LaGriT code is written mostly in Fortran, but also includes C and C++ codes. See the files in src and lg_util for more examples.
The following template is a Fortran code example of using the an existing mesh object and of creating a new mesh object. The existing mesh object is a 3d object. The object to be created is a 2d object. It is first necessary to set up the pointer statements for both the existing and new mesh objects. All these mesh object attributes are integers except for xic,yix,zic which are real*8.
C Definitions for incoming (existing) cmo
pointer (ipimt1, imt1)
pointer (ipitp1, itp1)
pointer (ipicr1, icr1)
pointer (ipisn1, isn1)
integer imt1(1000000), itp1(1000000)
integer icr1(1000000), isn1(1000000)
pointer (ipxic, xic)
pointer (ipyic, yic)
pointer (ipzic, zic)
real*8 xic(1000000), yic(1000000), zic(1000000)
pointer (ipitetclr, itetclr)
pointer (ipitettyp, itettyp)
pointer (ipitetoff, itetoff)
pointer (ipjtetoff, jtetoff)
pointer (ipitet, itet)
pointer (ipjtet, jtet)
integer itetclr(1000000), itettyp(1000000)
integer itetoff(1000000), jtetoff(1000000)
integer itet(4,1000000) , jtet(4,1000000)
C Definitions for cmo that is to be created
pointer (ipimt1a, imt1a)
pointer (ipitp1a, itp1a)
pointer (ipicr1a, icr1a)
pointer (ipisn1a, isn1a)
integer imt1a(1000000), itp1a(1000000)
integer icr1a(1000000), isn1a(1000000)
pointer (ipxica, xica)
pointer (ipyica, yica)
pointer (ipzica, zica)
real*8 xica(1000000), yica(1000000), zica(1000000)
pointer (ipitetclra, itetclra)
pointer (ipitettypa, itettypa)
pointer (ipitetoffa, itetoffa)
pointer (ipjtetoffa, jtetoffa)
pointer (ipiteta, iteta)
pointer (ipjteta, jteta)
integer itetclra(1000000), itettypa(1000000)
integer itetoffa(1000000), jtetoffa(1000000)
integer iteta(3,1000000), jteta(3,1000000)
C Get the existing cmo - its name is in the variable cmoin
call cmo_get_name(cmoin,ier)
C Get the scalar mesh variables
call cmo_get_intinfo('nnodes',cmoin,npoints,lencm,itypcm,ier)
call cmo_get_intinfo('nelements',cmoin,ntets,lencm,itypcm,ier)
call cmo_get_intinfo('ndimensions\_topo',cmoin,ndt,lencm,itypcm,ier)
call cmo_get_intinfo('ndimensions\_geom',cmoin,ndg,lencm,itypcm,ier)
call cmo_get_intinfo('nodes\_per\_element',cmoin,npe,lencm,itypcm,ier)
call cmo_get_intinfo('faces\_per\_element',cmoin,nfpe,lencm,itypcm,ier)
call cmo_get_intinfo('mbndry',cmoin,mbndry,lencm,itypcm,ier)
C Get pointers to the vector variables
call cmo_get_info('ialias',cmoin,ipialias,lenialias,ictype,ier)
call cmo_get_info('imt1',cmoin,ipimt1,lenimt1,ictype,ier)
call cmo_get_info('itp1',cmoin,ipitp1,lenitp1,ictype,ier)
call cmo_get_info('icr1',cmoin,ipicr1,lenicr1,ictype,ier)
call cmo_get_info('isn1',cmoin,ipisn1,lenisn1,ictype,ier)
call cmo_get_info('xic',cmoin,ipxic,lenxic,ictype,ier)
call cmo_get_info('yic',cmoin,ipyic,lenyic,ictype,ier)
call cmo_get_info('zic',cmoin,ipzic,lenzic,ictype,ier)
call cmo_get_info('itetclr',cmoin,ipitetclr,lenitetclr,ictype,ier)
call cmo_get_info('itettyp',cmoin,ipitettyp,lenitettyp,ictype,ier)
call cmo_get_info('itetoff',cmoin,ipitetoff,lenitetoff,ictype,ier)
call cmo_get_info('jtetoff',cmoin,ipjtetoff,lenjtetoff,ictype,ier)
call cmo_get_info('itet',cmoin,ipitet,lenitet,ictype,ier)
call cmo_get_info('jtet',cmoin,ipjtet,lenjtet,icmotype,ier)
C Create the new 2d cmo - call it cmoout.
call cmo_exist(cmoout,ier)
C ier.eq.0 means that the cmo already exists - if so release it.
if(ier.eq.0) call cmo_release(cmoout,idelete)
C Set active cmo to cmoout
call cmo_set_name(cmoout,ier)
C set scalar mesh variables
call cmo_set_intinfo('nnodes',cmoout,npoints,1,1,ier)
call cmo_set\intinfo('nelements',cmoout,ntets,1,1,ier)
C the following scalars need to be set for a 2d cmo
call cmo_set_info('ndimensions_topo',cmoout,2,1,1,ier)
call cmo_set_info('ndimensions_geom',cmoout,3,1,1,ier)
call cmo_set_info('nodes_per_element',cmoout,3,1,1,ier)
call cmo_set_info('faces_per_element',cmoout,3,1,1,ier)
C allocate memory for vector variables
call cmo_newlen(cmoout,ier)
C now get the pointers to the allocated memory for the vector data
call cmo_get_info('imt1',cmoout,ipimt1a,lenimt1a,icmotype,ier)
call cmo_get_info('itp1',cmoout,ipitp1a,lenitp1a,icmotype,ier)
call cmo_get_info('icr1',cmoout,ipicr1a,lenicr1a,icmotype,ier)
call cmo_get_info('isn1',cmoout,ipisn1a,lenisn1a,icmotype,ier)
call cmo_get_info('xic',cmoout,ipxica,lenxica,icmotype,ier)
call cmo_get_info('yic',cmoout,ipyica,lenyica,icmotype,ier)
call cmo_get_info('zic',cmoout,ipzica,lenzica,icmotype,ier)
call cmo_get_info('itetclr',cmoout,ipitetclra,lenclra,icmotype,ier)
call cmo_get_info('itettyp',cmoout,ipitettypa,lentypa,icmotype,ier)
call cmo_get_info('itetoff',cmoout,ipitetoffa,lenoffa,icmotype,ier)
call cmo_get_info('jtetoff',cmoout,ipjtetoffa,lenoffa,icmotype,ier)
call cmo_get_info('itet',cmoout,ipiteta,leniteta,icmotype,ier)
call cmo_get_info('jtet',cmoout,ipjteta,lenjteta,icmotype,ier)
C now the values for the components of the 2d mesh object can be assigned.