mark_util_impl.h

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/*
 * Copyright (c) 2014-2015:  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__UG_mark_util_impl
#define __H__UG_mark_util_impl
 
#include "lib_grid/algorithms/geom_obj_util/edge_util.h"
namespace ug{
 
template <class TEdgeIterator>
void MarkCreaseEdges(Grid& grid, ISubsetHandler& sh,
          TEdgeIterator edgesBegin, TEdgeIterator edgesEnd,
          int subsetIndex, number angle,
          APosition& aPos,
          ANormal* paFaceNormal)
{
 
//  get the position accessor
  if(!grid.has_vertex_attachment(aPos))
    return;
  
  Grid::VertexAttachmentAccessor<APosition> aaPos(grid, aPos);
  
//  we'll store face normals in those vectors:
  vector3 n[2];
  
//  associated faces are stored in this array
  Face* f[2];
  
//  all dot-products between normals lower than minDot mark a crease.
  number minDot = cos(angle * 3.14159265 / 180.f);
  
//  iterate through the edges
  for(TEdgeIterator iter = edgesBegin; iter != edgesEnd; ++iter)
  {
    Edge* e = *iter;
  //  get the associated faces
  //  all edges that do not have exactly 2 associated edges
  //  are regarded as seam-edges
    if(GetAssociatedFaces(f, grid, e, 2) == 2){
    //  get the normals of the associated faces
      CalculateNormal(n[0], f[0], aaPos);
      CalculateNormal(n[1], f[1], aaPos);
    //  if the dot-product is lower than minDot, then the edge is a crease edge.
      if(VecDot(n[0], n[1]) < minDot)
        sh.assign_subset(e, subsetIndex);
    }
    else{
      sh.assign_subset(e, subsetIndex);
    }
  }
}
 
template <class TVertexIterator, class TAPosition>
void MarkCorners(Grid& grid, ISubsetHandler& sh,
         TVertexIterator vrtsBegin, TVertexIterator vrtsEnd,
         Grid::edge_traits::callback cbPathEdge,
         int subsetIndex, number angle,
         TAPosition& aPos)
{
  typedef typename TAPosition::ValueType  vector_t;
 
  if(!grid.has_vertex_attachment(aPos))
    return;
  
  Grid::VertexAttachmentAccessor<APosition> aaPos(grid, aPos);
 
  Grid::edge_traits::secure_container edges;
  vector_t  dir[2];
  Edge*   pathEdge[2];
 
  number dotThreshold = cos(deg_to_rad(angle));
 
  for(TVertexIterator iter = vrtsBegin; iter != vrtsEnd; ++iter){
    Vertex* vrt = *iter;
    grid.associated_elements(edges, vrt);
    int numPathEdges = 0;
 
    for(size_t i = 0; i < edges.size(); ++i){
      Edge* e = edges[i];
      if(cbPathEdge(e)){
        if(numPathEdges < 2)
          pathEdge[numPathEdges] = e;
        ++numPathEdges;
      }
    }
 
    if(numPathEdges == 2){
      for(size_t i = 0; i < 2; ++i){
        Vertex* cv = GetConnectedVertex(pathEdge[i], vrt);
        VecSubtract(dir[i], aaPos[cv], aaPos[vrt]);
        VecNormalize(dir[i], dir[i]);
      }
 
      dir[1] *= -1;
      if(VecDot(dir[0], dir[1]) < dotThreshold)
        sh.assign_subset(vrt, subsetIndex);
    }
    else if(numPathEdges > 0){
      sh.assign_subset(vrt, subsetIndex);
    }
  }
}
 
}// end of namespace
 
#endif  //__H__mark_util_impl