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 function coordcalcextra(). For more information, see the description of the function coordcalcextra(). The following Extra Parameters are available: 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. 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 function coordcalcextra(). 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. |