Prototype and description of the function setntvbinautodir()

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

 

setntvbinautodir()
Sets a directory for the automatically use of NTv2 binary files.

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

Prototype of the DLL function in Visual Objects syntax:
_DLL function setntvbinautodir;
     (pszBinaryDir as psz)                 // 4 Byte, char*
as logic pascal:geodll32.setntvbinautodir  // 4 Byte


With the function setntvbinautodir() 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 with up to
three subdirectories. When changing to a NTv2-based reference system, the
required NTv2 file is searched there. If the file is present in the common
directory, it is initialized automatically.

When calling setntvbinautodir() a still existing NTv2 class instance is
destroyed. When doing the first NTv2 Reference System Transition, GeoDLL
automatically creates a new NTv2 instance using the automatically found NTv2
file. The NTv2 instance remains for further NTv2 calculations until the
another NTv2 Reference System is adjusted. Thereby a new NTv2 instance
useing the required NTv2 file will be created. With calls of the functions
setntvbinaryfile() and setntvbinautofile() also the existing NTv2 instance
will be destroyed and replaced with a new one.

For geodetic calculations with NTv2 grid files GeoDLL can make aware of the
paths of the files with further functions:

With the function setntvbinaryfile(), a particular NTv2 file can be
initialized specifically in any directory. That is, for example, necessary
if with the GeoDLL Reference Systems 208 and 209 any, not implicitly by
GeoDLL supported NTv2 file must be initialized. However, the function also
works with all implicitly by GeoDLL supported NTv2 files.

The function setntvbinautofile() can be used to store the NTv2 file
path 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/p_gdln_e.htm#download
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 path name may contain a drive letter and a directory path. The path name
should end with a backslash (\)
Example: "c:\calculations\ntv2_files\"
Attention, in C syntax double backslashes must be used!

Subdirectories are scanned to the third level for NTv2 binaries.
Example:
c:\calculations\ntv2_files\world.gsb
c:\calculations\ntv2_files\australia\A66_NAT.gsb
c:\calculations\ntv2_files\brasilia\SAD69_003.gsb
c:\calculations\ntv2_files\germany\beta2007.gsb
c:\calculations\ntv2_files\germany\berlin\ntv2berlin.gsb
c:\calculations\ntv2_files\germany\hessen\HeTa2010.gsb


The parameters are passed and/or returned as follows:
pszBinaryDir  Path of a common directory for NTv2 binary file.
              The path may must contain a drive letter and a directory path
              with a trailing backslash.

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.