Prototype and description of the function setntvbinaryfile()

(Function of the unlock requiring group "NTv2 grid data")

 

setntvbinaryfile()
Initializes a NTv2 grid data binary file for Reference System Transition.

Prototype of the DLL function in C++ syntax (attend lower case!):
extern "C" __declspec(dllimport) unsigned long __stdcall setntvbinaryfile(
     char *pszFileBinary);

Prototype of the DLL function in Visual Objects syntax:
_DLL function setntvbinaryfile(;
     pszFileBinary AS PSZ);                 // 4 Byte, char*
as logic pascal:geodll32.setntvbinaryfile   // 4 Byte


The function tests and initializes a NTv2 grid data binary file containing
grid data for NTv2 Reference System Transitions. The grid data are used,
when one of the functions coordtrans???() has set the Reference System flags
for a NTv2 Reference System Transition. The memory space required for NTv2
Reference System Transitions is allocated regardless of the actual execution
of NTv2 Reference System Transitions. The testing of the file content is made
directly with the function call and any error messages are directly
initialized by the function setntvbinaryfile().

Alternatively, the function setntvbinautofile() can be used, which stores
the NTv2 file name only in a waiting position. Testing and the allocation of
memory space takes place primary with the first NTv2 Reference System
Transition.

You can download the NTv2 files supported by GeoDLL directly from the
KilletSoft Internet site "http://www.killetsoft.de", product descriptions
of TRANSDAT or GeoDLL or use the download links to the original sources
there. On the Internet site you also find a detailed description of the
NTv2 standards.

The file name may contain a drive letter, a directory path and a file name
extension. The file name extension for NTv2 binary files is by standard "gsb".
Example: "c:\program_ntv2data\beta2007.gsb".
Attention, in C syntax double backslashes must be used!

With the functions getntvbinaryfile() and setntvbinaryfile() an
automatically selection and initializtion of the required NTv2 file can be
realized. For this purpose, the required NTv2 files must be stored in a
common directory. When changing to a NTv2-based reference system, the name of
the required NTv2 file is determined by the function getntvbinaryfile(). If
the file is present in the common directory, it is initialized there with the
function setntvbinaryfile().


The parameters are passed and/or returned as follows:
pszFileBinary File name of a NTv2 binary file.
              The file name may contain a drive letter, a directory path
              and a file name extension.

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


Unlocking
This function is a component of the unlock requiring function group
"NTv2 grid data". 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. It should be noted that in addition the function
group "Coordinate Transformations" must be unlocked.