add while loop for comb_cross_field.cpp, making comb support manifold that

is made up with several separated part


Former-commit-id: 247043cc71956e121501ef1422dbfe95ce2a3d7d

include/igl/comb_cross_field.cpp

@@ -86,35 +86,42 @@ namespace igl {
 
       std::deque<int> d;
 
-      d.push_back(0);
-      mark(0) = true;
-
-      while (!d.empty())
+      while (!mark.all()) // Stop until all vertices are marked
       {
-        int f0 = d.at(0);
-        d.pop_front();
-        for (int k=0; k<3; k++)
+        int unmarked = 0;
+        while (mark(unmarked))
+          unmarked++;
+        
+        d.push_back(unmarked);
+        mark(unmarked) = true;
+
+        while (!d.empty())
         {
-          int f1 = TT(f0,k);
-          if (f1==-1) continue;
-          if (mark(f1)) continue;
+          int f0 = d.at(0);
+          d.pop_front();
+          for (int k=0; k<3; k++)
+          {
+            int f1 = TT(f0,k);
+            if (f1==-1) continue;
+            if (mark(f1)) continue;
 
-          Eigen::Matrix<typename DerivedV::Scalar, 3, 1> dir0    = PD1out.row(f0);
-          Eigen::Matrix<typename DerivedV::Scalar, 3, 1> dir1    = PD1out.row(f1);
-          Eigen::Matrix<typename DerivedV::Scalar, 3, 1> n0    = N.row(f0);
-          Eigen::Matrix<typename DerivedV::Scalar, 3, 1> n1    = N.row(f1);
+            Eigen::Matrix<typename DerivedV::Scalar, 3, 1> dir0    = PD1out.row(f0);
+            Eigen::Matrix<typename DerivedV::Scalar, 3, 1> dir1    = PD1out.row(f1);
+            Eigen::Matrix<typename DerivedV::Scalar, 3, 1> n0    = N.row(f0);
+            Eigen::Matrix<typename DerivedV::Scalar, 3, 1> n1    = N.row(f1);
 
 
-          Eigen::Matrix<typename DerivedV::Scalar, 3, 1> dir0Rot = igl::rotation_matrix_from_directions(n0, n1)*dir0;
-          dir0Rot.normalize();
-          Eigen::Matrix<typename DerivedV::Scalar, 3, 1> targD   = K_PI_new(dir1,dir0Rot,n1);
+            Eigen::Matrix<typename DerivedV::Scalar, 3, 1> dir0Rot = igl::rotation_matrix_from_directions(n0, n1)*dir0;
+            dir0Rot.normalize();
+            Eigen::Matrix<typename DerivedV::Scalar, 3, 1> targD   = K_PI_new(dir1,dir0Rot,n1);
 
-          PD1out.row(f1)  = targD;
-          PD2out.row(f1)  = n1.cross(targD).normalized();
+            PD1out.row(f1)  = targD;
+            PD2out.row(f1)  = n1.cross(targD).normalized();
 
-          mark(f1) = true;
-          d.push_back(f1);
+            mark(f1) = true;
+            d.push_back(f1);
 
+          }
         }
       }