DenseCoeffsBase.h

00001 // This file is part of Eigen, a lightweight C++ template library
00002 // for linear algebra.
00003 //
00004 // Copyright (C) 2006-2010 Benoit Jacob <jacob.benoit.1@gmail.com>
00005 //
00006 // This Source Code Form is subject to the terms of the Mozilla
00007 // Public License v. 2.0. If a copy of the MPL was not distributed
00008 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
00009 
00010 #ifndef EIGEN_DENSECOEFFSBASE_H
00011 #define EIGEN_DENSECOEFFSBASE_H
00012 
00013 namespace Eigen {
00014 
00015 namespace internal {
00016 template<typename T> struct add_const_on_value_type_if_arithmetic
00017 {
00018   typedef typename conditional<is_arithmetic<T>::value, T, typename add_const_on_value_type<T>::type>::type type;
00019 };
00020 }
00021 
00022 /** \brief Base class providing read-only coefficient access to matrices and arrays.
00023   * \ingroup Core_Module
00024   * \tparam Derived Type of the derived class
00025   * \tparam #ReadOnlyAccessors Constant indicating read-only access
00026   *
00027   * This class defines the \c operator() \c const function and friends, which can be used to read specific
00028   * entries of a matrix or array.
00029   * 
00030   * \sa DenseCoeffsBase<Derived, WriteAccessors>, DenseCoeffsBase<Derived, DirectAccessors>,
00031   *     \ref TopicClassHierarchy
00032   */
00033 template<typename Derived>
00034 class DenseCoeffsBase<Derived,ReadOnlyAccessors> : public EigenBase<Derived>
00035 {
00036   public:
00037     typedef typename internal::traits<Derived>::StorageKind StorageKind;
00038     typedef typename internal::traits<Derived>::Index Index;
00039     typedef typename internal::traits<Derived>::Scalar Scalar;
00040     typedef typename internal::packet_traits<Scalar>::type PacketScalar;
00041 
00042     // Explanation for this CoeffReturnType typedef.
00043     // - This is the return type of the coeff() method.
00044     // - The LvalueBit means exactly that we can offer a coeffRef() method, which means exactly that we can get references
00045     // to coeffs, which means exactly that we can have coeff() return a const reference (as opposed to returning a value).
00046     // - The is_artihmetic check is required since "const int", "const double", etc. will cause warnings on some systems
00047     // while the declaration of "const T", where T is a non arithmetic type does not. Always returning "const Scalar&" is
00048     // not possible, since the underlying expressions might not offer a valid address the reference could be referring to.
00049     typedef typename internal::conditional<bool(internal::traits<Derived>::Flags&LvalueBit),
00050                          const Scalar&,
00051                          typename internal::conditional<internal::is_arithmetic<Scalar>::value, Scalar, const Scalar>::type
00052                      >::type CoeffReturnType;
00053 
00054     typedef typename internal::add_const_on_value_type_if_arithmetic<
00055                          typename internal::packet_traits<Scalar>::type
00056                      >::type PacketReturnType;
00057 
00058     typedef EigenBase<Derived> Base;
00059     using Base::rows;
00060     using Base::cols;
00061     using Base::size;
00062     using Base::derived;
00063 
00064     EIGEN_STRONG_INLINE Index rowIndexByOuterInner(Index outer, Index inner) const
00065     {
00066       return int(Derived::RowsAtCompileTime) == 1 ? 0
00067           : int(Derived::ColsAtCompileTime) == 1 ? inner
00068           : int(Derived::Flags)&RowMajorBit ? outer
00069           : inner;
00070     }
00071 
00072     EIGEN_STRONG_INLINE Index colIndexByOuterInner(Index outer, Index inner) const
00073     {
00074       return int(Derived::ColsAtCompileTime) == 1 ? 0
00075           : int(Derived::RowsAtCompileTime) == 1 ? inner
00076           : int(Derived::Flags)&RowMajorBit ? inner
00077           : outer;
00078     }
00079 
00080     /** Short version: don't use this function, use
00081       * \link operator()(Index,Index) const \endlink instead.
00082       *
00083       * Long version: this function is similar to
00084       * \link operator()(Index,Index) const \endlink, but without the assertion.
00085       * Use this for limiting the performance cost of debugging code when doing
00086       * repeated coefficient access. Only use this when it is guaranteed that the
00087       * parameters \a row and \a col are in range.
00088       *
00089       * If EIGEN_INTERNAL_DEBUGGING is defined, an assertion will be made, making this
00090       * function equivalent to \link operator()(Index,Index) const \endlink.
00091       *
00092       * \sa operator()(Index,Index) const, coeffRef(Index,Index), coeff(Index) const
00093       */
00094     EIGEN_STRONG_INLINE CoeffReturnType coeff(Index row, Index col) const
00095     {
00096       eigen_internal_assert(row >= 0 && row < rows()
00097                         && col >= 0 && col < cols());
00098       return derived().coeff(row, col);
00099     }
00100 
00101     EIGEN_STRONG_INLINE CoeffReturnType coeffByOuterInner(Index outer, Index inner) const
00102     {
00103       return coeff(rowIndexByOuterInner(outer, inner),
00104                    colIndexByOuterInner(outer, inner));
00105     }
00106 
00107     /** \returns the coefficient at given the given row and column.
00108       *
00109       * \sa operator()(Index,Index), operator[](Index)
00110       */
00111     EIGEN_STRONG_INLINE CoeffReturnType operator()(Index row, Index col) const
00112     {
00113       eigen_assert(row >= 0 && row < rows()
00114           && col >= 0 && col < cols());
00115       return derived().coeff(row, col);
00116     }
00117 
00118     /** Short version: don't use this function, use
00119       * \link operator[](Index) const \endlink instead.
00120       *
00121       * Long version: this function is similar to
00122       * \link operator[](Index) const \endlink, but without the assertion.
00123       * Use this for limiting the performance cost of debugging code when doing
00124       * repeated coefficient access. Only use this when it is guaranteed that the
00125       * parameter \a index is in range.
00126       *
00127       * If EIGEN_INTERNAL_DEBUGGING is defined, an assertion will be made, making this
00128       * function equivalent to \link operator[](Index) const \endlink.
00129       *
00130       * \sa operator[](Index) const, coeffRef(Index), coeff(Index,Index) const
00131       */
00132 
00133     EIGEN_STRONG_INLINE CoeffReturnType
00134     coeff(Index index) const
00135     {
00136       eigen_internal_assert(index >= 0 && index < size());
00137       return derived().coeff(index);
00138     }
00139 
00140 
00141     /** \returns the coefficient at given index.
00142       *
00143       * This method is allowed only for vector expressions, and for matrix expressions having the LinearAccessBit.
00144       *
00145       * \sa operator[](Index), operator()(Index,Index) const, x() const, y() const,
00146       * z() const, w() const
00147       */
00148 
00149     EIGEN_STRONG_INLINE CoeffReturnType
00150     operator[](Index index) const
00151     {
00152       #ifndef EIGEN2_SUPPORT
00153       EIGEN_STATIC_ASSERT(Derived::IsVectorAtCompileTime,
00154                           THE_BRACKET_OPERATOR_IS_ONLY_FOR_VECTORS__USE_THE_PARENTHESIS_OPERATOR_INSTEAD)
00155       #endif
00156       eigen_assert(index >= 0 && index < size());
00157       return derived().coeff(index);
00158     }
00159 
00160     /** \returns the coefficient at given index.
00161       *
00162       * This is synonymous to operator[](Index) const.
00163       *
00164       * This method is allowed only for vector expressions, and for matrix expressions having the LinearAccessBit.
00165       *
00166       * \sa operator[](Index), operator()(Index,Index) const, x() const, y() const,
00167       * z() const, w() const
00168       */
00169 
00170     EIGEN_STRONG_INLINE CoeffReturnType
00171     operator()(Index index) const
00172     {
00173       eigen_assert(index >= 0 && index < size());
00174       return derived().coeff(index);
00175     }
00176 
00177     /** equivalent to operator[](0).  */
00178 
00179     EIGEN_STRONG_INLINE CoeffReturnType
00180     x() const { return (*this)[0]; }
00181 
00182     /** equivalent to operator[](1).  */
00183 
00184     EIGEN_STRONG_INLINE CoeffReturnType
00185     y() const { return (*this)[1]; }
00186 
00187     /** equivalent to operator[](2).  */
00188 
00189     EIGEN_STRONG_INLINE CoeffReturnType
00190     z() const { return (*this)[2]; }
00191 
00192     /** equivalent to operator[](3).  */
00193 
00194     EIGEN_STRONG_INLINE CoeffReturnType
00195     w() const { return (*this)[3]; }
00196 
00197     /** \internal
00198       * \returns the packet of coefficients starting at the given row and column. It is your responsibility
00199       * to ensure that a packet really starts there. This method is only available on expressions having the
00200       * PacketAccessBit.
00201       *
00202       * The \a LoadMode parameter may have the value \a #Aligned or \a #Unaligned. Its effect is to select
00203       * the appropriate vectorization instruction. Aligned access is faster, but is only possible for packets
00204       * starting at an address which is a multiple of the packet size.
00205       */
00206 
00207     template<int LoadMode>
00208     EIGEN_STRONG_INLINE PacketReturnType packet(Index row, Index col) const
00209     {
00210       eigen_internal_assert(row >= 0 && row < rows()
00211                       && col >= 0 && col < cols());
00212       return derived().template packet<LoadMode>(row,col);
00213     }
00214 
00215 
00216     /** \internal */
00217     template<int LoadMode>
00218     EIGEN_STRONG_INLINE PacketReturnType packetByOuterInner(Index outer, Index inner) const
00219     {
00220       return packet<LoadMode>(rowIndexByOuterInner(outer, inner),
00221                               colIndexByOuterInner(outer, inner));
00222     }
00223 
00224     /** \internal
00225       * \returns the packet of coefficients starting at the given index. It is your responsibility
00226       * to ensure that a packet really starts there. This method is only available on expressions having the
00227       * PacketAccessBit and the LinearAccessBit.
00228       *
00229       * The \a LoadMode parameter may have the value \a #Aligned or \a #Unaligned. Its effect is to select
00230       * the appropriate vectorization instruction. Aligned access is faster, but is only possible for packets
00231       * starting at an address which is a multiple of the packet size.
00232       */
00233 
00234     template<int LoadMode>
00235     EIGEN_STRONG_INLINE PacketReturnType packet(Index index) const
00236     {
00237       eigen_internal_assert(index >= 0 && index < size());
00238       return derived().template packet<LoadMode>(index);
00239     }
00240 
00241   protected:
00242     // explanation: DenseBase is doing "using ..." on the methods from DenseCoeffsBase.
00243     // But some methods are only available in the DirectAccess case.
00244     // So we add dummy methods here with these names, so that "using... " doesn't fail.
00245     // It's not private so that the child class DenseBase can access them, and it's not public
00246     // either since it's an implementation detail, so has to be protected.
00247     void coeffRef();
00248     void coeffRefByOuterInner();
00249     void writePacket();
00250     void writePacketByOuterInner();
00251     void copyCoeff();
00252     void copyCoeffByOuterInner();
00253     void copyPacket();
00254     void copyPacketByOuterInner();
00255     void stride();
00256     void innerStride();
00257     void outerStride();
00258     void rowStride();
00259     void colStride();
00260 };
00261 
00262 /** \brief Base class providing read/write coefficient access to matrices and arrays.
00263   * \ingroup Core_Module
00264   * \tparam Derived Type of the derived class
00265   * \tparam #WriteAccessors Constant indicating read/write access
00266   *
00267   * This class defines the non-const \c operator() function and friends, which can be used to write specific
00268   * entries of a matrix or array. This class inherits DenseCoeffsBase<Derived, ReadOnlyAccessors> which
00269   * defines the const variant for reading specific entries.
00270   * 
00271   * \sa DenseCoeffsBase<Derived, DirectAccessors>, \ref TopicClassHierarchy
00272   */
00273 template<typename Derived>
00274 class DenseCoeffsBase<Derived, WriteAccessors> : public DenseCoeffsBase<Derived, ReadOnlyAccessors>
00275 {
00276   public:
00277 
00278     typedef DenseCoeffsBase<Derived, ReadOnlyAccessors> Base;
00279 
00280     typedef typename internal::traits<Derived>::StorageKind StorageKind;
00281     typedef typename internal::traits<Derived>::Index Index;
00282     typedef typename internal::traits<Derived>::Scalar Scalar;
00283     typedef typename internal::packet_traits<Scalar>::type PacketScalar;
00284     typedef typename NumTraits<Scalar>::Real RealScalar;
00285 
00286     using Base::coeff;
00287     using Base::rows;
00288     using Base::cols;
00289     using Base::size;
00290     using Base::derived;
00291     using Base::rowIndexByOuterInner;
00292     using Base::colIndexByOuterInner;
00293     using Base::operator[];
00294     using Base::operator();
00295     using Base::x;
00296     using Base::y;
00297     using Base::z;
00298     using Base::w;
00299 
00300     /** Short version: don't use this function, use
00301       * \link operator()(Index,Index) \endlink instead.
00302       *
00303       * Long version: this function is similar to
00304       * \link operator()(Index,Index) \endlink, but without the assertion.
00305       * Use this for limiting the performance cost of debugging code when doing
00306       * repeated coefficient access. Only use this when it is guaranteed that the
00307       * parameters \a row and \a col are in range.
00308       *
00309       * If EIGEN_INTERNAL_DEBUGGING is defined, an assertion will be made, making this
00310       * function equivalent to \link operator()(Index,Index) \endlink.
00311       *
00312       * \sa operator()(Index,Index), coeff(Index, Index) const, coeffRef(Index)
00313       */
00314     EIGEN_STRONG_INLINE Scalar& coeffRef(Index row, Index col)
00315     {
00316       eigen_internal_assert(row >= 0 && row < rows()
00317                         && col >= 0 && col < cols());
00318       return derived().coeffRef(row, col);
00319     }
00320 
00321     EIGEN_STRONG_INLINE Scalar&
00322     coeffRefByOuterInner(Index outer, Index inner)
00323     {
00324       return coeffRef(rowIndexByOuterInner(outer, inner),
00325                       colIndexByOuterInner(outer, inner));
00326     }
00327 
00328     /** \returns a reference to the coefficient at given the given row and column.
00329       *
00330       * \sa operator[](Index)
00331       */
00332 
00333     EIGEN_STRONG_INLINE Scalar&
00334     operator()(Index row, Index col)
00335     {
00336       eigen_assert(row >= 0 && row < rows()
00337           && col >= 0 && col < cols());
00338       return derived().coeffRef(row, col);
00339     }
00340 
00341 
00342     /** Short version: don't use this function, use
00343       * \link operator[](Index) \endlink instead.
00344       *
00345       * Long version: this function is similar to
00346       * \link operator[](Index) \endlink, but without the assertion.
00347       * Use this for limiting the performance cost of debugging code when doing
00348       * repeated coefficient access. Only use this when it is guaranteed that the
00349       * parameters \a row and \a col are in range.
00350       *
00351       * If EIGEN_INTERNAL_DEBUGGING is defined, an assertion will be made, making this
00352       * function equivalent to \link operator[](Index) \endlink.
00353       *
00354       * \sa operator[](Index), coeff(Index) const, coeffRef(Index,Index)
00355       */
00356 
00357     EIGEN_STRONG_INLINE Scalar&
00358     coeffRef(Index index)
00359     {
00360       eigen_internal_assert(index >= 0 && index < size());
00361       return derived().coeffRef(index);
00362     }
00363 
00364     /** \returns a reference to the coefficient at given index.
00365       *
00366       * This method is allowed only for vector expressions, and for matrix expressions having the LinearAccessBit.
00367       *
00368       * \sa operator[](Index) const, operator()(Index,Index), x(), y(), z(), w()
00369       */
00370 
00371     EIGEN_STRONG_INLINE Scalar&
00372     operator[](Index index)
00373     {
00374       #ifndef EIGEN2_SUPPORT
00375       EIGEN_STATIC_ASSERT(Derived::IsVectorAtCompileTime,
00376                           THE_BRACKET_OPERATOR_IS_ONLY_FOR_VECTORS__USE_THE_PARENTHESIS_OPERATOR_INSTEAD)
00377       #endif
00378       eigen_assert(index >= 0 && index < size());
00379       return derived().coeffRef(index);
00380     }
00381 
00382     /** \returns a reference to the coefficient at given index.
00383       *
00384       * This is synonymous to operator[](Index).
00385       *
00386       * This method is allowed only for vector expressions, and for matrix expressions having the LinearAccessBit.
00387       *
00388       * \sa operator[](Index) const, operator()(Index,Index), x(), y(), z(), w()
00389       */
00390 
00391     EIGEN_STRONG_INLINE Scalar&
00392     operator()(Index index)
00393     {
00394       eigen_assert(index >= 0 && index < size());
00395       return derived().coeffRef(index);
00396     }
00397 
00398     /** equivalent to operator[](0).  */
00399 
00400     EIGEN_STRONG_INLINE Scalar&
00401     x() { return (*this)[0]; }
00402 
00403     /** equivalent to operator[](1).  */
00404 
00405     EIGEN_STRONG_INLINE Scalar&
00406     y() { return (*this)[1]; }
00407 
00408     /** equivalent to operator[](2).  */
00409 
00410     EIGEN_STRONG_INLINE Scalar&
00411     z() { return (*this)[2]; }
00412 
00413     /** equivalent to operator[](3).  */
00414 
00415     EIGEN_STRONG_INLINE Scalar&
00416     w() { return (*this)[3]; }
00417 
00418     /** \internal
00419       * Stores the given packet of coefficients, at the given row and column of this expression. It is your responsibility
00420       * to ensure that a packet really starts there. This method is only available on expressions having the
00421       * PacketAccessBit.
00422       *
00423       * The \a LoadMode parameter may have the value \a #Aligned or \a #Unaligned. Its effect is to select
00424       * the appropriate vectorization instruction. Aligned access is faster, but is only possible for packets
00425       * starting at an address which is a multiple of the packet size.
00426       */
00427 
00428     template<int StoreMode>
00429     EIGEN_STRONG_INLINE void writePacket
00430     (Index row, Index col, const typename internal::packet_traits<Scalar>::type& val)
00431     {
00432       eigen_internal_assert(row >= 0 && row < rows()
00433                         && col >= 0 && col < cols());
00434       derived().template writePacket<StoreMode>(row,col,val);
00435     }
00436 
00437 
00438     /** \internal */
00439     template<int StoreMode>
00440     EIGEN_STRONG_INLINE void writePacketByOuterInner
00441     (Index outer, Index inner, const typename internal::packet_traits<Scalar>::type& val)
00442     {
00443       writePacket<StoreMode>(rowIndexByOuterInner(outer, inner),
00444                             colIndexByOuterInner(outer, inner),
00445                             val);
00446     }
00447 
00448     /** \internal
00449       * Stores the given packet of coefficients, at the given index in this expression. It is your responsibility
00450       * to ensure that a packet really starts there. This method is only available on expressions having the
00451       * PacketAccessBit and the LinearAccessBit.
00452       *
00453       * The \a LoadMode parameter may have the value \a Aligned or \a Unaligned. Its effect is to select
00454       * the appropriate vectorization instruction. Aligned access is faster, but is only possible for packets
00455       * starting at an address which is a multiple of the packet size.
00456       */
00457     template<int StoreMode>
00458     EIGEN_STRONG_INLINE void writePacket
00459     (Index index, const typename internal::packet_traits<Scalar>::type& val)
00460     {
00461       eigen_internal_assert(index >= 0 && index < size());
00462       derived().template writePacket<StoreMode>(index,val);
00463     }
00464 
00465 #ifndef EIGEN_PARSED_BY_DOXYGEN
00466 
00467     /** \internal Copies the coefficient at position (row,col) of other into *this.
00468       *
00469       * This method is overridden in SwapWrapper, allowing swap() assignments to share 99% of their code
00470       * with usual assignments.
00471       *
00472       * Outside of this internal usage, this method has probably no usefulness. It is hidden in the public API dox.
00473       */
00474 
00475     template<typename OtherDerived>
00476     EIGEN_STRONG_INLINE void copyCoeff(Index row, Index col, const DenseBase<OtherDerived>& other)
00477     {
00478       eigen_internal_assert(row >= 0 && row < rows()
00479                         && col >= 0 && col < cols());
00480       derived().coeffRef(row, col) = other.derived().coeff(row, col);
00481     }
00482 
00483     /** \internal Copies the coefficient at the given index of other into *this.
00484       *
00485       * This method is overridden in SwapWrapper, allowing swap() assignments to share 99% of their code
00486       * with usual assignments.
00487       *
00488       * Outside of this internal usage, this method has probably no usefulness. It is hidden in the public API dox.
00489       */
00490 
00491     template<typename OtherDerived>
00492     EIGEN_STRONG_INLINE void copyCoeff(Index index, const DenseBase<OtherDerived>& other)
00493     {
00494       eigen_internal_assert(index >= 0 && index < size());
00495       derived().coeffRef(index) = other.derived().coeff(index);
00496     }
00497 
00498 
00499     template<typename OtherDerived>
00500     EIGEN_STRONG_INLINE void copyCoeffByOuterInner(Index outer, Index inner, const DenseBase<OtherDerived>& other)
00501     {
00502       const Index row = rowIndexByOuterInner(outer,inner);
00503       const Index col = colIndexByOuterInner(outer,inner);
00504       // derived() is important here: copyCoeff() may be reimplemented in Derived!
00505       derived().copyCoeff(row, col, other);
00506     }
00507 
00508     /** \internal Copies the packet at position (row,col) of other into *this.
00509       *
00510       * This method is overridden in SwapWrapper, allowing swap() assignments to share 99% of their code
00511       * with usual assignments.
00512       *
00513       * Outside of this internal usage, this method has probably no usefulness. It is hidden in the public API dox.
00514       */
00515 
00516     template<typename OtherDerived, int StoreMode, int LoadMode>
00517     EIGEN_STRONG_INLINE void copyPacket(Index row, Index col, const DenseBase<OtherDerived>& other)
00518     {
00519       eigen_internal_assert(row >= 0 && row < rows()
00520                         && col >= 0 && col < cols());
00521       derived().template writePacket<StoreMode>(row, col,
00522         other.derived().template packet<LoadMode>(row, col));
00523     }
00524 
00525     /** \internal Copies the packet at the given index of other into *this.
00526       *
00527       * This method is overridden in SwapWrapper, allowing swap() assignments to share 99% of their code
00528       * with usual assignments.
00529       *
00530       * Outside of this internal usage, this method has probably no usefulness. It is hidden in the public API dox.
00531       */
00532 
00533     template<typename OtherDerived, int StoreMode, int LoadMode>
00534     EIGEN_STRONG_INLINE void copyPacket(Index index, const DenseBase<OtherDerived>& other)
00535     {
00536       eigen_internal_assert(index >= 0 && index < size());
00537       derived().template writePacket<StoreMode>(index,
00538         other.derived().template packet<LoadMode>(index));
00539     }
00540 
00541     /** \internal */
00542     template<typename OtherDerived, int StoreMode, int LoadMode>
00543     EIGEN_STRONG_INLINE void copyPacketByOuterInner(Index outer, Index inner, const DenseBase<OtherDerived>& other)
00544     {
00545       const Index row = rowIndexByOuterInner(outer,inner);
00546       const Index col = colIndexByOuterInner(outer,inner);
00547       // derived() is important here: copyCoeff() may be reimplemented in Derived!
00548       derived().template copyPacket< OtherDerived, StoreMode, LoadMode>(row, col, other);
00549     }
00550 #endif
00551 
00552 };
00553 
00554 /** \brief Base class providing direct read-only coefficient access to matrices and arrays.
00555   * \ingroup Core_Module
00556   * \tparam Derived Type of the derived class
00557   * \tparam #DirectAccessors Constant indicating direct access
00558   *
00559   * This class defines functions to work with strides which can be used to access entries directly. This class
00560   * inherits DenseCoeffsBase<Derived, ReadOnlyAccessors> which defines functions to access entries read-only using
00561   * \c operator() .
00562   *
00563   * \sa \ref TopicClassHierarchy
00564   */
00565 template<typename Derived>
00566 class DenseCoeffsBase<Derived, DirectAccessors> : public DenseCoeffsBase<Derived, ReadOnlyAccessors>
00567 {
00568   public:
00569 
00570     typedef DenseCoeffsBase<Derived, ReadOnlyAccessors> Base;
00571     typedef typename internal::traits<Derived>::Index Index;
00572     typedef typename internal::traits<Derived>::Scalar Scalar;
00573     typedef typename NumTraits<Scalar>::Real RealScalar;
00574 
00575     using Base::rows;
00576     using Base::cols;
00577     using Base::size;
00578     using Base::derived;
00579 
00580     /** \returns the pointer increment between two consecutive elements within a slice in the inner direction.
00581       *
00582       * \sa outerStride(), rowStride(), colStride()
00583       */
00584     inline Index innerStride() const
00585     {
00586       return derived().innerStride();
00587     }
00588 
00589     /** \returns the pointer increment between two consecutive inner slices (for example, between two consecutive columns
00590       *          in a column-major matrix).
00591       *
00592       * \sa innerStride(), rowStride(), colStride()
00593       */
00594     inline Index outerStride() const
00595     {
00596       return derived().outerStride();
00597     }
00598 
00599     // FIXME shall we remove it ?
00600     inline Index stride() const
00601     {
00602       return Derived::IsVectorAtCompileTime ? innerStride() : outerStride();
00603     }
00604 
00605     /** \returns the pointer increment between two consecutive rows.
00606       *
00607       * \sa innerStride(), outerStride(), colStride()
00608       */
00609     inline Index rowStride() const
00610     {
00611       return Derived::IsRowMajor ? outerStride() : innerStride();
00612     }
00613 
00614     /** \returns the pointer increment between two consecutive columns.
00615       *
00616       * \sa innerStride(), outerStride(), rowStride()
00617       */
00618     inline Index colStride() const
00619     {
00620       return Derived::IsRowMajor ? innerStride() : outerStride();
00621     }
00622 };
00623 
00624 /** \brief Base class providing direct read/write coefficient access to matrices and arrays.
00625   * \ingroup Core_Module
00626   * \tparam Derived Type of the derived class
00627   * \tparam #DirectWriteAccessors Constant indicating direct access
00628   *
00629   * This class defines functions to work with strides which can be used to access entries directly. This class
00630   * inherits DenseCoeffsBase<Derived, WriteAccessors> which defines functions to access entries read/write using
00631   * \c operator().
00632   *
00633   * \sa \ref TopicClassHierarchy
00634   */
00635 template<typename Derived>
00636 class DenseCoeffsBase<Derived, DirectWriteAccessors>
00637   : public DenseCoeffsBase<Derived, WriteAccessors>
00638 {
00639   public:
00640 
00641     typedef DenseCoeffsBase<Derived, WriteAccessors> Base;
00642     typedef typename internal::traits<Derived>::Index Index;
00643     typedef typename internal::traits<Derived>::Scalar Scalar;
00644     typedef typename NumTraits<Scalar>::Real RealScalar;
00645 
00646     using Base::rows;
00647     using Base::cols;
00648     using Base::size;
00649     using Base::derived;
00650 
00651     /** \returns the pointer increment between two consecutive elements within a slice in the inner direction.
00652       *
00653       * \sa outerStride(), rowStride(), colStride()
00654       */
00655     inline Index innerStride() const
00656     {
00657       return derived().innerStride();
00658     }
00659 
00660     /** \returns the pointer increment between two consecutive inner slices (for example, between two consecutive columns
00661       *          in a column-major matrix).
00662       *
00663       * \sa innerStride(), rowStride(), colStride()
00664       */
00665     inline Index outerStride() const
00666     {
00667       return derived().outerStride();
00668     }
00669 
00670     // FIXME shall we remove it ?
00671     inline Index stride() const
00672     {
00673       return Derived::IsVectorAtCompileTime ? innerStride() : outerStride();
00674     }
00675 
00676     /** \returns the pointer increment between two consecutive rows.
00677       *
00678       * \sa innerStride(), outerStride(), colStride()
00679       */
00680     inline Index rowStride() const
00681     {
00682       return Derived::IsRowMajor ? outerStride() : innerStride();
00683     }
00684 
00685     /** \returns the pointer increment between two consecutive columns.
00686       *
00687       * \sa innerStride(), outerStride(), rowStride()
00688       */
00689     inline Index colStride() const
00690     {
00691       return Derived::IsRowMajor ? innerStride() : outerStride();
00692     }
00693 };
00694 
00695 namespace internal {
00696 
00697 template<typename Derived, bool JustReturnZero>
00698 struct first_aligned_impl
00699 {
00700   static inline typename Derived::Index run(const Derived&)
00701   { return 0; }
00702 };
00703 
00704 template<typename Derived>
00705 struct first_aligned_impl<Derived, false>
00706 {
00707   static inline typename Derived::Index run(const Derived& m)
00708   {
00709     return internal::first_aligned(&m.const_cast_derived().coeffRef(0,0), m.size());
00710   }
00711 };
00712 
00713 /** \internal \returns the index of the first element of the array that is well aligned for vectorization.
00714   *
00715   * There is also the variant first_aligned(const Scalar*, Integer) defined in Memory.h. See it for more
00716   * documentation.
00717   */
00718 template<typename Derived>
00719 static inline typename Derived::Index first_aligned(const Derived& m)
00720 {
00721   return first_aligned_impl
00722           <Derived, (Derived::Flags & AlignedBit) || !(Derived::Flags & DirectAccessBit)>
00723           ::run(m);
00724 }
00725 
00726 template<typename Derived, bool HasDirectAccess = has_direct_access<Derived>::ret>
00727 struct inner_stride_at_compile_time
00728 {
00729   enum { ret = traits<Derived>::InnerStrideAtCompileTime };
00730 };
00731 
00732 template<typename Derived>
00733 struct inner_stride_at_compile_time<Derived, false>
00734 {
00735   enum { ret = 0 };
00736 };
00737 
00738 template<typename Derived, bool HasDirectAccess = has_direct_access<Derived>::ret>
00739 struct outer_stride_at_compile_time
00740 {
00741   enum { ret = traits<Derived>::OuterStrideAtCompileTime };
00742 };
00743 
00744 template<typename Derived>
00745 struct outer_stride_at_compile_time<Derived, false>
00746 {
00747   enum { ret = 0 };
00748 };
00749 
00750 } // end namespace internal
00751 
00752 } // end namespace Eigen
00753 
00754 #endif // EIGEN_DENSECOEFFSBASE_H