Function coonsPatch

Engine/CoonsRegularization.cpp:734–793

}

static void
coonsPatch(const BezierCPs& p,
           double time,
           Point ret[4][4])
{
    assert(p.size() >= 3);
    Point internal[4];
    BezierCPs::const_iterator cur = p.begin();
    BezierCPs::const_iterator prev = p.end();
    --prev;
    BezierCPs::const_iterator next = cur;
    ++next;
    BezierCPs::const_iterator nextNext = next;
    ++nextNext;

    for (int j = 0; j < 4; ++j,
         ++prev, ++cur, ++next, ++nextNext) {
        if ( cur == p.end() ) {
            cur = p.begin();
        }
        if ( prev == p.end() ) {
            prev = p.begin();
        }
        if ( next == p.end() ) {
            next = p.begin();
        }
        if ( nextNext == p.end() ) {
            nextNext = p.begin();
        }

        Point p1;
        (*cur)->getPositionAtTime(false, time, ViewIdx(0), &p1.x, &p1.y);

        Point p1left;
        (*cur)->getLeftBezierPointAtTime(false, time, ViewIdx(0), &p1left.x, &p1left.y);

        Point p1right;
        (*cur)->getRightBezierPointAtTime(false, time, ViewIdx(0), &p1right.x, &p1right.y);

        Point p0;
        (*prev)->getPositionAtTime(false, time, ViewIdx(0), &p0.x, &p0.y);

        Point p2;
        (*next)->getPositionAtTime(false, time, ViewIdx(0), &p2.x, &p2.y);

        Point p0left;
        (*prev)->getLeftBezierPointAtTime(false, time, ViewIdx(0), &p0left.x, &p0left.y);

        Point p2right;
        (*next)->getRightBezierPointAtTime(false, time, ViewIdx(0), &p2right.x, &p2right.y);

        Point p3;
        (*nextNext)->getPositionAtTime(false, time, ViewIdx(0), &p3.x, &p3.y);

        internal[j].x = 1. / 9. * (-4. * p1.x + 6. * (p1left.x + p1right.x) - 2. * (p0.x + p2.x) + 3. * (p0left.x + p2right.x) - p3.x);
        internal[j].y = 1. / 9. * (-4. * p1.y + 6. * (p1left.y + p1right.y) - 2. * (p0.y + p2.y) + 3. * (p0left.y + p2right.y) - p3.y);
    }