Prototype and description of the function point2pointutm() (Function of the unlock requiring group "Distance calculations") |

point2pointutm() Calculation of a UTM destination point on the earth ellipsoid by given UTM start point, bearing and distance. Prototype of the DLL function in C++ syntax (attend lower case!): extern "C" __declspec(dllimport) unsigned long __stdcall point2pointutm( double nUtmEast1, double nUtmNorth1, double nDistance, double nAzimut, double *nUtmEast2, double *nUtmNorth2, unsigned short nEllipsoid) Prototype of the DLL function in Visual Objects syntax: _DLL function point2pointutm(; nUtmEast1 as real8,; // 8 Byte nUtmNorth1 as real8,; // 8 Byte nDistance as real8,; // 8 Byte nAzimut as real8,; // 8 Byte nUtmEast2 ref real8,; // 4 Byte nUtmNorth2 ref real8,; // 4 Byte nEllipsoid as word); // 2 Byte as logic pascal:geodll32.point2pointutm // 4 Byte The function calculates the UTM coordinates of a destination point on the earth ellipsoid. The calculation uses the UTM coordinates of a start point, its forward bearing (azimuth) and the distance in meters between the points. The "Vincenty Direct Formula" is used for the calculation on the earth ellipsoid, which returns the result with high accuracy. The UTM coordinate nUtmEast1 / nUtmNorth1 of the start point must be passed to the function. The easting value must contain the UTM strip number. The forward bearing nAzimut from the start point to the destination point must be passed in [degrees]-notation [ggg.ggg] to the function. The bearing must be in the range of 0 up to 360 degrees, where 0 degrees points north and 90 degrees points east. The distance between the points must be passed in meter with the parameter nDistance. In nEllipsoid the necessary ellipsoid is passed. If in nEllipsoid the value 0 is passed, then the geodetic ellipsoid WGS84 is used. If in nEllipsoid the value 1000 is passed, the function uses the semi axes of the user-defined earth ellipsoid passed before by the function setuserellsource(). The function returns as result the UTM coordinate nUtmEast2 (UTM easting) and nUtmNorth2 (UTM northing) of the destination point. The Easting includes the UTM zone number. The parameters are passed and/or returned as follows: nUtmEast1 UTM easting of the start point in meters including the UTM zone number nUtmNorth1 UTM northing of the start point in meters nDistance Distance between the points in meters on the earth ellipsoid nAzimut Forward bearing from the start point in direction of the destination point in [degrees] notation ggg.ggg nUtmEast2 UTM easting of the destination point in meters including the UTM (ref) zone number as result nUtmNorth2 UTM northing of the destination point in meters as result (ref) nEllipsoid Geodetic ellipsoid. The ellipsoid numbers are specified at the bottom part of the list "Systems sorted alphabetical". The numbers of the Reference Systems specified in the list "Systems sorted by countries" can be used also. returnVal In case of an error the function returns FALSE, otherwise TRUE. For geographic coordinates in [degrees] notation applies: g degrees and decimal fraction of a degree. Unlocking: This function is a component of the unlock requiring function group "distance calculations". It is unlocked for unrestricted use together with the other functions of the group by passing the unlock parameters, acquired from the software distribution company, trough the function setunlockcode(). Without unlocking only a few function calls for test purposes (shareware principle) are possible. |