Added inner radius for hexahedrons

Geo/MHexahedron.cpp

@@ -2,12 +2,12 @@
 //
 // See the LICENSE.txt file for license information. Please report all
 // bugs and problems to <gmsh@geuz.org>.
-
+#include <limits>
 #include "MHexahedron.h"
 #include "Numeric.h"
 #include "Context.h"
 #include "polynomialBasis.h"
-
+#include "MQuadrangle.h"
 int MHexahedron::getVolumeSign()
 {
   double mat[3][3];
@@ -32,6 +32,17 @@ void MHexahedron::getIntegrationPoints(int pOrder, int *npts, IntPt **pts)
   *pts = getGQHPts(pOrder);
 }
 
+double MHexahedron::getInnerRadius()
+{
+  //Only for vertically aligned elements (not inclined)
+  double innerRadius=std::numeric_limits<double>::max();
+  for (int i=0; i<getNumFaces(); i++){
+    MQuadrangle quad(getFace(i).getVertex(0), getFace(i).getVertex(1), getFace(i).getVertex(2), getFace(i).getVertex(3));
+    innerRadius=std::min(innerRadius,quad.getInnerRadius());
+  }
+  return innerRadius;
+}
+
 void MHexahedron::getFaceInfo(const MFace &face, int &ithFace, int &sign, int &rot) const
 {
   for (ithFace = 0; ithFace < 6; ithFace++){

Geo/MHexahedron.h

@@ -88,6 +88,7 @@ class MHexahedron : public MElement {
                  _v[faces_hexa(num, 2)],
                  _v[faces_hexa(num, 3)]);
   }
+  virtual double getInnerRadius();
   virtual void getFaceInfo (const MFace & face, int &ithFace, int &sign, int &rot)const;
   virtual int getNumFacesRep(){ return 12; }
   virtual void getFaceRep(int num, double *x, double *y, double *z, SVector3 *n)