source: src/Tesselation/TriangleMatcher/Triangle.hpp@ 1b6415a

/*
 * Triangle.hpp
 *
 *  Created on: Jun 15, 2015
 *      Author: heber
 */

#ifndef TRIANGLE_HPP_
#define TRIANGLE_HPP_

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <array>
#include <cassert>
#include <utility>

#include "types.hpp"

namespace detail {

struct Triangle
{
        //!> typedef for the triangle index type
        typedef size_t index_t;

        //!> typedef for the structure to store triangle indices
        typedef std::array<index_t, 3> indices_t;

        //!> constant for invalid index
        enum { INVALIDINDEX=-1 };

        /** Constructor for struct triangle.
         *
         */
        Triangle()
        {
                indices = {{
                                (index_t)INVALIDINDEX,
                                (index_t)INVALIDINDEX,
                                (index_t)INVALIDINDEX
                }};
        }

        /** Constructor for struct triangle.
         *
         * \param _indices initial indices to set
         */
        Triangle(const indices_t &_indices) :
                indices(_indices)
        {
                if (!isSorted())
                        sortIndices();
        }

        /** Setter for the indices of the triangle.
         *
         * \param _elements indices to be set (need not be sorted)
         */
        void set(const indices_t &_elements) {
                indices = _elements;
                if (!isSorted())
                        sortIndices();
        }

        /** Getter for the indices.
         *
         * \return set of sorted indices
         */
        const indices_t &get() const {
                return indices;
        }

        /** Less comparator for triangle, comparing indices.
         *
         * \return true - at least one index in this triangle is smaller
         */
        bool operator<(const Triangle &_other) const {
                return indices < _other.indices;
        }

        /** Comparator for equivalence of triangle.
         *
         * \return true - both index triples are the same
         */
        bool operator==(const Triangle &_other) const {
                return indices == _other.indices;
        }

        /** Comparator for non-equivalence of triangle.
         *
         * \return true - both index triples are not the same
         */
        bool operator!=(const Triangle &_other) const {
                return !(*this == _other);
        }

private:
        /** Sort the indices.
         *
         */
        void sortIndices() {
                std::sort(indices.begin(), indices.end());
//              if (indices[0] > indices[1]) {
//                      if (indices[0] > indices[2])
//                              std::swap(indices[0], indices[2]);
//                      if (indices[0] > indices[1])
//                              std::swap(indices[0], indices[1]);
//              } else {
//                      // last element in between or up front?
//                      if (indices[0] > indices[2]) {
//                              std::swap(indices[1], indices[2]);
//                              std::swap(indices[0], indices[1]);
//                      } else
//                              std::swap(indices[1], indices[2]);
//              }
                assert( isSorted() );
        }

private:
        /** Check whether indices are sorted.
         *
         * \return true - indices are sorted ascendingly
         */
        bool isSorted() const
        {
                return (( indices[0] <= indices[1]) && (indices[1] <= indices[2]));
        }

private:
        //!> fixed size array for containing indices
        indices_t indices;
};

}; /* namespace detail */

std::ostream& operator<<(std::ostream &_ost, const detail::Triangle &_t) {
        const detail::Triangle::indices_t &indices = _t.get();
        _ost << "[" << indices[0] << ","  << indices[1] << "," << indices[2] << "]";
        return _ost;
}

#endif /* TRIANGLE_HPP_ */