cgal/Mesh_3/include/CGAL/Mesh_3/polylines_to_protect.h

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// Copyright (c) 2015,2016 GeometryFactory
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL$
// $Id$
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s) : Laurent Rineau
#ifndef CGAL_MESH_3_POLYLINES_TO_PROTECT_H
#define CGAL_MESH_3_POLYLINES_TO_PROTECT_H
#include <CGAL/license/Mesh_3.h>
#include <vector>
#include <map>
#include <utility> // std::swap
#include <algorithm> // std::min
#include <CGAL/Image_3.h>
#include <CGAL/number_utils.h>
#include <CGAL/squared_distance_3.h>
#include <CGAL/boost/graph/split_graph_into_polylines.h>
#include <CGAL/Mesh_3/internal/Graph_manipulations.h>
#include <boost/graph/adjacency_list.hpp>
#include <CGAL/Search_traits_3.h>
#include <CGAL/Orthogonal_incremental_neighbor_search.h>
#include <CGAL/Mesh_3/Null_subdomain_index.h>
#include <type_traits>
#include <optional>
namespace CGAL {
namespace Mesh_3 {
namespace internal {
template <typename K, typename NT>
struct Returns_midpoint {
typedef typename K::Point_3 Point_3;
Point_3 operator()(const Point_3& a,
const Point_3& b,
const NT,
const NT) const
{
typename K::Construct_midpoint_3 midpt
= K().construct_midpoint_3_object();
return a < b ? midpt(a, b) : midpt(b, a);
}
double operator()(const NT,
const NT) const
{
return 0.5;
}
};
template <typename K, typename NT>
struct Linear_interpolator {
typedef typename K::Point_3 Point_3;
Point_3 interpolate(const Point_3& pa,
const Point_3& pb,
const NT a,
const NT b) const
{
return pa + (a / (a - b)) * ( pb - pa);
}
Point_3 operator()(const Point_3& pa,
const Point_3& pb,
const NT a,
const NT b) const
{
return
(a < b) ?
interpolate(pa, pb, a, b) :
interpolate(pb, pa, b, a);
}
double operator()(const NT a,
const NT b) const
{
return a / ( a - b );
}
};
class Isoline_equation {
double a;
double b;
double c;
double d;
public:
Isoline_equation(double a, double b, double c, double d)
: a(a)
, b(b)
, c(c)
, d(d)
{}
double y(double x) const {
return ( x*(a-b)-a ) /
( c-a+x*(a-b-c+d) );
// If (a+d) == (b+c), then the curve is a straight line.
}
double x(double y) const {
return ( y*(a-c)-a ) /
( b-a+y*(a-b-c+d) );
// If (a+d) == (b+c), then the curve is a straight line.
}
}; // end of class Isoline_equation
template <typename G_manip, typename vertex_descriptor, typename Geom_traits>
class Insert_curve_in_graph {
typedef typename Geom_traits::Point_3 Point;
typedef typename Geom_traits::Vector_3 Vector;
G_manip& g_manip;
const vertex_descriptor null_vertex;
const Geom_traits& gt;
const typename Geom_traits::Construct_translated_point_3 translate;
const typename Geom_traits::Construct_scaled_vector_3 scale;
const int prec;
const double max_squared_distance;
public:
Insert_curve_in_graph(G_manip& g_manip,
const Geom_traits& gt,
const int prec = 10,
const double max_squared_distance = 0)
: g_manip(g_manip)
, null_vertex(g_manip.null_vertex())
, gt(gt)
, translate(gt.construct_translated_point_3_object())
, scale(gt.construct_scaled_vector_3_object())
, prec(prec)
, max_squared_distance(max_squared_distance)
{}
struct Coords {
Coords(double x, double y) : x(x), y(y) {}
double x;
double y;
};
void insert_curve(Isoline_equation equation,
vertex_descriptor start_v,
vertex_descriptor end_v,
Coords start,
Coords end,
Point p00,
Vector vx,
Vector vy)
{
if(CGAL::abs(start.x - end.x) >= CGAL::abs(start.y - end.y)) {
insert_curve(equation, &Isoline_equation::y,
start_v, end_v,
start.x, end.x, p00, vx, vy);
} else {
insert_curve(equation, &Isoline_equation::x,
start_v, end_v,
start.y, end.y, p00, vy, vx);
}
}
private:
void insert_curve(Isoline_equation equation,
double (Isoline_equation::* f)(double) const,
vertex_descriptor start_v,
vertex_descriptor end_v,
double start,
double end,
Point p00,
Vector vx,
Vector vy)
{
#ifdef CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
std::cerr << "New curve:\n"
<< " base("
<< p00 << " , "
<< p00+vx << " , "
<< p00+vy << ")\n"
<< " vectors: "
<< "( " << vx << " ) "
<< " ( " << vy << " )\n";
#endif // CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
const double step = (end - start)/prec;
const double stop = end-step/2;
const bool step_is_positive = (step > 0);
vertex_descriptor old = start_v;
vertex_descriptor v_int = null_vertex;
for(double x = start + step;
(step_is_positive ? x < stop : x > stop);
x += step)
{
const double y = (equation.*f)(x);
#ifdef CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
std::cerr << " (" << x << ", " << y << ") -> ";
#endif // CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
const Point inter_p =
translate(translate(p00,
scale(vx, x)),
scale(vy, y));
#ifdef CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
std::cerr << "( " << inter_p << ")\n";
#endif // CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
v_int = g_manip.get_vertex(inter_p, false);
g_manip.try_add_edge(old, v_int);
CGAL_assertion_msg(max_squared_distance == 0 ||
CGAL::squared_distance(g_manip.g[old].point,
g_manip.g[v_int].point) <
max_squared_distance,
([this, old, v_int] {
std::stringstream s;
s << "Problem at segment ("
<< this->g_manip.g[old].point << ", "
<< this->g_manip.g[v_int].point << ")";
return s.str();
}().c_str()));
old = v_int;
}
if(null_vertex != v_int) {
// v_int can be null if the curve is degenerated into one point.
g_manip.try_add_edge(v_int, end_v);
CGAL_assertion_msg(max_squared_distance == 0 ||
CGAL::squared_distance(g_manip.g[end_v].point,
g_manip.g[v_int].point) <
max_squared_distance,
([this, end_v, v_int] {
std::stringstream s;
s << "Problem at segment ("
<< this->g_manip.g[end_v].point << ", "
<< this->g_manip.g[v_int].point << ")";
return s.str();
}().c_str()));
}
}
};
template <typename Pixel,
typename Point,
typename Domain_type,
typename Image_word_type>
struct Enriched_pixel {
Pixel pixel;
Point point;
Domain_type domain;
Image_word_type word;
bool on_edge_of_the_cube;
bool on_corner_of_the_cube;
}; // end struct template Enriched_pixel<Pix,P,D,C>
} // end namespace internal
template<typename P, typename G>
struct Polyline_visitor
{
std::vector<std::vector<P> >& polylines;
G& graph;
Polyline_visitor(typename std::vector<std::vector<P> >& lines, G& p_graph)
: polylines(lines), graph(p_graph)
{}
~Polyline_visitor()
{//DEBUG
#if CGAL_MESH_3_PROTECTION_DEBUG & 2
std::ofstream og("polylines_graph.polylines.txt");
og.precision(17);
for(const std::vector<P>& poly : polylines)
{
og << poly.size() << " ";
for(const P& p : poly)
og << p << " ";
og << std::endl;
}
#endif // CGAL_MESH_3_PROTECTION_DEBUG & 2
}
void start_new_polyline()
{
std::vector<P> V;
polylines.push_back(V);
}
void add_node(typename boost::graph_traits<G>::vertex_descriptor vd)
{
std::vector<P>& polyline = polylines.back();
polyline.push_back(graph[vd].point);
}
void end_polyline()
{
// ignore degenerated polylines
if(polylines.back().size() < 2)
polylines.resize(polylines.size() - 1);
}
};
template <typename Kernel>
struct Angle_tester
{
const double m_angle_sq_cosine;// squared cosine of `std:max(90, angle_deg)`
Angle_tester()
: m_angle_sq_cosine(0)
{}
Angle_tester(const double angle_deg)//angle given in degrees for readability
: m_angle_sq_cosine(CGAL::square(std::cos((std::max)(90.,angle_deg) * CGAL_PI / 180.)))
{}
template <typename vertex_descriptor, typename Graph>
bool operator()(vertex_descriptor& v, const Graph& g) const
{
typedef typename boost::graph_traits<Graph>::out_edge_iterator out_edge_iterator;
if (g[v].force_terminal || out_degree(v, g) != 2)
return true;
else
{
out_edge_iterator out_edge_it, out_edges_end;
std::tie(out_edge_it, out_edges_end) = out_edges(v, g);
vertex_descriptor v1 = target(*out_edge_it++, g);
vertex_descriptor v2 = target(*out_edge_it++, g);
CGAL_assertion(out_edge_it == out_edges_end);
const typename Kernel::Point_3& p = g[v].point;
const typename Kernel::Point_3& p1 = g[v1].point;
const typename Kernel::Point_3& p2 = g[v2].point;
//if angle at v is acute, v must be considered as a terminal vertex
// to ensure termination
if (CGAL::angle(p1, p, p2) == CGAL::ACUTE)
return true;
else if (m_angle_sq_cosine > 0.)//check angle only if angle is > 90.
{
const typename Kernel::Vector_3 e1 = p1 - p;
const typename Kernel::Vector_3 e2 = p2 - p;
const auto scalar_product = e1 * e2;
if (CGAL::is_positive(scalar_product))
return true;
const auto sq_scalar_product = CGAL::square(scalar_product);
if (sq_scalar_product <= m_angle_sq_cosine * (e1 * e1) * (e2 * e2))
return true;
}
}
return false;
}
};
}//namespace Mesh_3
// this function is overloaded for when `PolylineInputIterator` is `int`.
template <typename K,
typename Graph,
typename PolylineInputIterator>
void snap_graph_vertices(Graph& graph,
const double vx, const double vy, const double vz,
PolylineInputIterator existing_polylines_begin,
PolylineInputIterator existing_polylines_end,
K)
{
const double dist_bound = (std::min)(vx,
(std::min)(vy, vz)) / 256;
const double sq_dist_bound = dist_bound * dist_bound;
typedef CGAL::Search_traits_3<K> Tree_traits;
typedef CGAL::Orthogonal_incremental_neighbor_search<Tree_traits> NN_search;
typedef typename NN_search::Tree Tree;
Tree tree;
// insert the extremities of the polylines in the kd-tree
for(PolylineInputIterator poly_it = existing_polylines_begin;
poly_it != existing_polylines_end; ++poly_it)
{
if(poly_it->begin() != poly_it->end()) {
tree.insert(*poly_it->begin());
if(std::next(poly_it->begin()) != poly_it->end()) {
tree.insert(*std::prev(poly_it->end()));
}
}
}
if(tree.size() == 0) return;
for(typename boost::graph_traits<Graph>::vertex_descriptor v :
make_range(vertices(graph)))
{
const typename K::Point_3 p = graph[v].point;
NN_search nn(tree, p);
CGAL_assertion(nn.begin() != nn.end());
if(squared_distance(nn.begin()->first, p) < sq_dist_bound) {
graph[v].point = nn.begin()->first;
}
}
}
template <typename K,
typename Graph>
void snap_graph_vertices(Graph&, double, double, double, int, int, K)
{}
template <typename Graph>
struct Less_for_Graph_vertex_descriptors
{
const Graph& graph;
Less_for_Graph_vertex_descriptors(const Graph& graph) : graph(graph) {}
template <typename vertex_descriptor>
bool operator()(vertex_descriptor v1, vertex_descriptor v2) const {
return graph[v1].point < graph[v2].point;
}
}; // end of Less_for_Graph_vertex_descriptors<Graph>
namespace internal {
namespace polylines_to_protect_namespace {
template <typename Point>
struct Vertex_info {
Point point;
bool force_terminal;
Vertex_info() : force_terminal(false) {}
Vertex_info(const Point& p) : point(p), force_terminal(false) {}
};
} // end namespace polylines_to_protect_namespace
} // end namespace internal
template <typename P,
typename Image_word_type,
typename Null_subdomain_index,
typename DomainFunctor,
typename InterpolationFunctor,
typename PolylineInputIterator>
void
polylines_to_protect
(const CGAL::Image_3& cgal_image,
const double vx, const double vy, const double vz,
std::vector<std::vector<P> >& polylines,
Image_word_type*,
Null_subdomain_index null,
DomainFunctor domain_fct,
InterpolationFunctor interpolate,
PolylineInputIterator existing_polylines_begin,
PolylineInputIterator existing_polylines_end,
std::optional<Image_word_type> scalar_interpolation_value = std::nullopt,
int prec = 10)
{
typedef typename DomainFunctor::result_type Domain_type;
typedef typename Kernel_traits<P>::Kernel K;
typedef P Point_3;
using CGAL::internal::polylines_to_protect_namespace::Vertex_info;
typedef boost::adjacency_list<boost::setS, boost::vecS, boost::undirectedS,
Vertex_info<Point_3> > Graph;
typedef typename boost::graph_traits<Graph>::vertex_descriptor vertex_descriptor;
// typedef typename boost::graph_traits<Graph>::edge_iterator edge_iterator;
const int xdim = static_cast<int>(cgal_image.xdim());
const int ydim = static_cast<int>(cgal_image.ydim());
const int zdim = static_cast<int>(cgal_image.zdim());
const int image_dims[3] = { xdim, ydim, zdim };
Graph graph;
using namespace CGAL::Mesh_3::internal;
typedef Graph_manipulations<Graph,
Point_3,
Image_word_type,
InterpolationFunctor> G_manip;
G_manip g_manip(graph, interpolate);
const float& tx = cgal_image.image()->tx;
const float& ty = cgal_image.image()->ty;
const float& tz = cgal_image.image()->tz;
double max_squared_distance =
(std::max)( (std::max)(vx, vy), vz );
max_squared_distance *= max_squared_distance;
max_squared_distance *= 2;
typedef Insert_curve_in_graph<G_manip, vertex_descriptor, K> Insert_c_in_g;
Insert_c_in_g insert_curve_in_graph(g_manip, K(), prec,
max_squared_distance);
typedef typename Insert_c_in_g::Coords Coords;
std::size_t
case4 = 0, // 4 colors
case211 = 0, case121 = 0, // 3 colors
case31 = 0, case22 = 0, // 2 colors
case1 = 0; // 1 color
typename K::Construct_midpoint_3 midpoint =
K().construct_midpoint_3_object();
typename K::Construct_vector_3 vector =
K().construct_vector_3_object();
typename K::Construct_translated_point_3 translate =
K().construct_translated_point_3_object();
for(int axis = 0; axis < 3; ++axis)
{
#ifdef CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
std::cerr << "axis = " << axis << "\n";
#endif // CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
for(int i = 0; i < xdim; i+= (axis == 0 ? (std::max)(1, xdim-1) : 1 ) )
for(int j = 0; j < ydim; j+= (axis == 1 ? (std::max)(1, ydim-1) : 1 ) )
for(int k = 0; k < zdim; k+= (axis == 2 ? (std::max)(1, zdim-1) : 1 ) )
{
using std::array;
typedef array<int, 3> Pixel;
#ifdef CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
std::cerr << "Pixel(" << i << ", " << j << ", " << k << ")\n";
#endif // CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
Pixel pix00 = {{i , j , k }},
pix10 = pix00, pix01 = pix00, pix11 = pix00;
const int axis_xx = (axis + 1) % 3;
const int axis_yy = (axis + 2) % 3;
++pix10[axis_xx];
++pix11[axis_xx]; ++pix11[axis_yy];
++pix01[axis_yy];
if(pix11[0] >= xdim || pix11[1] >= ydim || pix11[2] >= zdim) {
// we have gone too far
#ifdef CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
std::cerr << " ... continue\n";
#endif // CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
continue;
}
typedef Enriched_pixel<Pixel,
Point_3,
Domain_type,
Image_word_type> Enriched_pixel;
array<array<Enriched_pixel, 2>, 2> square =
{{ {{ { pix00, Point_3(), Domain_type(), 0, false, false },
{ pix01, Point_3(), Domain_type(), 0, false, false } }},
{{ { pix10, Point_3(), Domain_type(), 0, false, false },
{ pix11, Point_3(), Domain_type(), 0, false, false } }} }};
std::map<Domain_type, int> pixel_values_set;
for(int ii = 0; ii < 2; ++ii) {
for(int jj = 0; jj < 2; ++jj) {
const Pixel& pixel = square[ii][jj].pixel;
double x = pixel[0] * vx + tx;
double y = pixel[1] * vy + ty;
double z = pixel[2] * vz + tz;
short sum_faces = ((0 == pixel[0] || (xdim - 1) == pixel[0]) ? 1 : 0)
+ ((0 == pixel[1] || (ydim - 1) == pixel[1]) ? 1 : 0)
+ ((0 == pixel[2] || (zdim - 1) == pixel[2]) ? 1 : 0);
square[ii][jj].on_edge_of_the_cube = (sum_faces > 1);
square[ii][jj].on_corner_of_the_cube = (sum_faces > 2);
#ifdef CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
if(square[ii][jj].on_edge_of_the_cube) {
std::cerr << " Pixel(" << pixel[0] << ", " << pixel[1] << ", "
<< pixel[2] << ") is on edge\n";
}
if (square[ii][jj].on_corner_of_the_cube) {
std::cerr << " Pixel(" << pixel[0] << ", " << pixel[1] << ", "
<< pixel[2] << ") is on corner\n";
}
#endif // CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
square[ii][jj].point = Point_3(x, y, z);
square[ii][jj].word =
CGAL::IMAGEIO::static_evaluate<Image_word_type>
(cgal_image.image(),
pixel[0],
pixel[1],
pixel[2]);
square[ii][jj].domain = domain_fct(square[ii][jj].word);
if(scalar_interpolation_value != std::nullopt) {
square[ii][jj].word =
Image_word_type(square[ii][jj].word -
(*scalar_interpolation_value));
}
++pixel_values_set[square[ii][jj].domain];
}
}
const Point_3& p00 = square[0][0].point;
const Point_3& p10 = square[1][0].point;
const Point_3& p01 = square[0][1].point;
const Point_3& p11 = square[1][1].point;
const Image_word_type& v00 = square[0][0].word;
const Image_word_type& v10 = square[1][0].word;
const Image_word_type& v01 = square[0][1].word;
const Image_word_type& v11 = square[1][1].word;
{
bool out00 = null(square[0][0].domain);
bool out10 = null(square[1][0].domain);
bool out01 = null(square[0][1].domain);
bool out11 = null(square[1][1].domain);
bool is_corner00 = square[0][0].on_corner_of_the_cube;
bool is_corner10 = square[1][0].on_corner_of_the_cube;
bool is_corner01 = square[0][1].on_corner_of_the_cube;
bool is_corner11 = square[1][1].on_corner_of_the_cube;
//
// Protect the edges of the cube
//
if(pix00[axis_xx] == 0 &&
! ( out00 && out01 ) )
{
g_manip.try_add_edge(g_manip.get_vertex(p00, is_corner00),
g_manip.get_vertex(p01, is_corner01));
}
if(pix11[axis_xx] == image_dims[axis_xx]-1 &&
! ( out10 && out11 ) )
{
g_manip.try_add_edge(g_manip.get_vertex(p10, is_corner10),
g_manip.get_vertex(p11, is_corner11));
}
if(pix00[axis_yy] == 0 &&
! ( out00 && out10 ) )
{
g_manip.try_add_edge(g_manip.get_vertex(p00, is_corner00),
g_manip.get_vertex(p10, is_corner10));
}
if(pix11[axis_yy] == image_dims[axis_yy]-1 &&
! ( out01 && out11 ) )
{
g_manip.try_add_edge(g_manip.get_vertex(p01, is_corner01),
g_manip.get_vertex(p11, is_corner11));
}
} // end of scope for outIJ and on_edgeIJ
//
// Protect lines inside the square
//
switch(pixel_values_set.size()) {
case 4: {
CGAL_assertion(square[0][0].domain != square[0][1].domain);
CGAL_assertion(square[0][0].domain != square[1][0].domain);
CGAL_assertion(square[0][0].domain != square[1][1].domain);
CGAL_assertion(square[1][0].domain != square[1][1].domain);
CGAL_assertion(square[0][1].domain != square[1][1].domain);
CGAL_assertion(square[0][1].domain != square[1][0].domain);
case_4:
// case 4 or case 2-2
//
// ---------------
// | | |
// | | |
// |______|______|
// | | |
// | | |
// | | |
// ---------------
//
++case4;
vertex_descriptor left = g_manip.split(square[0][0],
square[0][1], null);
vertex_descriptor right = g_manip.split(square[1][0],
square[1][1], null);
vertex_descriptor top = g_manip.split(square[0][1],
square[1][1], null);
vertex_descriptor bottom = g_manip.split(square[0][0],
square[1][0], null);
vertex_descriptor vmid = g_manip.split(graph[left].point,
graph[right].point,
v00, v10,
false, false,
false, false);
g_manip.try_add_edge(left , vmid);
g_manip.try_add_edge(right , vmid);
g_manip.try_add_edge(top , vmid);
g_manip.try_add_edge(bottom , vmid);
}
break;
case 3: {
if(square[0][0].domain == square[1][1].domain) {
// Diagonal, but the wrong one.
// Vertical swap
std::swap(square[0][1], square[0][0]);
std::swap(square[1][1], square[1][0]);
}
if(square[0][1].domain == square[1][0].domain) {
// diagonal case 1-2-1
//
// A-------------C
// | | |
// | \ |
// |___ \__|
// | \ |
// | \ |
// | | |
// B-------------A
//
// two curves: -1 ------------- 0 -1 ------------- 1
// | | | | |
// | | | \ |
// |___ | | \__|
// | \ | | |
// | \ | | |
// | | | | |
// 1 ------------- -1 0 ------------- -1
//
CGAL_assertion(square[0][1].domain == square[1][0].domain);
CGAL_assertion(square[1][1].domain != square[0][0].domain);
CGAL_assertion(square[0][1].domain != square[0][0].domain);
CGAL_assertion(square[0][1].domain != square[1][1].domain);
case_1_2_1:
++case121;
vertex_descriptor left = g_manip.split(square[0][0],
square[0][1], null);
vertex_descriptor right = g_manip.split(square[1][0],
square[1][1], null);
vertex_descriptor top = g_manip.split(square[0][1],
square[1][1], null);
vertex_descriptor bottom = g_manip.split(square[0][0],
square[1][0], null);
Isoline_equation equation =
(scalar_interpolation_value == std::nullopt) ?
Isoline_equation(1, -1, -1, 0) :
Isoline_equation(v00, v10, v01, v11);
insert_curve_in_graph.insert_curve(equation,
left, bottom,
Coords(0., interpolate(v00, v01) ),
Coords(interpolate(v00, v10), 0. ),
p00,
p10 - p00,
p01 - p00);
if(scalar_interpolation_value == std::nullopt) {
equation = Isoline_equation(0, -1, -1, 1);
}
insert_curve_in_graph.insert_curve(equation,
top, right,
Coords(interpolate(v01, v11), 1. ),
Coords(1., interpolate(v10, v11) ),
p00,
p10 - p00,
p01 - p00);
} else {
// case 2-1-1
if(square[0][0].domain == square[1][0].domain) {
// Diagonal swap
std::swap(square[0][1], square[1][0]);
} else
if(square[0][1].domain == square[1][1].domain) {
// The other diagonal swap
std::swap(square[0][0], square[1][1]);
} else
if(square[1][0].domain == square[1][1].domain) {
// Vertical swap
std::swap(square[0][0], square[1][0]);
std::swap(square[0][1], square[1][1]);
}
CGAL_assertion(square[0][0].domain == square[0][1].domain);
CGAL_assertion(square[0][0].domain != square[1][0].domain);
CGAL_assertion(square[0][0].domain != square[1][1].domain);
CGAL_assertion(square[1][0].domain != square[1][1].domain);
++case211;
// Note: this case cannot occur with non-segmented scalar
// images, because it needs three domains.
//
// A-------------B
// | | |
// | \ |
// | \__|
// | / |
// | / |
// | | |
// A-------------C
//
// Two curves portions:
//
// 1 ------------- 0 1 ------------- -1
// | /| | | |
// | / | | \ |
// | / | | \ |
// | / | | \ |
// | / | | \ |
// | | | | \|
// 1 ------------- -1 1 ------------- 0
//
// ...and a segment.
Point_3 midleft = midpoint(p00, p01);
Point_3 midright = midpoint(p10, p11);
Point_3 inter = translate(midleft
, (2./3) * vector(midleft, midright));
vertex_descriptor v_inter = g_manip.get_vertex(inter, false);
vertex_descriptor right = g_manip.split(square[1][0],
square[1][1], null);
vertex_descriptor top = g_manip.split(square[0][1],
square[1][1], null);
vertex_descriptor bottom = g_manip.split(square[0][0],
square[1][0], null);
insert_curve_in_graph.insert_curve(Isoline_equation(1, -1, 1, 0),
bottom, v_inter,
Coords( 0.5 , 0. ),
Coords( 2./3., 0.5 ),
p00,
p10 - p00,
p01 - p00);
insert_curve_in_graph.insert_curve(Isoline_equation(1, 0, 1, -1),
top, v_inter,
Coords( 0.5 , 1. ),
Coords( 2./3., 0.5 ),
p00,
p10 - p00,
p01 - p00);
g_manip.try_add_edge(right, v_inter);
} // end case 2-1-1
} // end `case 3:`
break;
case 2: {
if(pixel_values_set.begin()->second ==
pixel_values_set.rbegin()->second)
{
// Case of two colors with two pixels each.
if(square[0][0].domain==square[1][0].domain) {
// case 2-2, diagonal swap
std::swap(square[0][1], square[1][0]);
CGAL_assertion(square[0][0].domain==square[0][1].domain);
}
if(square[1][0].domain==square[1][1].domain) {
// case 2-2, vertical swap
std::swap(square[0][1], square[1][1]);
std::swap(square[0][0], square[1][0]);
CGAL_assertion(square[0][0].domain==square[0][1].domain);
}
if(square[0][1].domain==square[1][1].domain) {
// case 2-2, diagonal swap
std::swap(square[0][0], square[1][1]);
CGAL_assertion(square[0][0].domain==square[0][1].domain);
}
if(square[0][0].domain==square[0][1].domain) {
// vertical case 2-2
++case22;
// case 2-2
//
// A-------------B
// | | |
// | | |
// | | |
// | | |
// | | |
// | | |
// A-------------B
//
CGAL_assertion(square[1][0].domain==square[1][1].domain);
CGAL_assertion(square[1][0].domain!=square[0][1].domain);
vertex_descriptor top = g_manip.split(square[0][1],
square[1][1], null);
vertex_descriptor bottom = g_manip.split(square[0][0],
square[1][0], null);
if(scalar_interpolation_value == std::nullopt) {
g_manip.try_add_edge(top, bottom);
} else {
insert_curve_in_graph.insert_curve(Isoline_equation(v00, v10,
v01, v11),
top, bottom,
Coords(interpolate(v01,v11), 1.),
Coords(interpolate(v00,v10), 0.),
p00,
p10 - p00,
p01 - p00);
}
} else {
// Else diagonal case case 2-2
// Same as the case with 4 colors
CGAL_assertion(square[0][0].domain==square[1][1].domain);
CGAL_assertion(square[1][0].domain==square[0][1].domain);
CGAL_assertion(square[0][0].domain!=square[0][1].domain);
if(scalar_interpolation_value != std::nullopt) {
// Compute the squared distance between the two branches of
// the hyperbola.
const double discrimant = double(v00) * v11 - double(v01) * v10;
const double squared_distance =
8 * CGAL::abs(discrimant) / CGAL::square(double(v00) - v10 - v01 + v11);
#ifdef CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
std::cerr << "squared_distance: " << squared_distance << "\n";
#endif // CGAL_MESH_3_DEBUG_POLYLINES_TO_PROTECT
if(CGAL::square(prec) * squared_distance > 1)
{
// In that case, the case 1-2-1 will be applied
if(discrimant > 0.) {
// Vertical swap
std::swap(square[0][1], square[0][0]);
std::swap(square[1][1], square[1][0]);
}
goto case_1_2_1;
}
} // scalar interpolation
goto case_4;
}
}
else {
// case of two colors with one pixel green and three red
Domain_type value_alone;
if(pixel_values_set.begin()->second == 1) {
value_alone = pixel_values_set.begin()->first;
} else {
CGAL_assertion(pixel_values_set.begin()->second == 3);
CGAL_assertion(pixel_values_set.rbegin()->second ==1);
value_alone = pixel_values_set.rbegin()->first;
}
if(square[0][1].domain == value_alone) {
// central symmetry
std::swap(square[0][1], square[1][0]);
std::swap(square[0][0], square[1][1]);
CGAL_assertion(square[1][0].domain == value_alone);
}
if(square[1][1].domain == value_alone) {
// vertical swap
std::swap(square[0][0], square[0][1]);
std::swap(square[1][0], square[1][1]);
CGAL_assertion(square[1][0].domain == value_alone);
}
if(square[0][0].domain == value_alone) {
// horizontal swap
std::swap(square[0][1], square[1][1]);
std::swap(square[0][0], square[1][0]);
CGAL_assertion(square[1][0].domain == value_alone);
}
++case31;
//
// A-------------A 1 ------------- 1
// | | | |
// | | | |
// | ____| | ____|
// | / | | / |
// | / | | / |
// | | | | | |
// A-------------B 1 ------------- -1
//
CGAL_assertion(square[1][0].domain == value_alone);
CGAL_assertion(square[1][0].domain != square[0][0].domain);
CGAL_assertion(square[1][1].domain == square[0][0].domain);
CGAL_assertion(square[0][1].domain == square[0][0].domain);
vertex_descriptor bottom = g_manip.split(square[0][0],
square[1][0], null);
vertex_descriptor right = g_manip.split(square[1][0],
square[1][1], null);
Isoline_equation equation =
(scalar_interpolation_value == std::nullopt) ?
Isoline_equation(1, -1, 1, 1) :
Isoline_equation(v00, v10, v01, v11);
insert_curve_in_graph.insert_curve(equation,
bottom, right,
Coords(interpolate(v00, v10), 0. ),
Coords(1., interpolate(v10, v11) ),
p00,
p10 - p00,
p01 - p00);
}
}
break;
default: // case 1
++case1;
// nothing to do
break;
}
}
}
// std::cerr << "case 4: " << case4 << std::endl;
// std::cerr << "case 2-1-1: " << case211 << std::endl;
// std::cerr << "case 1-2-1: " << case121 << std::endl;
// std::cerr << "case 3-1: " << case31 << std::endl;
// std::cerr << "case 2-2: " << case22 << std::endl;
// std::cerr << "case 1: " << case1 << std::endl;
const std::ptrdiff_t nb_facets =
case4 + case211 + case121 + case31 + case22 + case1;
const std::ptrdiff_t expected_nb_facets =
((xdim != 1 && ydim != 1 && zdim != 1) ? 2 : 1)
*
((xdim-1)*(ydim-1) + (ydim-1)*(zdim-1) + (xdim-1)*(zdim-1));
// std::cerr << "nb of facets: " << nb_facets << std::endl
// << " expected nb of facets: " << expected_nb_facets << std::endl;
CGAL_assertion(nb_facets == expected_nb_facets);
CGAL_USE(nb_facets); CGAL_USE(expected_nb_facets);
snap_graph_vertices(graph,
vx, vy, vz,
existing_polylines_begin, existing_polylines_end,
K());
Mesh_3::Polyline_visitor<Point_3, Graph> visitor(polylines, graph);
Less_for_Graph_vertex_descriptors<Graph> less(graph);
const Graph& const_graph = graph;
split_graph_into_polylines(const_graph, visitor,
Mesh_3::Angle_tester<K>(), less);
}
template <typename P,
typename PolylineInputIterator>
void
polylines_to_protect(std::vector<std::vector<P> >& polylines,
PolylineInputIterator existing_polylines_begin,
PolylineInputIterator existing_polylines_end,
const double& angle = 90.)//when not provided, check only for acute angles
{
typedef P Point_3;
typedef typename Kernel_traits<P>::Kernel K;
using CGAL::internal::polylines_to_protect_namespace::Vertex_info;
typedef boost::adjacency_list<boost::setS, boost::vecS, boost::undirectedS,
Vertex_info<Point_3> > Graph;
typedef typename boost::graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename std::iterator_traits<PolylineInputIterator>::value_type Polyline;
Graph graph;
typedef Mesh_3::internal::Returns_midpoint<K, int> Midpoint_fct;
Mesh_3::internal::Graph_manipulations<Graph,
Point_3,
int,
Midpoint_fct> g_manip(graph);
for (PolylineInputIterator poly_it = existing_polylines_begin;
poly_it != existing_polylines_end; ++poly_it)
{
const Polyline& polyline = *poly_it;
if (polyline.size() < 2)
continue;
typename Polyline::const_iterator pit = polyline.begin();
while (std::next(pit) != polyline.end())
{
vertex_descriptor v = g_manip.get_vertex(*pit, false);
vertex_descriptor w = g_manip.get_vertex(*std::next(pit), false);
g_manip.try_add_edge(v, w);
++pit;
}
}
Mesh_3::Polyline_visitor<Point_3, Graph> visitor(polylines, graph);
Less_for_Graph_vertex_descriptors<Graph> less(graph);
const Graph& const_graph = graph;
typedef typename Kernel_traits<P>::Kernel K;
Mesh_3::Angle_tester<K> angle_tester(angle);
split_graph_into_polylines(const_graph, visitor,
angle_tester, less);
}
template <typename P, typename Image_word_type, typename Null_subdomain_index>
void
polylines_to_protect(const CGAL::Image_3& cgal_image,
std::vector<std::vector<P> >& polylines,
Image_word_type* word_type,
Null_subdomain_index null)
{
polylines_to_protect<P>
(cgal_image,
polylines,
word_type,
null,
0,
0);
}
template <typename P, typename Image_word_type>
void
polylines_to_protect(const CGAL::Image_3& cgal_image,
std::vector<std::vector<P> >& polylines)
{
polylines_to_protect<P, Image_word_type>(cgal_image, polylines, 0, 0);
}
template <typename P,
typename Image_word_type,
typename Null_subdomain_index,
typename PolylineInputIterator>
void
polylines_to_protect(const CGAL::Image_3& cgal_image,
std::vector<std::vector<P> >& polylines,
Image_word_type* word_type,
Null_subdomain_index null,
PolylineInputIterator existing_polylines_begin,
PolylineInputIterator existing_polylines_end)
{
typedef typename Kernel_traits<P>::Kernel K;
polylines_to_protect<P>
(cgal_image,
cgal_image.vx(), cgal_image.vy(),cgal_image.vz(),
polylines,
word_type,
null,
CGAL::Identity<Image_word_type>(),
Mesh_3::internal::Returns_midpoint<K, Image_word_type>(),
existing_polylines_begin,
existing_polylines_end);
}
template <typename P,
typename Image_word_type,
typename PolylineInputIterator>
void
polylines_to_protect(const CGAL::Image_3& cgal_image,
std::vector<std::vector<P> >& polylines,
PolylineInputIterator existing_polylines_begin,
PolylineInputIterator existing_polylines_end)
{
polylines_to_protect<P>
(cgal_image,
polylines,
(Image_word_type*)0,
CGAL::Null_subdomain_index(),
existing_polylines_begin,
existing_polylines_end);
}
template <typename P,
typename Image_word_type,
typename PolylineInputIterator>
void
polylines_to_protect_on_bbox(const CGAL::Image_3& cgal_image,
std::vector<std::vector<P> >& polylines,
PolylineInputIterator existing_polylines_begin,
PolylineInputIterator existing_polylines_end)
{
polylines_to_protect<P, Image_word_type>(cgal_image,
polylines,
existing_polylines_begin,
existing_polylines_end);
}
template <typename PolylineRange1, typename PolylineRange2>
void
merge_and_snap_polylines(const CGAL::Image_3& image,
PolylineRange1& polylines_to_snap,
const PolylineRange2& existing_polylines)
{
static_assert(std::is_same<typename PolylineRange1::value_type::value_type,
typename PolylineRange2::value_type::value_type>::value,
"Polyline ranges should have same point type");
using P = typename PolylineRange1::value_type::value_type;
using K = typename Kernel_traits<P>::Kernel;
using CGAL::internal::polylines_to_protect_namespace::Vertex_info;
using Graph = boost::adjacency_list<boost::setS, boost::vecS, boost::undirectedS,
Vertex_info<P> >;
using vertex_descriptor = typename boost::graph_traits<Graph>::vertex_descriptor;
// build graph of polylines_to_snap
Graph graph;
typedef Mesh_3::internal::Returns_midpoint<K, int> Midpoint_fct;
Mesh_3::internal::Graph_manipulations<Graph,
P,
int,
Midpoint_fct> g_manip(graph);
for (const auto& polyline : polylines_to_snap)
{
if (polyline.size() < 2)
continue;
auto pit = polyline.begin();
while (std::next(pit) != polyline.end())
{
vertex_descriptor v = g_manip.get_vertex(*pit, false);
vertex_descriptor w = g_manip.get_vertex(*std::next(pit), false);
g_manip.try_add_edge(v, w);
++pit;
}
}
// snap graph to existing_polylines
snap_graph_vertices(graph,
image.vx(), image.vy(), image.vz(),
std::begin(existing_polylines), std::end(existing_polylines),
K());
// rebuild polylines_to_snap
polylines_to_snap.clear();
Mesh_3::Polyline_visitor<P, Graph> visitor(polylines_to_snap, graph);
Less_for_Graph_vertex_descriptors<Graph> less(graph);
const Graph& const_graph = graph;
Mesh_3::Angle_tester<K> angle_tester(90.);
split_graph_into_polylines(const_graph, visitor, angle_tester, less);
}
} // namespace CGAL
#endif // CGAL_MESH_3_POLYLINES_TO_PROTECT_H