sub_grid.cpp

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#include <nav_grid_iterators/sub_grid.h>

namespace nav_grid_iterators
{
SubGrid::SubGrid(const nav_grid::NavGridInfo* info, const nav_grid::Index& index,
                 unsigned int min_x, unsigned int min_y,
                 unsigned int width, unsigned int height)
  : BaseIterator(info, index), min_x_(min_x), min_y_(min_y), width_(width), height_(height)
{
  // If the start coordinate is entirely off the grid or the size is 0
  // we invalidate the entire iterator and give up immediately
  if (min_x_ >= info->width || min_y_ >= info->height || width_ == 0 || height_ == 0)
  {
    index_ = nav_grid::Index(0, 0);
    width_ = 0;
    height_ = 0;
    min_x_ = 0;
    min_y_ = 0;
    return;
  }

  // If the end coordinate is off the grid, we shorten the dimensions to
  // cover the on-grid potion
  if (min_x_ + width_ > info->width)
  {
    width_ = info->width - min_x_;
  }
  if (min_y_ + height_ > info->height)
  {
    height_ = info->height - min_y_;
  }
}

SubGrid SubGrid::begin() const
{
  return SubGrid(info_, min_x_, min_y_, width_, height_);
}

SubGrid SubGrid::end() const
{
  return SubGrid(info_, nav_grid::Index(min_x_, min_y_ + height_), min_x_, min_y_, width_, height_);
}

void SubGrid::increment()
{
  ++index_.x;
  if (index_.x >= min_x_ + width_)
  {
    index_.x = min_x_;
    ++index_.y;
  }
}

bool SubGrid::fieldsEqual(const SubGrid& other)
{
  return min_x_ == other.min_x_ && min_y_ == other.min_y_ && width_ == other.width_ && height_ == other.height_;
}

}  // namespace nav_grid_iterators