Function dirVect

Engine/CoonsRegularization.cpp:373–398

}

static Point
dirVect(const BezierCPs& cps,
        double time,
        double t,
        int sign)
{
    Point ret;

    if (sign == 0) {
        Point pre = predir(cps, time, t);
        Point post = postdir(cps, time, t);
        ret.x = pre.x + post.x;
        ret.y = pre.y + post.y;
    } else if (sign < 0) {
        ret = predir(cps, time, t);
    } else if (sign > 0) {
        ret = postdir(cps, time, t);
    }

    double norm = std::sqrt(ret.x * ret.x + ret.y * ret.y);
    assert(norm != 0);
    ret.x /= norm;
    ret.y /= norm;

    return ret;
}

static Point
dirVect(const BezierCPs& cps,