1// Ceres Solver - A fast non-linear least squares minimizer
2// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
3// http://code.google.com/p/ceres-solver/
4//
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are met:
7//
8// * Redistributions of source code must retain the above copyright notice,
9//   this list of conditions and the following disclaimer.
10// * Redistributions in binary form must reproduce the above copyright notice,
11//   this list of conditions and the following disclaimer in the documentation
12//   and/or other materials provided with the distribution.
13// * Neither the name of Google Inc. nor the names of its contributors may be
14//   used to endorse or promote products derived from this software without
15//   specific prior written permission.
16//
17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27// POSSIBILITY OF SUCH DAMAGE.
28//
29// Author: sameeragarwal@google.com (Sameer Agarwal)
30//
31// Block structure objects are used to carry information about the
32// dense block structure of sparse matrices. The BlockSparseMatrix
33// object uses the BlockStructure objects to keep track of the matrix
34// structure and operate upon it. This allows us to use more cache
35// friendly block oriented linear algebra operations on the matrix
36// instead of accessing it one scalar entry at a time.
37
38#ifndef CERES_INTERNAL_BLOCK_STRUCTURE_H_
39#define CERES_INTERNAL_BLOCK_STRUCTURE_H_
40
41#include <vector>
42#include "ceres/internal/port.h"
43#include "ceres/types.h"
44
45namespace ceres {
46namespace internal {
47
48typedef int32 BlockSize;
49
50struct Block {
51  Block() : size(-1), position(-1) {}
52  Block(int size_, int position_) : size(size_), position(position_) {}
53
54  BlockSize size;
55  int position;  // Position along the row/column.
56};
57
58struct Cell {
59  Cell() : block_id(-1), position(-1) {}
60  Cell(int block_id_, int position_)
61      : block_id(block_id_), position(position_) {}
62
63  // Column or row block id as the case maybe.
64  int block_id;
65  // Where in the values array of the jacobian is this cell located.
66  int position;
67};
68
69// Order cell by their block_id;
70bool CellLessThan(const Cell& lhs, const Cell& rhs);
71
72struct CompressedList {
73  Block block;
74  vector<Cell> cells;
75};
76
77typedef CompressedList CompressedRow;
78typedef CompressedList CompressedColumn;
79
80struct CompressedRowBlockStructure {
81  vector<Block> cols;
82  vector<CompressedRow> rows;
83};
84
85struct CompressedColumnBlockStructure {
86  vector<Block> rows;
87  vector<CompressedColumn> cols;
88};
89
90}  // namespace internal
91}  // namespace ceres
92
93#endif  // CERES_INTERNAL_BLOCK_STRUCTURE_H_
94