AABB.h

#pragma once
#include <algorithm>
#include <limits>

namespace WorldStone
{
template<typename T>
struct AABB
{
    T xLower; 
    T yLower; 
    T xUpper; 
    T yUpper; 

    T width() const { return xUpper - xLower; }
    T height() const { return yUpper - yLower; }

    void maximize()
    {
        xLower = std::numeric_limits<T>::lowest();
        yLower = std::numeric_limits<T>::lowest();
        xUpper = std::numeric_limits<T>::max();
        yUpper = std::numeric_limits<T>::max();
    }

    void initializeForExtension() { *this = AABB::getInitializedForExtension(); }

    void extend(const AABB& other)
    {
        xLower = std::min(xLower, other.xLower);
        yLower = std::min(yLower, other.yLower);
        xUpper = std::max(xUpper, other.xUpper);
        yUpper = std::max(yUpper, other.yUpper);
    }

    static constexpr AABB getInitializedForExtension()
    {
        return {std::numeric_limits<T>::max(), std::numeric_limits<T>::max(),
                std::numeric_limits<T>::lowest(), std::numeric_limits<T>::lowest()};
    }
};
}