OpenMesh: OpenMesh/Tools/Utils/HeapT.hh Source File

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HeapT.hh
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67 //=============================================================================
68 //
69 // CLASS HeapT
70 //
71 //=============================================================================
72
73 #ifndef OPENMESH_UTILS_HEAPT_HH
74 #define OPENMESH_UTILS_HEAPT_HH
75
76
77 //== INCLUDES =================================================================
78
79 #include "Config.hh"
80 #include <vector>
81 #include <OpenMesh/Core/System/omstream.hh>
82 #if (defined(_MSC_VER) && (_MSC_VER >= 1800)) || __cplusplus > 199711L || defined(__GXX_EXPERIMENTAL_CXX0X__)
83 #include <utility>
84 #endif
85
86 //== NAMESPACE ================================================================
87
88 namespace OpenMesh { // BEGIN_NS_OPENMESH
89 namespace Utils { // BEGIN_NS_UTILS
90
91 //== CLASS DEFINITION =========================================================
92
93
102 template <class HeapEntry>
103 struct HeapInterfaceT
104 {
106 bool less(const HeapEntry& _e1, const HeapEntry& _e2);
107
109 bool greater(const HeapEntry& _e1, const HeapEntry& _e2);
110
112 int get_heap_position(const HeapEntry& _e);
113
115 void set_heap_position(HeapEntry& _e, int _i);
116 };
117
118
119
142 template <class HeapEntry, class HeapInterface=HeapEntry>
143 class HeapT : private std::vector<HeapEntry>
144 {
145 private:
146 typedef std::vector<HeapEntry> Base;
147
148 public:
149
151 HeapT() : HeapVector() {}
152
153 #if (defined(_MSC_VER) && (_MSC_VER >= 1800)) || __cplusplus > 199711L || defined(__GXX_EXPERIMENTAL_CXX0X__)
154 HeapT(HeapInterface _interface)
156 : HeapVector(), interface_(std::move(_interface))
157 {}
158 #else
159 HeapT(const HeapInterface &_interface)
161 : HeapVector(), interface_(_interface)
162 {}
163 #endif
164
166 ~HeapT(){};
167
168 HeapInterface &getInterface() {
169 return interface_;
170 }
171
172 const HeapInterface &getInterface() const {
173 return interface_;
174 }
175
177 void clear() { HeapVector::clear(); }
178
180 bool empty() const { return HeapVector::empty(); }
181
183 size_t size() const { return HeapVector::size(); }
184
186 void reserve(size_t _n) { HeapVector::reserve(_n); }
187
189 void reset_heap_position(HeapEntry _h)
190 { interface_.set_heap_position(_h, -1); }
191
193 bool is_stored(HeapEntry _h)
194 { return interface_.get_heap_position(_h) != -1; }
195
197 void insert(HeapEntry _h)
198 {
199 this->push_back(_h);
200 upheap(size()-1);
201 }
202
204 HeapEntry front() const
205 {
206 assert(!empty());
207 return HeapVector::front();
208 }
209
211 void pop_front()
212 {
213 assert(!empty());
214 reset_heap_position(HeapVector::front());
215 if (size() > 1)
216 {
217 entry(0, entry(size()-1));
218 Base::pop_back();
219 downheap(0);
220 }
221 else
222 {
223 Base::pop_back();
224 }
225 }
226
228 void remove(HeapEntry _h)
229 {
230 int pos = interface_.get_heap_position(_h);
231 reset_heap_position(_h);
232
233 assert(pos != -1);
234 assert((unsigned int) pos < size());
235
236 // last item ?
237 if ((unsigned int) pos == size()-1)
238 {
239 Base::pop_back();
240 }
241 else
242 {
243 entry(pos, entry(size()-1)); // move last elem to pos
244 Base::pop_back();
245 downheap(pos);
246 upheap(pos);
247 }
248 }
249
253 void update(HeapEntry _h)
254 {
255 int pos = interface_.get_heap_position(_h);
256 assert(pos != -1);
257 assert((unsigned int)pos < size());
258 downheap(pos);
259 upheap(pos);
260 }
261
263 bool check()
264 {
265 bool ok(true);
266 unsigned int i, j;
267 for (i=0; i<size(); ++i)
268 {
269 if (((j=left(i))<size()) && interface_.greater(entry(i), entry(j)))
270 {
271 omerr() << "Heap condition violated\n";
272 ok=false;
273 }
274 if (((j=right(i))<size()) && interface_.greater(entry(i), entry(j)))
275 {
276 omerr() << "Heap condition violated\n";
277 ok=false;
278 }
279 }
280 return ok;
281 }
282
283 protected:
285 HeapInterface interface_;
286
287 private:
288 // typedef
289 typedef std::vector<HeapEntry> HeapVector;
290
291
293 void upheap(size_t _idx);
294
295
297 void downheap(size_t _idx);
298
299
301 inline HeapEntry entry(size_t _idx) const
302 {
303 assert(_idx < size());
304 return (Base::operator[](_idx));
305 }
306
307
309 inline void entry(size_t _idx, HeapEntry _h)
310 {
311 assert(_idx < size());
312 Base::operator[](_idx) = _h;
313 interface_.set_heap_position(_h, int(_idx));
314 }
315
316
318 inline size_t parent(size_t _i) { return (_i-1)>>1; }
320 inline size_t left(size_t _i) { return (_i<<1)+1; }
322 inline size_t right(size_t _i) { return (_i<<1)+2; }
323
324 };
325
326
327
328
329 //== IMPLEMENTATION ==========================================================
330
331
332 template <class HeapEntry, class HeapInterface>
333 void
334 HeapT<HeapEntry, HeapInterface>::
335 upheap(size_t _idx)
336 {
337 HeapEntry h = entry(_idx);
338 size_t parentIdx;
339
340 while ((_idx>0) && interface_.less(h, entry(parentIdx=parent(_idx))))
341 {
342 entry(_idx, entry(parentIdx));
343 _idx = parentIdx;
344 }
345
346 entry(_idx, h);
347 }
348
349
350 //-----------------------------------------------------------------------------
351
352
353 template <class HeapEntry, class HeapInterface>
354 void
355 HeapT<HeapEntry, HeapInterface>::
356 downheap(size_t _idx)
357 {
358 const HeapEntry h = entry(_idx);
359 size_t childIdx;
360 const size_t s = size();
361
362 while(_idx < s)
363 {
364 childIdx = left(_idx);
365 if (childIdx >= s) break;
366
367 if ((childIdx + 1 < s) && (interface_.less(entry(childIdx + 1), entry(childIdx))))
368 ++childIdx;
369
370 if (interface_.less(h, entry(childIdx))) break;
371
372 entry(_idx, entry(childIdx));
373 _idx = childIdx;
374 }
375
376 entry(_idx, h);
377 }
378
379
380 //=============================================================================
381 } // END_NS_UTILS
382 } // END_NS_OPENMESH
383 //=============================================================================
384 #endif // OSG_HEAP_HH defined
385 //=============================================================================
386
OpenMesh::Utils::HeapT::front
HeapEntry front() const
get the first entry
Definition: HeapT.hh:204
omstream.hh
This file provides the streams omlog, omout, and omerr.
OpenMesh::Utils::HeapT::clear
void clear()
clear the heap
Definition: HeapT.hh:177
Config.hh
OpenMesh::Utils::HeapInterfaceT::less
bool less(const HeapEntry &_e1, const HeapEntry &_e2)
Comparison of two HeapEntry&#39;s: strict less.
OpenMesh::Utils::HeapT::is_stored
bool is_stored(HeapEntry _h)
is an entry in the heap?
Definition: HeapT.hh:193
OpenMesh::Utils::HeapT::insert
void insert(HeapEntry _h)
insert the entry _h
Definition: HeapT.hh:197
OpenMesh::Utils::HeapT::reserve
void reserve(size_t _n)
reserve space for _n entries
Definition: HeapT.hh:186
OpenMesh
Contains all the mesh ingredients like the polygonal mesh, the triangle mesh, different mesh kernels ...
Definition: MeshItems.hh:64
OpenMesh::Utils::HeapT::update
void update(HeapEntry _h)
update an entry: change the key and update the position to reestablish the heap property.
Definition: HeapT.hh:253
OpenMesh::Utils::HeapT::empty
bool empty() const
is heap empty?
Definition: HeapT.hh:180
OpenMesh::Utils::HeapInterfaceT::get_heap_position
int get_heap_position(const HeapEntry &_e)
Get the heap position of HeapEntry _e.
OpenMesh::Utils::HeapInterfaceT::set_heap_position
void set_heap_position(HeapEntry &_e, int _i)
Set the heap position of HeapEntry _e.
OpenMesh::Utils::HeapT::~HeapT
~HeapT()
Destructor.
Definition: HeapT.hh:166
OpenMesh::Utils::HeapT::check
bool check()
check heap condition
Definition: HeapT.hh:263
OpenMesh::Utils::HeapT::size
size_t size() const
returns the size of heap
Definition: HeapT.hh:183
OpenMesh::Utils::HeapT::HeapT
HeapT()
Constructor.
Definition: HeapT.hh:151
OpenMesh::Utils::HeapT
An efficient, highly customizable heap.
Definition: HeapT.hh:143
OpenMesh::Utils::HeapT::interface_
HeapInterface interface_
Instance of HeapInterface.
Definition: HeapT.hh:285
OpenMesh::Utils::HeapInterfaceT::greater
bool greater(const HeapEntry &_e1, const HeapEntry &_e2)
Comparison of two HeapEntry&#39;s: strict greater.
OpenMesh::Utils::HeapT::pop_front
void pop_front()
delete the first entry
Definition: HeapT.hh:211
OpenMesh::Utils::HeapT::reset_heap_position
void reset_heap_position(HeapEntry _h)
reset heap position to -1 (not in heap)
Definition: HeapT.hh:189
OpenMesh::Utils::HeapInterfaceT
This class demonstrates the HeapInterface&#39;s interface.
Definition: HeapT.hh:103