hyperrectangle.hpp

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/*
 * Copyright (C) 2023  Christopher J. Howard
 *
 * This file is part of Antkeeper source code.
 *
 * Antkeeper source code 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Antkeeper source code is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * 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
 * along with Antkeeper source code.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef ANTKEEPER_GEOM_PRIMITIVES_HYPERRECTANGLE_HPP
#define ANTKEEPER_GEOM_PRIMITIVES_HYPERRECTANGLE_HPP
 
#include <engine/math/vector.hpp>
#include <algorithm>
 
namespace geom {
namespace primitives {
 
template <class T, std::size_t N>
struct hyperrectangle
{
    using vector_type = math::vector<T, N>;
    
    vector_type min;
    
    vector_type max;
    
    [[nodiscard]] constexpr bool contains(const vector_type& point) const noexcept
    {
        for (std::size_t i = 0; i < N; ++i)
        {
            if (point[i] < min[i] || point[i] > max[i])
            {
                return false;
            }
        }
        return true;
    }
    
    [[nodiscard]] constexpr bool contains(const hyperrectangle& other) const noexcept
    {
        for (std::size_t i = 0; i < N; ++i)
        {
            if (other.min[i] < min[i] || other.max[i] > max[i])
            {
                return false;
            }
        }
        return true;
    }
    
    [[nodiscard]] inline constexpr vector_type center() const noexcept
    {
        return (min + max) / T{2};
    }
    
    [[nodiscard]] T distance(const vector_type& point) const noexcept
    {
        const vector_type d = math::abs(point - center()) - extents();
        return math::length(math::max(vector_type::zero(), d)) + std::min<T>(T{0}, math::max(d));
    }
    
    void extend(const vector_type& point) noexcept
    {
        min = math::min(min, point);
        max = math::max(max, point);
    }
    
    void extend(const hyperrectangle& other) noexcept
    {
        min = math::min(min, other.min);
        max = math::max(max, other.max);
    }
    
    [[nodiscard]] constexpr bool intersects(const hyperrectangle& other) const noexcept
    {
        for (std::size_t i = 0; i < N; ++i)
        {
            if (other.min[i] > max[i] || other.max[i] < min[i])
            {
                return false;
            }
        }
        return true;
    }
    
    [[nodiscard]] inline constexpr vector_type size() const noexcept
    {
        return max - min;
    }
    
    [[nodiscard]] inline constexpr vector_type extents() const noexcept
    {
        return size() / T{2};
    }
    
    [[nodiscard]] constexpr bool degenerate() const noexcept
    {
        for (std::size_t i = 0; i < N; ++i)
        {
            if (min[i] > max[i])
            {
                return true;
            }
        }
        
        return false;
    }
    
    [[nodiscard]] constexpr T volume() const noexcept
    {
        T v = max[0] - min[0];
        for (std::size_t i = 1; i < N; ++i)
        {
            v *= max[i] - min[i];
        }
        return v;
    }
    
    [[nodiscard]] constexpr vector_type corner(std::size_t index) const noexcept
    {
        vector_type p;
        
        for (std::size_t i = 0; i < N; ++i)
        {
            p[i] = ((index >> ((N - 1) - i)) & 1) ? max[i] : min[i];
        }
        
        return p;
    }
};
 
} // namespace primitives
 
using namespace primitives;
 
} // namespace geom
 
#endif // ANTKEEPER_GEOM_PRIMITIVES_HYPERRECTANGLE_HPP