triangle_fill_sweep_line_impl.hpp

Go to the documentation of this file.

/*
 * Copyright (c) 2012-2015:  G-CSC, Goethe University Frankfurt
 * Author: Sebastian Reiter
 * 
 * This file is part of UG4.
 * 
 * UG4 is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License version 3 (as published by the
 * Free Software Foundation) with the following additional attribution
 * requirements (according to LGPL/GPL v3 §7):
 * 
 * (1) The following notice must be displayed in the Appropriate Legal Notices
 * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (2) The following notice must be displayed at a prominent place in the
 * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (3) The following bibliography is recommended for citation and must be
 * preserved in all covered files:
 * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
 *   parallel geometric multigrid solver on hierarchically distributed grids.
 *   Computing and visualization in science 16, 4 (2013), 151-164"
 * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
 *   flexible software system for simulating pde based models on high performance
 *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 */
 
#ifndef __H__UG4__LIB_GRID__TRIANGLE_FILL_SWEEP_LINE_IMPL__
#define __H__UG4__LIB_GRID__TRIANGLE_FILL_SWEEP_LINE_IMPL__
 
namespace ug
{
template <class TIterator>
bool TriangleFill_SweepLine(Grid& grid, TIterator edgesBegin,
              TIterator edgesEnd, APosition& aPosVRT,
              AInt& aIntVRT,
              SubsetHandler* pSH,
              int newSubsetIndex)
{
  if(!grid.has_vertex_attachment(aPosVRT)){
    UG_LOG("position attachment missing in TriangleFill_SweepLine");
    return false;
  }
 
  if(!grid.has_vertex_attachment(aIntVRT)){
    UG_LOG("int attachment missing in TriangleFill_SweepLine");
    return false;
  }
 
  Grid::VertexAttachmentAccessor<APosition> aaPos(grid, aPosVRT);
  Grid::VertexAttachmentAccessor<AInt> aaInt(grid, aIntVRT);
 
//  set up the vertex and edge arrays and build some additional
//  information that is required when it comes to building the triangles.
  std::vector<Vertex*> vrtPtrs;
  std::vector<vector3> vrts;
  std::vector<int>  edges;
 
  grid.begin_marking();
  for(TIterator iter = edgesBegin; iter != edgesEnd; ++iter)
  {
    Edge* e = *iter;
 
    for(size_t i = 0; i < 2; ++i){
      Vertex* vrt = e->vertex(i);
      if(!grid.is_marked(vrt)){
        aaInt[vrt] = (int)vrts.size();
        vrts.push_back(aaPos[vrt]);
        //vrts.push_back(vector2(aaPos[vrt].x(), aaPos[vrt].y()));
        vrtPtrs.push_back(vrt);
        grid.mark(vrt);
      }
 
      edges.push_back(aaInt[vrt]);
    }
  }
  grid.end_marking();
 
//  now call the original implementation
  size_t numInitialEdges = edges.size();
  std::vector<int> faces;
  if(TriangleFill_SweepLine(faces, vrts, edges)){
 
  //  now create the triangles
    for(size_t i = 0; i < faces.size(); i+=3){
      Triangle* tri = *grid.create<Triangle>(TriangleDescriptor(vrtPtrs[faces[i]],
                                    vrtPtrs[faces[i + 1]],
                                    vrtPtrs[faces[i + 2]]));
      if(pSH){
        pSH->assign_subset(tri, newSubsetIndex);
      }
    }
 
    return true;
  }
 
  else{
  //DEBUG ONLY
  //  create edges
    for(size_t i = numInitialEdges; i < edges.size(); i+=2){
      Edge* e = *grid.create<RegularEdge>(EdgeDescriptor(vrtPtrs[edges[i]], vrtPtrs[edges[i+1]]));
      if(pSH){
        pSH->assign_subset(e, newSubsetIndex);
      }
    }
  }
 
  return false;
}
 
}// namespace ug
 
#endif