> ## Documentation Index
> Fetch the complete documentation index at: https://resq-dependabot-github-actions-github-actions-478e18be3d.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Resq common geo

# geo

### Classes

| Name                                                       | Description                                              |
| ---------------------------------------------------------- | -------------------------------------------------------- |
| [`GeoPoint`](./resq-common-geo-GeoPoint.md#geopoint)       | Geographic point with latitude, longitude, and altitude. |
| [`GeoSegment`](./resq-common-geo-GeoSegment.md#geosegment) | Line segment in geographic coordinates.                  |
| [`NoFlyZone`](./resq-common-geo-NoFlyZone.md#noflyzone)    | No-Fly Zone polygon definition.                          |

### Enumerations

| Name                  | Description          |
| --------------------- | -------------------- |
| [`NFZType`](#nfztype) | Type of no-fly zone. |

***

#### NFZType

```cpp theme={null}
enum NFZType
```

Type of no-fly zone.

| Value           | Description                              |
| --------------- | ---------------------------------------- |
| `AIRPORT`       | FAA restricted airspace around airports. |
| `TEMPORARY`     | Temporary flight restrictions (TFR)      |
| `MILITARY`      | Military restricted zones.               |
| `NATIONAL_PARK` | National park no-drone zones.            |
| `PRISON`        | Correctional facility airspace.          |
| `HOSPITAL`      | Hospital/helipad emergency zones.        |
| `CUSTOM`        | Custom user-defined zone.                |

### Functions

| Return                                                       | Name                                                        | Description                                                       |
| ------------------------------------------------------------ | ----------------------------------------------------------- | ----------------------------------------------------------------- |
| `double`                                                     | [`haversine_distance_meters`](#haversine_distance_meters)   | Calculate Haversine distance between two geographic points.       |
| `bool`                                                       | [`is_point_in_polygon`](#is_point_in_polygon)               | Check if a point is inside a polygon using ray casting.           |
| `bool`                                                       | [`segment_intersects_polygon`](#segment_intersects_polygon) | Check if a line segment intersects a polygon (bounding box check) |
| `std::optional< std::reference_wrapper< const NoFlyZone > >` | [`path_intersects_nfz`](#path_intersects_nfz)               | Check if a flight path (waypoint to waypoint) intersects any NFZ. |
| `std::optional< std::reference_wrapper< const NoFlyZone > >` | [`path_intersects_nfz`](#path_intersects_nfz-1)             | Check if any point in a path intersects NFZ.                      |

***

#### haversine\_distance\_meters

`inline`

```cpp theme={null}
inline double haversine_distance_meters(const GeoPoint & p1, const GeoPoint & p2)
```

Calculate Haversine distance between two geographic points.

Computes the great-circle distance between two points on Earth's surface using the Haversine formula. This provides accurate results for most navigation purposes, though for survey-grade precision consider Vincenty's formulae.

#### Parameters

* `p1` First geographic point

* `p2` Second geographic point

#### Returns

Distance in meters between the two points

Returns 0.0 if both points are identical

Returns approximately 20,000,000 meters for antipodal points

:::note
Uses Earth radius of 6,371,000 meters (mean radius)

:::

:::note
Accuracy degrades for very large distances due to Earth's ellipsoidal shape

:::

## Example:

```cpp theme={null}
[GeoPoint](./resq-common-geo-GeoPoint.md#geopoint) base{40.7128, -74.0060, 0.0};  // New York
GeoPoint target{34.0522, -118.2437, 0.0}; // Los Angeles
double distance = [haversine_distance_meters](#haversine_distance_meters)(base, target);
// distance ≈ 3,944,000 meters
```

***

#### is\_point\_in\_polygon

`inline`

```cpp theme={null}
inline bool is_point_in_polygon(const GeoPoint & point, const std::vector< GeoPoint > & vertices)
```

Check if a point is inside a polygon using ray casting.

Uses the even-odd rule (ray casting algorithm).

#### Parameters

* `point` The point to check

* `vertices` Polygon vertices

#### Returns

true if point is inside the polygon

***

#### segment\_intersects\_polygon

`inline`

```cpp theme={null}
inline bool segment_intersects_polygon(const GeoSegment & segment, const std::vector< GeoPoint > & polygon)
```

Check if a line segment intersects a polygon (bounding box check)

This is a simplified check using bounding boxes. For more accurate results, consider great circle paths.

#### Parameters

* `segment` The line segment

* `polygon` The polygon vertices

#### Returns

true if segment might intersect polygon

***

#### path\_intersects\_nfz

`inline`

```cpp theme={null}
inline std::optional< std::reference_wrapper< const NoFlyZone > > path_intersects_nfz(const GeoPoint & from, const GeoPoint & to, const std::vector< NoFlyZone > & nfz_list)
```

Check if a flight path (waypoint to waypoint) intersects any NFZ.

#### Parameters

* `from` Starting point

* `to` Ending point

* `nfz_list` List of no-fly zones to check against

#### Returns

Pointer to the NFZ that the path intersects, or nullopt if clear

***

#### path\_intersects\_nfz

`inline`

```cpp theme={null}
inline std::optional< std::reference_wrapper< const NoFlyZone > > path_intersects_nfz(const std::vector< GeoPoint > & waypoints, const std::vector< NoFlyZone > & nfz_list)
```

Check if any point in a path intersects NFZ.

#### Parameters

* `waypoints` List of waypoints defining the path

* `nfz_list` List of no-fly zones

#### Returns

Pointer to first intersecting NFZ, or nullopt if clear

### Variables

| Return             | Name          | Description |
| ------------------ | ------------- | ----------- |
| `constexpr double` | [`kPi`](#kpi) |             |

***

#### kPi

```cpp theme={null}
constexpr double kPi = 3.14159265358979323846
```