Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files
2025-10-24 09:11:23 -06:00 · 2018-10-26 15:45:52 +02:00 · 2018-10-26 15:45:52 +02:00 · 7681d00ee5
commit 7681d00ee5
parent c1e6eda554 f651182101
2865 changed files with 142806 additions and 22325 deletions
--- a/src/igl/loop.cpp
+++ b/src/igl/loop.cpp
@ -0,0 +1,173 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2016 Oded Stein <oded.stein@columbia.edu>
+//
+// 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 "loop.h"
+
+#include <igl/adjacency_list.h>
+#include <igl/triangle_triangle_adjacency.h>
+#include <igl/unique.h>
+
+#include <vector>
+
+template <
+  typename DerivedF,
+  typename SType,
+  typename DerivedNF>
+IGL_INLINE void igl::loop(
+  const int n_verts,
+  const Eigen::PlainObjectBase<DerivedF> & F,
+  Eigen::SparseMatrix<SType>& S,
+  Eigen::PlainObjectBase<DerivedNF> & NF)
+{
+  typedef Eigen::SparseMatrix<SType> SparseMat;
+  typedef Eigen::Triplet<SType> Triplet_t;
+  
+  //Ref. https://graphics.stanford.edu/~mdfisher/subdivision.html
+  //Heavily borrowing from igl::upsample
+  
+  DerivedF FF, FFi;
+  triangle_triangle_adjacency(F, FF, FFi);
+  std::vector<std::vector<typename DerivedF::Scalar>> adjacencyList;
+  adjacency_list(F, adjacencyList, true);
+  
+  //Compute the number and positions of the vertices to insert (on edges)
+  Eigen::MatrixXi NI = Eigen::MatrixXi::Constant(FF.rows(), FF.cols(), -1);
+  Eigen::MatrixXi NIdoubles = Eigen::MatrixXi::Zero(FF.rows(), FF.cols());
+  Eigen::VectorXi vertIsOnBdry = Eigen::VectorXi::Zero(n_verts);
+  int counter = 0;
+  for(int i=0; i<FF.rows(); ++i)
+  {
+    for(int j=0; j<3; ++j)
+    {
+      if(NI(i,j) == -1)
+      {
+        NI(i,j) = counter;
+        NIdoubles(i,j) = 0;
+        if (FF(i,j) != -1) 
+        {
+          //If it is not a boundary
+          NI(FF(i,j), FFi(i,j)) = counter;
+          NIdoubles(i,j) = 1;
+        } else 
+        {
+          //Mark boundary vertices for later
+          vertIsOnBdry(F(i,j)) = 1;
+          vertIsOnBdry(F(i,(j+1)%3)) = 1;
+        }
+        ++counter;
+      }
+    }
+  }
+  
+  const int& n_odd = n_verts;
+  const int& n_even = counter;
+  const int n_newverts = n_odd + n_even;
+  
+  //Construct vertex positions
+  std::vector<Triplet_t> tripletList;
+  for(int i=0; i<n_odd; ++i) 
+  {
+    //Old vertices
+    const std::vector<int>& localAdjList = adjacencyList[i];
+    if(vertIsOnBdry(i)==1) 
+    {
+      //Boundary vertex
+      tripletList.emplace_back(i, localAdjList.front(), 1./8.);
+      tripletList.emplace_back(i, localAdjList.back(), 1./8.);
+      tripletList.emplace_back(i, i, 3./4.);
+    } else 
+    {
+      const int n = localAdjList.size();
+      const SType dn = n;
+      SType beta;
+      if(n==3)
+      {
+        beta = 3./16.;
+      } else
+      {
+        beta = 3./8./dn;
+      }
+      for(int j=0; j<n; ++j)
+      {
+        tripletList.emplace_back(i, localAdjList[j], beta);
+      }
+      tripletList.emplace_back(i, i, 1.-dn*beta);
+    }
+  }
+  for(int i=0; i<FF.rows(); ++i) 
+  {
+    //New vertices
+    for(int j=0; j<3; ++j) 
+    {
+      if(NIdoubles(i,j)==0) 
+      {
+        if(FF(i,j)==-1) 
+        {
+          //Boundary vertex
+          tripletList.emplace_back(NI(i,j) + n_odd, F(i,j), 1./2.);
+          tripletList.emplace_back(NI(i,j) + n_odd, F(i, (j+1)%3), 1./2.);
+        } else 
+        {
+          tripletList.emplace_back(NI(i,j) + n_odd, F(i,j), 3./8.);
+          tripletList.emplace_back(NI(i,j) + n_odd, F(i, (j+1)%3), 3./8.);
+          tripletList.emplace_back(NI(i,j) + n_odd, F(i, (j+2)%3), 1./8.);
+          tripletList.emplace_back(NI(i,j) + n_odd, F(FF(i,j), (FFi(i,j)+2)%3), 1./8.);
+        }
+      }
+    }
+  }
+  S.resize(n_newverts, n_verts);
+  S.setFromTriplets(tripletList.begin(), tripletList.end());
+  
+  // Build the new topology (Every face is replaced by four)
+  NF.resize(F.rows()*4, 3);
+  for(int i=0; i<F.rows();++i)
+  {
+    Eigen::VectorXi VI(6);
+    VI << F(i,0), F(i,1), F(i,2), NI(i,0) + n_odd, NI(i,1) + n_odd, NI(i,2) + n_odd;
+    
+    Eigen::VectorXi f0(3), f1(3), f2(3), f3(3);
+    f0 << VI(0), VI(3), VI(5);
+    f1 << VI(1), VI(4), VI(3);
+    f2 << VI(3), VI(4), VI(5);
+    f3 << VI(4), VI(2), VI(5);
+    
+    NF.row((i*4)+0) = f0;
+    NF.row((i*4)+1) = f1;
+    NF.row((i*4)+2) = f2;
+    NF.row((i*4)+3) = f3;
+  }
+}
+
+template <
+  typename DerivedV, 
+  typename DerivedF,
+  typename DerivedNV,
+  typename DerivedNF>
+IGL_INLINE void igl::loop(
+  const Eigen::PlainObjectBase<DerivedV>& V,
+  const Eigen::PlainObjectBase<DerivedF>& F,
+  Eigen::PlainObjectBase<DerivedNV>& NV,
+  Eigen::PlainObjectBase<DerivedNF>& NF,
+  const int number_of_subdivs)
+{
+  NV = V;
+  NF = F;
+  for(int i=0; i<number_of_subdivs; ++i) 
+  {
+    DerivedNF tempF = NF;
+    Eigen::SparseMatrix<typename DerivedV::Scalar> S;
+    loop(NV.rows(), tempF, S, NF);
+    // This .eval is super important
+    NV = (S*NV).eval();
+  }
+}
+
+#ifdef IGL_STATIC_LIBRARY
+template void igl::loop<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&, int);
+#endif