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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
|
/*
Copyright 2008 Intel Corporation
Use, modification and distribution are subject to the Boost Software License,
Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt).
*/
#ifndef BOOST_POLYGON_MAX_COVER_HPP
#define BOOST_POLYGON_MAX_COVER_HPP
namespace boost { namespace polygon{
template <typename Unit>
struct MaxCover {
typedef interval_data<Unit> Interval;
typedef rectangle_data<Unit> Rectangle;
class Node {
private:
std::vector<Node*> children_;
std::set<Interval> tracedPaths_;
public:
Rectangle rect;
Node() : children_(), tracedPaths_(), rect() {}
Node(const Rectangle rectIn) : children_(), tracedPaths_(), rect(rectIn) {}
typedef typename std::vector<Node*>::iterator iterator;
inline iterator begin() { return children_.begin(); }
inline iterator end() { return children_.end(); }
inline void add(Node* child) { children_.push_back(child); }
inline bool tracedPath(const Interval& ivl) const {
return tracedPaths_.find(ivl) != tracedPaths_.end();
}
inline void addPath(const Interval& ivl) {
tracedPaths_.insert(tracedPaths_.end(), ivl);
}
};
typedef std::pair<std::pair<Unit, Interval>, Node* > EdgeAssociation;
class lessEdgeAssociation : public std::binary_function<const EdgeAssociation&, const EdgeAssociation&, bool> {
public:
inline lessEdgeAssociation() {}
inline bool operator () (const EdgeAssociation& elem1, const EdgeAssociation& elem2) const {
if(elem1.first.first < elem2.first.first) return true;
if(elem1.first.first > elem2.first.first) return false;
return elem1.first.second < elem2.first.second;
}
};
template <class cT>
static inline void getMaxCover(cT& outputContainer, Node* node, orientation_2d orient) {
Interval rectIvl = node->rect.get(orient);
if(node->tracedPath(rectIvl)) {
return;
}
node->addPath(rectIvl);
if(node->begin() == node->end()) {
//std::cout << "WRITE OUT 3: " << node->rect << std::endl;
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(node->rect));
return;
}
bool writeOut = true;
for(typename Node::iterator itr = node->begin(); itr != node->end(); ++itr) {
getMaxCover(outputContainer, *itr, orient, node->rect); //get rectangles down path
Interval nodeIvl = (*itr)->rect.get(orient);
if(contains(nodeIvl, rectIvl, true)) writeOut = false;
}
if(writeOut) {
//std::cout << "WRITE OUT 2: " << node->rect << std::endl;
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(node->rect));
}
}
struct stack_element {
inline stack_element() :
node(), rect(), itr() {}
inline stack_element(Node* n,
const Rectangle& r,
typename Node::iterator i) :
node(n), rect(r), itr(i) {}
Node* node;
Rectangle rect;
typename Node::iterator itr;
};
template <class cT>
static inline void getMaxCover(cT& outputContainer, Node* node, orientation_2d orient,
Rectangle rect) {
//std::cout << "New Root\n";
std::vector<stack_element> stack;
typename Node::iterator itr = node->begin();
do {
//std::cout << "LOOP\n";
//std::cout << node->rect << std::endl;
Interval rectIvl = rect.get(orient);
Interval nodeIvl = node->rect.get(orient);
bool iresult = intersect(rectIvl, nodeIvl, false);
bool tresult = !node->tracedPath(rectIvl);
//std::cout << (itr != node->end()) << " " << iresult << " " << tresult << std::endl;
Rectangle nextRect1 = Rectangle(rectIvl, rectIvl);
Unit low = rect.get(orient.get_perpendicular()).low();
Unit high = node->rect.get(orient.get_perpendicular()).high();
nextRect1.set(orient.get_perpendicular(), Interval(low, high));
if(iresult && tresult) {
node->addPath(rectIvl);
bool writeOut = true;
//check further visibility beyond this node
for(typename Node::iterator itr2 = node->begin(); itr2 != node->end(); ++itr2) {
Interval nodeIvl3 = (*itr2)->rect.get(orient);
//if a child of this node can contain the interval then we can extend through
if(contains(nodeIvl3, rectIvl, true)) writeOut = false;
//std::cout << "child " << (*itr2)->rect << std::endl;
}
Rectangle nextRect2 = Rectangle(rectIvl, rectIvl);
Unit low2 = rect.get(orient.get_perpendicular()).low();
Unit high2 = node->rect.get(orient.get_perpendicular()).high();
nextRect2.set(orient.get_perpendicular(), Interval(low2, high2));
if(writeOut) {
//std::cout << "write out " << nextRect << std::endl;
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(nextRect2));
} else {
//std::cout << "suppress " << nextRect << std::endl;
}
}
if(itr != node->end() && iresult && tresult) {
//std::cout << "recurse into child\n";
stack.push_back(stack_element(node, rect, itr));
rect = nextRect1;
node = *itr;
itr = node->begin();
} else {
if(!stack.empty()) {
//std::cout << "recurse out of child\n";
node = stack.back().node;
rect = stack.back().rect;
itr = stack.back().itr;
stack.pop_back();
} else {
//std::cout << "empty stack\n";
//if there were no children of the root node
// Rectangle nextRect = Rectangle(rectIvl, rectIvl);
// Unit low = rect.get(orient.get_perpendicular()).low();
// Unit high = node->rect.get(orient.get_perpendicular()).high();
// nextRect.set(orient.get_perpendicular(), Interval(low, high));
// outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(nextRect));
}
//std::cout << "increment " << (itr != node->end()) << std::endl;
if(itr != node->end()) {
++itr;
if(itr != node->end()) {
//std::cout << "recurse into next child.\n";
stack.push_back(stack_element(node, rect, itr));
Interval rectIvl2 = rect.get(orient);
Interval nodeIvl2 = node->rect.get(orient);
/*bool iresult =*/ intersect(rectIvl2, nodeIvl2, false);
Rectangle nextRect2 = Rectangle(rectIvl2, rectIvl2);
Unit low2 = rect.get(orient.get_perpendicular()).low();
Unit high2 = node->rect.get(orient.get_perpendicular()).high();
nextRect2.set(orient.get_perpendicular(), Interval(low2, high2));
rect = nextRect2;
//std::cout << "rect for next child" << rect << std::endl;
node = *itr;
itr = node->begin();
}
}
}
} while(!stack.empty() || itr != node->end());
}
/* Function recursive version of getMaxCover
Because the code is so much simpler than the loop algorithm I retain it for clarity
template <class cT>
static inline void getMaxCover(cT& outputContainer, Node* node, orientation_2d orient,
const Rectangle& rect) {
Interval rectIvl = rect.get(orient);
Interval nodeIvl = node->rect.get(orient);
if(!intersect(rectIvl, nodeIvl, false)) {
return;
}
if(node->tracedPath(rectIvl)) {
return;
}
node->addPath(rectIvl);
Rectangle nextRect(rectIvl, rectIvl);
Unit low = rect.get(orient.get_perpendicular()).low();
Unit high = node->rect.get(orient.get_perpendicular()).high();
nextRect.set(orient.get_perpendicular(), Interval(low, high));
bool writeOut = true;
rectIvl = nextRect.get(orient);
for(typename Node::iterator itr = node->begin(); itr != node->end(); ++itr) {
nodeIvl = (*itr)->rect.get(orient);
if(contains(nodeIvl, rectIvl, true)) writeOut = false;
}
if(writeOut) {
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(nextRect));
}
for(typename Node::iterator itr = node->begin(); itr != node->end(); ++itr) {
getMaxCover(outputContainer, *itr, orient, nextRect);
}
}
*/
//iterator range is assummed to be in topological order meaning all node's trailing
//edges are in sorted order
template <class iT>
static inline void computeDag(iT beginNode, iT endNode, orientation_2d orient,
std::size_t size) {
std::vector<EdgeAssociation> leadingEdges;
leadingEdges.reserve(size);
for(iT iter = beginNode; iter != endNode; ++iter) {
Node* nodep = &(*iter);
Unit leading = nodep->rect.get(orient.get_perpendicular()).low();
Interval rectIvl = nodep->rect.get(orient);
leadingEdges.push_back(EdgeAssociation(std::pair<Unit, Interval>(leading, rectIvl), nodep));
}
polygon_sort(leadingEdges.begin(), leadingEdges.end(), lessEdgeAssociation());
typename std::vector<EdgeAssociation>::iterator leadingBegin = leadingEdges.begin();
iT trailingBegin = beginNode;
while(leadingBegin != leadingEdges.end()) {
EdgeAssociation& leadingSegment = (*leadingBegin);
Unit trailing = (*trailingBegin).rect.get(orient.get_perpendicular()).high();
Interval ivl = (*trailingBegin).rect.get(orient);
std::pair<Unit, Interval> trailingSegment(trailing, ivl);
if(leadingSegment.first.first < trailingSegment.first) {
++leadingBegin;
continue;
}
if(leadingSegment.first.first > trailingSegment.first) {
++trailingBegin;
continue;
}
if(leadingSegment.first.second.high() <= trailingSegment.second.low()) {
++leadingBegin;
continue;
}
if(trailingSegment.second.high() <= leadingSegment.first.second.low()) {
++trailingBegin;
continue;
}
//leading segment intersects trailing segment
(*trailingBegin).add((*leadingBegin).second);
if(leadingSegment.first.second.high() > trailingSegment.second.high()) {
++trailingBegin;
continue;
}
if(trailingSegment.second.high() > leadingSegment.first.second.high()) {
++leadingBegin;
continue;
}
++leadingBegin;
++trailingBegin;
}
}
template <class cT>
static inline void getMaxCover(cT& outputContainer,
const std::vector<Rectangle>& rects, orientation_2d orient) {
if(rects.empty()) return;
std::vector<Node> nodes;
{
if(rects.size() == 1) {
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(rects[0]));
return;
}
nodes.reserve(rects.size());
for(std::size_t i = 0; i < rects.size(); ++i) { nodes.push_back(Node(rects[i])); }
}
computeDag(nodes.begin(), nodes.end(), orient, nodes.size());
for(std::size_t i = 0; i < nodes.size(); ++i) {
getMaxCover(outputContainer, &(nodes[i]), orient);
}
}
};
}
}
#endif
|
