NormalAttribT_impl.hh

#pragma once
/*===========================================================================*\
 *                                                                           *
 *                            OpenVolumeMesh                                 *
 *        Copyright (C) 2011 by Computer Graphics Group, RWTH Aachen         *
 *                        www.openvolumemesh.org                             *
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 *  This file is part of OpenVolumeMesh.                                     *
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\*===========================================================================*/
 
#include <set>
 
#include <OpenVolumeMesh/Attribs/NormalAttrib.hh>
 
#include <OpenVolumeMesh/Core/GeometryKernel.hh>
 
namespace OpenVolumeMesh {
 
template <class GeomKernelT>
NormalAttrib<GeomKernelT>::NormalAttrib(GeomKernelT& _kernel) :
kernel_(&_kernel),
v_normals_(_kernel.template request_vertex_property<typename GeomKernelT::PointT>("vertex_normals", typename GeomKernelT::PointT(0.0))),
f_normals_(_kernel.template request_face_property<typename GeomKernelT::PointT>("face_normals", typename GeomKernelT::PointT(0.0)))
{
 
}
 
template <class GeomKernelT>
NormalAttrib<GeomKernelT>::~NormalAttrib() {
 
}
 
template <class GeomKernelT>
void NormalAttrib<GeomKernelT>::update_vertex_normals() {
 
    if(!kernel_->has_face_bottom_up_incidences()) {
        std::cerr << "Error: update_vertex_normals() needs bottom-up incidences!" << std::endl;
        return;
    }
 
    // Compute face normals
    update_face_normals();
 
    for(const auto &_vh: kernel_->vertices())
    {
        compute_vertex_normal(_vh);
    }
}
 
template <class GeomKernelT>
void NormalAttrib<GeomKernelT>::update_face_normals() {
 
    if(!kernel_->has_face_bottom_up_incidences()) {
        std::cerr << "Error: update_normals() needs bottom-up incidences!" << std::endl;
        return;
    }
 
    for (const auto &_fh: kernel_->faces()) {
        f_normals_[_fh] = kernel_->normal(_fh.halfface_handle(0));
    }
}
 
template <class GeomKernelT>
void NormalAttrib<GeomKernelT>::compute_vertex_normal(const VertexHandle& _vh) {
 
    std::set<HalfFaceHandle> halffaces;
    for(VertexOHalfEdgeIter voh_it = kernel_->voh_iter(_vh);
            voh_it.valid(); ++voh_it) {
 
        for(HalfEdgeHalfFaceIter hehf_it = kernel_->hehf_iter(*voh_it);
                hehf_it.valid(); ++hehf_it) {
            if(kernel_->is_boundary(*hehf_it)) {
                halffaces.insert(*hehf_it);
            }
        }
    }
    typename GeomKernelT::PointT normal = typename GeomKernelT::PointT(0.0);
    for(std::set<HalfFaceHandle>::const_iterator hf_it = halffaces.begin();
            hf_it != halffaces.end(); ++hf_it) {
        normal += (*this)[*hf_it];
    }
 
    normal.normalize();
    v_normals_[_vh] = normal;
}
 
} // Namespace OpenVolumeMesh