KSG-Framework/Vec2.h

#ifndef Vec2_H
#define Vec2_H

#include "FrameworkMath.h"

namespace Framework
{
    //! A two-dimensional vector
    template<typename T> class Vec2
    {
    public:
        T x; //! x component of the vector
        T y; //! y component of the vector

        //! Constructor
        inline Vec2() noexcept
            : x(0),
              y(0)
        {}

        //! Constructor
        //! \param x X component of the vector
        //! \param y Y component of the vector
        inline Vec2(T x, T y)
            : x(x),
              y(y)
        {}

        //! Constructor
        //! \param vect A vector whose components are adopted
        inline Vec2(const Vec2& vect)
            : x((T)vect.x),
              y((T)vect.y)
        {}

        //! Scales the vector so that it has length 1
        inline Vec2& normalize()
        {
            const T length = getLength();
            x /= length;
            y /= length;
            return *this;
        }

        //! Rotates the vector 90 degrees counter-clockwise
        inline Vec2& CCW90()
        {
            T temp = y;
            y = -x;
            x = temp;
            return *this;
        }

        //! Rotates the vector 90 degrees clockwise
        inline Vec2& CW90()
        {
            T temp = y;
            y = x;
            x = -temp;
            return *this;
        }

        //! Swaps the values of the vectors
        //! \param vect The vector to swap with
        inline Vec2& Swap(Vec2& vect)
        {
            const Vec2 tmp = vect;
            vect = *this;
            *this = tmp;
            return *this;
        }

        //! Adopts the values of another vector
        //! \param r The other vector
        inline Vec2 operator=(const Vec2& r)
        {
            x = r.x;
            y = r.y;
            return *this;
        }

        //! Adds another vector to this one
        //! \param r The other vector
        inline Vec2 operator+=(const Vec2& r)
        {
            x += r.x;
            y += r.y;
            return *this;
        }

        //! Subtracts another vector from this one
        //! \param r The other vector
        inline Vec2 operator-=(const Vec2& r)
        {
            x -= r.x;
            y -= r.y;
            return *this;
        }

        //! Scales this vector by a scalar
        //! \param r The scalar
        inline Vec2 operator*=(const T& r)
        {
            x *= r;
            y *= r;
            return *this;
        }

        //! Divides this vector by a scalar
        //! \param r The scalar
        inline Vec2 operator/=(const T& r)
        {
            x /= r;
            y /= r;
            return *this;
        }

        //! Negates the vector
        inline Vec2 operator-() const
        {
            return Vec2<T>(-x, -y);
        }

        //! Converts the vector to a vector of another type
        template<typename T2> inline operator Vec2<T2>() const
        {
            return Vec2<T2>((T2)x, (T2)y);
        }

        //! Calculates the square of the vector's length
        inline T getLengthSq() const
        {
            return *this * *this;
        }

        //! Calculates the length of the vector
        inline T getLength() const
        {
            return (T)sqrt(getLengthSq());
        }

        //! Calculates the dot product between two vectors
        //! \param r The other vector
        inline T operator*(const Vec2& r) const
        {
            return x * r.x + y * r.y;
        }

        //! Adds two vectors
        //! \param r The other vector
        inline Vec2 operator+(const Vec2& r) const
        {
            return Vec2(*this) += r;
        }

        //! Subtracts two vectors
        //! \param r The other vector
        inline Vec2 operator-(const Vec2& r) const
        {
            return Vec2(*this) -= r;
        }

        //! Multiplies the components of two vectors
        //! \param r The other vector
        inline Vec2 operator*(const T& r) const
        {
            return Vec2(*this) *= r;
        }

        //! Divides the components of two vectors
        //! \param r The other vector
        inline Vec2 operator/(const T& r) const
        {
            return Vec2(*this) /= r;
        }

        //! Checks whether the vector is in the rectangle between two vectors
        //!  p1: A vector to one corner of the rectangle
        //!  p2: A vector to the opposite corner of the rectangle
        inline bool isInRegion(const Vec2& p1, const Vec2& p2) const
        {
            const T medianX = (T)((p1.x + p2.x) / 2.0);
            const T medianY = (T)((p1.y + p2.y) / 2.0);
            return abs<T>(medianX - x) <= abs<T>(medianX - p1.x)
                && abs<T>(medianY - y) <= abs<T>(medianY - p1.y);
        }

        //! Checks two vectors for equality
        //! \param r The other vector
        inline bool operator==(const Vec2& r) const
        {
            return x == r.x && y == r.y;
        }

        //! Checks two vectors for inequality
        //! \param r The other vector
        inline bool operator!=(const Vec2& r) const
        {
            return !(*this == r);
        }

        //! Calculates the midpoint between two vectors
        //!  p2: The other vector
        inline Vec2 centerWith(const Vec2& p2) const
        {
            return Vec2((T)((x + p2.x) / 2.0), (T)((y + p2.y) / 2.0));
        }

        //! Rotates the vector counter-clockwise
        //! \param angle The angle in radians
        inline Vec2 rotation(const float angle) const
        {
            Vec2 result;
            float cosine = lowPrecisionCos(angle);
            float sine = lowPrecisionSin(angle);
            result.x = (T)(x * cosine - y * sine);
            result.y = (T)(x * sine + y * cosine);
            return result;
        }

        //! Determines the angle between two vectors
        inline T angle(const Vec2& v2) const
        {
            return (T)atan2((float)(x * v2.y - y * v2.x), (float)(*this * v2));
        }
    };
} // namespace Framework

#endif