1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
5// Copyright (C) 2006-2010 Benoit Jacob <jacob.benoit.1@gmail.com>
6//
7// This Source Code Form is subject to the terms of the Mozilla
8// Public License v. 2.0. If a copy of the MPL was not distributed
9// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
10
11#ifndef EIGEN_BLOCK_H
12#define EIGEN_BLOCK_H
13
14namespace Eigen {
15
16/** \class Block
17  * \ingroup Core_Module
18  *
19  * \brief Expression of a fixed-size or dynamic-size block
20  *
21  * \param XprType the type of the expression in which we are taking a block
22  * \param BlockRows the number of rows of the block we are taking at compile time (optional)
23  * \param BlockCols the number of columns of the block we are taking at compile time (optional)
24  *
25  * This class represents an expression of either a fixed-size or dynamic-size block. It is the return
26  * type of DenseBase::block(Index,Index,Index,Index) and DenseBase::block<int,int>(Index,Index) and
27  * most of the time this is the only way it is used.
28  *
29  * However, if you want to directly maniputate block expressions,
30  * for instance if you want to write a function returning such an expression, you
31  * will need to use this class.
32  *
33  * Here is an example illustrating the dynamic case:
34  * \include class_Block.cpp
35  * Output: \verbinclude class_Block.out
36  *
37  * \note Even though this expression has dynamic size, in the case where \a XprType
38  * has fixed size, this expression inherits a fixed maximal size which means that evaluating
39  * it does not cause a dynamic memory allocation.
40  *
41  * Here is an example illustrating the fixed-size case:
42  * \include class_FixedBlock.cpp
43  * Output: \verbinclude class_FixedBlock.out
44  *
45  * \sa DenseBase::block(Index,Index,Index,Index), DenseBase::block(Index,Index), class VectorBlock
46  */
47
48namespace internal {
49template<typename XprType, int BlockRows, int BlockCols, bool InnerPanel>
50struct traits<Block<XprType, BlockRows, BlockCols, InnerPanel> > : traits<XprType>
51{
52  typedef typename traits<XprType>::Scalar Scalar;
53  typedef typename traits<XprType>::StorageKind StorageKind;
54  typedef typename traits<XprType>::XprKind XprKind;
55  typedef typename nested<XprType>::type XprTypeNested;
56  typedef typename remove_reference<XprTypeNested>::type _XprTypeNested;
57  enum{
58    MatrixRows = traits<XprType>::RowsAtCompileTime,
59    MatrixCols = traits<XprType>::ColsAtCompileTime,
60    RowsAtCompileTime = MatrixRows == 0 ? 0 : BlockRows,
61    ColsAtCompileTime = MatrixCols == 0 ? 0 : BlockCols,
62    MaxRowsAtCompileTime = BlockRows==0 ? 0
63                         : RowsAtCompileTime != Dynamic ? int(RowsAtCompileTime)
64                         : int(traits<XprType>::MaxRowsAtCompileTime),
65    MaxColsAtCompileTime = BlockCols==0 ? 0
66                         : ColsAtCompileTime != Dynamic ? int(ColsAtCompileTime)
67                         : int(traits<XprType>::MaxColsAtCompileTime),
68    XprTypeIsRowMajor = (int(traits<XprType>::Flags)&RowMajorBit) != 0,
69    IsDense = is_same<StorageKind,Dense>::value,
70    IsRowMajor = (IsDense&&MaxRowsAtCompileTime==1&&MaxColsAtCompileTime!=1) ? 1
71               : (IsDense&&MaxColsAtCompileTime==1&&MaxRowsAtCompileTime!=1) ? 0
72               : XprTypeIsRowMajor,
73    HasSameStorageOrderAsXprType = (IsRowMajor == XprTypeIsRowMajor),
74    InnerSize = IsRowMajor ? int(ColsAtCompileTime) : int(RowsAtCompileTime),
75    InnerStrideAtCompileTime = HasSameStorageOrderAsXprType
76                             ? int(inner_stride_at_compile_time<XprType>::ret)
77                             : int(outer_stride_at_compile_time<XprType>::ret),
78    OuterStrideAtCompileTime = HasSameStorageOrderAsXprType
79                             ? int(outer_stride_at_compile_time<XprType>::ret)
80                             : int(inner_stride_at_compile_time<XprType>::ret),
81    MaskPacketAccessBit = (InnerSize == Dynamic || (InnerSize % packet_traits<Scalar>::size) == 0)
82                       && (InnerStrideAtCompileTime == 1)
83                        ? PacketAccessBit : 0,
84    MaskAlignedBit = (InnerPanel && (OuterStrideAtCompileTime!=Dynamic) && (((OuterStrideAtCompileTime * int(sizeof(Scalar))) % 16) == 0)) ? AlignedBit : 0,
85    FlagsLinearAccessBit = (RowsAtCompileTime == 1 || ColsAtCompileTime == 1 || (InnerPanel && (traits<XprType>::Flags&LinearAccessBit))) ? LinearAccessBit : 0,
86    FlagsLvalueBit = is_lvalue<XprType>::value ? LvalueBit : 0,
87    FlagsRowMajorBit = IsRowMajor ? RowMajorBit : 0,
88    Flags0 = traits<XprType>::Flags & ( (HereditaryBits & ~RowMajorBit) |
89                                        DirectAccessBit |
90                                        MaskPacketAccessBit |
91                                        MaskAlignedBit),
92    Flags = Flags0 | FlagsLinearAccessBit | FlagsLvalueBit | FlagsRowMajorBit
93  };
94};
95
96template<typename XprType, int BlockRows=Dynamic, int BlockCols=Dynamic, bool InnerPanel = false,
97         bool HasDirectAccess = internal::has_direct_access<XprType>::ret> class BlockImpl_dense;
98
99} // end namespace internal
100
101template<typename XprType, int BlockRows, int BlockCols, bool InnerPanel, typename StorageKind> class BlockImpl;
102
103template<typename XprType, int BlockRows, int BlockCols, bool InnerPanel> class Block
104  : public BlockImpl<XprType, BlockRows, BlockCols, InnerPanel, typename internal::traits<XprType>::StorageKind>
105{
106    typedef BlockImpl<XprType, BlockRows, BlockCols, InnerPanel, typename internal::traits<XprType>::StorageKind> Impl;
107  public:
108    //typedef typename Impl::Base Base;
109    typedef Impl Base;
110    EIGEN_GENERIC_PUBLIC_INTERFACE(Block)
111    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Block)
112
113    /** Column or Row constructor
114      */
115    inline Block(XprType& xpr, Index i) : Impl(xpr,i)
116    {
117      eigen_assert( (i>=0) && (
118          ((BlockRows==1) && (BlockCols==XprType::ColsAtCompileTime) && i<xpr.rows())
119        ||((BlockRows==XprType::RowsAtCompileTime) && (BlockCols==1) && i<xpr.cols())));
120    }
121
122    /** Fixed-size constructor
123      */
124    inline Block(XprType& xpr, Index a_startRow, Index a_startCol)
125      : Impl(xpr, a_startRow, a_startCol)
126    {
127      EIGEN_STATIC_ASSERT(RowsAtCompileTime!=Dynamic && ColsAtCompileTime!=Dynamic,THIS_METHOD_IS_ONLY_FOR_FIXED_SIZE)
128      eigen_assert(a_startRow >= 0 && BlockRows >= 1 && a_startRow + BlockRows <= xpr.rows()
129             && a_startCol >= 0 && BlockCols >= 1 && a_startCol + BlockCols <= xpr.cols());
130    }
131
132    /** Dynamic-size constructor
133      */
134    inline Block(XprType& xpr,
135          Index a_startRow, Index a_startCol,
136          Index blockRows, Index blockCols)
137      : Impl(xpr, a_startRow, a_startCol, blockRows, blockCols)
138    {
139      eigen_assert((RowsAtCompileTime==Dynamic || RowsAtCompileTime==blockRows)
140          && (ColsAtCompileTime==Dynamic || ColsAtCompileTime==blockCols));
141      eigen_assert(a_startRow >= 0 && blockRows >= 0 && a_startRow  <= xpr.rows() - blockRows
142          && a_startCol >= 0 && blockCols >= 0 && a_startCol <= xpr.cols() - blockCols);
143    }
144};
145
146// The generic default implementation for dense block simplu forward to the internal::BlockImpl_dense
147// that must be specialized for direct and non-direct access...
148template<typename XprType, int BlockRows, int BlockCols, bool InnerPanel>
149class BlockImpl<XprType, BlockRows, BlockCols, InnerPanel, Dense>
150  : public internal::BlockImpl_dense<XprType, BlockRows, BlockCols, InnerPanel>
151{
152    typedef internal::BlockImpl_dense<XprType, BlockRows, BlockCols, InnerPanel> Impl;
153    typedef typename XprType::Index Index;
154  public:
155    typedef Impl Base;
156    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(BlockImpl)
157    inline BlockImpl(XprType& xpr, Index i) : Impl(xpr,i) {}
158    inline BlockImpl(XprType& xpr, Index a_startRow, Index a_startCol) : Impl(xpr, a_startRow, a_startCol) {}
159    inline BlockImpl(XprType& xpr, Index a_startRow, Index a_startCol, Index blockRows, Index blockCols)
160      : Impl(xpr, a_startRow, a_startCol, blockRows, blockCols) {}
161};
162
163namespace internal {
164
165/** \internal Internal implementation of dense Blocks in the general case. */
166template<typename XprType, int BlockRows, int BlockCols, bool InnerPanel, bool HasDirectAccess> class BlockImpl_dense
167  : public internal::dense_xpr_base<Block<XprType, BlockRows, BlockCols, InnerPanel> >::type
168{
169    typedef Block<XprType, BlockRows, BlockCols, InnerPanel> BlockType;
170  public:
171
172    typedef typename internal::dense_xpr_base<BlockType>::type Base;
173    EIGEN_DENSE_PUBLIC_INTERFACE(BlockType)
174    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(BlockImpl_dense)
175
176    class InnerIterator;
177
178    /** Column or Row constructor
179      */
180    inline BlockImpl_dense(XprType& xpr, Index i)
181      : m_xpr(xpr),
182        // It is a row if and only if BlockRows==1 and BlockCols==XprType::ColsAtCompileTime,
183        // and it is a column if and only if BlockRows==XprType::RowsAtCompileTime and BlockCols==1,
184        // all other cases are invalid.
185        // The case a 1x1 matrix seems ambiguous, but the result is the same anyway.
186        m_startRow( (BlockRows==1) && (BlockCols==XprType::ColsAtCompileTime) ? i : 0),
187        m_startCol( (BlockRows==XprType::RowsAtCompileTime) && (BlockCols==1) ? i : 0),
188        m_blockRows(BlockRows==1 ? 1 : xpr.rows()),
189        m_blockCols(BlockCols==1 ? 1 : xpr.cols())
190    {}
191
192    /** Fixed-size constructor
193      */
194    inline BlockImpl_dense(XprType& xpr, Index a_startRow, Index a_startCol)
195      : m_xpr(xpr), m_startRow(a_startRow), m_startCol(a_startCol),
196                    m_blockRows(BlockRows), m_blockCols(BlockCols)
197    {}
198
199    /** Dynamic-size constructor
200      */
201    inline BlockImpl_dense(XprType& xpr,
202          Index a_startRow, Index a_startCol,
203          Index blockRows, Index blockCols)
204      : m_xpr(xpr), m_startRow(a_startRow), m_startCol(a_startCol),
205                    m_blockRows(blockRows), m_blockCols(blockCols)
206    {}
207
208    inline Index rows() const { return m_blockRows.value(); }
209    inline Index cols() const { return m_blockCols.value(); }
210
211    inline Scalar& coeffRef(Index rowId, Index colId)
212    {
213      EIGEN_STATIC_ASSERT_LVALUE(XprType)
214      return m_xpr.const_cast_derived()
215               .coeffRef(rowId + m_startRow.value(), colId + m_startCol.value());
216    }
217
218    inline const Scalar& coeffRef(Index rowId, Index colId) const
219    {
220      return m_xpr.derived()
221               .coeffRef(rowId + m_startRow.value(), colId + m_startCol.value());
222    }
223
224    EIGEN_STRONG_INLINE const CoeffReturnType coeff(Index rowId, Index colId) const
225    {
226      return m_xpr.coeff(rowId + m_startRow.value(), colId + m_startCol.value());
227    }
228
229    inline Scalar& coeffRef(Index index)
230    {
231      EIGEN_STATIC_ASSERT_LVALUE(XprType)
232      return m_xpr.const_cast_derived()
233             .coeffRef(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index),
234                       m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
235    }
236
237    inline const Scalar& coeffRef(Index index) const
238    {
239      return m_xpr.const_cast_derived()
240             .coeffRef(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index),
241                       m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
242    }
243
244    inline const CoeffReturnType coeff(Index index) const
245    {
246      return m_xpr
247             .coeff(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index),
248                    m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
249    }
250
251    template<int LoadMode>
252    inline PacketScalar packet(Index rowId, Index colId) const
253    {
254      return m_xpr.template packet<Unaligned>
255              (rowId + m_startRow.value(), colId + m_startCol.value());
256    }
257
258    template<int LoadMode>
259    inline void writePacket(Index rowId, Index colId, const PacketScalar& val)
260    {
261      m_xpr.const_cast_derived().template writePacket<Unaligned>
262              (rowId + m_startRow.value(), colId + m_startCol.value(), val);
263    }
264
265    template<int LoadMode>
266    inline PacketScalar packet(Index index) const
267    {
268      return m_xpr.template packet<Unaligned>
269              (m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index),
270               m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
271    }
272
273    template<int LoadMode>
274    inline void writePacket(Index index, const PacketScalar& val)
275    {
276      m_xpr.const_cast_derived().template writePacket<Unaligned>
277         (m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index),
278          m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0), val);
279    }
280
281    #ifdef EIGEN_PARSED_BY_DOXYGEN
282    /** \sa MapBase::data() */
283    inline const Scalar* data() const;
284    inline Index innerStride() const;
285    inline Index outerStride() const;
286    #endif
287
288    const typename internal::remove_all<typename XprType::Nested>::type& nestedExpression() const
289    {
290      return m_xpr;
291    }
292
293    Index startRow() const
294    {
295      return m_startRow.value();
296    }
297
298    Index startCol() const
299    {
300      return m_startCol.value();
301    }
302
303  protected:
304
305    const typename XprType::Nested m_xpr;
306    const internal::variable_if_dynamic<Index, XprType::RowsAtCompileTime == 1 ? 0 : Dynamic> m_startRow;
307    const internal::variable_if_dynamic<Index, XprType::ColsAtCompileTime == 1 ? 0 : Dynamic> m_startCol;
308    const internal::variable_if_dynamic<Index, RowsAtCompileTime> m_blockRows;
309    const internal::variable_if_dynamic<Index, ColsAtCompileTime> m_blockCols;
310};
311
312/** \internal Internal implementation of dense Blocks in the direct access case.*/
313template<typename XprType, int BlockRows, int BlockCols, bool InnerPanel>
314class BlockImpl_dense<XprType,BlockRows,BlockCols, InnerPanel,true>
315  : public MapBase<Block<XprType, BlockRows, BlockCols, InnerPanel> >
316{
317    typedef Block<XprType, BlockRows, BlockCols, InnerPanel> BlockType;
318  public:
319
320    typedef MapBase<BlockType> Base;
321    EIGEN_DENSE_PUBLIC_INTERFACE(BlockType)
322    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(BlockImpl_dense)
323
324    /** Column or Row constructor
325      */
326    inline BlockImpl_dense(XprType& xpr, Index i)
327      : Base(internal::const_cast_ptr(&xpr.coeffRef(
328              (BlockRows==1) && (BlockCols==XprType::ColsAtCompileTime) ? i : 0,
329              (BlockRows==XprType::RowsAtCompileTime) && (BlockCols==1) ? i : 0)),
330             BlockRows==1 ? 1 : xpr.rows(),
331             BlockCols==1 ? 1 : xpr.cols()),
332        m_xpr(xpr)
333    {
334      init();
335    }
336
337    /** Fixed-size constructor
338      */
339    inline BlockImpl_dense(XprType& xpr, Index startRow, Index startCol)
340      : Base(internal::const_cast_ptr(&xpr.coeffRef(startRow,startCol))), m_xpr(xpr)
341    {
342      init();
343    }
344
345    /** Dynamic-size constructor
346      */
347    inline BlockImpl_dense(XprType& xpr,
348          Index startRow, Index startCol,
349          Index blockRows, Index blockCols)
350      : Base(internal::const_cast_ptr(&xpr.coeffRef(startRow,startCol)), blockRows, blockCols),
351        m_xpr(xpr)
352    {
353      init();
354    }
355
356    const typename internal::remove_all<typename XprType::Nested>::type& nestedExpression() const
357    {
358      return m_xpr;
359    }
360
361    /** \sa MapBase::innerStride() */
362    inline Index innerStride() const
363    {
364      return internal::traits<BlockType>::HasSameStorageOrderAsXprType
365             ? m_xpr.innerStride()
366             : m_xpr.outerStride();
367    }
368
369    /** \sa MapBase::outerStride() */
370    inline Index outerStride() const
371    {
372      return m_outerStride;
373    }
374
375  #ifndef __SUNPRO_CC
376  // FIXME sunstudio is not friendly with the above friend...
377  // META-FIXME there is no 'friend' keyword around here. Is this obsolete?
378  protected:
379  #endif
380
381    #ifndef EIGEN_PARSED_BY_DOXYGEN
382    /** \internal used by allowAligned() */
383    inline BlockImpl_dense(XprType& xpr, const Scalar* data, Index blockRows, Index blockCols)
384      : Base(data, blockRows, blockCols), m_xpr(xpr)
385    {
386      init();
387    }
388    #endif
389
390  protected:
391    void init()
392    {
393      m_outerStride = internal::traits<BlockType>::HasSameStorageOrderAsXprType
394                    ? m_xpr.outerStride()
395                    : m_xpr.innerStride();
396    }
397
398    typename XprType::Nested m_xpr;
399    Index m_outerStride;
400};
401
402} // end namespace internal
403
404} // end namespace Eigen
405
406#endif // EIGEN_BLOCK_H
407