Eigen/src/Core/Map.h - eigen - Git at Google

 // 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

 // IWYU pragma: private
 #include "./InternalHeaderCheck.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
 };
 }  // namespace internal

 /** \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) {}

   /** 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) {}

   /** 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) {}

   EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Map)

  protected:
   StrideType m_stride;
 };

 }  // end namespace Eigen

 #endif  // EIGEN_MAP_H
	// 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

	// IWYU pragma: private
	#include "./InternalHeaderCheck.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
	};
	} // namespace internal

	/** \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) {}

	/** 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) {}

	/** 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) {}

	EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Map)

	protected:
	StrideType m_stride;
	};

	} // end namespace Eigen

	#endif // EIGEN_MAP_H