BoundingBox.hpp

//---- GPL ---------------------------------------------------------------------
//
// Copyright (C)  Stichting Deltares, 2011-2021.
//
// 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 version 3.
//
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// 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
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//------------------------------------------------------------------------------
 
#pragma once
 
#include "MeshKernel/Point.hpp"
 
#include <algorithm>
#include <limits>
 
namespace meshkernel
{
 
    class BoundingBox
    {
    public:
        BoundingBox() : m_lowerLeft(std::numeric_limits<double>::lowest(), std::numeric_limits<double>::lowest()),
                        m_upperRight(std::numeric_limits<double>::max(), std::numeric_limits<double>::max()) {}
 
        BoundingBox(const Point& lowerLeft, const Point& upperRight)
            : m_lowerLeft(lowerLeft),
              m_upperRight(upperRight)
        {
        }
 
        template <typename T>
        explicit BoundingBox(const std::vector<T>& points)
        {
            Reset(points);
        }
 
        template <typename T>
        void Reset(const std::vector<T>& points);
 
        template <typename T>
        void Reset(const std::vector<T>& points, size_t start, size_t end);
 
        template <typename T>
        BoundingBox(const std::vector<T>& points, size_t start, size_t end)
        {
            Reset(points, start, end);
        }
 
        bool operator!=(const BoundingBox& other) const
        {
            return other.m_lowerLeft != m_lowerLeft || other.m_upperRight != m_upperRight;
        }
 
        template <typename T>
        bool Contains(const T& point) const
        {
 
            return point.x >= m_lowerLeft.x && point.x <= m_upperRight.x &&
                   point.y >= m_lowerLeft.y && point.y <= m_upperRight.y;
        }
 
        bool Overlaps(const BoundingBox& boundingBox) const;
 
        [[nodiscard]] auto& lowerLeft() const { return m_lowerLeft; }
 
        [[nodiscard]] auto& upperRight() const { return m_upperRight; }
 
        Point MassCentre() const { return (m_lowerLeft + m_upperRight) * 0.5; }
 
        double Width() const { return m_upperRight.x - m_lowerLeft.x; }
 
        double Height() const { return m_upperRight.y - m_lowerLeft.y; }
 
        void Extend(double factor)
        {
            // TODO should check that the BB does not cover the entire fp space.
            const double width = Width();
            const double height = Height();
            m_lowerLeft.x -= width * factor;
            m_lowerLeft.y -= height * factor;
            m_upperRight.x += width * factor;
            m_upperRight.y += height * factor;
        }
 
        Vector Delta() const;
 
        template <std::derived_from<Point> T>
        static BoundingBox CreateBoundingBox(const T& first, const T& second)
        {
            const auto lowerLeftX = std::min(first.x, second.x);
            const auto lowerLeftY = std::min(first.y, second.y);
            const auto upperRightX = std::max(first.x, second.x);
            const auto upperRightY = std::max(first.y, second.y);
 
            return BoundingBox({lowerLeftX, lowerLeftY}, {upperRightX, upperRightY});
        }
 
    private:
        Point m_lowerLeft;  
        Point m_upperRight; 
    };
 
    static BoundingBox Merge(const BoundingBox& b1, const BoundingBox& b2);
 
    static BoundingBox CreateNonOverlappingBoundingBox();
 
} // namespace meshkernel
 
template <typename T>
void meshkernel::BoundingBox::Reset(const std::vector<T>& points)
{
 
    if (points.size() > 0)
    {
        Reset(points, 0, points.size() - 1);
    }
    else
    {
        m_lowerLeft = Point(std::numeric_limits<double>::lowest(), std::numeric_limits<double>::lowest());
        m_upperRight = Point(std::numeric_limits<double>::max(), std::numeric_limits<double>::max());
    }
 
} // namespace meshkernel
 
template <typename T>
void meshkernel::BoundingBox::Reset(const std::vector<T>& points, size_t start, size_t end)
{
    double minx = std::numeric_limits<double>::max();
    double maxx = std::numeric_limits<double>::lowest();
    double miny = std::numeric_limits<double>::max();
    double maxy = std::numeric_limits<double>::lowest();
 
    for (size_t i = start; i <= end; ++i)
    {
        const auto& point = points[i];
 
        if (point.IsValid())
        {
            minx = std::min(minx, point.x);
            maxx = std::max(maxx, point.x);
            miny = std::min(miny, point.y);
            maxy = std::max(maxy, point.y);
        }
    }
    m_lowerLeft = Point(minx, miny);
    m_upperRight = Point(maxx, maxy);
}
 
meshkernel::BoundingBox meshkernel::Merge(const BoundingBox& b1, const BoundingBox& b2)
{
    Point lowerLeft{std::min(b1.lowerLeft().x, b2.lowerLeft().x), std::min(b1.lowerLeft().y, b2.lowerLeft().y)};
    Point upperRight{std::max(b1.upperRight().x, b2.upperRight().x), std::max(b1.upperRight().y, b2.upperRight().y)};
 
    return {lowerLeft, upperRight};
}
 
meshkernel::BoundingBox meshkernel::CreateNonOverlappingBoundingBox()
{
    Point lowerLeft(std::numeric_limits<double>::max(), std::numeric_limits<double>::max());
    Point upperRight(std::numeric_limits<double>::lowest(), std::numeric_limits<double>::lowest());
    return {lowerLeft, upperRight};
}
 
inline meshkernel::Vector meshkernel::BoundingBox::Delta() const
{
    return Vector(m_upperRight.x - m_lowerLeft.x, m_upperRight.y - m_lowerLeft.y);
}
 
inline bool meshkernel::BoundingBox::Overlaps(const BoundingBox& other) const
{
    const auto& otherLowerleft = other.lowerLeft();
    const auto& otherUpperRight = other.upperRight();
    if (m_upperRight.x < otherLowerleft.x ||
        otherUpperRight.x < m_lowerLeft.x ||
        m_upperRight.y < otherLowerleft.y ||
        otherUpperRight.y < m_lowerLeft.y)
    {
        return false;
    }
 
    return true;
}