Yesterday I tried a very similar approach as I used for Ruby:
++
// g++ -c -lCGAL -lgmp cdt.cpp
// ar rvs cdt.a cdt.o
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Constrained_Delaunay_triangulation_2.h>
//#include <cassert>
//#include <iostream>
typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Exact_predicates_tag Itag;
typedef CGAL::Constrained_Delaunay_triangulation_2<K, CGAL::Default, Itag>
CDT;
typedef CDT::Point Point;
extern "C" void *newCDT();
extern "C" void insertConstraint(CDT *cdt, double x0, double y0, double x1,
double y1);
extern "C" int numConstraints(CDT *cdt);
void *newCDT()
{
CDT *cdt;
cdt = new CDT;
return cdt;
}
void insertConstraint(CDT *cdt, double x0, double y0, double x1, double y1)
{
cdt->insert_constraint( Point(x0, y0), Point(x1, y1));
}
int numConstraints(CDT *cdt)
{
int count = 0;
for (CDT::Finite_edges_iterator eit = cdt->finite_edges_begin();
eit != cdt->finite_edges_end();
++eit)
if (cdt->is_constrained(*eit)) ++count;
return count;
}
#nim cpp --passL:cdt.a --passL:-lCGAL --passL:-lgmp cdt.nim
type
CDT = ptr object
proc newCDT(): CDT {.importc.}
proc insertConstraint(cdt: CDT; x0, y0, x1, y1: cdouble) {.importc.}
proc numConstraints(cdt: CDT): cint {.importc.}
var cdt = newCDT()
for i in 1 ..< 6:
cdt.insertConstraint(0.cdouble, i.cdouble, 6.cdouble, i.cdouble)
for j in 1 ..< 6:
cdt.insertConstraint(j.cdouble, 0.cdouble, j.cdouble, 6.cdouble)
echo cdt.numConstraints
Seems to compile and work. I have to invoke nim compiler with cpp -- initially
I assumed that cpp backand is not necessary due to extern "C"
g++ -c -lCGAL -lgmp cdt.cpp
ar rvs cdt.a cdt.o
nim cpp --passL:cdt.a --passL:-lCGAL --passL:-lgmp cdt.nim
I assume this will not work with llvm backend. Of course releasing memory with
GC is still work in progress, for Triangulation data structure it is not really
simple, because Triangulation is some sort of container, so objects can live
inside triangulation and at the same time outside in Nim world. I think I did
it wrong for Ruby some years ago -- never fixed, as it was working for me...
