cart-elc

Map.h (7256B)

---

 // This file is part of Eigen, a lightweight C++ template library
 // for linear algebra.
 //
 // Copyright (C) 2007-2010 Benoit Jacob <jacob.benoit.1@gmail.com>
 // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
 //
 // This Source Code Form is subject to the terms of the Mozilla
 // Public License v. 2.0. If a copy of the MPL was not distributed
 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #ifndef EIGEN_MAP_H
 #define EIGEN_MAP_H
 
 namespace Eigen {
 
 namespace internal {
 template<typename PlainObjectType, int MapOptions, typename StrideType>
 struct traits<Map<PlainObjectType, MapOptions, StrideType> >
   : public traits<PlainObjectType>
 {
   typedef traits<PlainObjectType> TraitsBase;
   enum {
     PlainObjectTypeInnerSize = ((traits<PlainObjectType>::Flags&RowMajorBit)==RowMajorBit)
                              ? PlainObjectType::ColsAtCompileTime
                              : PlainObjectType::RowsAtCompileTime,
 
     InnerStrideAtCompileTime = StrideType::InnerStrideAtCompileTime == 0
                              ? int(PlainObjectType::InnerStrideAtCompileTime)
                              : int(StrideType::InnerStrideAtCompileTime),
     OuterStrideAtCompileTime = StrideType::OuterStrideAtCompileTime == 0
                              ? (InnerStrideAtCompileTime==Dynamic || PlainObjectTypeInnerSize==Dynamic
                                 ? Dynamic
                                 : int(InnerStrideAtCompileTime) * int(PlainObjectTypeInnerSize))
                              : int(StrideType::OuterStrideAtCompileTime),
     Alignment = int(MapOptions)&int(AlignedMask),
     Flags0 = TraitsBase::Flags & (~NestByRefBit),
     Flags = is_lvalue<PlainObjectType>::value ? int(Flags0) : (int(Flags0) & ~LvalueBit)
   };
 private:
   enum { Options }; // Expressions don't have Options
 };
 }
 
 /** \class Map
   * \ingroup Core_Module
   *
   * \brief A matrix or vector expression mapping an existing array of data.
   *
   * \tparam PlainObjectType the equivalent matrix type of the mapped data
   * \tparam MapOptions specifies the pointer alignment in bytes. It can be: \c #Aligned128, \c #Aligned64, \c #Aligned32, \c #Aligned16, \c #Aligned8 or \c #Unaligned.
   *                The default is \c #Unaligned.
   * \tparam StrideType optionally specifies strides. By default, Map assumes the memory layout
   *                   of an ordinary, contiguous array. This can be overridden by specifying strides.
   *                   The type passed here must be a specialization of the Stride template, see examples below.
   *
   * This class represents a matrix or vector expression mapping an existing array of data.
   * It can be used to let Eigen interface without any overhead with non-Eigen data structures,
   * such as plain C arrays or structures from other libraries. By default, it assumes that the
   * data is laid out contiguously in memory. You can however override this by explicitly specifying
   * inner and outer strides.
   *
   * Here's an example of simply mapping a contiguous array as a \ref TopicStorageOrders "column-major" matrix:
   * \include Map_simple.cpp
   * Output: \verbinclude Map_simple.out
   *
   * If you need to map non-contiguous arrays, you can do so by specifying strides:
   *
   * Here's an example of mapping an array as a vector, specifying an inner stride, that is, the pointer
   * increment between two consecutive coefficients. Here, we're specifying the inner stride as a compile-time
   * fixed value.
   * \include Map_inner_stride.cpp
   * Output: \verbinclude Map_inner_stride.out
   *
   * Here's an example of mapping an array while specifying an outer stride. Here, since we're mapping
   * as a column-major matrix, 'outer stride' means the pointer increment between two consecutive columns.
   * Here, we're specifying the outer stride as a runtime parameter. Note that here \c OuterStride<> is
   * a short version of \c OuterStride<Dynamic> because the default template parameter of OuterStride
   * is  \c Dynamic
   * \include Map_outer_stride.cpp
   * Output: \verbinclude Map_outer_stride.out
   *
   * For more details and for an example of specifying both an inner and an outer stride, see class Stride.
   *
   * \b Tip: to change the array of data mapped by a Map object, you can use the C++
   * placement new syntax:
   *
   * Example: \include Map_placement_new.cpp
   * Output: \verbinclude Map_placement_new.out
   *
   * This class is the return type of PlainObjectBase::Map() but can also be used directly.
   *
   * \sa PlainObjectBase::Map(), \ref TopicStorageOrders
   */
 template<typename PlainObjectType, int MapOptions, typename StrideType> class Map
   : public MapBase<Map<PlainObjectType, MapOptions, StrideType> >
 {
   public:
 
     typedef MapBase<Map> Base;
     EIGEN_DENSE_PUBLIC_INTERFACE(Map)
 
     typedef typename Base::PointerType PointerType;
     typedef PointerType PointerArgType;
     EIGEN_DEVICE_FUNC
     inline PointerType cast_to_pointer_type(PointerArgType ptr) { return ptr; }
 
     EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR
     inline Index innerStride() const
     {
       return StrideType::InnerStrideAtCompileTime != 0 ? m_stride.inner() : 1;
     }
 
     EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR
     inline Index outerStride() const
     {
       return StrideType::OuterStrideAtCompileTime != 0 ? m_stride.outer()
            : internal::traits<Map>::OuterStrideAtCompileTime != Dynamic ? Index(internal::traits<Map>::OuterStrideAtCompileTime)
            : IsVectorAtCompileTime ? (this->size() * innerStride())
            : int(Flags)&RowMajorBit ? (this->cols() * innerStride())
            : (this->rows() * innerStride());
     }
 
     /** Constructor in the fixed-size case.
       *
       * \param dataPtr pointer to the array to map
       * \param stride optional Stride object, passing the strides.
       */
     EIGEN_DEVICE_FUNC
     explicit inline Map(PointerArgType dataPtr, const StrideType& stride = StrideType())
       : Base(cast_to_pointer_type(dataPtr)), m_stride(stride)
     {
       PlainObjectType::Base::_check_template_params();
     }
 
     /** Constructor in the dynamic-size vector case.
       *
       * \param dataPtr pointer to the array to map
       * \param size the size of the vector expression
       * \param stride optional Stride object, passing the strides.
       */
     EIGEN_DEVICE_FUNC
     inline Map(PointerArgType dataPtr, Index size, const StrideType& stride = StrideType())
       : Base(cast_to_pointer_type(dataPtr), size), m_stride(stride)
     {
       PlainObjectType::Base::_check_template_params();
     }
 
     /** Constructor in the dynamic-size matrix case.
       *
       * \param dataPtr pointer to the array to map
       * \param rows the number of rows of the matrix expression
       * \param cols the number of columns of the matrix expression
       * \param stride optional Stride object, passing the strides.
       */
     EIGEN_DEVICE_FUNC
     inline Map(PointerArgType dataPtr, Index rows, Index cols, const StrideType& stride = StrideType())
       : Base(cast_to_pointer_type(dataPtr), rows, cols), m_stride(stride)
     {
       PlainObjectType::Base::_check_template_params();
     }
 
     EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Map)
 
   protected:
     StrideType m_stride;
 };
 
 
 } // end namespace Eigen
 
 #endif // EIGEN_MAP_H