Ellipsoid Class

Geodetic Class

Members

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Ellipsoid ()

Constructor. Creates a new Ellipsoid class instance (WGS84 Ellipsoid).

Ellipsoid (double semimajor_axis, double flattening)

Constructor. Creates a new Ellipsoid class instance with given semi-major axis and flattening.

Arguments

• double semimajor_axis - Semimajor axis (the longest radius) of the ellipsoid.
• double flattening - Flattening of a sphere. If the value is 0, the ellipsoid has a sphere shape, for 1 the ellipsoid has a circle (completely flat) shape.

Math::vec3 getENUTangentPoint (const Math::dvec3 & geodetic_coords, const Math::vec3 & surface_coords)

Returns local point coordinates based on the geographical coordinates.

Arguments

• const Math::dvec3 & geodetic_coords - Ellipsoid coordinates (latitude (degrees), longitude (degrees) and altitude (meters) as an point of junction.
• const Math::vec3 & surface_coords - Surface coordinates to be converted (flatten) to local (offset related to point of junction).

Return value

Local point coordinates.

Math::vec3 getENUSurfacePoint (const Math::dvec3 & geodetic_coords, const Math::vec3 & local_coords)

Returns surface point by using local point coordinates.

Arguments

• const Math::dvec3 & geodetic_coords - Ellipsoid coordinates (latitude (degrees), longitude (degrees) and altitude (meters) as an point of junction.
• const Math::vec3 & local_coords - Local coordinates to converted (curved) to surface coordinates (offset related to point of junction).

Return value

Surface point coordinates.

double getSemimajorAxis ()

Returns semimajor axis length of the ellipsoid in units.

Return value

Semimajor axis of the ellipsoid.

void setSemimajorAxis (double axis)

Sets new semimajor axis of the ellipsoid.

Arguments

• double axis - Semimajor axis length in units.

double getSemiminorAxis ()

Returns semiminor axis of the ellipsoid in units.

Return value

Semiminor axis of the ellipsoid in units.

double getFlattening ()

Returns flattening coefficient of the ellipsoid.

Return value

Flattening coefficient of the ellipsoid.

void setFlattening (double flattening)

Sets new flattening for the ellipsoid.

Arguments

• double flattening - Flattening coefficient of the ellipsoid. If the value is 0, the ellipsoid has a sphere shape, for 1 the ellipsoid has a circle (completely flat) shape.

double getSemimajorEccentricitySqr ()

Returns the squared eccentricity calculated along the semimajor axis.

Return value

Squared eccentricity calculated along the semimajor axis.

double getSemiminorEccentricitySqr ()

Returns the squared eccentricity calculated along the semiminor axis.

Return value

Squared eccentricity calculated along the semiminor axis.

int getMode ()

Returns the calculation mode int value: 1 if the mode is MODE_ACCURATE, 0 if the mode is MODE_FAST.

Return value

1 if the mode is MODE_ACCURATE, 0 if the mode is MODE_FAST.

void setMode (int mode)

Set the calculation mode.

Arguments

• int mode - The variable of the calculation mode. It can be one of the following:
  • MODE_FAST
  • MODE_ACCURATE

double getMeanRadius ()

Returns the mean radius of the ellipsoid.

Return value

The mean radius of the ellipsoid.

Math::dmat4 getSurfaceWorldTransform (const Math::dvec3 & geodetic_coords)

Returns world transformation matrix of the given geo coordinates.

Arguments

• const Math::dvec3 & geodetic_coords - Ellipsoid coordinates (latitude (degrees), longitude (degrees) and altitude (meters)).

Return value

World transformation matrix of the given coordinates.

Math::mat3 getSurfaceBasis (const Math::dvec3 & geodetic_coords)

Returns surface basis (the matrix without translate).

Arguments

• const Math::dvec3 & geodetic_coords - Ellipsoid coordinates (latitude (degrees), longitude (degrees) and altitude (meters)).

Return value

Surface basis (the matrix without translate).

Math::dvec3 toECF (const Math::dvec3 & geodetic_coords)

Converts geodetic coordinates to Cartesian (ECF).

Arguments

• const Math::dvec3 & geodetic_coords - Ellipsoid coordinates (latitude (degrees), longitude (degrees) and altitude (meters)) to be converted to Cartesian.

Return value

Cartesian coordinates.

Math::dvec3 toGeodetic (const Math::dvec3 & cartesian_coords)

Converts Cartesian (ECF) coordinates to Ellipsoid.

Arguments

• const Math::dvec3 & cartesian_coords - Cartesian coordinates to be converted.

Return value

Ellipsoid coordinates (latitude (degrees), longitude (degrees) and altitude (meters)

toENU (const Math::dvec3 & geodetic_origin, const Math::dvec3 & geodetic_coords)

Arguments

• const Math::dvec3 & geodetic_origin
• const Math::dvec3 & geodetic_coords

getNEDWorldRotation (const Math::dvec3 & geodetic_origin)

Arguments

• const Math::dvec3 & geodetic_origin

getENUWorldRotation (const Math::dvec3 & geodetic_origin)

Arguments

• const Math::dvec3 & geodetic_origin

getNEDWorldTransform (const Math::dvec3 & geodetic_origin)

Arguments

• const Math::dvec3 & geodetic_origin

getNEDSurfacePoint (const Math::dvec3 & geodetic_origin, const Math::dvec3 & tangent_point)

Arguments

• const Math::dvec3 & geodetic_origin
• const Math::dvec3 & tangent_point

toNED (const Math::dvec3 & geodetic_origin, const Math::dvec3 & geodetic_coords)

Arguments

• const Math::dvec3 & geodetic_origin
• const Math::dvec3 & geodetic_coords

getENUWorldTransform (const Math::dvec3 & geodetic_origin)

Arguments

• const Math::dvec3 & geodetic_origin

getNEDTangentPoint (const Math::dvec3 & geodetic_origin, const Math::dvec3 & surface_point)

Arguments

• const Math::dvec3 & geodetic_origin
• const Math::dvec3 & surface_point

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int MODE_FAST

Description

A calculation mode is computed by using Great-circle distance formula. It works pretty fast, but you'll get positioning errors on big (~80000x80000 units) distances.

int MODE_ACCURATE

Description

A calculation mode uses Vincenty's formula to calculate distances on the surface of the ellipsoid with a millimeter precision. It takes more time for calculation, but the accuracy of positioning is awesome.