Prototype and description of the function getepsgcrsname() (Function of the unlock requiring group "Parameter determination") |
getepsgcrsname() Determination of the designation of a EPSG CRS by an EPSG code. Prototype of the DLL function in C++ syntax (attend lower case!): extern "C" __declspec(dllimport) unsigned long __stdcall getepsgcrsname( unsigned short nEpsg, char **pszEpsgCrsName); Prototype of the DLL function in Visual Objects syntax: _DLL function getepsgcrsname(; nEpsg as word,; // 2 Byte pszEpsgCrsName ref psz); // 4 Byte, char**, 55 alloc. as logic pascal:geodll32.getepsgcrsname // 4 Byte The allocation of memory for "ref psz" / "char**" is necessary only if setstringallocate(FALSE) is called before. The function determines for an EPSG code the designation of the EPSG Coordinate Reference System. EPSG is the acronym for "European Petroleum Survey Group Geodesy". This is a working group of the European oil and gas exploration companies. The EPSG and their successors OGP "International Association of Oil and Gas Producers" have made it to their task to build a system with globally unique identitfiers (EPSG codes) for geodetic data, such as Coordinate Reference Systems, Reference Ellipsoids or Map Projections. Since the EPSG coding is used in many GIS and thus has obtained a high level of awareness, we provide some functions, that simplifies the selection of the required Coordinate Systems and Reference Systems when coding with GeoDLL. Functions using EPSG coding: coordtransepsg() Coordinate Transformation with EPSG code getepsg2geodll() Determination of GeoDLL codes equivalent to EPSG code getepsgcrsname() This function The parameters are passed and/or returned as follows: nEpsg Code of the EPSG coordinate Reference System for which the designation is to be determined. pszEpsgCrsName Pointer to the Designation of the EPSG Coordinate (ref) Reference System. Note: "ref pszEpsgCrsName" corresponds to "char**" in C. 55 bytes of memory for the zero terminated string must be allocated with dependence to the call of the function setstringallocate(). Please consider the notes in the description of the function setstringallocate(). returnVal In case of an error the function returns FALSE, otherwise TRUE. Unlocking: This function is a component of the unlock requiring function group "parameter determination". 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. |