| [0b990d] | 1 | //
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 | 2 | // surfse.cc
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 | 3 | //
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 | 4 | // Copyright (C) 1996 Limit Point Systems, Inc.
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 | 5 | //
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 | 6 | // Author: Curtis Janssen <cljanss@limitpt.com>
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 | 7 | // Maintainer: LPS
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 | 8 | //
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 | 9 | // This file is part of the SC Toolkit.
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 | 10 | //
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 | 11 | // The SC Toolkit is free software; you can redistribute it and/or modify
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 | 12 | // it under the terms of the GNU Library General Public License as published by
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 | 13 | // the Free Software Foundation; either version 2, or (at your option)
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 | 14 | // any later version.
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 | 15 | //
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 | 16 | // The SC Toolkit is distributed in the hope that it will be useful,
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 | 17 | // but WITHOUT ANY WARRANTY; without even the implied warranty of
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 | 18 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 | 19 | // GNU Library General Public License for more details.
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 | 20 | //
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 | 21 | // You should have received a copy of the GNU Library General Public License
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 | 22 | // along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
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 | 23 | // the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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 | 24 | //
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 | 25 | // The U.S. Government is granted a limited license as per AL 91-7.
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 | 26 | //
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 | 27 | 
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 | 28 | #include <algorithm>
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 | 29 | 
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 | 30 | #include <util/misc/formio.h>
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 | 31 | 
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 | 32 | #include <math/scmat/matrix.h>
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 | 33 | #include <math/isosurf/surf.h>
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 | 34 | 
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 | 35 | using namespace std;
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 | 36 | using namespace sc;
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 | 37 | 
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 | 38 | void
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 | 39 | TriangulatedSurface::remove_short_edges(double length_cutoff,
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 | 40 |                                         const Ref<Volume> &vol, double isoval)
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 | 41 | {
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 | 42 |   int j,k;
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 | 43 |   std::set<Ref<Triangle> >::iterator it,jt,kt;
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 | 44 |   std::set<Ref<Edge> >::iterator ie,je;
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 | 45 | 
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 | 46 |   int surface_was_completed = _completed_surface;
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 | 47 | 
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 | 48 |   if (!_completed_surface) {
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 | 49 |       complete_ref_arrays();
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 | 50 |     }
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 | 51 |   else {
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 | 52 |       clear_int_arrays();
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 | 53 |     }
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 | 54 | 
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 | 55 |   _have_values = 0;
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 | 56 |   _values.clear();
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 | 57 |   
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 | 58 |   if (_verbose) {
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 | 59 |       ExEnv::outn() << "TriangulatedSurface::remove_short_edges:" << endl
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 | 60 |            << "initial: ";
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 | 61 |       topology_info();
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 | 62 |     }
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 | 63 | 
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 | 64 |   int deleted_edges_length;
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 | 65 |   do {
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 | 66 |       std::set<Ref<Triangle> > deleted_triangles;
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 | 67 |       std::set<Ref<Edge> > deleted_edges;
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 | 68 |       std::set<Ref<Vertex> > deleted_vertices;
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 | 69 | 
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 | 70 |       std::set<Ref<Triangle> > new_triangles;
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 | 71 |       std::set<Ref<Edge> > new_edges;
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 | 72 |       std::set<Ref<Vertex> > new_vertices;
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 | 73 | 
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 | 74 |       // a vertex to set-of-connected-triangles map
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 | 75 |       std::map<Ref<Vertex>,std::set<Ref<Triangle> > > connected_triangle_map;
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 | 76 |       for (it = _triangles.begin(); it != _triangles.end(); it++) {
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 | 77 |           Ref<Triangle> tri = *it;
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 | 78 |           for (j = 0; j<3; j++) {
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 | 79 |               Ref<Vertex> v  = tri->vertex(j);
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 | 80 |               connected_triangle_map[v].insert(tri);
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 | 81 |             }
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 | 82 |         }
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 | 83 | 
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 | 84 |       // a vertex to set-of-connected-edges map
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 | 85 |       std::map<Ref<Vertex>,std::set<Ref<Edge> > > connected_edge_map;
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 | 86 |       for (ie = _edges.begin(); ie != _edges.end(); ie++) {
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 | 87 |           Ref<Edge> e = *ie;
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 | 88 |           for (j = 0; j<2; j++) {
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 | 89 |               Ref<Vertex> v = e->vertex(j);
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 | 90 |               connected_edge_map[v].insert(e);
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 | 91 |             }
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 | 92 |         }
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 | 93 |   
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 | 94 |       for (ie = _edges.begin(); ie != _edges.end(); ie++) {
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 | 95 |           Ref<Edge> edge = *ie;
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 | 96 |           double length = edge->straight_length();
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 | 97 |           if (length < length_cutoff) {
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 | 98 |               std::set<Ref<Triangle> > connected_triangles;
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 | 99 |               Ref<Vertex> v0 = edge->vertex(0);
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 | 100 |               Ref<Vertex> v1 = edge->vertex(1);
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 | 101 |               connected_triangles.insert(connected_triangle_map[v0].begin(),
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 | 102 |                                          connected_triangle_map[v0].end());
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 | 103 |               connected_triangles.insert(connected_triangle_map[v1].begin(),
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 | 104 |                                          connected_triangle_map[v1].end());
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 | 105 |               int skip = 0;
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 | 106 |               for (jt = connected_triangles.begin();
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 | 107 |                    jt != connected_triangles.end();
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 | 108 |                    jt++) {
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 | 109 |                   Ref<Triangle> tri = *jt;
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 | 110 |                   if (tri->edge(0)->straight_length() < length
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 | 111 |                       ||tri->edge(1)->straight_length() < length
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 | 112 |                       ||tri->edge(2)->straight_length() < length
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 | 113 |                       ||deleted_triangles.find(tri)!=deleted_triangles.end()) {
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 | 114 |                       skip = 1;
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 | 115 |                       break;
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 | 116 |                     }
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 | 117 |                 }
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 | 118 |               if (skip) continue;
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 | 119 |               deleted_triangles.insert(connected_triangles.begin(),
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 | 120 |                                        connected_triangles.end());
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 | 121 |               v0 = edge->vertex(0);
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 | 122 |               v1 = edge->vertex(1);
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 | 123 |               deleted_vertices.insert(v0);
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 | 124 |               deleted_vertices.insert(v1);
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 | 125 |               // find all of the edges connected to the short edge
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 | 126 |               // (including the short edge)
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 | 127 |               std::set<Ref<Edge> > connected_edges;
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 | 128 |               v0 = edge->vertex(0);
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 | 129 |               v1 = edge->vertex(1);
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 | 130 |               connected_edges.insert(connected_edge_map[v0].begin(),
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 | 131 |                                      connected_edge_map[v0].end());
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 | 132 |               connected_edges.insert(connected_edge_map[v1].begin(),
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 | 133 |                                      connected_edge_map[v1].end());
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 | 134 |               deleted_edges.insert(connected_edges.begin(),
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 | 135 |                                    connected_edges.end());
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 | 136 |               // find the edges forming the perimeter of the deleted triangles
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 | 137 |               // (these are used to form the new triangles)
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 | 138 |               std::set<Ref<Edge> > perimeter_edges;
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 | 139 |               int embedded_triangle = 0;
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 | 140 |               for (jt = connected_triangles.begin();
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 | 141 |                    jt != connected_triangles.end();
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 | 142 |                    jt++) {
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 | 143 |                   Ref<Triangle> tri = *jt;
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 | 144 |                   for (j=0; j<3; j++) {
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 | 145 |                       Ref<Edge> e = tri->edge(j);
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 | 146 |                       if (connected_edges.find(e) == connected_edges.end()) {
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 | 147 |                           // check to see if another triangle has claimed
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 | 148 |                           // that this edge is a perimeter edge.  if so
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 | 149 |                           // then this isn't a perimeter edge after all
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 | 150 |                           // and it must be deleted.  this also implies
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 | 151 |                           // that there is at least one triangle that
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 | 152 |                           // has no perimeter edge.  these triangles and
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 | 153 |                           // their nonperimeter vertices must be
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 | 154 |                           // deleted.
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 | 155 |                           Ref<Edge> e = tri->edge(j);
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 | 156 |                           if (perimeter_edges.find(e)
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 | 157 |                               != perimeter_edges.end()) {
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 | 158 |                               perimeter_edges.erase(e);
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 | 159 |                               deleted_edges.insert(e);
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 | 160 |                               embedded_triangle = 1;
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 | 161 |                             }
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 | 162 |                           else {
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 | 163 |                               perimeter_edges.insert(e);
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 | 164 |                             }
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 | 165 |                         }
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 | 166 |                     }
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 | 167 |                 }
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 | 168 |               // if a triangle is embedded make sure its vertices are
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 | 169 |               // all deleted.  (the triangle itself should already be
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 | 170 |               // connected and thus deleted).
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 | 171 |               if (embedded_triangle) {
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 | 172 |                   // make a list of vertices on the perimeter (so i
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 | 173 |                   // don't delete them
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 | 174 |                   std::set<Ref<Vertex> > perimeter_vertices;
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 | 175 |                   for (je = perimeter_edges.begin();
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 | 176 |                        je != perimeter_edges.end();
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 | 177 |                        je++) {
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 | 178 |                       Ref<Edge> e = *je;
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 | 179 |                       for (j=0; j<2; j++) {
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 | 180 |                           Ref<Vertex> v = e->vertex(j);
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 | 181 |                           perimeter_vertices.insert(v);
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 | 182 |                         }
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 | 183 |                     }
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 | 184 |                   // find the embedded_triangle
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 | 185 |                   for (jt = connected_triangles.begin();
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 | 186 |                        jt != connected_triangles.end();
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 | 187 |                        jt++) {
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 | 188 |                       Ref<Triangle> tri = *jt;
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 | 189 |                       // see if this triangle is embedded
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 | 190 |                       for (j=0; j<3; j++) {
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 | 191 |                           Ref<Edge> e = tri->edge(j);
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 | 192 |                           if (perimeter_edges.find(e) != perimeter_edges.end())
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 | 193 |                               break;
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 | 194 |                         }
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 | 195 |                       // if embedded then delete the triangle's vertices
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 | 196 |                       if (j==3) {
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 | 197 |                           for (j=0; j<3; j++) {
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 | 198 |                               Ref<Vertex> v = tri->vertex(j);
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 | 199 |                               if (perimeter_vertices.find(v) == perimeter_vertices.end())
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 | 200 |                                   deleted_vertices.insert(v);
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 | 201 |                             }
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 | 202 |                         }
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 | 203 |                     }
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 | 204 |                 }
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 | 205 |               // find a new point that replaces the deleted edge
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 | 206 |               // (for now use one of the original, since it must lie on the
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 | 207 |               // analytic surface)
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 | 208 |               Ref<Vertex> replacement_vertex = edge->vertex(0);
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 | 209 |               // however, if we have a volume, find a new vertex on
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 | 210 |               // the analytic surface near the center of the edge
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 | 211 |               if (vol.nonnull()) {
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 | 212 |                   SCVector3 point, norm;
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 | 213 |                   int hn = edge->interpolate(0.5,point,norm,vol,isoval);
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 | 214 |                   replacement_vertex = new Vertex(point);
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 | 215 |                   if (hn) replacement_vertex->set_normal(norm);
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 | 216 |                 }
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 | 217 |               new_vertices.insert(replacement_vertex);
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 | 218 |               // for each vertex on the perimeter form a new edge to the
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 | 219 |               // replacement vertex
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 | 220 |               std::map<Ref<Vertex>,Ref<Edge> > new_edge_map;
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 | 221 |               for (je = perimeter_edges.begin(); je!=perimeter_edges.end();
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 | 222 |                    je++) {
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 | 223 |                   Ref<Edge> e = *je;
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 | 224 |                   for (k = 0; k<2; k++) {
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 | 225 |                       Ref<Vertex> v = e->vertex(k);
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 | 226 |                       if (new_edge_map.find(v) == new_edge_map.end()) {
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 | 227 |                           Ref<Edge> new_e = newEdge(
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 | 228 |                               replacement_vertex,
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 | 229 |                               v
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 | 230 |                               );
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 | 231 |                           new_edge_map[v] = new_e;
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 | 232 |                           new_edges.insert(new_e);
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 | 233 |                         }
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 | 234 |                     }
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 | 235 |                 }
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 | 236 |               // for each edge on the perimeter form a new triangle with the
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 | 237 |               // replacement vertex
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 | 238 |               for (je = perimeter_edges.begin(); je != perimeter_edges.end();
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 | 239 |                    je++) {
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 | 240 |                   Ref<Edge> e1 = *je;
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 | 241 |                   Ref<Vertex> v0 = e1->vertex(0);
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 | 242 |                   Ref<Vertex> v1 = e1->vertex(1);
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 | 243 |                   Ref<Edge> e2 = new_edge_map[v0];
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 | 244 |                   Ref<Edge> e3 = new_edge_map[v1];
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 | 245 |                   if (e1.null() || e2.null() || e3.null()) {
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 | 246 |                       ExEnv::errn() << "TriangulatedSurface::remove_short_edges: "
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 | 247 |                            << "building new triangle but edges are null:"
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 | 248 |                            << endl;
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 | 249 |                       if (e1.null()) ExEnv::errn() << "  e1" << endl;
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 | 250 |                       if (e2.null()) ExEnv::errn() << "  e2" << endl;
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 | 251 |                       if (e3.null()) ExEnv::errn() << "  e3" << endl;
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 | 252 |                       abort();
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 | 253 |                     }
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 | 254 |                   // Compute the correct orientation of e1 within the new
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 | 255 |                   // triangle, by finding the orientation within the old
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 | 256 |                   // triangle.
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 | 257 |                   int orientation = 0;
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 | 258 |                   for (kt = connected_triangles.begin();
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 | 259 |                        kt != connected_triangles.end();
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 | 260 |                        kt++) {
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 | 261 |                       if ((*kt)->contains(e1)) {
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 | 262 |                           orientation
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 | 263 |                               = (*kt)->orientation(e1);
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 | 264 |                           break;
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 | 265 |                         }
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 | 266 |                     }
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 | 267 |                   Ref<Triangle> newtri(newTriangle(e1,e2,e3,orientation));
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 | 268 |                   new_triangles.insert(newtri);
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 | 269 |                 }
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 | 270 |               //ExEnv::outn() << "WARNING: only one short edge removed" << endl;
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 | 271 |               //break;
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 | 272 |             }
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 | 273 |         }
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 | 274 | 
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 | 275 |       erase_elements_by_value(_triangles,
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 | 276 |                               deleted_triangles.begin(),
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 | 277 |                               deleted_triangles.end());
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 | 278 | 
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 | 279 |       erase_elements_by_value(_edges,
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 | 280 |                               deleted_edges.begin(),
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 | 281 |                               deleted_edges.end());
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 | 282 | 
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 | 283 |       erase_elements_by_value(_vertices,
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 | 284 |                               deleted_vertices.begin(),
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 | 285 |                               deleted_vertices.end());
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 | 286 | 
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 | 287 |       _triangles.insert(new_triangles.begin(), new_triangles.end());
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 | 288 |       _edges.insert(new_edges.begin(), new_edges.end());
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 | 289 |       _vertices.insert(new_vertices.begin(), new_vertices.end());
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 | 290 | 
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 | 291 |       if (_verbose) {
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 | 292 |           topology_info();
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 | 293 |         }
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 | 294 | 
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 | 295 |       deleted_edges_length = deleted_edges.size();
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 | 296 |       //ExEnv::outn() << "WARNING: one pass short edge removal" << endl;
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 | 297 |       //deleted_edges_length = 0; // do one pass
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 | 298 |     } while(deleted_edges_length != 0);
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 | 299 | 
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 | 300 |   // fix the index maps
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 | 301 |   recompute_index_maps();
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 | 302 | 
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 | 303 |   // restore the int arrays if they were there to begin with
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 | 304 |   if (surface_was_completed) {
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 | 305 |       complete_int_arrays();
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 | 306 |       _completed_surface = 1;
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 | 307 |     }
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 | 308 | 
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 | 309 |   if (_verbose) {
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 | 310 |       ExEnv::outn() << "final: ";
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 | 311 |       topology_info();
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 | 312 |     }
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 | 313 | }
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 | 314 | 
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 | 315 | /////////////////////////////////////////////////////////////////////////////
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 | 316 | 
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 | 317 | // Local Variables:
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 | 318 | // mode: c++
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 | 319 | // c-file-style: "CLJ"
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 | 320 | // End:
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