Prototype and description of the function kartgeo2tk()

(Function of the unlock requiring group "Map calculations")


Determination of a topographic map from geographic coordinates.

Prototype of the DLL function in C++ syntax (attend lower case!):
extern "C" __declspec(dllimport) unsigned long __stdcall kartgeo2tk(
     double nGeoLon,
     double nGeoLat,
     unsigned short *nTK1,
     unsigned short *nTK2,
     unsigned short *nTK3,
     unsigned short *nTK4);

Prototype of the DLL function in Visual Objects syntax:
_DLL function kartgeo2tk(;
     nGeoLon as real8,;                    // 8 Byte
     nGeoLat as real8,;                    // 8 Byte
     nTK1 ref word,;                       // 4 Byte
     nTK2 ref word,;                       // 4 Byte
     nTK3 ref word,;                       // 4 Byte
     nTK4 ref word);                       // 4 Byte
as logic pascal:geodll32.kartgeo2tk        // 4 Byte

The function returns the numbers of the official topographic maps with
the scale 1:25.000 (TK25, ordnance map) of the Federal Republic of
Germany, in whose surface the geographical coordinate is present.
Theoretically up to four maps can be calculated for one coordinate, if
it is on the edge or in a corner of the map sheet. In determining the
standard map cutting blade is considered.

The function must receive the geographic coordinate nGeoLon and nGeoLat
in [degrees] notation (ggg.nnn). The degrees portion (g) is integer,
the minute and second portions are represented as decimal fraction of
a degree (n).

The parameters are passed and/or returned as follows:
nGeoLon     Geographic longitude in [degrees] notation.

nGeoLat     Geographic latitude in [degrees] notation.

nTK1        Number of the first found TK25 as reference.

nTK2        Number of the second found TK25 as reference.

nTK3        Number of the third found TK25 as reference.

nTK4        Number of the forth found TK25 as reference.

returnVal   In case of an error the function returns FALSE, otherwise TRUE.

This function is a component of the unlock requiring function group
"map 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.