vec2

2D euclidean vector class using float values

features

• dual cartesian / polar representation

vec2 v1{4.21f,7.5f};
float x = v1.x();
float y = v1.y();
float length = v1.magnitude();
float angle = v1.angle();

const float pi = 3.14159274101257324219;
vec2 v2 = vec2::from_polar(0,pi/6.0f);

• vector sum and difference

vec2 v1{3,4};
vec2 v2{5,6};
vec3 v3{1,1};
vec2 v4 = v1 + v2 - v3;         // v4 is (7,9)

• multiplication and division by a scalar

vec2 v1{4,10};
vec2 v2 = 1 * 3.0f;             // v2 is (12,30)
v2 /= 2.0 f;                    // v2 is now (6,15)  

• rotation

const float pi = 3.14159274101257324219;
vec2 v1{1,1};
vec2 v2 = v1 << (pi/2.0f);      // counter-clockwise rotation: v2 is (-1,1)
vec2 v3 = v1 >> (pi/2.0f);      // clockwise rotation: v3 is (1,-1)

• opposite vector

vec2 v = - vec2{4,-8}           // v is (-4,8)

• normalization

vec2 v{-12,0};
v.normalize();                  // v is now (-1,0)

• scalar product (aka dot product)

vec2 v1{4,6};
vec2 v2{2.5,7};
float p = v1 * v2;              // p is 52.0 

• extraction to std::ostream

#include <iostream>

vec2 v;
std::cout << v;                 // output: (0,0)

what is missing:

• equality / inequality operations are notoriously tricky to get right when dealing with floating point values. If you need them, just implement them as free function operator overloads using a technique that suits your needs:

bool operator==(const vec2 & v1, const vec2 & v2)
{
    // your code here
}

bool operator!=(const vec2 & v1, const vec2 & v2)
{
    return ! (v1 == v2);
}

• relational operators (<,<=,>,>=) as they do not really have a widely accepted meaning for 2d vectors. If you need them, just implement them as free function operator overloads.

License

Distributed under the MIT License. See LICENSE.txt for more information.

Contact

https://github.com/straykangaroo/vec2d