include/rive/math/vec2d.hpp

#ifndef _RIVE_VEC2D_HPP_
#define _RIVE_VEC2D_HPP_

#include "rive/rive_types.hpp"

namespace rive {
    class Mat2D;
    class Vec2D {
    public:
        float x, y;

        constexpr Vec2D() : x(0), y(0) {}
        constexpr Vec2D(float x, float y) : x(x), y(y) {}
        constexpr Vec2D(const Vec2D&) = default;

        float lengthSquared() const { return x * x + y * y; }
        float length() const;
        Vec2D normalized() const;

        // Normalize this Vec, and return its previous length
        float normalizeLength() {
            const float len = this->length();
            x /= len;
            y /= len;
            return len;
        }

        Vec2D operator-() const { return {-x, -y}; }

        void operator*=(float s) {
            x *= s;
            y *= s;
        }

        void operator/=(float s) {
            x /= s;
            y /= s;
        }

        friend inline Vec2D operator-(const Vec2D& a, const Vec2D& b) {
            return {a.x - b.x, a.y - b.y};
        }

        static inline Vec2D lerp(Vec2D a, Vec2D b, float f);

        static Vec2D transformDir(const Vec2D& a, const Mat2D& m);

        static float dot(Vec2D a, Vec2D b) { return a.x * b.x + a.y * b.y; }
        static Vec2D scaleAndAdd(Vec2D a, Vec2D b, float scale) {
            return {
                a.x + b.x * scale,
                a.y + b.y * scale,
            };
        }
        static float distance(const Vec2D& a, const Vec2D& b) { return (a - b).length(); }
        static float distanceSquared(const Vec2D& a, const Vec2D& b) {
            return (a - b).lengthSquared();
        }

        Vec2D& operator+=(Vec2D v) {
            x += v.x;
            y += v.y;
            return *this;
        }
        Vec2D& operator-=(Vec2D v) {
            x -= v.x;
            y -= v.y;
            return *this;
        }
    };

    inline Vec2D operator*(const Vec2D& v, float s) { return {v.x * s, v.y * s}; }
    inline Vec2D operator*(float s, const Vec2D& v) { return {v.x * s, v.y * s}; }
    inline Vec2D operator/(const Vec2D& v, float s) { return {v.x / s, v.y / s}; }

    inline Vec2D operator+(const Vec2D& a, const Vec2D& b) { return {a.x + b.x, a.y + b.y}; }

    inline bool operator==(const Vec2D& a, const Vec2D& b) { return a.x == b.x && a.y == b.y; }
    inline bool operator!=(const Vec2D& a, const Vec2D& b) { return a.x != b.x || a.y != b.y; }

    Vec2D Vec2D::lerp(Vec2D a, Vec2D b, float t) {
        return a + (b - a) * t;
    }

} // namespace rive
#endif