1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/**
* \file
* \brief TopoSweep - topology / graph representation of a PathVector, for boolean operations and related tasks
*
* Authors:
* Michael Sloan <mgsloan at gmail.com>
* Nathan Hurst <njhurst at njhurst.com>
*
* Copyright 2007-2009 authors
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*/
#ifndef SEEN_GEOM_TOPOSWEEP_H
#define SEEN_GEOM_TOPOSWEEP_H
#include <2geom/coord.h>
#include <2geom/point.h>
#include <2geom/pathvector.h>
#include <2geom/rect.h>
#include <2geom/path.h>
#include <2geom/curve.h>
#include <boost/shared_ptr.hpp>
namespace Geom {
// indicates a particular curve in a pathvector
struct CurveIx {
unsigned path, ix;
CurveIx(unsigned p, unsigned i) : path(p), ix(i) {}
// retrieves the indicated curve from the pathvector
Curve const &get(PathVector const &ps) const {
return ps[path][ix];
}
bool operator==(CurveIx const &other) const {
return other.path == path && other.ix == ix;
}
};
// represents a monotonic section of a path
struct Section {
CurveIx curve;
double f, t;
Point fp, tp;
std::vector<int> windings;
Section(CurveIx cix, double fd, double td, Point fdp, Point tdp) : curve(cix), f(fd), t(td), fp(fdp), tp(tdp) { }
Section(CurveIx cix, double fd, double td, PathVector ps, Dim2 d) : curve(cix), f(fd), t(td) {
fp = curve.get(ps).pointAt(f), tp = curve.get(ps).pointAt(t);
if (Point::LexOrderRt(d)(tp, fp)) {
//swap from and to, since tp is left or above fp
std::swap(f, t);
std::swap(fp, tp);
}
}
Rect bbox() const { return Rect(fp, tp); }
bool operator==(Section const &other) const {
return (curve == other.curve) && (f == other.f) && (t == other.t);
}
};
class TopoGraph {
public:
// Represents an e double tol;dge on a vertex
class Edge {
public:
boost::shared_ptr<Section> section; // section associated with this edge
unsigned other; // index of the vertex this edge points to
Edge(boost::shared_ptr<Section> s, unsigned o) : section(s), other(o) {}
};
// Represents a vertex in the graph, in terms of a point and edges which enter and exit.
// A vertex has an "avg" point, which is a representative point for the vertex. All
// edges have an endpoint tol away.
class Vertex {
public:
std::vector<Edge> enters, exits; // indexes of the enter / exit edges
Point avg;
Vertex(Point p) : avg(p) {}
inline unsigned degree() const { return enters.size() + exits.size(); }
Edge operator[](unsigned ix) const;
Edge &operator[](unsigned ix);
void erase(unsigned ix);
void insert(unsigned ix, Edge e);
unsigned find_section(boost::shared_ptr<Section> section) const;
};
TopoGraph(PathVector const &ps, Dim2 d, double t);
unsigned size() const { return vertices.size(); }
Vertex &operator[](unsigned ix) { return vertices[ix]; }
Vertex const &operator[](unsigned ix) const { return vertices[ix]; }
//removes both edges, and returns the vertices[ix][jx] one
Edge remove_edge(unsigned ix, unsigned jx);
//returns a graph with all zero degree vertices and unused edges removed
void cannonize();
//checks invariants
void assert_invariants() const;
std::vector<Vertex> vertices;
Dim2 dim;
double tol;
};
//TODO: convert to classes
typedef std::vector<boost::shared_ptr<Section> > Area;
typedef std::vector<Area> Areas;
//TopoGraph sweep_graph(PathVector const &ps, Dim2 d = X, double tol = 0.00001);
void trim_whiskers(TopoGraph &g);
void double_whiskers(TopoGraph &g);
//void remove_degenerate(TopoGraph &g);
//void remove_vestigial(TopoGraph &g);
//Areas traverse_areas(TopoGraph const &g);
void remove_area_whiskers(Areas &areas);
PathVector areas_to_paths(PathVector const &ps, Areas const &areas);
class SectionSorter {
const PathVector &ps;
Dim2 dim;
double tol;
bool section_order(Section const &a, double at, Section const &b, double bt) const;
public:
typedef Section first_argument_type;
typedef Section second_argument_type;
typedef bool result_type;
SectionSorter(const PathVector &rs, Dim2 d, double t = 0.00001) : ps(rs), dim(d), tol(t) {}
bool operator()(Section const &a, Section const &b) const;
};
//sorter used to create the initial sweep of sections, such that they are dealt with in order
struct SweepSorter {
typedef Section first_argument_type;
typedef Section second_argument_type;
typedef bool result_type;
Dim2 dim;
SweepSorter(Dim2 d) : dim(d) {}
bool operator()(const Section &a, const Section &b) const {
return Point::LexOrderRt(dim)(a.fp, b.fp);
}
};
struct UnionOp {
unsigned ix;
bool nz1, nz2;
UnionOp(unsigned i, bool a, bool b) : ix(i), nz1(a), nz2(b) {}
bool operator()(std::vector<int> const &windings) const {
int w1 = 0, w2 = 0;
for(unsigned j = 0; j < ix; j++) w1 += windings[j];
for(unsigned j = ix; j < windings.size(); j++) w2 += windings[j];
return (nz1 ? w1 : w1 % 2) != 0 || (nz2 ? w2 : w2 % 2) != 0;
}
};
//returns all areas for which the winding -> bool function yields true
template<class Z>
Areas filter_areas(PathVector const &ps, Areas const & areas, Z const &z) {
Areas ret;
SweepSorter sorty = SweepSorter(Y);
SectionSorter sortx = SectionSorter(ps, X);
for(unsigned i = 0; i < areas.size(); i++) {
if(areas[i].size() < 2) continue;
//find a representative section
unsigned rj = 0;
bool rev = are_near(areas[i][0]->fp, areas[i][1]->tp);
for(unsigned j = 1; j < areas[i].size(); j++)
if(sorty(*areas[i][rj], *areas[i][j])) rj = j;
if(sortx(*areas[i][rj], *areas[i][(rj+areas[i].size() - 1) % areas[i].size()])) {
rj = 0;
for(unsigned j = 1; j < areas[i].size(); j++)
if(sorty(*areas[i][j], *areas[i][rj])) rj = j;
}
if(z(areas[i][rj]->windings)) ret.push_back(areas[i]);
}
return ret;
}
} // end namespace Geom
#endif // SEEN_GEOM_TOPOSWEEP_H
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
|