vec2.h

/*
**  ClanLib SDK
**  Copyright (c) 1997-2020 The ClanLib Team
**
**  This software is provided 'as-is', without any express or implied
**  warranty.  In no event will the authors be held liable for any damages
**  arising from the use of this software.
**
**  Permission is granted to anyone to use this software for any purpose,
**  including commercial applications, and to alter it and redistribute it
**  freely, subject to the following restrictions:
**
**  1. The origin of this software must not be misrepresented; you must not
**     claim that you wrote the original software. If you use this software
**     in a product, an acknowledgment in the product documentation would be
**     appreciated but is not required.
**  2. Altered source versions must be plainly marked as such, and must not be
**     misrepresented as being the original software.
**  3. This notice may not be removed or altered from any source distribution.
**
**  Note: Some of the libraries ClanLib may link to may have additional
**  requirements or restrictions.
**
**  File Author(s):
**
**    Magnus Norddahl
**    Mark Page
**    Harry Storbacka
*/

#pragma once

#include <cmath>
#include "vec3.h"
#include "vec4.h"
#include "origin.h"

namespace clan
{

        template<typename Type>
        class Vec2;

        template<typename Type>
        class Vec3;

        template<typename Type>
        class Vec4;

        template<typename Type>
        class Mat2;

        template<typename Type>
        class Mat3;

        template<typename Type>
        class Mat4;

        template<typename Type>
        class Sizex;

        template<typename Type>
        class Pointx;

        class Angle;

        template<typename Type>
        class Vec2
        {
        public:
                typedef Type datatype;

                union { Type x; Type s; Type r; };
                union { Type y; Type t; Type g; };

                Vec2() : x(0), y(0) { }
                explicit Vec2(const Type &scalar) : x(scalar), y(scalar) { }
                explicit Vec2(const Vec3<Type> &copy) : x(copy.x), y(copy.y) {}
                explicit Vec2(const Vec4<Type> &copy) : x(copy.x), y(copy.y) {}
                explicit Vec2(const Type &p1, const Type &p2) : x(p1), y(p2) { }
                explicit Vec2(const Type *array_xy) : x(array_xy[0]), y(array_xy[1]) { }

                Vec2(const Vec2<Type> &copy) = default;

                template<typename OtherType, typename std::enable_if_t<std::is_integral<Type>::value && !std::is_integral<OtherType>::value, int> = 0>
                Vec2(const Vec2<OtherType>& copy) : x(static_cast<Type>(std::floor(copy.x + 0.5f))), y(static_cast<Type>(std::floor(copy.y + 0.5f))) {}

                template<typename OtherType, typename std::enable_if_t<!std::is_integral<Type>::value || std::is_integral<OtherType>::value, int> = 0>
                Vec2(const Vec2<OtherType>& copy) : x(static_cast<Type>(copy.x)), y(static_cast<Type>(copy.y)) {}

                static Vec2<Type> normalize(const Vec2<Type>& vector);

                static Type dot(const Vec2<Type>& vector_1, const Vec2<Type>& vector_2) { return vector_1.x*vector_2.x + vector_1.y*vector_2.y; }

                static Vec2<Type> round(const Vec2<Type>& vector);

                static Vec2<Type> rotate(const Vec2<Type>& vector, const Vec2<Type>& hotspot, const Angle &angle);

                static Pointx<Type> calc_origin(Origin origin, const Sizex<Type> &size);

                static bool is_equal(const Vec2<Type> &first, const Vec2<Type> &second, Type epsilon)
                {
                        Type diff_x = second.x - first.x; Type diff_y = second.y - first.y;
                        return (diff_x >= -epsilon && diff_x <= epsilon && diff_y >= -epsilon && diff_y <= epsilon);
                }

                Type length() const;

                Vec2<Type> &normalize();

                Type dot(const Vec2<Type>& vector) const { return x*vector.x + y*vector.y; }

                Angle angle(const Vec2<Type>& vector) const;

                Angle angle_normed(const Vec2<Type>& vector) const;

                Angle angle_line(const Vec2<Type>& point) const;

                Type distance(const Vec2<Type>& vector) const;

                Vec2<Type> &round();

                Vec2<Type> &rotate(const Vec2<Type>& hotspot, const Angle &angle);

                Type round_value(float value) const;

                bool is_equal(const Vec2<Type> &other, Type epsilon) const { return Vec2<Type>::is_equal(*this, other, epsilon); }

                void operator += (const Vec2<Type>& vector) { x += vector.x; y += vector.y; }

                void operator += (Type value) { x += value; y += value; }

                void operator -= (const Vec2<Type>& vector) { x -= vector.x; y -= vector.y; }

                void operator -= (Type value) { x -= value; y -= value; }

                Vec2<Type> operator - () const { return Vec2<Type>(-x, -y); }

                void operator *= (const Vec2<Type>& vector) { x *= vector.x; y *= vector.y; }

                void operator *= (Type value) { x *= value; y *= value; }

                void operator /= (const Vec2<Type>& vector) { x /= vector.x; y /= vector.y; }

                void operator /= (Type value) { x /= value; y /= value; }

                Vec2<Type> &operator = (const Vec2<Type>& vector) = default;

                bool operator == (const Vec2<Type>& vector) const { return ((x == vector.x) && (y == vector.y)); }

                bool operator != (const Vec2<Type>& vector) const { return ((x != vector.x) || (y != vector.y)); }

                bool operator < (const Vec2<Type>& vector) const { return y < vector.y || (y == vector.y && x < vector.x); }
        };

        template<typename Type>
        Vec2<Type> operator + (const Vec2<Type>& v1, const Vec2<Type>& v2) { return Vec2<Type>(v1.x + v2.x, v1.y + v2.y); }

        template<typename Type>
        Vec2<Type> operator + (Type s, const Vec2<Type>& v) { return Vec2<Type>(s + v.x, s + v.y); }

        template<typename Type>
        Vec2<Type> operator + (const Vec2<Type>& v, Type s) { return Vec2<Type>(v.x + s, v.y + s); }

        template<typename Type>
        Vec2<Type> operator - (const Vec2<Type>& v1, const Vec2<Type>& v2) { return Vec2<Type>(v1.x - v2.x, v1.y - v2.y); }

        template<typename Type>
        Vec2<Type> operator - (Type s, const Vec2<Type>& v) { return Vec2<Type>(s - v.x, s - v.y); }

        template<typename Type>
        Vec2<Type> operator - (const Vec2<Type>& v, Type s) { return Vec2<Type>(v.x - s, v.y - s); }

        template<typename Type>
        Vec2<Type> operator * (const Vec2<Type>& v1, const Vec2<Type>& v2) { return Vec2<Type>(v1.x * v2.x, v1.y * v2.y); }

        template<typename Type>
        Vec2<Type> operator * (Type s, const Vec2<Type>& v) { return Vec2<Type>(s * v.x, s * v.y); }

        template<typename Type>
        Vec2<Type> operator * (const Vec2<Type>& v, Type s) { return Vec2<Type>(v.x * s, v.y * s); }

        template<typename Type>
        Vec2<Type> operator / (const Vec2<Type>& v1, const Vec2<Type>& v2) { return Vec2<Type>(v1.x / v2.x, v1.y / v2.y); }

        template<typename Type>
        Vec2<Type> operator / (Type s, const Vec2<Type>& v) { return Vec2<Type>(s / v.x, s / v.y); }

        template<typename Type>
        Vec2<Type> operator / (const Vec2<Type>& v, Type s) { return Vec2<Type>(v.x / s, v.y / s); }

        template<typename Type>
        Vec2<Type> operator * (const Vec2<Type>& v, const Mat2<Type>& matrix)
        {
                return Vec2<Type>(
                        matrix[0 * 2 + 0] * v.x + matrix[0 * 2 + 1] * v.y,
                        matrix[1 * 2 + 0] * v.x + matrix[1 * 2 + 1] * v.y);
        }

        template<typename Type>
        Vec2<Type> operator * (const Mat2<Type>& matrix, const Vec2<Type>& v)
        {
                return Vec2<Type>(
                        matrix[0 * 2 + 0] * v.x + matrix[1 * 2 + 0] * v.y,
                        matrix[0 * 2 + 1] * v.x + matrix[1 * 2 + 1] * v.y);
        }


        template<typename Type>
        inline Type Vec2<Type>::length() const { return (Type)floor(sqrt(float(x*x + y*y)) + 0.5f); }

        template<>
        inline double Vec2<double>::length() const { return sqrt(x*x + y*y); }

        template<>
        inline float Vec2<float>::length() const { return sqrt(x*x + y*y); }

        template<typename Type>
        inline Vec2<Type> &Vec2<Type>::normalize() { Type f = length(); if (f != 0) { x /= f; y /= f; } return *this; }

        template<typename Type>
        inline Vec2<Type> Vec2<Type>::normalize(const Vec2<Type>& vector) { Vec2<Type> dest(vector); dest.normalize(); return dest; }


        typedef Vec2<unsigned char> Vec2ub;
        typedef Vec2<char> Vec2b;
        typedef Vec2<unsigned short> Vec2us;
        typedef Vec2<short> Vec2s;
        typedef Vec2<unsigned int> Vec2ui;
        typedef Vec2<int> Vec2i;
        typedef Vec2<float> Vec2f;
        typedef Vec2<double> Vec2d;

}