0
# Vector Features and Geometries
1

2
Feature system with comprehensive geometry support including points, lines, polygons, and collections with spatial operations.
3

4
## Capabilities
5

6
### Feature Class
7

8
Features represent geographic objects with geometry and properties.
9

10
```typescript { .api }
11
/**
12
 * Vector feature with geometry and attributes
13
 */
14
class Feature {
15
  constructor(geometry?: Geometry);
16
  
17
  /** Get feature geometry */
18
  getGeometry(): Geometry | undefined;
19
  /** Set feature geometry */
20
  setGeometry(geometry: Geometry | undefined): void;
21
  
22
  /** Get feature ID */
23
  getId(): string | number | undefined;
24
  /** Set feature ID */
25
  setId(id: string | number | undefined): void;
26
  
27
  /** Get property value */
28
  get(key: string): any;
29
  /** Set property value */
30
  set(key: string, value: any): void;
31
  /** Get all properties */
32
  getProperties(): {[key: string]: any};
33
  /** Set all properties */
34
  setProperties(values: {[key: string]: any}): void;
35
  
36
  /** Get feature style */
37
  getStyle(): StyleLike | undefined;
38
  /** Set feature style */
39
  setStyle(style: StyleLike): void;
40
  
41
  /** Clone the feature */
42
  clone(): Feature;
43
}
44
```
45

46
### Base Geometry Classes
47

48
Foundation classes for all geometry types.
49

50
```typescript { .api }
51
/**
52
 * Base class for all geometries
53
 */
54
abstract class Geometry {
55
  constructor();
56
  
57
  /** Get geometry type */
58
  getType(): GeometryType;
59
  
60
  /** Get geometry extent */
61
  getExtent(): Extent;
62
  
63
  /** Transform geometry to different projection */
64
  transform(source: ProjectionLike, destination: ProjectionLike): Geometry;
65
  
66
  /** Clone the geometry */
67
  clone(): Geometry;
68
  
69
  /** Get closest point on geometry to coordinate */
70
  getClosestPoint(point: Coordinate): Coordinate;
71
  
72
  /** Check if geometry intersects extent */
73
  intersectsExtent(extent: Extent): boolean;
74
  
75
  /** Apply transform function to coordinates */
76
  applyTransform(transformFn: TransformFunction): void;
77
  
78
  /** Rotate geometry around anchor point */
79
  rotate(angle: number, anchor: Coordinate): void;
80
  
81
  /** Scale geometry */
82
  scale(sx: number, sy?: number, anchor?: Coordinate): void;
83
  
84
  /** Translate geometry */
85
  translate(deltaX: number, deltaY: number): void;
86
}
87

88
/**
89
 * Base class for simple geometries with coordinate arrays
90
 */
91
abstract class SimpleGeometry extends Geometry {
92
  constructor();
93
  
94
  /** Get geometry coordinates */
95
  getCoordinates(): any;
96
  /** Set geometry coordinates */
97
  setCoordinates(coordinates: any): void;
98
  
99
  /** Get first coordinate */
100
  getFirstCoordinate(): Coordinate;
101
  /** Get last coordinate */
102
  getLastCoordinate(): Coordinate;
103
  
104
  /** Get geometry layout */
105
  getLayout(): GeometryLayout;
106
  
107
  /** Get stride (number of values per coordinate) */
108
  getStride(): number;
109
  
110
  /** Get flat coordinates array */
111
  getFlatCoordinates(): number[];
112
}
113

114
type GeometryType = 'Point' | 'LineString' | 'LinearRing' | 'Polygon' | 'MultiPoint' | 'MultiLineString' | 'MultiPolygon' | 'GeometryCollection' | 'Circle';
115
type GeometryLayout = 'XY' | 'XYZ' | 'XYM' | 'XYZM';
116
```
117

118
### Point Geometries
119

120
```typescript { .api }
121
/**
122
 * Point geometry representing a single coordinate
123
 */
124
class Point extends SimpleGeometry {
125
  constructor(coordinates: Coordinate, layout?: GeometryLayout);
126
  
127
  /** Get point coordinates */
128
  getCoordinates(): Coordinate;
129
  /** Set point coordinates */
130
  setCoordinates(coordinates: Coordinate): void;
131
}
132

133
/**
134
 * Multi-point geometry for multiple points
135
 */
136
class MultiPoint extends SimpleGeometry {
137
  constructor(coordinates: Coordinate[], layout?: GeometryLayout);
138
  
139
  /** Get coordinates of all points */
140
  getCoordinates(): Coordinate[];
141
  /** Set coordinates of all points */
142
  setCoordinates(coordinates: Coordinate[]): void;
143
  
144
  /** Get specific point geometry */
145
  getPoint(index: number): Point;
146
  /** Get all point geometries */
147
  getPoints(): Point[];
148
}
149
```
150

151
### Line Geometries
152

153
```typescript { .api }
154
/**
155
 * Line string geometry
156
 */
157
class LineString extends SimpleGeometry {
158
  constructor(coordinates: Coordinate[], layout?: GeometryLayout);
159
  
160
  /** Get line coordinates */
161
  getCoordinates(): Coordinate[];
162
  /** Set line coordinates */
163
  setCoordinates(coordinates: Coordinate[]): void;
164
  
165
  /** Get coordinate at index */
166
  getCoordinateAt(fraction: number): Coordinate;
167
  /** Get line length */
168
  getLength(): number;
169
  
170
  /** Append coordinate to line */
171
  appendCoordinate(coordinate: Coordinate): void;
172
}
173

174
/**
175
 * Linear ring (closed line string)
176
 */
177
class LinearRing extends SimpleGeometry {
178
  constructor(coordinates: Coordinate[], layout?: GeometryLayout);
179
  
180
  /** Get ring coordinates */
181
  getCoordinates(): Coordinate[];
182
  /** Set ring coordinates */
183
  setCoordinates(coordinates: Coordinate[]): void;
184
  
185
  /** Get ring area */
186
  getArea(): number;
187
}
188

189
/**
190
 * Multi-line string geometry
191
 */
192
class MultiLineString extends SimpleGeometry {
193
  constructor(coordinates: Coordinate[][], layout?: GeometryLayout);
194
  
195
  /** Get coordinates of all lines */
196
  getCoordinates(): Coordinate[][];
197
  /** Set coordinates of all lines */
198
  setCoordinates(coordinates: Coordinate[][]): void;
199
  
200
  /** Get specific line string */
201
  getLineString(index: number): LineString;
202
  /** Get all line strings */
203
  getLineStrings(): LineString[];
204
}
205
```
206

207
### Polygon Geometries
208

209
```typescript { .api }
210
/**
211
 * Polygon geometry with optional holes
212
 */
213
class Polygon extends SimpleGeometry {
214
  constructor(coordinates: Coordinate[][], layout?: GeometryLayout);
215
  
216
  /** Get polygon coordinates [exterior, ...holes] */
217
  getCoordinates(): Coordinate[][];
218
  /** Set polygon coordinates */
219
  setCoordinates(coordinates: Coordinate[][]): void;
220
  
221
  /** Get exterior ring */
222
  getLinearRing(index: number): LinearRing;
223
  /** Get all linear rings */
224
  getLinearRings(): LinearRing[];
225
  
226
  /** Get polygon area */
227
  getArea(): number;
228
  /** Get polygon perimeter */
229
  getPerimeter(): number;
230
  
231
  /** Get interior point */
232
  getInteriorPoint(): Point;
233
}
234

235
/**
236
 * Multi-polygon geometry
237
 */
238
class MultiPolygon extends SimpleGeometry {
239
  constructor(coordinates: Coordinate[][][], layout?: GeometryLayout);
240
  
241
  /** Get coordinates of all polygons */
242
  getCoordinates(): Coordinate[][][];
243
  /** Set coordinates of all polygons */
244
  setCoordinates(coordinates: Coordinate[][][]): void;
245
  
246
  /** Get specific polygon */
247
  getPolygon(index: number): Polygon;
248
  /** Get all polygons */
249
  getPolygons(): Polygon[];
250
  
251
  /** Get interior points of all polygons */
252
  getInteriorPoints(): MultiPoint;
253
}
254
```
255

256
### Special Geometries
257

258
```typescript { .api }
259
/**
260
 * Circle geometry
261
 */
262
class Circle extends SimpleGeometry {
263
  constructor(center: Coordinate, radius?: number, layout?: GeometryLayout);
264
  
265
  /** Get circle center */
266
  getCenter(): Coordinate;
267
  /** Set circle center */
268
  setCenter(center: Coordinate): void;
269
  
270
  /** Get circle radius */
271
  getRadius(): number;
272
  /** Set circle radius */
273
  setRadius(radius: number): void;
274
  
275
  /** Set center and radius together */
276
  setCenterAndRadius(center: Coordinate, radius: number): void;
277
}
278

279
/**
280
 * Collection of multiple geometries
281
 */
282
class GeometryCollection extends Geometry {
283
  constructor(geometries?: Geometry[]);
284
  
285
  /** Get all geometries in collection */
286
  getGeometries(): Geometry[];
287
  /** Set geometries in collection */
288
  setGeometries(geometries: Geometry[]): void;
289
  
290
  /** Get specific geometry by index */
291
  getGeometry(index: number): Geometry;
292
  /** Set specific geometry by index */
293
  setGeometry(index: number, geometry: Geometry): void;
294
}
295
```
296

297
**Usage Examples:**
298

299
```typescript
300
import Feature from 'ol/Feature';
301
import { Point, LineString, Polygon } from 'ol/geom';
302

303
// Create a point feature
304
const pointFeature = new Feature({
305
  geometry: new Point([0, 0]),
306
  name: 'My Point',
307
  population: 1000
308
});
309

310
// Create a line feature
311
const lineFeature = new Feature({
312
  geometry: new LineString([
313
    [0, 0], [10, 10], [20, 0]
314
  ])
315
});
316

317
// Create a polygon feature
318
const polygonFeature = new Feature({
319
  geometry: new Polygon([
320
    // Exterior ring
321
    [[0, 0], [10, 0], [10, 10], [0, 10], [0, 0]],
322
    // Interior hole
323
    [[2, 2], [8, 2], [8, 8], [2, 8], [2, 2]]
324
  ])
325
});
326

327
// Get geometry properties
328
const area = polygonFeature.getGeometry().getArea();
329
const center = polygonFeature.getGeometry().getInteriorPoint();
330
```
331

332
## Types
333

334
```typescript { .api }
335
type TransformFunction = (input: number[], output?: number[], dimension?: number) => number[];
336
```