Add support to float.

Former-commit-id: 4bb385a979320bf70dc91d4a346b7eb45071cc21

include/igl/copyleft/cgal/assign_scalar.cpp

@@ -15,11 +15,9 @@ IGL_INLINE void igl::copyleft::cgal::assign_scalar(
 }
 
 IGL_INLINE void igl::copyleft::cgal::assign_scalar(
-  const typename CGAL::Epeck::FT & _cgal,
+  const typename CGAL::Epeck::FT & cgal,
   double & d)
 {
-  // FORCE evaluation of the exact type otherwise interval might be huge.
-  const typename CGAL::Epeck::FT cgal = _cgal.exact();
   const auto interval = CGAL::to_interval(cgal);
   d = interval.first;
   do {
@@ -29,9 +27,36 @@ IGL_INLINE void igl::copyleft::cgal::assign_scalar(
   } while (d < interval.second);
 }
 
+IGL_INLINE void igl::copyleft::cgal::assign_scalar(
+  const typename CGAL::Epeck::FT & cgal,
+  float& d)
+{
+  const auto interval = CGAL::to_interval(cgal);
+  d = interval.first;
+  do {
+      const float next = nextafter(d, interval.second);
+      if (CGAL::abs(cgal-d) < CGAL::abs(cgal-next)) break;
+      d = next;
+  } while (d < interval.second);
+}
+
 IGL_INLINE void igl::copyleft::cgal::assign_scalar(
   const double & c,
   double & d)
 {
   d = c;
 }
+
+IGL_INLINE void igl::copyleft::cgal::assign_scalar(
+  const float& c,
+  float& d)
+{
+  d = c;
+}
+
+IGL_INLINE void igl::copyleft::cgal::assign_scalar(
+  const float& c,
+  double& d)
+{
+  d = c;
+}

include/igl/copyleft/cgal/assign_scalar.h

@@ -25,9 +25,18 @@ namespace igl
       IGL_INLINE void assign_scalar(
         const typename CGAL::Epeck::FT & cgal,
         double & d);
+      IGL_INLINE void assign_scalar(
+        const typename CGAL::Epeck::FT & cgal,
+        float& d);
       IGL_INLINE void assign_scalar(
         const double & c,
         double & d);
+      IGL_INLINE void assign_scalar(
+        const float& c,
+        float & d);
+      IGL_INLINE void assign_scalar(
+        const float& c,
+        double& d);
     }
   }
 }