| // This file is part of Eigen, a lightweight C++ template library |
| // for linear algebra. |
| // |
| // Copyright (C) 2010 Benoit Jacob <jacob.benoit.1@gmail.com> |
| // |
| // 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_STRIDE_H |
| #define EIGEN_STRIDE_H |
| |
| // IWYU pragma: private |
| #include "./InternalHeaderCheck.h" |
| |
| namespace Eigen { |
| |
| /** \class Stride |
| * \ingroup Core_Module |
| * |
| * \brief Holds strides information for Map |
| * |
| * This class holds the strides information for mapping arrays with strides with class Map. |
| * |
| * It holds two values: the inner stride and the outer stride. |
| * |
| * The inner stride is the pointer increment between two consecutive entries within a given row of a |
| * row-major matrix or within a given column of a column-major matrix. |
| * |
| * The outer stride is the pointer increment between two consecutive rows of a row-major matrix or |
| * between two consecutive columns of a column-major matrix. |
| * |
| * These two values can be passed either at compile-time as template parameters, or at runtime as |
| * arguments to the constructor. |
| * |
| * Indeed, this class takes two template parameters: |
| * \tparam OuterStrideAtCompileTime_ the outer stride, or Dynamic if you want to specify it at runtime. |
| * \tparam InnerStrideAtCompileTime_ the inner stride, or Dynamic if you want to specify it at runtime. |
| * |
| * Here is an example: |
| * \include Map_general_stride.cpp |
| * Output: \verbinclude Map_general_stride.out |
| * |
| * Both strides can be negative. However, a negative stride of -1 cannot be specified at compile time |
| * because of the ambiguity with Dynamic which is defined to -1 (historically, negative strides were |
| * not allowed). |
| * |
| * Note that for compile-time vectors (ColsAtCompileTime==1 or RowsAtCompile==1), |
| * the inner stride is the pointer increment between two consecutive elements, |
| * regardless of storage layout. |
| * |
| * \sa class InnerStride, class OuterStride, \ref TopicStorageOrders |
| */ |
| template<int OuterStrideAtCompileTime_, int InnerStrideAtCompileTime_> |
| class Stride |
| { |
| public: |
| typedef Eigen::Index Index; ///< \deprecated since Eigen 3.3 |
| enum { |
| InnerStrideAtCompileTime = InnerStrideAtCompileTime_, |
| OuterStrideAtCompileTime = OuterStrideAtCompileTime_ |
| }; |
| |
| /** Default constructor, for use when strides are fixed at compile time */ |
| EIGEN_DEVICE_FUNC |
| Stride() |
| : m_outer(OuterStrideAtCompileTime), m_inner(InnerStrideAtCompileTime) |
| { |
| // FIXME: for Eigen 4 we should use DynamicIndex instead of Dynamic. |
| // FIXME: for Eigen 4 we should also unify this API with fix<> |
| eigen_assert(InnerStrideAtCompileTime != Dynamic && OuterStrideAtCompileTime != Dynamic); |
| } |
| |
| /** Constructor allowing to pass the strides at runtime */ |
| EIGEN_DEVICE_FUNC |
| Stride(Index outerStride, Index innerStride) |
| : m_outer(outerStride), m_inner(innerStride) |
| { |
| } |
| |
| /** Copy constructor */ |
| EIGEN_DEVICE_FUNC |
| Stride(const Stride& other) |
| : m_outer(other.outer()), m_inner(other.inner()) |
| {} |
| |
| /** \returns the outer stride */ |
| EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR |
| inline Index outer() const { return m_outer.value(); } |
| /** \returns the inner stride */ |
| EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR |
| inline Index inner() const { return m_inner.value(); } |
| |
| protected: |
| internal::variable_if_dynamic<Index, OuterStrideAtCompileTime> m_outer; |
| internal::variable_if_dynamic<Index, InnerStrideAtCompileTime> m_inner; |
| }; |
| |
| /** \brief Convenience specialization of Stride to specify only an inner stride |
| * See class Map for some examples */ |
| template<int Value> |
| class InnerStride : public Stride<0, Value> |
| { |
| typedef Stride<0, Value> Base; |
| public: |
| EIGEN_DEVICE_FUNC InnerStride() : Base() {} |
| EIGEN_DEVICE_FUNC InnerStride(Index v) : Base(0, v) {} // FIXME making this explicit could break valid code |
| }; |
| |
| /** \brief Convenience specialization of Stride to specify only an outer stride |
| * See class Map for some examples */ |
| template<int Value> |
| class OuterStride : public Stride<Value, 0> |
| { |
| typedef Stride<Value, 0> Base; |
| public: |
| EIGEN_DEVICE_FUNC OuterStride() : Base() {} |
| EIGEN_DEVICE_FUNC OuterStride(Index v) : Base(v,0) {} // FIXME making this explicit could break valid code |
| }; |
| |
| } // end namespace Eigen |
| |
| #endif // EIGEN_STRIDE_H |