songsenand
/
cgal
mirror of https://github.com/CGAL/cgal
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Handled the cases where an intersection point lies on the boundary

This commit is contained in:
Efi Fogel 2017-12-31 19:02:23 +02:00
parent 60e23aa1b9
commit 75a733f1a6
1 changed files with 92 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

129
Arrangement_on_surface_2/include/CGAL/Arrangement_2/Arrangement_zone_2_impl.h
View File

@ -41,6 +41,10 @@ template <typename Arrangement, typename ZoneVisitor>
void Arrangement_zone_2<Arrangement, ZoneVisitor>::
init_with_hint(const X_monotone_curve_2& cv, const Object& obj)
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "init_with_hint()" << std::endl;
#endif
// Set the curve and check whether its ends are bounded, therefore
// associated with valid endpoints.
m_cv = cv;
@ -89,6 +93,10 @@ init_with_hint(const X_monotone_curve_2& cv, const Object& obj)
template <typename Arrangement, typename ZoneVisitor>
void Arrangement_zone_2<Arrangement, ZoneVisitor>::compute_zone()
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "compute_zone()" << std::endl;
#endif
// Initialize flags and set all handles to be invalid.
bool done = false;
@ -183,6 +191,7 @@ void Arrangement_zone_2<Arrangement, ZoneVisitor>::compute_zone()
// Compute the zone of the curve (or what is remaining of it) in the
// arrangement, starting from the current position we have computed.
while (! done) {
// Check if we know the face the curve is going to penetrate now.
if (m_left_he == invalid_he) {
@ -256,6 +265,10 @@ template <typename Arrangement, typename ZoneVisitor>
bool Arrangement_zone_2<Arrangement, ZoneVisitor>::
_find_prev_around_vertex(Vertex_handle v, Halfedge_handle& he)
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "_find_prev_around_vertex()" << std::endl;
#endif
// Go over the incident halfedges of v, going in a clockwise order.
typename Arrangement_2::Halfedge_around_vertex_circulator he_first;
typename Arrangement_2::Halfedge_around_vertex_circulator he_curr;
@ -347,6 +360,13 @@ _direct_intersecting_edge_to_right(const X_monotone_curve_2& cv_ins,
const Point_2& cv_left_pt,
Halfedge_handle query_he)
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "_direct_intersecting_edge_to_right() " << cv_left_pt
<< std::endl;
std::cout << " " << cv_ins << std::endl;
std::cout << " " << query_he->curve() << std::endl;
#endif
// Make sure that the left endpoint of cv_ins lies on query_he.
CGAL_exactness_assertion(m_geom_traits->compare_y_at_x_2_object()
(cv_left_pt, query_he->curve()) == EQUAL);
@ -393,6 +413,10 @@ Arrangement_zone_2<Arrangement,ZoneVisitor>::
_direct_intersecting_edge_to_left(const X_monotone_curve_2& cv_ins,
Halfedge_handle query_he)
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "_direct_intersecting_edge_to_left()" << std::endl;
#endif
// Make sure that the right endpoint of cv_ins lies on query_he.
CGAL_exactness_assertion
(m_geom_traits->compare_y_at_x_2_object()
@ -456,8 +480,16 @@ _compute_next_intersection(Halfedge_handle he,
bool skip_first_point,
bool& intersection_on_right_boundary)
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "_compute_next_intersection(): " << he->curve() << std::endl;
#endif
typename Traits_adaptor_2::Equal_2 equal = m_geom_traits->equal_2_object();
typename Traits_adaptor_2::Compare_xy_2 compare_xy =
m_geom_traits->compare_xy_2_object();
// Get a pointer to the curve associated with the halfedge.
const X_monotone_curve_2 *p_curve = &(he->curve());
const X_monotone_curve_2* p_curve = &(he->curve());
// Try to locate the intersections with this curve in the intersections map.
Intersect_map_iterator iter = m_inter_map.find(p_curve);
@ -478,39 +510,40 @@ _compute_next_intersection(Halfedge_handle he,
while (! inter_list.empty()) {
// Compare that current object with m_left_pt (if exists).
ip = object_cast<Intersect_point_2>(&(inter_list.front()));
if (m_left_on_boundary) {
// The left end lie on the left boundary, so all intersections are
// valid, as they lie to its right.
valid_intersection = true;
}
else if (ip != NULL) {
if (m_has_right_pt && m_right_on_boundary &&
m_geom_traits->equal_2_object()(ip->first, m_right_pt))
if (ip != NULL) {
// Process an intersection point.
if (m_left_on_boundary) {
// The leftend lies on the left boundary.
if (m_has_left_pt && equal(ip->first, m_left_pt))
valid_intersection = false;
else {
// All intersections are valid, as they lie to the right of the
// leftend.
valid_intersection = true;;
}
}
else if (m_right_on_boundary &&
m_has_right_pt && equal(ip->first, m_right_pt))
{
valid_intersection = true;
intersection_on_right_boundary = true;
}
else {
// We have a simple intersection point - make sure it lies to the
// right of m_left_pt.
valid_intersection =
(m_geom_traits->compare_xy_2_object()(ip->first, m_left_pt) ==
LARGER);
// Only intersections that lie to the right of the leftend are valid.
valid_intersection = (compare_xy(ip->first, m_left_pt) == LARGER);
}
}
else {
// We have an overlapping subcurve.
icv = object_cast<X_monotone_curve_2>(&(inter_list.front()));
CGAL_assertion (icv != NULL);
CGAL_assertion(icv != NULL);
if (m_geom_traits->is_closed_2_object()(*icv, ARR_MIN_END)) {
// The curve has a valid left point - make sure it lies to the
// right of m_left_pt.
valid_intersection =
(m_geom_traits->compare_xy_2_object()
(m_geom_traits->construct_min_vertex_2_object()(*icv), m_left_pt) !=
SMALLER);
(compare_xy(m_geom_traits->construct_min_vertex_2_object()(*icv),
m_left_pt) != SMALLER);
}
else {
// In this case the overlap is not valid.
@ -545,22 +578,29 @@ _compute_next_intersection(Halfedge_handle he,
while (! inter_list.empty()) {
// Compare that current object with m_left_pt (if exists).
ip = object_cast<Intersect_point_2>(&(inter_list.front()));
if (ip != NULL) {
// We have a simple intersection point - if we don't have to skip it,
// make sure it lies to the right of m_left_pt (if m_left_pt is on the left
// boundary, all points lie to it right).
// Process an intersection point.
// Skip the point if needed.
if (is_first && skip_first_point) valid_intersection = false;
else if (m_left_on_boundary) valid_intersection = true;
else if (m_has_right_pt && m_right_on_boundary &&
m_geom_traits->equal_2_object()(ip->first, m_right_pt))
else if (m_left_on_boundary) {
// The leftend lies on the left boundary.
if (m_has_left_pt && equal(ip->first, m_left_pt))
valid_intersection = false;
else {
// All intersections are valid, as they lie to the right of the
// leftend.
valid_intersection = true;
}
}
else if (m_right_on_boundary &&
m_has_right_pt && equal(ip->first, m_right_pt))
{
valid_intersection = true;
intersection_on_right_boundary = true;
}
else {
valid_intersection =
(m_geom_traits->compare_xy_2_object()(ip->first, m_left_pt) == LARGER);
// Only intersections that lie to the right of the leftend are valid.
valid_intersection = (compare_xy(ip->first, m_left_pt) == LARGER);
}
}
else if (m_left_on_boundary) {
@ -631,6 +671,10 @@ bool Arrangement_zone_2<Arrangement, ZoneVisitor>::
_is_to_left_impl(const Point_2& p, Halfedge_handle he,
Arr_not_all_sides_oblivious_tag) const
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "_is_to_left_impl()" << std::endl;
#endif
// Check the boundary conditions of the minimal end of the curve associated
// with the given halfedge.
const Arr_parameter_space ps_x =
@ -683,7 +727,7 @@ bool Arrangement_zone_2<Arrangement, ZoneVisitor>::
_is_to_right_impl(const Point_2& p, Halfedge_handle he,
Arr_not_all_sides_oblivious_tag) const
{
// Check the boundary conditions of the maximal end of the curve associated
// Check the boundary conditions of the maximal end of the curve associated
// with the given halfedge.
const Arr_parameter_space ps_x =
m_geom_traits->parameter_space_in_x_2_object()(he->curve(), ARR_MAX_END);
@ -722,6 +766,11 @@ template <typename Arrangement, typename ZoneVisitor>
void Arrangement_zone_2<Arrangement, ZoneVisitor>::
_leftmost_intersection_with_face_boundary(Face_handle face, bool on_boundary)
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "_leftmost_intersection_with_face_boundary() "
<< on_boundary << std::endl;
#endif
// Mark that we have not found any intersection (or overlap) yet.
m_found_intersect = false;
m_found_overlap = false;
@ -767,7 +816,7 @@ _leftmost_intersection_with_face_boundary(Face_handle face, bool on_boundary)
// If we have already found an intersection with the twin halfedge,
// we do not have to compute intersections with the current halfedge.
if (m_found_intersect && m_intersect_he == he_curr->twin()) {
if (m_found_intersect && (m_intersect_he == he_curr->twin())) {
++he_curr;
continue;
}
@ -894,7 +943,7 @@ _leftmost_intersection_with_face_boundary(Face_handle face, bool on_boundary)
do {
// If we have already found an intersection with the twin halfedge,
// we do not have to compute intersections with the current halfedge.
if (m_found_intersect && m_intersect_he == he_curr->twin()) {
if (m_found_intersect && (m_intersect_he == he_curr->twin())) {
++he_curr;
continue;
}
@ -938,6 +987,7 @@ _leftmost_intersection_with_face_boundary(Face_handle face, bool on_boundary)
}
}
}
// Check whether the two curves overlap in their x-range (in order
// to avoid unnecessary intersection computations).
if (! left_equals_curr_endpoint &&
@ -951,17 +1001,14 @@ _leftmost_intersection_with_face_boundary(Face_handle face, bool on_boundary)
}
// Compute the next intersection of cv and the current halfedge.
iobj = _compute_next_intersection (he_curr,
left_equals_curr_endpoint,
intersection_on_right_boundary);
iobj = _compute_next_intersection(he_curr, left_equals_curr_endpoint,
intersection_on_right_boundary);
if (! iobj.is_empty()) {
// We have found an intersection (either a simple point or an
// overlapping x-monotone curve).
int_p = object_cast<Intersect_point_2>(&iobj);
if (int_p != NULL) {
ip = int_p->first;
// Found a simple intersection point. Check if it is the leftmost
// intersection point so far.
if (! m_found_intersect ||
@ -1056,6 +1103,10 @@ template <typename Arrangement, typename ZoneVisitor>
bool Arrangement_zone_2<Arrangement, ZoneVisitor>::
_zone_in_face(Face_handle face, bool on_boundary)
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "_zone_in_face() " << on_boundary << std::endl;
#endif
CGAL_precondition((! on_boundary &&
(((m_left_v == invalid_v) && (m_left_he == invalid_he)) ||
m_left_v->is_isolated())) ||
@ -1275,7 +1326,7 @@ _zone_in_face(Face_handle face, bool on_boundary)
}
// We are not done with the zone-computation process yet:
return (false);
return false;
}
//-----------------------------------------------------------------------------
@ -1285,6 +1336,10 @@ _zone_in_face(Face_handle face, bool on_boundary)
template <typename Arrangement, typename ZoneVisitor>
bool Arrangement_zone_2<Arrangement, ZoneVisitor>::_zone_in_overlap()
{
#if defined(ARR_ZONE_VERBOSE)
std::cout << "_zone_in_overlap()" << std::endl;
#endif
// Check if the right end of m_overlap_cv is bounded. If so, compute its
// right endpoint.
const bool cv_has_right_pt =