Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/bfs_orient.cpp

@@ -0,0 +1,100 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "bfs_orient.h"
+#include "orientable_patches.h"
+#include <Eigen/Sparse>
+#include <queue>
+
+template <typename DerivedF, typename DerivedFF, typename DerivedC>
+IGL_INLINE void igl::bfs_orient(
+  const Eigen::PlainObjectBase<DerivedF> & F,
+  Eigen::PlainObjectBase<DerivedFF> & FF,
+  Eigen::PlainObjectBase<DerivedC> & C)
+{
+  using namespace Eigen;
+  using namespace std;
+  SparseMatrix<int> A;
+  orientable_patches(F,C,A);
+
+  // number of faces
+  const int m = F.rows();
+  // number of patches
+  const int num_cc = C.maxCoeff()+1;
+  VectorXi seen = VectorXi::Zero(m);
+
+  // Edge sets
+  const int ES[3][2] = {{1,2},{2,0},{0,1}};
+
+  if(&FF != &F)
+  {
+    FF = F;
+  }
+  // loop over patches
+#pragma omp parallel for
+  for(int c = 0;c<num_cc;c++)
+  {
+    queue<int> Q;
+    // find first member of patch c
+    for(int f = 0;f<FF.rows();f++)
+    {
+      if(C(f) == c)
+      {
+        Q.push(f);
+        break;
+      }
+    }
+    assert(!Q.empty());
+    while(!Q.empty())
+    {
+      const int f = Q.front();
+      Q.pop();
+      if(seen(f) > 0)
+      {
+        continue;
+      }
+      seen(f)++;
+      // loop over neighbors of f
+      for(typename SparseMatrix<int>::InnerIterator it (A,f); it; ++it)
+      {
+        // might be some lingering zeros, and skip self-adjacency
+        if(it.value() != 0 && it.row() != f)
+        {
+          const int n = it.row();
+          assert(n != f);
+          // loop over edges of f
+          for(int efi = 0;efi<3;efi++)
+          {
+            // efi'th edge of face f
+            Vector2i ef(FF(f,ES[efi][0]),FF(f,ES[efi][1]));
+            // loop over edges of n
+            for(int eni = 0;eni<3;eni++)
+            {
+              // eni'th edge of face n
+              Vector2i en(FF(n,ES[eni][0]),FF(n,ES[eni][1]));
+              // Match (half-edges go same direction)
+              if(ef(0) == en(0) && ef(1) == en(1))
+              {
+                // flip face n
+                FF.row(n) = FF.row(n).reverse().eval();
+              }
+            }
+          }
+          // add neighbor to queue
+          Q.push(n);
+        }
+      }
+    }
+  }
+
+  // make sure flip is OK if &FF = &F
+}
+
+#ifdef IGL_STATIC_LIBRARY
+// Explicit template instantiation
+template void igl::bfs_orient<Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, 1, 0, -1, 1> >(Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> >&);
+#endif