1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2009-2010 Gael Guennebaud <gael.guennebaud@inria.fr>
5 //
6 // This Source Code Form is subject to the terms of the Mozilla
7 // Public License v. 2.0. If a copy of the MPL was not distributed
8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9 
10 #ifndef EIGEN_CWISE_UNARY_VIEW_H
11 #define EIGEN_CWISE_UNARY_VIEW_H
12 
13 namespace Eigen {
14 
15 namespace internal {
16 template<typename ViewOp, typename MatrixType>
17 struct traits<CwiseUnaryView<ViewOp, MatrixType> >
18  : traits<MatrixType>
19 {
20   typedef typename result_of<
21                      ViewOp(const typename traits<MatrixType>::Scalar&)
22                    >::type Scalar;
23   typedef typename MatrixType::Nested MatrixTypeNested;
24   typedef typename remove_all<MatrixTypeNested>::type _MatrixTypeNested;
25   enum {
26     FlagsLvalueBit = is_lvalue<MatrixType>::value ? LvalueBit : 0,
27     Flags = traits<_MatrixTypeNested>::Flags & (RowMajorBit | FlagsLvalueBit | DirectAccessBit), // FIXME DirectAccessBit should not be handled by expressions
28     MatrixTypeInnerStride =  inner_stride_at_compile_time<MatrixType>::ret,
29     // need to cast the sizeof's from size_t to int explicitly, otherwise:
30     // "error: no integral type can represent all of the enumerator values
31     InnerStrideAtCompileTime = MatrixTypeInnerStride == Dynamic
32                              ? int(Dynamic)
33                              : int(MatrixTypeInnerStride) * int(sizeof(typename traits<MatrixType>::Scalar) / sizeof(Scalar)),
34     OuterStrideAtCompileTime = outer_stride_at_compile_time<MatrixType>::ret == Dynamic
35                              ? int(Dynamic)
36                              : outer_stride_at_compile_time<MatrixType>::ret * int(sizeof(typename traits<MatrixType>::Scalar) / sizeof(Scalar))
37   };
38 };
39 }
40 
41 template<typename ViewOp, typename MatrixType, typename StorageKind>
42 class CwiseUnaryViewImpl;
43 
44 /** \class CwiseUnaryView
45   * \ingroup Core_Module
46   *
47   * \brief Generic lvalue expression of a coefficient-wise unary operator of a matrix or a vector
48   *
49   * \tparam ViewOp template functor implementing the view
50   * \tparam MatrixType the type of the matrix we are applying the unary operator
51   *
52   * This class represents a lvalue expression of a generic unary view operator of a matrix or a vector.
53   * It is the return type of real() and imag(), and most of the time this is the only way it is used.
54   *
55   * \sa MatrixBase::unaryViewExpr(const CustomUnaryOp &) const, class CwiseUnaryOp
56   */
57 template<typename ViewOp, typename MatrixType>
58 class CwiseUnaryView : public CwiseUnaryViewImpl<ViewOp, MatrixType, typename internal::traits<MatrixType>::StorageKind>
59 {
60   public:
61 
62     typedef typename CwiseUnaryViewImpl<ViewOp, MatrixType,typename internal::traits<MatrixType>::StorageKind>::Base Base;
63     EIGEN_GENERIC_PUBLIC_INTERFACE(CwiseUnaryView)
64     typedef typename internal::ref_selector<MatrixType>::non_const_type MatrixTypeNested;
65     typedef typename internal::remove_all<MatrixType>::type NestedExpression;
66 
67     explicit inline CwiseUnaryView(MatrixType& mat, const ViewOp& func = ViewOp())
68       : m_matrix(mat), m_functor(func) {}
69 
70     EIGEN_INHERIT_ASSIGNMENT_OPERATORS(CwiseUnaryView)
71 
72     EIGEN_STRONG_INLINE Index rows() const { return m_matrix.rows(); }
73     EIGEN_STRONG_INLINE Index cols() const { return m_matrix.cols(); }
74 
75     /** \returns the functor representing unary operation */
76     const ViewOp& functor() const { return m_functor; }
77 
78     /** \returns the nested expression */
79     const typename internal::remove_all<MatrixTypeNested>::type&
80     nestedExpression() const { return m_matrix; }
81 
82     /** \returns the nested expression */
83     typename internal::remove_reference<MatrixTypeNested>::type&
84     nestedExpression() { return m_matrix.const_cast_derived(); }
85 
86   protected:
87     MatrixTypeNested m_matrix;
88     ViewOp m_functor;
89 };
90 
91 // Generic API dispatcher
92 template<typename ViewOp, typename XprType, typename StorageKind>
93 class CwiseUnaryViewImpl
94   : public internal::generic_xpr_base<CwiseUnaryView<ViewOp, XprType> >::type
95 {
96 public:
97   typedef typename internal::generic_xpr_base<CwiseUnaryView<ViewOp, XprType> >::type Base;
98 };
99 
100 template<typename ViewOp, typename MatrixType>
101 class CwiseUnaryViewImpl<ViewOp,MatrixType,Dense>
102   : public internal::dense_xpr_base< CwiseUnaryView<ViewOp, MatrixType> >::type
103 {
104   public:
105 
106     typedef CwiseUnaryView<ViewOp, MatrixType> Derived;
107     typedef typename internal::dense_xpr_base< CwiseUnaryView<ViewOp, MatrixType> >::type Base;
108 
109     EIGEN_DENSE_PUBLIC_INTERFACE(Derived)
110     EIGEN_INHERIT_ASSIGNMENT_OPERATORS(CwiseUnaryViewImpl)
111 
112     EIGEN_DEVICE_FUNC inline Scalar* data() { return &(this->coeffRef(0)); }
113     EIGEN_DEVICE_FUNC inline const Scalar* data() const { return &(this->coeff(0)); }
114 
115     EIGEN_DEVICE_FUNC inline Index innerStride() const
116     {
117       return derived().nestedExpression().innerStride() * sizeof(typename internal::traits<MatrixType>::Scalar) / sizeof(Scalar);
118     }
119 
120     EIGEN_DEVICE_FUNC inline Index outerStride() const
121     {
122       return derived().nestedExpression().outerStride() * sizeof(typename internal::traits<MatrixType>::Scalar) / sizeof(Scalar);
123     }
124 };
125 
126 } // end namespace Eigen
127 
128 #endif // EIGEN_CWISE_UNARY_VIEW_H
129