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Diffstat (limited to 'backend/genesys/utilities.h')
| -rw-r--r-- | backend/genesys/utilities.h | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/backend/genesys/utilities.h b/backend/genesys/utilities.h new file mode 100644 index 0000000..1e268b5 --- /dev/null +++ b/backend/genesys/utilities.h @@ -0,0 +1,180 @@ +/* sane - Scanner Access Now Easy. + + Copyright (C) 2019 Povilas Kanapickas <povilas@radix.lt> + + This file is part of the SANE package. + + 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., 59 Temple Place - Suite 330, Boston, + MA 02111-1307, USA. + + As a special exception, the authors of SANE give permission for + additional uses of the libraries contained in this release of SANE. + + The exception is that, if you link a SANE library with other files + to produce an executable, this does not by itself cause the + resulting executable to be covered by the GNU General Public + License. Your use of that executable is in no way restricted on + account of linking the SANE library code into it. + + This exception does not, however, invalidate any other reasons why + the executable file might be covered by the GNU General Public + License. + + If you submit changes to SANE to the maintainers to be included in + a subsequent release, you agree by submitting the changes that + those changes may be distributed with this exception intact. + + If you write modifications of your own for SANE, it is your choice + whether to permit this exception to apply to your modifications. + If you do not wish that, delete this exception notice. +*/ + +#ifndef BACKEND_GENESYS_UTILITIES_H +#define BACKEND_GENESYS_UTILITIES_H + +#include "error.h" +#include <algorithm> +#include <iostream> +#include <sstream> +#include <vector> + +namespace genesys { + +template<class T> +void compute_array_percentile_approx(T* result, const T* data, + std::size_t line_count, std::size_t elements_per_line, + float percentile) +{ + if (line_count == 0) { + throw SaneException("invalid line count"); + } + + if (line_count == 1) { + std::copy(data, data + elements_per_line, result); + return; + } + + std::vector<T> column_elems; + column_elems.resize(line_count, 0); + + std::size_t select_elem = std::min(static_cast<std::size_t>(line_count * percentile), + line_count - 1); + + auto select_it = column_elems.begin() + select_elem; + + for (std::size_t ix = 0; ix < elements_per_line; ++ix) { + for (std::size_t iy = 0; iy < line_count; ++iy) { + column_elems[iy] = data[iy * elements_per_line + ix]; + } + + std::nth_element(column_elems.begin(), select_it, column_elems.end()); + + *result++ = *select_it; + } +} + +template<class Char, class Traits> +class BasicStreamStateSaver +{ +public: + explicit BasicStreamStateSaver(std::basic_ios<Char, Traits>& stream) : + stream_{stream} + { + flags_ = stream_.flags(); + width_ = stream_.width(); + precision_ = stream_.precision(); + fill_ = stream_.fill(); + } + + ~BasicStreamStateSaver() + { + stream_.flags(flags_); + stream_.width(width_); + stream_.precision(precision_); + stream_.fill(fill_); + } + + BasicStreamStateSaver(const BasicStreamStateSaver&) = delete; + BasicStreamStateSaver& operator=(const BasicStreamStateSaver&) = delete; + +private: + std::basic_ios<Char, Traits>& stream_; + std::ios_base::fmtflags flags_; + std::streamsize width_ = 0; + std::streamsize precision_ = 0; + Char fill_ = ' '; +}; + +using StreamStateSaver = BasicStreamStateSaver<char, std::char_traits<char>>; + +template<class T> +std::string format_indent_braced_list(unsigned indent, const T& x) +{ + std::string indent_str(indent, ' '); + std::ostringstream out; + out << x; + auto formatted_str = out.str(); + if (formatted_str.empty()) { + return formatted_str; + } + + std::string out_str; + for (std::size_t i = 0; i < formatted_str.size(); ++i) { + out_str += formatted_str[i]; + + if (formatted_str[i] == '\n' && + i < formatted_str.size() - 1 && + formatted_str[i + 1] != '\n') + { + out_str += indent_str; + } + } + return out_str; +} + +template<class T> +std::string format_vector_unsigned(unsigned indent, const std::vector<T>& arg) +{ + std::ostringstream out; + std::string indent_str(indent, ' '); + + out << "std::vector<T>{ "; + for (const auto& el : arg) { + out << indent_str << static_cast<unsigned>(el) << "\n"; + } + out << "}"; + return out.str(); +} + +template<class T> +std::string format_vector_indent_braced(unsigned indent, const char* type, + const std::vector<T>& arg) +{ + if (arg.empty()) { + return "{}"; + } + std::string indent_str(indent, ' '); + std::stringstream out; + out << "std::vector<" << type << ">{\n"; + for (const auto& item : arg) { + out << indent_str << format_indent_braced_list(indent, item) << '\n'; + } + out << "}"; + return out.str(); +} + +} // namespace genesys + +#endif // BACKEND_GENESYS_UTILITIES_H |