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3rdparty/boost_1_81_0/libs/gil/example/hvstack.hpp 3.86 KB
977ed18d   Hu Chunming   提交三方库
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  //
  // // Copyright 2021 Olzhas Zhumabek <anonymous.from.applecity@gmail.com>
  //
  // Distributed under the Boost Software License, Version 1.0
  // See accompanying file LICENSE_1_0.txt or copy at
  // http://www.boost.org/LICENSE_1_0.txt
  //
  
  #include "boost/gil/image_view_factory.hpp"
  #include <boost/gil/image.hpp>
  #include <boost/gil/image_view.hpp>
  #include <cmath>
  #include <numeric>
  #include <stdexcept>
  #include <vector>
  
  namespace boost { namespace gil {
  template <typename View>
  void hstack(const std::vector<View>& views, const View& output_view)
  {
      if (views.size() == 0)
      {
          throw std::invalid_argument("empty views vector is passed - cannot create stacked image");
      }
  
      auto height = views.front().height();
      for (const auto& view : views)
      {
          if (view.height() != height)
          {
              throw std::invalid_argument("one or many views are not of the same height");
          }
      }
  
      std::ptrdiff_t full_width =
          std::accumulate(views.begin(), views.end(), 0,
                          [](std::ptrdiff_t old, const View& view) { return old + view.width(); });
      if (output_view.width() != full_width || output_view.height() != height)
      {
          throw std::invalid_argument("the destination view is not of the right dimensions");
      }
  
      std::ptrdiff_t current_x = 0;
      for (std::size_t i = 0; i < views.size(); ++i)
      {
          auto subview =
              subimage_view(output_view, current_x, 0, views[i].width(), views[i].height());
          copy_pixels(views[i], subview);
          current_x += views[i].width();
      }
  }
  
  template <typename View>
  image<typename View::value_type> hstack(const std::vector<View>& views)
  {
      if (views.size() == 0)
      {
          throw std::invalid_argument("empty views vector is passed - cannot create stacked image");
      }
  
      std::ptrdiff_t full_width =
          std::accumulate(views.begin(), views.end(), 0,
                          [](std::ptrdiff_t old, const View& view) { return old + view.width(); });
      std::ptrdiff_t height = views.front().height();
      image<typename View::value_type> result_image(full_width, height);
      hstack(views, view(result_image));
      return result_image;
  }
  
  template <typename View>
  void vstack(const std::vector<View>& views, const View& output_view)
  {
      if (views.size() == 0)
      {
          throw std::invalid_argument("empty views vector is passed - cannot create stacked image");
      }
  
      auto full_height =
          std::accumulate(views.begin(), views.end(), 0,
                          [](std::ptrdiff_t old, const View& view) { return old + view.height(); });
      std::ptrdiff_t width = views.front().height();
  
      for (const auto& view : views)
      {
          if (view.width() != width)
          {
              throw std::invalid_argument("one or many views are not of the same width");
          }
      }
  
      if (output_view != full_height || output_view.width() != width)
      {
          throw std::invalid_argument("the destination view is not of the right dimensions");
      }
  
      std::ptrdiff_t current_y = 0;
      for (std::size_t i = 0; i < views.size(); ++i)
      {
          auto subview =
              subimage_view(output_view, 0, current_y, views[i].width(), views[i].height());
          copy_pixels(views[i], subview);
          current_y += views[i].height();
      }
  }
  
  template <typename View>
  image<typename View::value_type> vstack(const std::vector<View>& views)
  {
      if (views.size() == 0)
      {
          throw std::invalid_argument("empty views vector is passed - cannot create stacked image");
      }
  
      auto full_height =
          std::accumulate(views.begin(), views.end(), 0,
                          [](std::ptrdiff_t old, const View& view) { return old + view.height(); });
      std::ptrdiff_t width = views.front().height();
  
      image<typename View::value_type> result_image(width, full_height);
      hstack(views, view(result_image));
      return result_image;
  }
  }} // namespace boost::gil