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      1 // This file is part of Eigen, a lightweight C++ template library
      2 // for linear algebra.
      3 //
      4 // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud (at) inria.fr>
      5 //
      6 // This Source Code Form is subject to the terms of the Mozilla
      7 // Public License v. 2.0. If a copy of the MPL was not distributed
      8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
      9 
     10 #ifndef EIGEN_ALIGNEDBOX_H
     11 #define EIGEN_ALIGNEDBOX_H
     12 
     13 namespace Eigen {
     14 
     15 /** \geometry_module \ingroup Geometry_Module
     16   *
     17   *
     18   * \class AlignedBox
     19   *
     20   * \brief An axis aligned box
     21   *
     22   * \tparam _Scalar the type of the scalar coefficients
     23   * \tparam _AmbientDim the dimension of the ambient space, can be a compile time value or Dynamic.
     24   *
     25   * This class represents an axis aligned box as a pair of the minimal and maximal corners.
     26   * \warning The result of most methods is undefined when applied to an empty box. You can check for empty boxes using isEmpty().
     27   * \sa alignedboxtypedefs
     28   */
     29 template <typename _Scalar, int _AmbientDim>
     30 class AlignedBox
     31 {
     32 public:
     33 EIGEN_MAKE_ALIGNED_OPERATOR_NEW_IF_VECTORIZABLE_FIXED_SIZE(_Scalar,_AmbientDim)
     34   enum { AmbientDimAtCompileTime = _AmbientDim };
     35   typedef _Scalar                                   Scalar;
     36   typedef NumTraits<Scalar>                         ScalarTraits;
     37   typedef DenseIndex                                Index;
     38   typedef typename ScalarTraits::Real               RealScalar;
     39   typedef typename ScalarTraits::NonInteger      NonInteger;
     40   typedef Matrix<Scalar,AmbientDimAtCompileTime,1>  VectorType;
     41 
     42   /** Define constants to name the corners of a 1D, 2D or 3D axis aligned bounding box */
     43   enum CornerType
     44   {
     45     /** 1D names @{ */
     46     Min=0, Max=1,
     47     /** @} */
     48 
     49     /** Identifier for 2D corner @{ */
     50     BottomLeft=0, BottomRight=1,
     51     TopLeft=2, TopRight=3,
     52     /** @} */
     53 
     54     /** Identifier for 3D corner  @{ */
     55     BottomLeftFloor=0, BottomRightFloor=1,
     56     TopLeftFloor=2, TopRightFloor=3,
     57     BottomLeftCeil=4, BottomRightCeil=5,
     58     TopLeftCeil=6, TopRightCeil=7
     59     /** @} */
     60   };
     61 
     62 
     63   /** Default constructor initializing a null box. */
     64   inline AlignedBox()
     65   { if (AmbientDimAtCompileTime!=Dynamic) setEmpty(); }
     66 
     67   /** Constructs a null box with \a _dim the dimension of the ambient space. */
     68   inline explicit AlignedBox(Index _dim) : m_min(_dim), m_max(_dim)
     69   { setEmpty(); }
     70 
     71   /** Constructs a box with extremities \a _min and \a _max.
     72    * \warning If either component of \a _min is larger than the same component of \a _max, the constructed box is empty. */
     73   template<typename OtherVectorType1, typename OtherVectorType2>
     74   inline AlignedBox(const OtherVectorType1& _min, const OtherVectorType2& _max) : m_min(_min), m_max(_max) {}
     75 
     76   /** Constructs a box containing a single point \a p. */
     77   template<typename Derived>
     78   inline explicit AlignedBox(const MatrixBase<Derived>& p) : m_min(p), m_max(m_min)
     79   { }
     80 
     81   ~AlignedBox() {}
     82 
     83   /** \returns the dimension in which the box holds */
     84   inline Index dim() const { return AmbientDimAtCompileTime==Dynamic ? m_min.size() : Index(AmbientDimAtCompileTime); }
     85 
     86   /** \deprecated use isEmpty() */
     87   inline bool isNull() const { return isEmpty(); }
     88 
     89   /** \deprecated use setEmpty() */
     90   inline void setNull() { setEmpty(); }
     91 
     92   /** \returns true if the box is empty.
     93    * \sa setEmpty */
     94   inline bool isEmpty() const { return (m_min.array() > m_max.array()).any(); }
     95 
     96   /** Makes \c *this an empty box.
     97    * \sa isEmpty */
     98   inline void setEmpty()
     99   {
    100     m_min.setConstant( ScalarTraits::highest() );
    101     m_max.setConstant( ScalarTraits::lowest() );
    102   }
    103 
    104   /** \returns the minimal corner */
    105   inline const VectorType& (min)() const { return m_min; }
    106   /** \returns a non const reference to the minimal corner */
    107   inline VectorType& (min)() { return m_min; }
    108   /** \returns the maximal corner */
    109   inline const VectorType& (max)() const { return m_max; }
    110   /** \returns a non const reference to the maximal corner */
    111   inline VectorType& (max)() { return m_max; }
    112 
    113   /** \returns the center of the box */
    114   inline const CwiseUnaryOp<internal::scalar_quotient1_op<Scalar>,
    115                             const CwiseBinaryOp<internal::scalar_sum_op<Scalar>, const VectorType, const VectorType> >
    116   center() const
    117   { return (m_min+m_max)/2; }
    118 
    119   /** \returns the lengths of the sides of the bounding box.
    120     * Note that this function does not get the same
    121     * result for integral or floating scalar types: see
    122     */
    123   inline const CwiseBinaryOp< internal::scalar_difference_op<Scalar>, const VectorType, const VectorType> sizes() const
    124   { return m_max - m_min; }
    125 
    126   /** \returns the volume of the bounding box */
    127   inline Scalar volume() const
    128   { return sizes().prod(); }
    129 
    130   /** \returns an expression for the bounding box diagonal vector
    131     * if the length of the diagonal is needed: diagonal().norm()
    132     * will provide it.
    133     */
    134   inline CwiseBinaryOp< internal::scalar_difference_op<Scalar>, const VectorType, const VectorType> diagonal() const
    135   { return sizes(); }
    136 
    137   /** \returns the vertex of the bounding box at the corner defined by
    138     * the corner-id corner. It works only for a 1D, 2D or 3D bounding box.
    139     * For 1D bounding boxes corners are named by 2 enum constants:
    140     * BottomLeft and BottomRight.
    141     * For 2D bounding boxes, corners are named by 4 enum constants:
    142     * BottomLeft, BottomRight, TopLeft, TopRight.
    143     * For 3D bounding boxes, the following names are added:
    144     * BottomLeftCeil, BottomRightCeil, TopLeftCeil, TopRightCeil.
    145     */
    146   inline VectorType corner(CornerType corner) const
    147   {
    148     EIGEN_STATIC_ASSERT(_AmbientDim <= 3, THIS_METHOD_IS_ONLY_FOR_VECTORS_OF_A_SPECIFIC_SIZE);
    149 
    150     VectorType res;
    151 
    152     Index mult = 1;
    153     for(Index d=0; d<dim(); ++d)
    154     {
    155       if( mult & corner ) res[d] = m_max[d];
    156       else                res[d] = m_min[d];
    157       mult *= 2;
    158     }
    159     return res;
    160   }
    161 
    162   /** \returns a random point inside the bounding box sampled with
    163    * a uniform distribution */
    164   inline VectorType sample() const
    165   {
    166     VectorType r;
    167     for(Index d=0; d<dim(); ++d)
    168     {
    169       if(!ScalarTraits::IsInteger)
    170       {
    171         r[d] = m_min[d] + (m_max[d]-m_min[d])
    172              * internal::random<Scalar>(Scalar(0), Scalar(1));
    173       }
    174       else
    175         r[d] = internal::random(m_min[d], m_max[d]);
    176     }
    177     return r;
    178   }
    179 
    180   /** \returns true if the point \a p is inside the box \c *this. */
    181   template<typename Derived>
    182   inline bool contains(const MatrixBase<Derived>& p) const
    183   {
    184     typename internal::nested<Derived,2>::type p_n(p.derived());
    185     return (m_min.array()<=p_n.array()).all() && (p_n.array()<=m_max.array()).all();
    186   }
    187 
    188   /** \returns true if the box \a b is entirely inside the box \c *this. */
    189   inline bool contains(const AlignedBox& b) const
    190   { return (m_min.array()<=(b.min)().array()).all() && ((b.max)().array()<=m_max.array()).all(); }
    191 
    192   /** \returns true if the box \a b is intersecting the box \c *this.
    193    * \sa intersection, clamp */
    194   inline bool intersects(const AlignedBox& b) const
    195   { return (m_min.array()<=(b.max)().array()).all() && ((b.min)().array()<=m_max.array()).all(); }
    196 
    197   /** Extends \c *this such that it contains the point \a p and returns a reference to \c *this.
    198    * \sa extend(const AlignedBox&) */
    199   template<typename Derived>
    200   inline AlignedBox& extend(const MatrixBase<Derived>& p)
    201   {
    202     typename internal::nested<Derived,2>::type p_n(p.derived());
    203     m_min = m_min.cwiseMin(p_n);
    204     m_max = m_max.cwiseMax(p_n);
    205     return *this;
    206   }
    207 
    208   /** Extends \c *this such that it contains the box \a b and returns a reference to \c *this.
    209    * \sa merged, extend(const MatrixBase&) */
    210   inline AlignedBox& extend(const AlignedBox& b)
    211   {
    212     m_min = m_min.cwiseMin(b.m_min);
    213     m_max = m_max.cwiseMax(b.m_max);
    214     return *this;
    215   }
    216 
    217   /** Clamps \c *this by the box \a b and returns a reference to \c *this.
    218    * \note If the boxes don't intersect, the resulting box is empty.
    219    * \sa intersection(), intersects() */
    220   inline AlignedBox& clamp(const AlignedBox& b)
    221   {
    222     m_min = m_min.cwiseMax(b.m_min);
    223     m_max = m_max.cwiseMin(b.m_max);
    224     return *this;
    225   }
    226 
    227   /** Returns an AlignedBox that is the intersection of \a b and \c *this
    228    * \note If the boxes don't intersect, the resulting box is empty.
    229    * \sa intersects(), clamp, contains()  */
    230   inline AlignedBox intersection(const AlignedBox& b) const
    231   {return AlignedBox(m_min.cwiseMax(b.m_min), m_max.cwiseMin(b.m_max)); }
    232 
    233   /** Returns an AlignedBox that is the union of \a b and \c *this.
    234    * \note Merging with an empty box may result in a box bigger than \c *this.
    235    * \sa extend(const AlignedBox&) */
    236   inline AlignedBox merged(const AlignedBox& b) const
    237   { return AlignedBox(m_min.cwiseMin(b.m_min), m_max.cwiseMax(b.m_max)); }
    238 
    239   /** Translate \c *this by the vector \a t and returns a reference to \c *this. */
    240   template<typename Derived>
    241   inline AlignedBox& translate(const MatrixBase<Derived>& a_t)
    242   {
    243     const typename internal::nested<Derived,2>::type t(a_t.derived());
    244     m_min += t;
    245     m_max += t;
    246     return *this;
    247   }
    248 
    249   /** \returns the squared distance between the point \a p and the box \c *this,
    250     * and zero if \a p is inside the box.
    251     * \sa exteriorDistance(const MatrixBase&), squaredExteriorDistance(const AlignedBox&)
    252     */
    253   template<typename Derived>
    254   inline Scalar squaredExteriorDistance(const MatrixBase<Derived>& p) const;
    255 
    256   /** \returns the squared distance between the boxes \a b and \c *this,
    257     * and zero if the boxes intersect.
    258     * \sa exteriorDistance(const AlignedBox&), squaredExteriorDistance(const MatrixBase&)
    259     */
    260   inline Scalar squaredExteriorDistance(const AlignedBox& b) const;
    261 
    262   /** \returns the distance between the point \a p and the box \c *this,
    263     * and zero if \a p is inside the box.
    264     * \sa squaredExteriorDistance(const MatrixBase&), exteriorDistance(const AlignedBox&)
    265     */
    266   template<typename Derived>
    267   inline NonInteger exteriorDistance(const MatrixBase<Derived>& p) const
    268   { using std::sqrt; return sqrt(NonInteger(squaredExteriorDistance(p))); }
    269 
    270   /** \returns the distance between the boxes \a b and \c *this,
    271     * and zero if the boxes intersect.
    272     * \sa squaredExteriorDistance(const AlignedBox&), exteriorDistance(const MatrixBase&)
    273     */
    274   inline NonInteger exteriorDistance(const AlignedBox& b) const
    275   { using std::sqrt; return sqrt(NonInteger(squaredExteriorDistance(b))); }
    276 
    277   /** \returns \c *this with scalar type casted to \a NewScalarType
    278     *
    279     * Note that if \a NewScalarType is equal to the current scalar type of \c *this
    280     * then this function smartly returns a const reference to \c *this.
    281     */
    282   template<typename NewScalarType>
    283   inline typename internal::cast_return_type<AlignedBox,
    284            AlignedBox<NewScalarType,AmbientDimAtCompileTime> >::type cast() const
    285   {
    286     return typename internal::cast_return_type<AlignedBox,
    287                     AlignedBox<NewScalarType,AmbientDimAtCompileTime> >::type(*this);
    288   }
    289 
    290   /** Copy constructor with scalar type conversion */
    291   template<typename OtherScalarType>
    292   inline explicit AlignedBox(const AlignedBox<OtherScalarType,AmbientDimAtCompileTime>& other)
    293   {
    294     m_min = (other.min)().template cast<Scalar>();
    295     m_max = (other.max)().template cast<Scalar>();
    296   }
    297 
    298   /** \returns \c true if \c *this is approximately equal to \a other, within the precision
    299     * determined by \a prec.
    300     *
    301     * \sa MatrixBase::isApprox() */
    302   bool isApprox(const AlignedBox& other, const RealScalar& prec = ScalarTraits::dummy_precision()) const
    303   { return m_min.isApprox(other.m_min, prec) && m_max.isApprox(other.m_max, prec); }
    304 
    305 protected:
    306 
    307   VectorType m_min, m_max;
    308 };
    309 
    310 
    311 
    312 template<typename Scalar,int AmbientDim>
    313 template<typename Derived>
    314 inline Scalar AlignedBox<Scalar,AmbientDim>::squaredExteriorDistance(const MatrixBase<Derived>& a_p) const
    315 {
    316   typename internal::nested<Derived,2*AmbientDim>::type p(a_p.derived());
    317   Scalar dist2(0);
    318   Scalar aux;
    319   for (Index k=0; k<dim(); ++k)
    320   {
    321     if( m_min[k] > p[k] )
    322     {
    323       aux = m_min[k] - p[k];
    324       dist2 += aux*aux;
    325     }
    326     else if( p[k] > m_max[k] )
    327     {
    328       aux = p[k] - m_max[k];
    329       dist2 += aux*aux;
    330     }
    331   }
    332   return dist2;
    333 }
    334 
    335 template<typename Scalar,int AmbientDim>
    336 inline Scalar AlignedBox<Scalar,AmbientDim>::squaredExteriorDistance(const AlignedBox& b) const
    337 {
    338   Scalar dist2(0);
    339   Scalar aux;
    340   for (Index k=0; k<dim(); ++k)
    341   {
    342     if( m_min[k] > b.m_max[k] )
    343     {
    344       aux = m_min[k] - b.m_max[k];
    345       dist2 += aux*aux;
    346     }
    347     else if( b.m_min[k] > m_max[k] )
    348     {
    349       aux = b.m_min[k] - m_max[k];
    350       dist2 += aux*aux;
    351     }
    352   }
    353   return dist2;
    354 }
    355 
    356 /** \defgroup alignedboxtypedefs Global aligned box typedefs
    357   *
    358   * \ingroup Geometry_Module
    359   *
    360   * Eigen defines several typedef shortcuts for most common aligned box types.
    361   *
    362   * The general patterns are the following:
    363   *
    364   * \c AlignedBoxSizeType where \c Size can be \c 1, \c 2,\c 3,\c 4 for fixed size boxes or \c X for dynamic size,
    365   * and where \c Type can be \c i for integer, \c f for float, \c d for double.
    366   *
    367   * For example, \c AlignedBox3d is a fixed-size 3x3 aligned box type of doubles, and \c AlignedBoxXf is a dynamic-size aligned box of floats.
    368   *
    369   * \sa class AlignedBox
    370   */
    371 
    372 #define EIGEN_MAKE_TYPEDEFS(Type, TypeSuffix, Size, SizeSuffix)    \
    373 /** \ingroup alignedboxtypedefs */                                 \
    374 typedef AlignedBox<Type, Size>   AlignedBox##SizeSuffix##TypeSuffix;
    375 
    376 #define EIGEN_MAKE_TYPEDEFS_ALL_SIZES(Type, TypeSuffix) \
    377 EIGEN_MAKE_TYPEDEFS(Type, TypeSuffix, 1, 1) \
    378 EIGEN_MAKE_TYPEDEFS(Type, TypeSuffix, 2, 2) \
    379 EIGEN_MAKE_TYPEDEFS(Type, TypeSuffix, 3, 3) \
    380 EIGEN_MAKE_TYPEDEFS(Type, TypeSuffix, 4, 4) \
    381 EIGEN_MAKE_TYPEDEFS(Type, TypeSuffix, Dynamic, X)
    382 
    383 EIGEN_MAKE_TYPEDEFS_ALL_SIZES(int,                  i)
    384 EIGEN_MAKE_TYPEDEFS_ALL_SIZES(float,                f)
    385 EIGEN_MAKE_TYPEDEFS_ALL_SIZES(double,               d)
    386 
    387 #undef EIGEN_MAKE_TYPEDEFS_ALL_SIZES
    388 #undef EIGEN_MAKE_TYPEDEFS
    389 
    390 } // end namespace Eigen
    391 
    392 #endif // EIGEN_ALIGNEDBOX_H
    393