Function getPointAt

Engine/CoonsRegularization.cpp:71–123

NATRON_NAMESPACE_ENTER


static Point
getPointAt(const BezierCPs& cps,
           double time,
           double t)
{
    int ncps = (int)cps.size();

    assert(ncps);
    if (!ncps) {
        throw std::logic_error("getPointAt()");
    }
    if (t < 0) {
        t += ncps;
    }
    int t_i = (int)std::floor(t) % ncps;
    int t_i_plus_1 = t_i % ncps;
    assert(t_i >= 0 && t_i < ncps && t_i_plus_1 >= 0 && t_i_plus_1 < ncps);
    if (t == t_i) {
        BezierCPs::const_iterator it = cps.begin();
        std::advance(it, t_i);
        Point ret;
        (*it)->getPositionAtTime(false, time, ViewIdx(0), &ret.x, &ret.y);

        return ret;
    } else if (t == t_i_plus_1) {
        BezierCPs::const_iterator it = cps.begin();
        std::advance(it, t_i_plus_1);
        Point ret;
        (*it)->getPositionAtTime(false, time, ViewIdx(0), &ret.x, &ret.y);

        return ret;
    }

    BezierCPs::const_iterator it = cps.begin();
    std::advance(it, t_i);
    BezierCPs::const_iterator next = it;
    ++next;
    if ( next == cps.end() ) {
        next = cps.begin();
    }
    Point p0, p1, p2, p3;
    (*it)->getPositionAtTime(false, time, ViewIdx(0), &p0.x, &p0.y);
    (*it)->getRightBezierPointAtTime(false, time, ViewIdx(0), &p1.x, &p1.y);
    (*next)->getLeftBezierPointAtTime(false, time, ViewIdx(0), &p2.x, &p2.y);
    (*next)->getPositionAtTime(false, time, ViewIdx(0), &p3.x, &p3.y);
    Point ret;
    Bezier::bezierPoint(p0, p1, p2, p3, t - t_i, &ret);

    return ret;
}

static Point
getLeftPointAt(const BezierCPs& cps,