MatrixBlock.h

// -*- mode: c++; c-file-style: "linux"; c-basic-offset: 2; indent-tabs-mode: nil -*-
//
//  Copyright (C) 2026 Gunter Königsmann <wxMaxima@physikbuch.de>
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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//  SPDX-License-Identifier: GPL-2.0+
 
#ifndef MATRIXBLOCK_H
#define MATRIXBLOCK_H
 
#include <algorithm>
#include <cstddef>
 
struct MatrixEntry
{
  std::size_t row = 0;
  std::size_t col = 0;
  bool operator==(const MatrixEntry &) const = default;
};
 
struct MatrixBlock
{
  std::size_t firstRow = 0;
  std::size_t lastRow = 0;
  std::size_t firstCol = 0;
  std::size_t lastCol = 0;
 
  std::size_t Rows() const { return lastRow - firstRow + 1; }
  std::size_t Columns() const { return lastCol - firstCol + 1; }
  bool Contains(std::size_t row, std::size_t col) const {
    return (row >= firstRow) && (row <= lastRow) &&
      (col >= firstCol) && (col <= lastCol);
  }
  bool operator==(const MatrixBlock &) const = default;
 
  static MatrixBlock Spanning(const MatrixEntry &a, const MatrixEntry &b) {
    return MatrixBlock{std::min(a.row, b.row), std::max(a.row, b.row),
                       std::min(a.col, b.col), std::max(a.col, b.col)};
  }
};
 
#endif // MATRIXBLOCK_H