﻿ Function karttk2geo()
 Prototype and description of the function karttk2geo() (Function of the unlock requiring group "Map calculations")
 ```karttk2geo() Determination of the corner coordinate of a topographic map. Prototype of the DLL function in C++ syntax (attend lower case!): extern "C" __declspec(dllimport) unsigned long __stdcall karttk2geo( unsigned short nTK25, double *nGeoLon, double *nGeoLat); Prototype of the DLL function in Visual Objects syntax: _DLL function karttk2geo(; nTk25 as word,; // 2 Byte nGeoLon ref real8,; // 4 Byte nGeoLat ref real8); // 4 Byte as logic pascal:geodll32.karttk2geo // 4 Byte The function returns the hitting corner coordinate of the left lower corner of an official topographic map of the Federal Republic of Germany on a scale of 1:25000 (TK25, ordnance map) to the calling program. Since all TK25 are exactly 6 minutes wide on the longitude and exactly 10 minutes wide on the latitude, the hitting corner coordinates of the other map corners can be calculated easy. The function returns the geographic coordinate nGeoLon and nGeoLat in [degrees] notation (ggg.nnn) by reference. 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: nTK25 Number of the TK25. nGeoLon Geographic longitude of the left lower corner in [degrees] (ref) notation as reference. nGeoLat Geographic latitude of the left lower corner in [degrees] (ref) notation as reference. returnVal In case of an error the function returns FALSE, otherwise TRUE. Unlocking: 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. ```