[136] | 1 | // This file is part of Eigen, a lightweight C++ template library
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| 2 | // for linear algebra.
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| 3 | //
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| 4 | // Copyright (C) 2010 Benoit Jacob <jacob.benoit.1@gmail.com>
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| 5 | //
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| 6 | // This Source Code Form is subject to the terms of the Mozilla
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| 7 | // Public License v. 2.0. If a copy of the MPL was not distributed
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| 8 | // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
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| 9 |
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| 10 | #ifndef EIGEN_STRIDE_H
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| 11 | #define EIGEN_STRIDE_H
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| 12 |
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| 13 | namespace Eigen {
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| 14 |
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| 15 | /** \class Stride
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| 16 | * \ingroup Core_Module
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| 17 | *
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| 18 | * \brief Holds strides information for Map
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| 19 | *
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| 20 | * This class holds the strides information for mapping arrays with strides with class Map.
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| 21 | *
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| 22 | * It holds two values: the inner stride and the outer stride.
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| 23 | *
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| 24 | * The inner stride is the pointer increment between two consecutive entries within a given row of a
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| 25 | * row-major matrix or within a given column of a column-major matrix.
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| 26 | *
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| 27 | * The outer stride is the pointer increment between two consecutive rows of a row-major matrix or
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| 28 | * between two consecutive columns of a column-major matrix.
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| 29 | *
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| 30 | * These two values can be passed either at compile-time as template parameters, or at runtime as
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| 31 | * arguments to the constructor.
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| 32 | *
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| 33 | * Indeed, this class takes two template parameters:
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| 34 | * \param _OuterStrideAtCompileTime the outer stride, or Dynamic if you want to specify it at runtime.
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| 35 | * \param _InnerStrideAtCompileTime the inner stride, or Dynamic if you want to specify it at runtime.
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| 36 | *
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| 37 | * Here is an example:
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| 38 | * \include Map_general_stride.cpp
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| 39 | * Output: \verbinclude Map_general_stride.out
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| 40 | *
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| 41 | * \sa class InnerStride, class OuterStride, \ref TopicStorageOrders
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| 42 | */
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| 43 | template<int _OuterStrideAtCompileTime, int _InnerStrideAtCompileTime>
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| 44 | class Stride
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| 45 | {
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| 46 | public:
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| 47 | typedef DenseIndex Index;
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| 48 | enum {
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| 49 | InnerStrideAtCompileTime = _InnerStrideAtCompileTime,
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| 50 | OuterStrideAtCompileTime = _OuterStrideAtCompileTime
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| 51 | };
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| 52 |
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| 53 | /** Default constructor, for use when strides are fixed at compile time */
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| 54 | Stride()
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| 55 | : m_outer(OuterStrideAtCompileTime), m_inner(InnerStrideAtCompileTime)
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| 56 | {
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| 57 | eigen_assert(InnerStrideAtCompileTime != Dynamic && OuterStrideAtCompileTime != Dynamic);
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| 58 | }
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| 59 |
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| 60 | /** Constructor allowing to pass the strides at runtime */
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| 61 | Stride(Index outerStride, Index innerStride)
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| 62 | : m_outer(outerStride), m_inner(innerStride)
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| 63 | {
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| 64 | eigen_assert(innerStride>=0 && outerStride>=0);
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| 65 | }
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| 66 |
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| 67 | /** Copy constructor */
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| 68 | Stride(const Stride& other)
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| 69 | : m_outer(other.outer()), m_inner(other.inner())
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| 70 | {}
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| 71 |
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| 72 | /** \returns the outer stride */
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| 73 | inline Index outer() const { return m_outer.value(); }
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| 74 | /** \returns the inner stride */
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| 75 | inline Index inner() const { return m_inner.value(); }
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| 76 |
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| 77 | protected:
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| 78 | internal::variable_if_dynamic<Index, OuterStrideAtCompileTime> m_outer;
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| 79 | internal::variable_if_dynamic<Index, InnerStrideAtCompileTime> m_inner;
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| 80 | };
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| 81 |
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| 82 | /** \brief Convenience specialization of Stride to specify only an inner stride
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| 83 | * See class Map for some examples */
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| 84 | template<int Value = Dynamic>
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| 85 | class InnerStride : public Stride<0, Value>
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| 86 | {
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| 87 | typedef Stride<0, Value> Base;
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| 88 | public:
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| 89 | typedef DenseIndex Index;
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| 90 | InnerStride() : Base() {}
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| 91 | InnerStride(Index v) : Base(0, v) {}
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| 92 | };
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| 93 |
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| 94 | /** \brief Convenience specialization of Stride to specify only an outer stride
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| 95 | * See class Map for some examples */
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| 96 | template<int Value = Dynamic>
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| 97 | class OuterStride : public Stride<Value, 0>
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| 98 | {
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| 99 | typedef Stride<Value, 0> Base;
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| 100 | public:
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| 101 | typedef DenseIndex Index;
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| 102 | OuterStride() : Base() {}
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| 103 | OuterStride(Index v) : Base(v,0) {}
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| 104 | };
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| 105 |
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| 106 | } // end namespace Eigen
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| 107 |
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| 108 | #endif // EIGEN_STRIDE_H
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