[Gmsh] Build the mesh in my own program
artemiev.mikhail at ngs.ru
Mon Oct 4 07:32:26 CEST 2010
Hi everybody once more!
Now I am ready to share my experience to use Gmsh
functions in my own program.
Thank to Mikhail Titov's advice I found in utils/api_demos
the examples of using Gmsh API.
Then I found in Gmsh reference manual this text:
<<Finally, to use Gmsh at the third level (i.e., to link
the Gmsh library with your own code),
you will need to learn the internal Gmsh Application
Programming Interface (API). No
complete documentation of this API is available yet; a
good starting point is Section C.2
[Source code structure], page 185, which gives a short
introduction to Gmsh's internal source
code structure. Then have a look e.g. at the examples in
the 'utils/api_demos/' directory
in the source code. Due to the many possible configuration
options (and associated external
dependencies), we currently do not distibute precompiled
versions of the Gmsh library.
To build the library see the instructions in the top-level
'README.txt' file in the source
Ok, cmake was downloaded and after some torture Gmsh.exe,
Gmsh.dll and Gmsh.lib was created.
Then I included Gmsh.lib in my Visual Studio project
(Properties->Linker->Input->Additional Dependencies) where
I had only one cpp-file (mainSimple.cpp from
int main(int argc, char **argv)
//GmshSetOption("Mesh", "Algorithm", 5);
GModel *m = new GModel();
//GmshMergeFile("../../tutorial/t5.geo"); // will also
set the bbox
for(GModel::riter it = m->firstRegion(); it !=
GRegion *r = *it;
printf("volume %d contains %d elements:\n", r->tag(),
for(unsigned int i = 0; i < r->getNumMeshElements();
printf(" %d", r->getMeshElement(i)->getNum());
After compilation I have 1225 errors like these:
Error 1 error LNK2001: unresolved external symbol "public:
static int __cdecl Fl::check(void)"
(?check at Fl@@SAHXZ) Gmsh.lib delme
Error 5 error LNK2001: unresolved external symbol "void
__cdecl fl_alert(char const *,...)"
(?fl_alert@@YAXPBDZZ) Gmsh.lib delme
If I delete Gmsh.lib from 'Additional Dependencies', after
compilation I have 8 errors like these:
Error 4 error LNK2001: unresolved external symbol "public:
int __thiscall GModel::mesh(int)"
(?mesh at GModel@@QAEHH at Z) main.obj delme
Error 7 error LNK2001: unresolved external symbol "int
__cdecl GmshFinalize(void)" (?GmshFinalize@@YAHXZ)
In first case I tried to include a fltk library (I thought
that 'Fl' means a part of 'fltk'), but I miscarried.
Because of <<no complete documentation of this API is
available yet>> can anybody help me?
Mikhail Artemiev, PhD student, NSTU
> Mikhail Titov:
> I would suggest to communicate with Gmsh using network.
>Take a look at the
> source code. It has a couple of nice examples in
>utils/solvers subfolder. It
> will definitely save some time since you can reuse
>existing instance instead
> of launching new process every time.
> IMHO it would be the last resort to link gmsh code in.