vec4f.hpp

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/*
 * Author: Sven Gothel <sgothel@jausoft.com>
 * Copyright Gothel Software e.K.
 *
 * SPDX-License-Identifier: MIT
 *
 * This Source Code Form is subject to the terms of the MIT License
 * If a copy of the MIT was not distributed with this file,
 * you can obtain one at https://opensource.org/license/mit/.
 */
 
#ifndef JAU_MATH_VEC4F_HPP_
#define JAU_MATH_VEC4F_HPP_
 
#include <cmath>
#include <cstdarg>
#include <cassert>
#include <limits>
#include <string>
#include <algorithm>
#include <initializer_list>
 
#include <jau/float_math.hpp>
 
#include <iostream>
 
#include <jau/math/vec3f.hpp>
 
namespace jau::math {
 
    /** \addtogroup Math
     *
     *  @{
     */
 
    /**
     * 4D vector using four value_type components.
     *
     * Component and overall alignment is natural as sizeof(value_type),
     * i.e. sizeof(value_type) == alignof(value_type)
     */
    template <typename Value_type,
              std::enable_if_t<std::is_floating_point_v<Value_type> &&
                               sizeof(Value_type) == alignof(Value_type), bool> = true>
    class alignas(sizeof(Value_type)) Vector4F {
        public:
            typedef Value_type               value_type;
            typedef value_type*              pointer;
            typedef const value_type*        const_pointer;
            typedef value_type&              reference;
            typedef const value_type&        const_reference;
            typedef value_type*              iterator;
            typedef const value_type*        const_iterator;
 
            /** value alignment is sizeof(value_type) */
            constexpr static int value_alignment = sizeof(value_type);
 
            /** Number of value_type components  */
            constexpr static const size_t components = 4;
 
            /** Size in bytes with value_alignment */
            constexpr static const size_t byte_size = components * sizeof(value_type);
 
            typedef Vector3F<value_type, std::is_floating_point_v<Value_type>> Vec3;
 
            constexpr static const value_type zero = value_type(0);
            constexpr static const value_type one = value_type(1);
 
            value_type x;
            value_type y;
            value_type z;
            value_type w;
 
            constexpr Vector4F() noexcept
            : x(zero), y(zero), z(zero), w(zero) {}
 
            constexpr Vector4F(const value_type v) noexcept
            : x(v), y(v), z(v), w(v) {}
 
            constexpr Vector4F(const value_type x_, const value_type y_, const value_type z_, const value_type w_) noexcept
            : x(x_), y(y_), z(z_), w(w_) {}
 
            constexpr Vector4F(const Vec3& o3, const value_type w_) noexcept
            : x(o3.x), y(o3.y), z(o3.z), w(w_) {}
 
            constexpr Vector4F(const_iterator v) noexcept
            : x(v[0]), y(v[1]), z(v[2]), w(v[3]) {}
 
            constexpr Vector4F(std::initializer_list<value_type> v) noexcept
            : x(v[0]), y(v[1]), z(v[2]), w(v[3]) {}
 
            constexpr Vector4F(const Vector4F& o) noexcept = default;
            constexpr Vector4F(Vector4F&& o) noexcept = default;
            constexpr Vector4F& operator=(const Vector4F&) noexcept = default;
            constexpr Vector4F& operator=(Vector4F&&) noexcept = default;
 
            constexpr Vector4F copy() noexcept { return Vector4F(*this); }
 
            /** Returns read-only component */
            constexpr value_type operator[](size_t i) const noexcept {
                assert(i < 4);
                return (&x)[i];
            }
 
            explicit operator const_pointer() const noexcept { return &x; }
            constexpr const_iterator cbegin() const noexcept { return &x; }
 
            /** Returns writeable reference to component */
            constexpr reference operator[](size_t i) noexcept {
                assert(i < 4);
                return (&x)[i];
            }
 
            explicit operator pointer() noexcept { return &x; }
            constexpr iterator begin() noexcept { return &x; }
 
            /** xyzw = this, returns xyzw. */
            constexpr iterator get(iterator xyzw) const noexcept
            { xyzw[0] = x; xyzw[1] = y; xyzw[2] = z; xyzw[3] = w; return xyzw; }
 
            /** out = { this.x, this.y, this.z } dropping w, returns out. */
            constexpr Vec3& getVec3(Vec3& out) const noexcept
            { out.x = x; out.y = y; out.z = z; return out; }
 
            constexpr bool operator==(const Vector4F& rhs) const noexcept {
                if (this == &rhs) {
                    return true;
                }
                return jau::is_zero(x - rhs.x) && jau::is_zero(y - rhs.y) &&
                       jau::is_zero(z - rhs.z) && jau::is_zero(w - rhs.w);
            }
            /** TODO
            constexpr std::strong_ordering operator<=>(const vec4f_t& rhs) const noexcept {
                return ...
            } */
 
            /** this = { o, w }, returns this. */
            constexpr Vector4F& set(const Vec3f& o, const value_type w_) noexcept
            { x = o.x; y = o.y; z = o.z; w = w_; return *this; }
 
            constexpr Vector4F& set(const value_type vx, const value_type vy, const value_type vz, const value_type vw) noexcept
            { x=vx; y=vy; z=vz; w=vw; return *this; }
 
            /** this = xyzw, returns this. */
            constexpr Vector4F& set(const_iterator xyzw) noexcept
            { x=xyzw[0]; y=xyzw[1]; z=xyzw[2]; z=xyzw[3]; return *this; }
 
            /** this = this + {d.x, d.y, d.z, d.w}, component wise. Returns this. */
            constexpr Vector4F& add(const Vector4F& d) noexcept
            { x+=d.x; y+=d.y; z+=d.z; w+=d.w; return *this; }
 
            /** this = this + {dx, dy, dz, dw}, component wise. Returns this. */
            constexpr Vector4F& add(const value_type dx, const value_type dy, const value_type dz, const value_type dw) noexcept
            { x+=dx; y+=dy; z+=dz; w+=dw; return *this; }
 
            /** this = this * {s.x, s.y, s.z}, component wise. Returns this. */
            constexpr Vector4F& mul(const Vector4F& s) noexcept
            { x*=s.x; y*=s.y; z*=s.z; w*=s.w; return *this; }
 
            /** this = this * {sx, sy, sz, sw}, component wise. Returns this. */
            constexpr Vector4F& mul(const value_type sx, const value_type sy, const value_type sz, const value_type sw) noexcept
            { x*=sx; y*=sy; z*=sz; w*=sw; return *this; }
 
            /** this = this * s, component wise. Returns this. */
            constexpr Vector4F& scale(const value_type s) noexcept
            { x*=s; y*=s; z*=s; w*=s; return *this; }
 
            /** this = this + rhs, component wise. Returns this. */
            constexpr Vector4F& operator+=(const Vector4F& rhs ) noexcept {
                x+=rhs.x; y+=rhs.y; z+=rhs.z; w+=rhs.w;
                return *this;
            }
 
            /** this = this - rhs, component wise. Returns this. */
            constexpr Vector4F& operator-=(const Vector4F& rhs ) noexcept
            { x-=rhs.x; y-=rhs.y; z-=rhs.z; w-=rhs.w; return *this;
            }
 
            /**
             * this = this * {s.x, s.y, s.z, s.w}, component wise.
             * @param s scale factor
             * @return this instance
             */
            constexpr Vector4F& operator*=(const Vector4F& s) noexcept {
                x*=s.x; y*=s.y; z*=s.z; w*=s.w;
                return *this;
            }
            /**
             * this = this / {s.x, s.y, s.z, s.w}, component wise.
             * @param s scale factor
             * @return this instance
             */
            constexpr Vector4F& operator/=(const Vector4F& s) noexcept {
                x/=s.x; y/=s.y; z/=s.z; w/=s.w;
                return *this;
            }
 
            /**
             * this = this * s, component wise.
             * @param s scale factor
             * @return this instance
             */
            constexpr Vector4F& operator*=(const value_type s ) noexcept
            { x*=s; y*=s; z*=s; w*=s; return *this; }
 
            /**
             * this = this / s, component wise.
             * @param s scale factor
             * @return this instance
             */
            constexpr Vector4F& operator/=(const value_type s ) noexcept
            { x/=s; y/=s; z/=s; w/=s; return *this; }
 
            std::string toString() const noexcept { return std::to_string(x) + ", " + std::to_string(y) + ", " + std::to_string(z) + ", " + std::to_string(w); }
 
            constexpr bool is_zero() const noexcept {
                return jau::is_zero(x) && jau::is_zero(y) && jau::is_zero(z) && jau::is_zero(w);
            }
 
            /**
             * Return the squared length of a vector, a.k.a the squared <i>norm</i> or squared <i>magnitude</i>
             */
            constexpr value_type length_sq() const noexcept {
                return x*x + y*y + z*z + w*w;
            }
 
            /**
             * Return the length of a vector, a.k.a the <i>norm</i> or <i>magnitude</i>
             */
            constexpr value_type length() const noexcept {
                return std::sqrt(length_sq());
            }
 
            /**
             * Normalize this vector in place
             */
            constexpr Vector4F& normalize() noexcept {
                const value_type lengthSq = length_sq();
                if (jau::is_zero(lengthSq)) {
                    x = zero;
                    y = zero;
                    z = zero;
                    w = zero;
                } else {
                    const value_type invSqr = one / std::sqrt(lengthSq);
                    x *= invSqr;
                    y *= invSqr;
                    z *= invSqr;
                    w *= invSqr;
                }
                return *this;
            }
 
            /**
             * Return the squared distance between this vector and the given one.
             * <p>
             * When comparing the relative distance between two points it is usually sufficient to compare the squared
             * distances, thus avoiding an expensive square root operation.
             * </p>
             */
            constexpr value_type dist_sq(const Vector4F& o) const noexcept {
                const value_type dx = x - o.x;
                const value_type dy = y - o.y;
                const value_type dz = z - o.z;
                const value_type dw = w - o.w;
                return dx*dx + dy*dy + dz*dz + dw*dw;
            }
 
            /**
             * Return the distance between this vector and the given one.
             */
            constexpr value_type dist(const Vector4F& o) const noexcept {
                return std::sqrt(dist_sq(o));
            }
 
            constexpr_cxx23 bool intersects(const Vector4F& o) const noexcept {
                const value_type eps = std::numeric_limits<value_type>::epsilon();
                if (std::abs(x - o.x) >= eps || std::abs(y - o.y) >= eps ||
                    std::abs(z - o.z) >= eps || std::abs(w - o.w) >= eps) {
                    return false;
                }
                return true;
            }
    };
 
    template <typename T,
              std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> operator+(const Vector4F<T>& lhs, const Vector4F<T>& rhs) noexcept {
        // Returning a Vector4 object from the returned reference of operator+=()
        // may hinder copy-elision or "named return value optimization" (NRVO).
        // return Vector4<T>(lhs) += rhs;
 
        // Returning named object allows copy-elision (NRVO),
        // only one object is created 'on target'.
        Vector4F<T> r(lhs); r += rhs; return r;
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> operator-(const Vector4F<T>& lhs, const Vector4F<T>& rhs ) noexcept {
        Vector4F<T> r(lhs); r -= rhs; return r;
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> operator-(const Vector4F<T>& lhs) noexcept {
        Vector4F<T> r(lhs);
        r *= -1;
        return r;
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> operator*(const Vector4F<T>& lhs, const T s ) noexcept {
        Vector4F<T> r(lhs); r *= s; return r;
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> operator*(const T s, const Vector4F<T>& rhs) noexcept {
        Vector4F<T> r(rhs); r *= s; return r;
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> operator/(const Vector4F<T>& lhs, const T s ) noexcept {
        Vector4F<T> r(lhs); r /= s; return r;
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> operator/(const T s, const Vector4F<T>& rhs) noexcept {
        Vector4F<T> r(rhs);
        r.x=s/r.x; r.y=s/r.y; r.z=s/r.z; r.w=s/r.w;
        return r;
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> min(const Vector4F<T>& lhs, const Vector4F<T>& rhs) noexcept {
        return Vector4F<T>(std::min(lhs.x, rhs.x), std::min(lhs.y, rhs.y), std::min(lhs.z, rhs.z), std::min(lhs.w, rhs.w));
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> max(const Vector4F<T>& lhs, const Vector4F<T>& rhs) noexcept {
        return Vector4F<T>(std::max(lhs.x, rhs.x), std::max(lhs.y, rhs.y), std::max(lhs.z, rhs.z), std::max(lhs.w, rhs.w));
    }
 
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector4F<T> abs(const Vector4F<T>& lhs) noexcept {
        return Vector4F<T>(std::abs(lhs.x), std::abs(lhs.y), std::abs(lhs.z), std::abs(lhs.w));
    }
 
    /** out = { this.x, this.y, this.z } dropping w, returns out. */
    template<typename T,
             std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    constexpr Vector3F<T> to_vec3(const Vector4F<T>& v) noexcept {
        Vector3F<T> r; v.getVec3(r); return r;
    }
 
    template <typename T,
              std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
    std::ostream& operator<<(std::ostream& out, const Vector4F<T>& v) noexcept {
        return out << v.toString();
    }
 
    static_assert(4 == Vector4F<double>::components);
    static_assert(sizeof(double) == Vector4F<double>::value_alignment);
    static_assert(sizeof(double) == alignof(Vector4F<double>));
    static_assert(sizeof(double) * 4 == Vector4F<double>::byte_size);
    static_assert(sizeof(double) * 4 == sizeof(Vector4F<double>));
 
    typedef Vector4F<float> Vec4f;
    static_assert(4 == Vec4f::components);
    static_assert(sizeof(float) == Vec4f::value_alignment);
    static_assert(sizeof(float) == alignof(Vec4f));
    static_assert(sizeof(float) * 4 == Vec4f::byte_size);
    static_assert(sizeof(float) * 4 == sizeof(Vec4f));
 
    /**
     * Point4F alias of Vector4F
     */
    template <typename Value_type,
              std::enable_if_t<std::is_floating_point_v<Value_type> &&
                               sizeof(Value_type) == alignof(Value_type), bool> = true>
    using Point4F = Vector4F<Value_type>;
 
    typedef Point4F<float> Point4f;
    static_assert(4 == Point4f::components);
    static_assert(sizeof(float) == Point4f::value_alignment);
    static_assert(sizeof(float) == alignof(Point4f));
    static_assert(sizeof(float) * 4 == Point4f::byte_size);
    static_assert(sizeof(float) * 4 == sizeof(Point4f));
 
    /**@}*/
 
}  // namespace jau::math
 
#endif /*  JAU_MATH_VEC4F_HPP_ */