void Vector2::RotateAround(Vector2 origin, double rotation) {
Vector2 fromMid = *this - origin;
Vector2 unitVec(1, 0);
double angleFrom0 = fromMid.AngleBetween(unitVec);
if (fromMid.y < 0) {
angleFrom0 *= -1;
}
angleFrom0 += rotation;
Vector2 endMove(cos(angleFrom0), sin(angleFrom0));
endMove *= fromMid.Magnitude();
endMove = origin + endMove;
*this = endMove;
}
Vector2 Vector2::RotateAround(Vector2 origin, float rotation) const {
if (rotation == 0) {
return *this;
}
Vector2 fromMid = *this - origin;
Vector2 unitVec(1, 0);
float angleFrom0 = fromMid.AngleBetween(unitVec);
angleFrom0 -= rotation;
Vector2 endMove(cos(angleFrom0), sin(angleFrom0));
endMove *= fromMid.Magnitude();
endMove = origin + endMove;
return endMove;
}