udGeoZone

udGeoZone.h provides support for transforming geodetic and cartesian coordinates

Defines

udGeoZone_SetFromWKT

Enums

enum udGeoZoneEllipsoid

Supported udGeoZone ellipsoids

Values:

Value	Description
`udGZE_WGS84`	EPSG:7030.
`udGZE_Airy1830`	EPSG:7001.
`udGZE_AiryModified`	EPSG:7002.
`udGZE_Bessel1841`	EPSG:7004.
`udGZE_BesselModified`	EPSG:7005.
`udGZE_Clarke1866`	EPSG:7008.
`udGZE_Clarke1880IGN`	EPSG:7011.
`udGZE_GRS80`	EPSG:7019.
`udGZE_Intl1924`	EPSG:7022 (Same numbers as Hayford).
`udGZE_WGS72`	EPSG:7043.
`udGZE_CGCS2000`	EPSG:1024.
`udGZE_Clarke1858`	EPSG:7007.
`udGZE_Clarke1880FOOT`	EPSG:7055.
`udGZE_Krassowsky1940`	EPSG:7024.
`udGZE_Everest1930M`	EPSG:7018.
`udGZE_Mars`
`udGZE_Moon`
`udGZE_IAG1975`
`udGZE_Everest1830`
`udGZE_GRS67`
`udGZE_ANS`	EPSG:7003.
`udGZE_INS`	EPSG:7021.
`udGZE_Count`

enum udGeoZoneGeodeticDatum

Supported udGeoZone geodetic datums

Values:

Value	Description
`udGZGD_WGS84`	EPSG:4326.
`udGZGD_ED50`	EPSG:4230.
`udGZGD_ETRS89`	EPSG:4258,4936.
`udGZGD_TM75`	EPSG:4300.
`udGZGD_NAD27`	EPSG:4267.
`udGZGD_NAD27CGQ77`	EPSG:4609.
`udGZGD_NAD83`	EPSG:4269.
`udGZGD_NAD83_1996`	EPSG:6307.
`udGZGD_NAD83_CSRS`	EPSG:2955.
`udGZGD_NAD83_NSRS2007`	EPSG:3465.
`udGZGD_NAD83_2011`	EPSG:6318.
`udGZGD_NTF`	EPSG:4275.
`udGZGD_OSGB36`	EPSG:4277.
`udGZGD_Potsdam`	EPSG:4746.
`udGZGD_Tokyo`	EPSG:7414.
`udGZGD_WGS72`	EPSG:4322.
`udGZGD_JGD2000`	EPSG:4612.
`udGZGD_JGD2011`	EPSG:6668.
`udGZGD_GDA94`	EPSG:4283.
`udGZGD_GDA2020`	EPSG:7844.
`udGZGD_RGF93`	EPSG:4171.
`udGZGD_NAD83_HARN`	EPSG:4152.
`udGZGD_CGCS2000`	EPSG:4490.
`udGZGD_HK1980`	EPSG:4611.
`udGZGD_SVY21`	EPSG:4757.
`udGZGD_MGI`	EPSG:6312.
`udGZGD_NZGD2000`	EPSG:2193.
`udGZGD_AMERSFOORT`	EPSG:28992.
`udGZGD_TRI1903`	EPSG:30200.
`udGZGD_VANUA1915`	EPSG:3139.
`udGZGD_DEALUL1970`	EPSG:31700.
`udGZGD_SINGGRID`	EPSG:19920.
`udGZGD_MARS_MERC`	EPSG:49974,49975.
`udGZGD_MARS_PCPF`	EPSG:8705.
`udGZGD_MOON_MERC`	EPSG:30174,30175.
`udGZGD_MOON_PCPF`	EPSG:30100,30100.
`udGZGD_DBREF`	EPSG:5681.
`udGZGD_DHDN`	EPSG:4314.
`udGZGD_SJTSK03`	EPSG:8353.
`udGZGD_PULK1942`	EPSG:4284.
`udGZGD_PULK194258`	EPSG:4179.
`udGZGD_PULK194283`	EPSG:4178.
`udGZGD_PULK1995`	EPSG:20004.
`udGZGD_WGS_72BE`	EPSG:32401.
`udGZGD_BEIJING1954`	EPSG:21413.
`udGZGD_NEWBEIJING`	EPSG:4555.
`udGZGD_XIAN1980`	EPSG:4610.
`udGZGD_TIMB1948`	EPSG:28973.
`udGZGD_NZGD49`	EPSG:4272.
`udGZGD_SWEREF99`	EPSG:4619.
`udGZGD_SAD69`	EPSG:4291.
`udGZGD_GR96`	EPSG:4747.
`udGZGD_DGN95`	EPSG:4755.
`udGZGD_UCS2000`	EPSG:5561.
`udGZGD_H94`	EPSG:4148.
`udGZGD_ID74`	EPSG:4238.
`udGZGD_NGO1948`	EPSG:4273.
`udGZGD_RGF93v2b`	EPSG:9782.
`udGZGD_Count`

enum udGeoZoneProjectionType

Supported udGeoZone projection types

Values:

Value	Description
`udGZPT_Unknown`
`udGZPT_ECEF`
`udGZPT_LongLat`
`udGZPT_LatLong`
`udGZPT_TransverseMercator`
`udGZPT_LambertConformalConic2SP`
`udGZPT_WebMercator`
`udGZPT_CassiniSoldner`
`udGZPT_CassiniSoldnerHyperbolic`
`udGZPT_SterographicObliqueNEquatorial`
`udGZPT_SterographicPolar_vB`
`udGZPT_Mercator`
`udGZPT_Krovak`
`udGZPT_KrovakNorthOrientated`
`udGZPT_HotineObliqueMercatorvA`
`udGZPT_HotineObliqueMercatorvB`
`udGZPT_AlbersEqualArea`
`udGZPT_EquidistantCylindrical`
`udGZPT_Count`

Functions

enum udError udGeoZone_LoadZonesFromJSON(const char pJSONStr, int pLoaded, int *pFailed)

Loads a set of zones from a JSON file where each member is defined as “AUTHORITY:SRID” (eg. “EPSG:32756”)

Parameter	Description
`pJSONStr`	A JSON-formatted string containing all the zones
`pLoaded`	Pointer to an integer that has the count of zones successfully loaded
`pFailed`	Pointer to an integer that has the count of zones unsuccessfully loaded

Returns: A udError code

enum udError udGeoZone_UnloadZones()

Unloads all loaded zones (only needs to be called once to unload all)

Returns: A udError code, typically udE_Success

enum udError udGeoZone_FindSRID(int32_t pSRIDCode, const udDouble3 pLatLong, enum udGeoZoneGeodeticDatum datum)

Find an appropriate SRID code for a given lat/long within UTM/WGS84 (for example using datum udGZGD_WGS84)

Parameter	Description
`pSRIDCode`	A pointer to which the SRID code is written upon success
`pLatLong`	A pointer to a udDouble3 where x is the latitude, y is the longitude (z is ignored)
`datum`	The geodetic datum (normally udGZGD_WGS84)

Returns: A udError code

enum udError udGeoZone_SetFromSRID(struct udGeoZone *pZone, int32_t sridCode)

Set the zone structure parameters from a given srid code

Parameter	Description
`pZone`	A udGeoZone structure that will be overwritten with parameters for the given sridCode
`sridCode`	The sridCode for the desired zone

Returns: A udError code

enum udError udGeoZone_SetFromWellKnownText(struct udGeoZone pZone, const char pWKT)

Initialise a geozone structure from well known text

Parameter	Description
`pZone`	A udGeoZone structure that will be overwritten with parameters taken from the supplied Well Known Text
`pWKT`	A Well Known Text formatted string

Returns: A udError code

enum udError udGeoZone_GetWellKnownText(const char **ppWKT, const struct udGeoZone *pZone)

Get the Well Known Text for a zone

!NOTE The Well Known Text must be freed using udGeoZone_FreeWellKnownText

Parameter	Description
`ppWKT`	A pointer to a string pointer that will be assigned with an allocated WKT string for the given zone
`pZone`	A valid udGeoZone structure used to generate the Well Known Text

Returns: A udError code

void udGeoZone_FreeWellKnownText(const char **ppWKT)

Free the Well Known Text returned by udGeoZone_GetWellKnownText

Parameter	Description
`ppWKT`	A pointer to a string pointer that was returned by udGeoZone_GetWellKnownText

enum udError udGeoZone_LatLongToCartesian(udDouble3 pCartesian, const struct udGeoZone pZone, const udDouble3 *pLatLong, enum udGeoZoneGeodeticDatum datum)

Convert a point from lat/long to the cartesian coordinate system defined by the zone

Parameter	Description
`pCartesian`	A pointer to a udDouble3 overwritten with the cartesian value of the transformed LatLong
`pZone`	A valid udGeoZone defining the coordinate system
`pLatLong`	A pointer to a udDouble3 containing the Latitude in x, Longitude in y, and altitude in Z
`datum`	The geodetic datum for the latlong coordinates, typically udGZGD_WGS84

Returns: A udError code

enum udError udGeoZone_CartesianToLatLong(udDouble3 pLatLong, const struct udGeoZone pZone, const udDouble3 *pPosition, enum udGeoZoneGeodeticDatum datum)

Convert a point from the cartesian coordinate system defined by the zone to lat/long

Parameter	Description
`pLatLong`	A pointer to a udDouble3 overwritten with the transformed Latitude in x, Longitude in y, and altitude in Z
`pZone`	A valid udGeoZone defining the coordinate system
`pCartesian`	A pointer to a udDouble3 containing the cartesian coordinates
`datum`	The geodetic datum for the latlong coordinates, typically udGZGD_WGS84

Returns: A udError code

enum udError udGeoZone_LatLongToGeocentric(udDouble3 pGeocentric, const udDouble3 pLatLong, const struct udGeoZoneEllipsoidInfo *pEllipsoid)

Conversion to and from Geocentric

Parameter	Description
`pGeocentric`	A pointer to a udDouble3 overwritten with the transformed geocentric coordinates
`pLatLong`	A pointer to a udDouble3 containing the Latitude in x, Longitude in y, and altitude in Z
`pEllipsoid`	The ellipsoid parameters as specified in the datum

Returns: A udError code

enum udError udGeoZone_GeocentricToLatLong(udDouble3 pLatLong, const udDouble3 pGeoCentric, const struct udGeoZoneEllipsoidInfo *pEllipsoid)

Conversion to and from Geocentric

Parameter	Description
`pLatLong`	A pointer to a udDouble3 with the Latitude in x, Longitude in y, and altitude in Z
`pGeocentric`	A pointer to a udDouble3 containing the geocentric coordinates
`pEllipsoid`	The ellipsoid parameters as specified in the datum

Returns: A udError code

enum udError udGeoZone_ConvertDatum(udDouble3 pOutLatLong, const udDouble3 pInLatLong, enum udGeoZoneGeodeticDatum currentDatum, enum udGeoZoneGeodeticDatum newDatum)

Convert a lat/long pair in one datum to another datum

Parameter	Description
`pOutLatLong`	A pointer to a udDouble3 with the output Latitude in x, Longitude in y, and altitude in Z
`pInLatLong`	A pointer to a udDouble3 with the input Latitude in x, Longitude in y, and altitude in Z
`currentDatum`	The datum that the pInLatLong references
`newDatum`	The datum that the pOutLatLong references

Returns: A udError code

enum udError udGeoZone_TransformPoint(udDouble3 pTransformed, const udDouble3 pPoint, const struct udGeoZone pSourceZone, const struct udGeoZone pDestZone)

Transform a point from one zone to another

Parameter	Description
`pTransformed`	A pointer to a udDouble3 with the output transformed coordinates, which may be cartesian or latlong depending on the destination zone
`pPoint`	A pointer to a udDouble3 with the input coordinates, which may be cartesian or latlong depending on the source zone
`pSourceZone`	The zone that pPoint references
`pDestZone`	The zone the point is transformed to, which pTransformed references

Returns: A udError code

enum udError udGeoZone_TransformMatrix(udDouble4x4 pTransformed, const udDouble4x4 pMatrix, const struct udGeoZone pSourceZone, const struct udGeoZone pDestZone)

Transform a matrix from one zone to another

Parameter	Description
`pTransformed`	A pointer to a matrix that has been transformed to the destination zone
`pMatrix`	A pointer to a matrix that is in the source zone coordinate system
`pSourceZone`	The zone that pMatrix references
`pDestZone`	The zone that pTransformed references

Returns: A udError code

enum udError udGeoZone_UpdateSphereoidInfo(struct udGeoZone *pZone)

Complete setup of a udGeoZone

!NOTE This is called after changing parameters of the zone

Parameter	Description
`pZone`	The zone to complete the setup of

Returns: A udError code

Structs

struct udGeoZone

udGeoZone structure. Do not rely on element order as they may change in a future release.

Field	Type	Description
`datum`	`enum udGeoZoneGeodeticDatum`
`projection`	`enum udGeoZoneProjectionType`
`latLongBoundMin`	`udDouble2`
`latLongBoundMax`	`udDouble2`
`meridian`	`double`
`parallel`	`double`	Parallel of origin for Transverse Mercator.
`latProjCentre`	`double`	Latitude of Projection Centre for Krovak Projection.
`coLatConeAxis`	`double`	Co Latitude of the cone axis for Krovak Projection.
`flattening`	`double`
`semiMajorAxis`	`double`
`semiMinorAxis`	`double`
`thirdFlattening`	`double`
`eccentricity`	`double`
`eccentricitySq`	`double`
`radius`	`double`
`scaleFactor`	`double`
`n[10]`	`double`
`alpha[9]`	`double`
`beta[9]`	`double`
`firstParallel`	`double`
`secondParallel`	`double`
`falseNorthing`	`double`
`falseEasting`	`double`
`unitMetreScale`	`double`	1.0 for metres, 0.3048006096012192 for feet
`zone`	`int32_t`
`srid`	`int32_t`
`datumShortName[16]`	`char`
`datumName[64]`	`char`
`zoneName[64]`	`char`	Full name for zone, only 33 characters required for longest known name “Japan Plane Rectangular CS XVIII”.
`displayName[128]`	`char`	This is the human readable name; often just datumShortName & zoneName concatenated.
`knownDatum`	`char`	boolean
`datumSrid`	`int32_t`
`toWGS84`	`char`	boolean
`axisInfo`	`char`	boolean
`zoneSpheroid`	`enum udGeoZoneEllipsoid`
`paramsHelmert7[7]`	`double`	TO-WGS84 as { Tx, Ty, Tz, Rx, Ry, Rz, DS }.

struct udGeoZoneGeodeticDatumDescriptor

Geodetic Datum descriptor, stored globally as g_udGZ_GeodeticDatumDescriptors

Field	Type	Description
`pFullName`	`const char \*`
`pShortName`	`const char \*`
`pDatumName`	`const char \*`
`ellipsoid`	`enum udGeoZoneEllipsoid`
`paramsHelmert7[7]`	`double`	TO-WGS84 as { Tx, Ty, Tz, Rx, Ry, Rz, DS }.
`epsg`	`int32_t`	epsg code for the datum
`authority`	`int32_t`	authority for this datum
`exportAxisInfo`	`char`
`exportToWGS84`	`char`

struct udGeoZoneEllipsoidInfo

Ellipsoid info

Field	Type	Description
`pName`	`const char \*`
`semiMajorAxis`	`double`
`flattening`	`double`
`authorityEpsg`	`int32_t`

udGeoZone

enum udError udGeoZone_LoadZonesFromJSON(const char *pJSONStr, int *pLoaded, int *pFailed)

enum udError udGeoZone_UnloadZones()

enum udError udGeoZone_FindSRID(int32_t *pSRIDCode, const udDouble3 *pLatLong, enum udGeoZoneGeodeticDatum datum)

enum udError udGeoZone_SetFromSRID(struct udGeoZone *pZone, int32_t sridCode)

enum udError udGeoZone_SetFromWellKnownText(struct udGeoZone *pZone, const char *pWKT)

enum udError udGeoZone_GetWellKnownText(const char **ppWKT, const struct udGeoZone *pZone)

enum udError udGeoZone_LatLongToCartesian(udDouble3 *pCartesian, const struct udGeoZone *pZone, const udDouble3 *pLatLong, enum udGeoZoneGeodeticDatum datum)

enum udError udGeoZone_CartesianToLatLong(udDouble3 *pLatLong, const struct udGeoZone *pZone, const udDouble3 *pPosition, enum udGeoZoneGeodeticDatum datum)

enum udError udGeoZone_LatLongToGeocentric(udDouble3 *pGeocentric, const udDouble3 *pLatLong, const struct udGeoZoneEllipsoidInfo *pEllipsoid)

enum udError udGeoZone_GeocentricToLatLong(udDouble3 *pLatLong, const udDouble3 *pGeoCentric, const struct udGeoZoneEllipsoidInfo *pEllipsoid)

enum udError udGeoZone_ConvertDatum(udDouble3 *pOutLatLong, const udDouble3 *pInLatLong, enum udGeoZoneGeodeticDatum currentDatum, enum udGeoZoneGeodeticDatum newDatum)

enum udError udGeoZone_TransformPoint(udDouble3 *pTransformed, const udDouble3 *pPoint, const struct udGeoZone *pSourceZone, const struct udGeoZone *pDestZone)

enum udError udGeoZone_TransformMatrix(udDouble4x4 *pTransformed, const udDouble4x4 *pMatrix, const struct udGeoZone *pSourceZone, const struct udGeoZone *pDestZone)

enum udError udGeoZone_UpdateSphereoidInfo(struct udGeoZone *pZone)

enum udError udGeoZone_LoadZonesFromJSON(const char pJSONStr, int pLoaded, int *pFailed)

enum udError udGeoZone_FindSRID(int32_t pSRIDCode, const udDouble3 pLatLong, enum udGeoZoneGeodeticDatum datum)

enum udError udGeoZone_SetFromWellKnownText(struct udGeoZone pZone, const char pWKT)

enum udError udGeoZone_LatLongToCartesian(udDouble3 pCartesian, const struct udGeoZone pZone, const udDouble3 *pLatLong, enum udGeoZoneGeodeticDatum datum)

enum udError udGeoZone_CartesianToLatLong(udDouble3 pLatLong, const struct udGeoZone pZone, const udDouble3 *pPosition, enum udGeoZoneGeodeticDatum datum)

enum udError udGeoZone_LatLongToGeocentric(udDouble3 pGeocentric, const udDouble3 pLatLong, const struct udGeoZoneEllipsoidInfo *pEllipsoid)

enum udError udGeoZone_GeocentricToLatLong(udDouble3 pLatLong, const udDouble3 pGeoCentric, const struct udGeoZoneEllipsoidInfo *pEllipsoid)

enum udError udGeoZone_ConvertDatum(udDouble3 pOutLatLong, const udDouble3 pInLatLong, enum udGeoZoneGeodeticDatum currentDatum, enum udGeoZoneGeodeticDatum newDatum)

enum udError udGeoZone_TransformPoint(udDouble3 pTransformed, const udDouble3 pPoint, const struct udGeoZone pSourceZone, const struct udGeoZone pDestZone)

enum udError udGeoZone_TransformMatrix(udDouble4x4 pTransformed, const udDouble4x4 pMatrix, const struct udGeoZone pSourceZone, const struct udGeoZone pDestZone)