Function arcAngle

MyGUIEngine/src/msdfgen/ext/import-svg.cpp:98–100

}

static double arcAngle(Vector2 u, Vector2 v) {
    return nonZeroSign(crossProduct(u, v))*acos(clamp(dotProduct(u, v)/(u.length()*v.length()), -1., +1.));
}

static Vector2 rotateVector(Vector2 v, Vector2 direction) {
    return Vector2(direction.x*v.x-direction.y*v.y, direction.y*v.x+direction.x*v.y);