done

lib/circle.dart

@@ -0,0 +1,4 @@
+library turf_transform;
+
+export 'package:geotypes/geotypes.dart';
+export 'src/circle.dart';

lib/src/circle.dart

@@ -0,0 +1,37 @@
+import 'package:turf/helpers.dart';
+import 'destination.dart';
+
+/// Takes a [Point] and calculates the circle polygon given a radius in degrees, radians, miles, or kilometers; and steps for precision.
+///
+///  example:
+/// ```dart
+/// var properties = { 'foo': 'bar' };
+/// var point = Feature(geometry: Point(coordinates: Position.of([-75.343, 39.984])));
+/// final polygonCircle = circle(
+///                 feature.geometry!,
+///                 radius,
+///                 steps: 32,
+///                 unit: Unit.meters,
+///                 properties: feature.properties,
+///               );
+/// ```
+Feature<Polygon> circle(
+  Point center,
+  num radius, {
+  num? steps = 64,
+  Unit? unit = Unit.kilometers,
+  Map<String, dynamic>? properties = const {},
+}) {
+  steps ??= 64;
+  unit ??= Unit.kilometers;
+  final List<Position> coordinates = [];
+  for (var i = 0; i < steps; i++) {
+    final c = destination(center, radius, (i * -360) / steps, unit).coordinates;
+    coordinates.add(c);
+  }
+  coordinates.add(coordinates[0]);
+  return Feature<Polygon>(
+    properties: properties,
+    geometry: Polygon(coordinates: [coordinates]),
+  );
+}