QuadTreeNode.hpp

/* Copyright (c) 2012 David Sichau <mail"at"sichau"dot"eu>

   Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the
   "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish,
   distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to
   the following conditions:

   The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
   LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
   NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef UTILLIB_GEOMETRY_QUADTREENODE_HPP
#define UTILLIB_GEOMETRY_QUADTREENODE_HPP

#include <UtilLib/include/geometry/Rectangle.hpp>
#include <UtilLib/include/Log.hpp>
#include <algorithm>
#include <array>
#include <memory>
#include <vector>


namespace UtilLib {
namespace geometry {
template<class Node>
class QuadTreeNode {
 public:
    explicit QuadTreeNode(
            const Rectangle& rect,
            int maximumItems);

    ~QuadTreeNode();

    bool put(std::shared_ptr<Node> pt);

    std::vector<std::shared_ptr<Node> >& get(
            const Rectangle& rect,
            std::vector<std::shared_ptr<Node> >& vector);

 private:
    void split();

    QuadTreeNode* getChild(
            double x,
            double y);

    bool hasChildren();

    enum Regions {NORTHWEST = 0, NORTHEAST = 1, SOUTHEAST = 2, SOUTHWEST = 3};

    std::vector<std::shared_ptr<Node> > items_;

    std::array<QuadTreeNode*, 4>* children_;

    unsigned int maxItems_;
    Rectangle bounds_;

    const double minSize_;
};

template<class Node>
QuadTreeNode<Node>::QuadTreeNode(
        const Rectangle& rect,
        int maximumItems) : children_(nullptr),
                            maxItems_(maximumItems),
                            bounds_(rect),
                            minSize_(1E-4) {
    LOG(UtilLib::logDEBUG2) << "new node generated with boarder n: " <<
    bounds_.north << " s: " << bounds_.south << " w: " <<
    bounds_.west << " e: " << bounds_.east;
}

template<class Node>
QuadTreeNode<Node>::~QuadTreeNode() {
    if (children_ != nullptr) {
        for (const auto& child :* children_) {
            delete child;
        }
        delete children_;
        children_ = nullptr;
    }
}

template<class Node>
bool QuadTreeNode<Node>::hasChildren() {
    return children_ != nullptr;
}

template<class Node>
void QuadTreeNode<Node>::split() {
    if ((std::abs(bounds_.north - bounds_.south) < minSize_) &&
        (std::abs(bounds_.east - bounds_.west) < minSize_) ) {
        LOG(UtilLib::logDEBUG4) << "below min size therefore no split";

        return;
    }

    LOG(UtilLib::logDEBUG4) << "split executed";

    double nsHalf =
        static_cast<double>(bounds_.north -
                            (bounds_.north - bounds_.south) / 2.0);
    double ewHalf =
        static_cast<double>(bounds_.east - (bounds_.east - bounds_.west) / 2.0);

    children_ = new std::array<QuadTreeNode*, 4>;

    (*children_)[NORTHWEST] =
        new QuadTreeNode(Rectangle(bounds_.north, nsHalf, bounds_.west,
                        ewHalf), maxItems_);
    (*children_)[NORTHEAST] =
        new QuadTreeNode(Rectangle(bounds_.north, nsHalf, ewHalf,
                        bounds_.east), maxItems_);
    (*children_)[SOUTHEAST] =
        new QuadTreeNode(Rectangle(nsHalf, bounds_.south, ewHalf,
                        bounds_.east), maxItems_);
    (*children_)[SOUTHWEST] =
        new QuadTreeNode(Rectangle(nsHalf, bounds_.south, bounds_.west,
                        ewHalf), maxItems_);

    for (auto item : items_) {
        put(item);
    }
    items_.clear();
}

template<class Node>
QuadTreeNode<Node>* QuadTreeNode<Node>::getChild(
        double x,
        double y)
{
    if (bounds_.pointWithinBounds(x, y))
    {
        if (children_ != nullptr) {
            for (QuadTreeNode<Node>* child :* children_)
            {
                if (child->bounds_.pointWithinBounds(x, y))
                    return child->getChild(x, y);
            }
        } else {
            return this;  // no children, x, y here...
        }
    }
    return nullptr;
}

template<class Node>
bool QuadTreeNode<Node>::put(std::shared_ptr<Node> pt) {
    if (children_ == nullptr) {
        items_.push_back(pt);
        if (items_.size() > maxItems_)
            split();

        return true;
    } else {
        QuadTreeNode* node = getChild(pt->getXPos(), pt->getYPos());
        if (node != nullptr) {
            return node->put(pt);
        }
    }
    return false;
}

template<class Node>
std::vector<std::shared_ptr<Node> >& QuadTreeNode<Node>::get(
        const Rectangle& rect,
        std::vector<std::shared_ptr<Node> >& vector) {
    if (children_ == nullptr) {
        for (std::shared_ptr<Node> pt : items_) {
            if (rect.pointWithinBounds(pt->getXPos(), pt->getYPos())) {
                vector.push_back(pt);
                LOG(UtilLib::logDEBUG4) << "point added: " << pt->getXPos() <<
                " " << pt->getYPos();
            }
        }
    } else {
        for (QuadTreeNode* child :* children_) {
            if (child->bounds_.within(rect)) {
                LOG(UtilLib::logDEBUG4) << "went to children";
                child->get(rect, vector);
            }
        }
    }
    return vector;
}
}   // end namepace
}  // end namepace

#endif  // UTILLIB_GEOMETRY_QUADTREENODE_HPP