Prototype and description of the function setcalcextra()

(This function needs no unlocking)

setcalcextra()
Switching the calculation of Extra Parameters during coordinate
transformations.

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

Prototype of the DLL function in Visual Objects syntax:
_DLL function setcalcextra(;
     lSwitch as logic);                    // 4 Byte
as logic pascal:geodll32.setcalcextra      // 4 Byte


Additional (extra) parameters can be calculated during the execution of
coordinate transformations. Because the permanent calculation of the
Extra Parameters would slightly reduce the execution speed of GeoDLL,
these calculations can be switched on and off. The Extra Parameters can
be called by the functions coordcalcextra() and getntvcalcextra() after
each coordinate transformation. For more information, see the
descriptions of the functions coordcalcextra() and getntvcalcextra().

The following Extra Parameters are available with coordcalcextra():
  Longitude of the Geographical Point coordinate in the source system.
  Latitude of the Geographical Point coordinate in the source system.
  Longitude of Origin Center in the source System.
  Meridian Convergence at the Geographical Point in the source system.
  Longitude of the Geographical Point coordinate in the target system.
  Latitude of the Geographical Point coordinate in the target system.
  Longitude of Origin Center in the target System.
  Meridian Convergence at the Geographical Point in the target system.

The following Extra Parameters are available with getntvcalcextra():
  Number of the subgrid identified during the calculation.
  Shift value of the longitude at the coordinate in seconds.
  Shift value of the latitude at the coordinate in seconds.
  Beared shift value at the coordinate in seconds.
  Beared shift value at the coordinate in meter.
  Angel at the coordinate in degree.
  Number of rows in the determined subgrid.
  Number of columns in the determined subgrid.
  Row of the grid mesh found for the coordinate.
  Column of the grid mesh found for the coordinate.
  Index of the grid mesh found for the coordinate.

If the value TRUE is passed in lSwitch, the calculation of the Extra
Parameters is performed during all coordinate transformations. In
addition, Extra Parameters that are still present are reset to zero.

If the value FALSE is passed in lSwitch, the calculation of the Extra
Parameters during coordinate transformations is blocked. The last
calculated Extra Parameters are retained and are available for retrieval
with the functions coordcalcextra() and getntvcalcextra().


The parameters are passed and/or returned as follows:
lSwitch       Switch for the calculation of additional parameters.
TRUE          Calculation on.
FALSE         Calculation off.
              (default)

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


Unlocking:
This function needs no unlocking.