<Point> pointGrid(BBox bbox, num cellSize, {Unit unit = Unit.kilometers})
```

### Parameters
#### Path Parameters
- **bbox** (BBox) - Required - Bounding box [minLng, minLat, maxLng, maxLat]
- **cellSize** (num) - Required - Distance between points
- **unit** (Unit) - Optional - Unit of cellSize (defaults to kilometers)

### Returns
`FeatureCollection<Point>` — Grid of points

### Example
```dart
var bbox = BBox.named(lng1: -10, lat1: 0, lng2: 10, lat2: 20);
var grid = pointGrid(bbox, 5, unit: Unit.kilometers);
// Creates grid of points 5 km apart within bbox
```
```

--------------------------------

### triangleGrid

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Generates a grid of triangular polygons within a bounding box. Suitable for creating triangular tessellations.

```APIDOC
## triangleGrid

### Description
Generates a grid of triangular polygons within a bounding box.

### Method
Dart Function

### Signature
FeatureCollection<Polygon> triangleGrid(BBox bbox, num cellSize, {Unit unit = Unit.kilometers})

### Parameters
#### Path Parameters
- **bbox** (BBox) - Required - Bounding box
- **cellSize** (num) - Required - Size of triangles
- **unit** (Unit) - Optional - Unit of cellSize (default: kilometers)

### Returns
`FeatureCollection<Polygon>` — Grid of triangular polygons
```

--------------------------------

### Create Positions (Coordinates)

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Create Position objects representing geographic coordinates using positional or named constructors. Supports longitude, latitude, and altitude.

```dart
// Indexed: [longitude, latitude]
var pos = Position(10.5, 45.2);

// Named constructor
var pos = Position.named(lng: 10.5, lat: 45.2);

// With altitude
var pos3d = Position(10.5, 45.2, 1000);

// Access
print(pos.lng);   // 10.5
print(pos.lat);   // 45.2
print(pos[0]);    // 10.5
print(pos[1]);    // 45.2
```

--------------------------------

### bearing

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/02-distance-bearing.md

Calculates the initial bearing (forward azimuth) from one point to another. Can also calculate the final bearing if specified.

```APIDOC
## bearing

### Description
Calculates the initial bearing (forward azimuth) from one point to another.

### Method
```dart
num bearing(Point start, Point end, {bool calcFinal = false})
```

### Parameters
#### Path Parameters
- **start** (Point) - Required - Starting point
- **end** (Point) - Required - Destination point
- **calcFinal** (bool) - Optional - If true, returns final bearing (reverse bearing); if false, returns initial bearing

### Returns
`num` — Bearing in degrees 0-360

### Example
```dart
var point1 = Point(coordinates: Position(-75.343, 39.984));
var point2 = Point(coordinates: Position(-75.543, 39.123));

var initialBearing = bearing(point1, point2);
var finalBearing = bearing(point1, point2, calcFinal: true);
```
```

--------------------------------

### Use Raw Functions for Bulk Operations

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Improves performance for processing many coordinates by using raw functions that avoid Point wrapping. Suitable for high-volume coordinate calculations.

```dart
// Faster for many coordinates
for (var coord in coords) {
  var dist = distanceRaw(start, coord);  // Avoid Point wrapping
}
```

--------------------------------

### hexGrid

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Generates a grid of hexagonal polygons within a bounding box. Useful for spatial analysis and creating honeycomb patterns.

```APIDOC
## hexGrid

### Description
Generates a grid of hexagonal polygons within a bounding box.

### Method
Dart Function

### Signature
FeatureCollection<Polygon> hexGrid(BBox bbox, num cellSize, {Unit unit = Unit.kilometers})

### Parameters
#### Path Parameters
- **bbox** (BBox) - Required - Bounding box
- **cellSize** (num) - Required - Size of hexagons
- **unit** (Unit) - Optional - Unit of cellSize (default: kilometers)

### Returns
`FeatureCollection<Polygon>` — Grid of hexagonal polygons

### Example
```dart
var bbox = BBox.named(lng1: 0, lat1: 0, lng2: 10, lat2: 10);
var hexes = hexGrid(bbox, 1, unit: Unit.kilometers);
// Creates honeycomb pattern of hexagons
```
```

--------------------------------

### Generate Square Grid

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Generates a grid of square polygons within a given bounding box. This is useful for creating tessellations or dividing an area into regular square cells for analysis.

```dart
FeatureCollection<Polygon> squareGrid(
  BBox bbox,
  num cellSize,
  {Unit unit = Unit.kilometers}
)
```

```dart
var bbox = BBox.named(lng1: 0, lat1: 0, lng2: 10, lat2: 10);
var grid = squareGrid(bbox, 1, unit: Unit.kilometers);
// Creates grid of 1km x 1km squares
```

--------------------------------

### Feature Collections with Mixed Types

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Illustrates creating a FeatureCollection with diverse geometry types and filtering it to extract specific feature types, such as only Point features.

```dart
var mixed = FeatureCollection(
  features: [
    Feature<Point>(geometry: Point(coordinates: Position(0, 0))),
    Feature<LineString>(geometry: LineString(coordinates: [
      Position(1, 1), Position(2, 2)
    ])),
    Feature<Polygon>(geometry: Polygon(coordinates: [[
      Position(3, 3), Position(4, 3), Position(4, 4), Position(3, 3)
    ]])),
  ],
);

// Filter by type
var pointFeatures = mixed.features
  .whereType<Feature<Point>>()
  .toList();
```

--------------------------------

### Calculate Round-Trip Distance

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/02-distance-bearing.md

Demonstrates calculating the total distance for a round trip by summing the distances in both directions between two points.

```javascript
var pointA = Point(coordinates: Position(-75.343, 39.984));
var pointB = Point(coordinates: Position(-75.543, 39.123));

var distAtoB = distance(pointA, pointB, Unit.kilometers);
var distBtoA = distance(pointB, pointA, Unit.kilometers);
var totalDistance = distAtoB + distBtoA;
```

--------------------------------

### simplify

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/06-line-operations.md

Simplifies a LineString feature by reducing the number of vertices while preserving its general shape.

```APIDOC
## simplify

### Description
Reduces points while maintaining shape.

### Method
```dart
var simplified = simplify(gpsTrack, tolerance: 0.1);
```

### Parameters
#### Path Parameters
- **line** (Feature<LineString>) - Required - The line to simplify.
- **tolerance** (double) - Required - The tolerance for simplification. Smaller values result in more vertices.
- **highQuality** (bool?) - Optional - Whether to use a high-quality simplification algorithm.

### Response
#### Success Response
- **Feature<LineString>** — The simplified line.
```

--------------------------------

### Create Circular Polygon

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/03-geometry-operations.md

Creates a circular polygon from a center point and radius. The number of steps determines the smoothness of the circle.

```dart
var centerPoint = Point(coordinates: Position(-75.343, 39.984));
var circleFeature = circle(
  centerPoint,
  10,
  steps: 32,
  unit: Unit.kilometers,
  properties: {'name': 'buffer-zone'},
);
// Creates 32-vertex circular polygon with 10 km radius
```

--------------------------------

### Define a Position with Longitude, Latitude, and Optional Altitude

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Represents a single coordinate point. Use the constructor or named constructor for initialization. Access coordinates by index or named properties.

```dart
class Position {
  final List<num> _coordinates;
  
  Position(num lng, num lat, [num? altitude]);
  Position.named({
    required num lng,
    required num lat,
    num? altitude,
  });
}
```

--------------------------------

### Generate Triangular Grid

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Generates a grid of triangular polygons within a specified bounding box. Suitable for applications requiring triangular tessellations.

```dart
FeatureCollection<Polygon> triangleGrid(
  BBox bbox,
  num cellSize,
  {Unit unit = Unit.kilometers}
)
```

--------------------------------

### Create Square Polygon

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Generates a square polygon centered at a given point with a specified side length. Use this to create square areas for spatial analysis or visualization.

```dart
Feature<Polygon> square(
  Feature<Point> center,
  num size,
  {Unit? unit}
)
```

```dart
var center = Feature<Point>(
  geometry: Point(coordinates: Position(10, 45))
);

var squareFeature = square(center, 10, unit: Unit.kilometers);
// Creates 10km x 10km square centered at (10, 45)
```

--------------------------------

### CoordinateSystem Enumeration

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/09-types-and-data-structures.md

Defines supported coordinate systems, primarily WGS84 (geographic lon/lat) and Web Mercator (EPSG:3857).

```dart
enum CoordinateSystem {
  wgs84,     // WGS84 geographic (lon/lat)
  mercator,  // Web Mercator (EPSG:3857)
}
```

--------------------------------

### squareGrid

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/08-utility-functions.md

Generates a grid of square polygons within a bounding box. This function is useful for creating regular spatial grids for analysis or mapping.

```APIDOC
## squareGrid

### Description
Generates a grid of square polygons within a bounding box.

### Method
```dart
FeatureCollection<Polygon> squareGrid(BBox bbox, num cellSize, {Unit unit = Unit.kilometers})
```

### Parameters
#### Path Parameters
- **bbox** (BBox) - Required - Bounding box
- **cellSize** (num) - Required - Side length of squares
- **unit** (Unit) - Optional - Unit of cellSize (defaults to kilometers)

### Returns
`FeatureCollection<Polygon>` — Grid of square polygons

### Example
```dart
var bbox = BBox.named(lng1: 0, lat1: 0, lng2: 10, lat2: 10);
var grid = squareGrid(bbox, 1, unit: Unit.kilometers);
// Creates grid of 1km x 1km squares
```
```

--------------------------------

### Convert Coordinate Systems (WGS84 and Web Mercator)

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Converts coordinates between the WGS84 (latitude/longitude) and Web Mercator projection systems. Useful for map rendering and analysis.

```dart
import 'package:turf/helpers.dart';

// WGS84 to Web Mercator
var wgs84 = Position(10.0, 45.0);  // [lon, lat]
var mercator = toMercator(wgs84);
// ~[1111949, 5621521]

// Web Mercator to WGS84
var backToWgs84 = toWGS84(mercator);
// ~[10, 45]
```

--------------------------------

### Common Unit and Coordinate Conversions in Turf.js Dart

Source: https://github.com/dartclub/turf_dart/blob/main/_autodocs/10-quick-start-guide.md

Provides a collection of utility functions for converting between different units of measurement (degrees, radians, distance, area) and coordinate systems (WGS84, Mercator).

```dart
// Degrees ↔ Radians
var rad = degreesToRadians(45);      // 0.7854
var deg = radiansToDegrees(pi / 4);  // 45

// Bearing ↔ Azimuth
var az = bearingToAzimuth(-45);      // 315

// Distance conversions
convertLength(100, Unit.kilometers, Unit.miles);       // 62.137
convertLength(100, Unit.miles, Unit.kilometers);       // 160.934
convertLength(100, Unit.meters, Unit.feet);            // 328.084

// Area conversions
convertArea(1000000, Unit.meters, Unit.kilometers);    // 1.0
convertArea(1, Unit.miles, Unit.kilometers);           // 2.59
convertArea(2000, Unit.meters, Unit.acres);            // 0.494

// Coordinate systems
toMercator(Position(10, 45));        // Web Mercator projection
toWGS84(Position(1111949, 5621521)); // Back to lat/lon
```