magnum/src/Math/Vector3.h

#ifndef Magnum_Math_Vector3_h
#define Magnum_Math_Vector3_h
/*
    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>

    This file is part of Magnum.

    Magnum is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License version 3
    only, as published by the Free Software Foundation.

    Magnum 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 Lesser General Public License version 3 for more details.
*/

/** @file
 * @brief Class Magnum::Math::Vector3
 */

#include "Vector2.h"

namespace Magnum { namespace Math {

/**
@brief Three-component vector
@tparam T   Data type

See @ref matrix-vector for brief introduction. See also Point2D for
homogeneous two-dimensional coordinates.
@configurationvalueref{Magnum::Math::Vector3}
*/
template<class T> class Vector3: public Vector<3, T> {
    public:
        /**
         * @brief %Vector in direction of X axis
         *
         * Usable for translation or rotation along given axis, for example:
         * @code
         * Matrix4::translation(Vector3::xAxis(5.0f)); // same as Matrix4::translation({5.0f, 0.0f, 0.0f});
         * Matrix4::rotation(deg(30.0f), Vector3::xAxis()); // same as Matrix::rotation(deg(30.0f), {1.0f, 0.0f, 0.0f});
         * @endcode
         * @see yAxis(), zAxis(), xScale()
         */
        inline constexpr static Vector3<T> xAxis(T length = T(1)) { return Vector3<T>(length, T(), T()); }

        /**
         * @brief %Vector in direction of Y axis
         *
         * See xAxis() for more information.
         * @see yScale()
         */
        inline constexpr static Vector3<T> yAxis(T length = T(1)) { return Vector3<T>(T(), length, T()); }

        /**
         * @brief %Vector in direction of Z axis
         *
         * See xAxis() for more information.
         * @see zScale()
         */
        inline constexpr static Vector3<T> zAxis(T length = T(1)) { return Vector3<T>(T(), T(), length); }

        /**
         * @brief Scaling vector in direction of X axis
         *
         * Usable for scaling along given direction, for example:
         * @code
         * Matrix4::scaling(Vector3::xScale(-2.0f)); // same as Matrix4::scaling({-2.0f, 1.0f, 1.0f});
         * @endcode
         * @see yScale(), zScale(), xAxis()
         */
        inline constexpr static Vector3<T> xScale(T scale) { return Vector3<T>(scale, T(1), T(1)); }

        /**
         * @brief Scaling vector in direction of Y axis
         *
         * See xScale() for more information.
         * @see yAxis()
         */
        inline constexpr static Vector3<T> yScale(T scale) { return Vector3<T>(T(1), scale, T(1)); }

        /**
         * @brief Scaling vector in direction of Z axis
         *
         * See xScale() for more information.
         * @see zAxis()
         */
        inline constexpr static Vector3<T> zScale(T scale) { return Vector3<T>(T(1), T(1), scale); }

        /**
         * @brief Cross product
         *
         * @f[
         * \begin{pmatrix} c_0 \\ c_1 \\ c_2 \end{pmatrix} =
         * \begin{pmatrix}a_1b_2 - a_2b_1 \\ a_2b_0 - a_0b_2 \\ a_0b_1 - a_1b_0 \end{pmatrix}
         * @f]
         */
        inline constexpr static Vector3<T> cross(const Vector3<T>& a, const Vector3<T>& b) {
            return Vector3<T>(a[1]*b[2]-a[2]*b[1],
                              a[2]*b[0]-a[0]*b[2],
                              a[0]*b[1]-a[1]*b[0]);
        }

        /** @copydoc Vector::Vector() */
        inline constexpr Vector3() {}

        /** @copydoc Vector::Vector(T) */
        inline constexpr explicit Vector3(T value): Vector<3, T>(value, value, value) {}

        /** @brief Copy constructor */
        inline constexpr Vector3(const RectangularMatrix<1, 3, T>& other): Vector<3, T>(other) {}

        /**
         * @brief Constructor
         * @param x     X component
         * @param y     Y component
         * @param z     Z component
         */
        inline constexpr Vector3(T x, T y, T z): Vector<3, T>(x, y, z) {}

        /**
         * @brief Constructor
         * @param xy    Two-component vector
         * @param z     Z component
         */
        inline constexpr Vector3(const Vector<2, T>& xy, T z): Vector<3, T>(xy[0], xy[1], z) {}

        inline T& x() { return (*this)[0]; }                /**< @brief X component */
        inline constexpr T x() const { return (*this)[0]; } /**< @overload */
        inline T& y() { return (*this)[1]; }                /**< @brief Y component */
        inline constexpr T y() const { return (*this)[1]; } /**< @overload */
        inline T& z() { return (*this)[2]; }                /**< @brief Z component */
        inline constexpr T z() const { return (*this)[2]; } /**< @overload */

        /**
         * @brief XY part of the vector
         * @return First two components of the vector
         *
         * @see swizzle()
         */
        inline Vector2<T>& xy() { return Vector2<T>::from(Vector<3, T>::data()); }
        inline constexpr Vector2<T> xy() const { return Vector2<T>::from(Vector<3, T>::data()); } /**< @overload */

        MAGNUM_VECTOR_SUBCLASS_IMPLEMENTATION(Vector3, 3)
        MAGNUM_RECTANGULARMATRIX_SUBCLASS_OPERATOR_IMPLEMENTATION(1, 3, Vector3<T>)
};

MAGNUM_VECTOR_SUBCLASS_OPERATOR_IMPLEMENTATION(Vector3, 3)

/** @debugoperator{Magnum::Math::Vector3} */
template<class T> Corrade::Utility::Debug operator<<(Corrade::Utility::Debug debug, const Magnum::Math::Vector3<T>& value) {
    return debug << static_cast<const Magnum::Math::Vector<3, T>&>(value);
}

}}

namespace Corrade { namespace Utility {
    /** @configurationvalue{Magnum::Math::Vector3} */
    template<class T> struct ConfigurationValue<Magnum::Math::Vector3<T>>: public ConfigurationValue<Magnum::Math::Vector<3, T>> {};
}}

#endif