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vec2.cpp
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vec2.cpp
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#include "vec2.hpp"
#include <cassert>
#include <cmath>
#include <iostream>
vec2::vec2()
: vec2(0.0f,0.0f)
{
}
vec2::vec2(float x, float y)
: _x(x), _y(y)
{
}
vec2 vec2::from_polar(float angle, float magnitude)
{
return {magnitude * std::cos(angle), magnitude * std::sin(angle)};
}
float vec2::x() const
{
return _x;
}
float vec2::y() const
{
return _y;
}
float vec2::angle() const
{
return ( (_x == 0.0f && _y == 0.0f) ? 0.0f : std::atan2(_y,_x) );
}
float vec2::magnitude() const
{
return std::hypot(_x,_y);
}
vec2 & vec2::operator+=(const vec2 & other)
{
_x += other._x;
_y += other._y;
return *this;
}
vec2 & vec2::operator-=(const vec2 & other)
{
_x -= other._x;
_y -= other._y;
return *this;
}
vec2 & vec2::operator*=(float a)
{
_x *= a;
_y *= a;
return *this;
}
vec2 & vec2::operator/=(float a)
{
assert( a != 0.0f );
*this *= (1.0f / a);
return *this;
}
vec2 & vec2::operator<<=(float angle)
{
const auto cos = std::cos(angle);
const auto sin = std::sin(angle);
float new_x = _x * cos - _y * sin;
float new_y = _x * sin + _y * cos;
_x = new_x;
_y = new_y;
return *this;
}
vec2 & vec2::operator>>=(float angle)
{
*this <<= -angle;
return *this;
}
vec2 vec2::operator-() const
{
return {-_x,-_y};
}
vec2 & vec2::normalize()
{
*this /= magnitude();
return *this;
}
// --non members--
vec2 operator+(vec2 v1, const vec2 & v2)
{
v1 += v2;
return v1;
}
vec2 operator-(vec2 v1, const vec2 & v2)
{
v1 -= v2;
return v1;
}
float operator*(const vec2 & v1, const vec2 & v2)
{
return v1.x() * v2.x() + v1.y() * v2.y();
}
vec2 operator*(vec2 v, float a)
{
v *= a;
return v;
}
vec2 operator*(float a, const vec2 & v)
{
return v * a;
}
vec2 operator/(vec2 v, float a)
{
v /= a;
return v;
}
vec2 operator<<(vec2 v, float angle)
{
v <<= angle;
return v;
}
vec2 operator>>(vec2 v, float angle)
{
v >>= angle;
return v;
}
std::ostream & operator<<(std::ostream & os, const vec2 & v)
{
os << "(" << v.x() << "," << v.y() << ")";
return os;
}
float angle_between(const vec2 & v1, const vec2 &v2)
{
const float magn_1 = v1.magnitude();
const float magn_2 = v2.magnitude();
if ( magn_1 == 0.0f || magn_2 == 0.0f ) {
return 0.0f;
} else {
return std::acos( v1 * v2 / magn_1 * magn_2 );
}
}