GCC Code Coverage Report


Directory: ./
File: openvdb/openvdb/tools/LevelSetAdvect.h
Date: 2022-07-25 17:40:05
Exec Total Coverage
Lines: 0 151 0.0%
Functions: 0 1990 0.0%
Branches: 0 376 0.0%

Line Branch Exec Source
1 // Copyright Contributors to the OpenVDB Project
2 // SPDX-License-Identifier: MPL-2.0
3
4 /// @author Ken Museth
5 ///
6 /// @file tools/LevelSetAdvect.h
7 ///
8 /// @brief Hyperbolic advection of narrow-band level sets
9
10 #ifndef OPENVDB_TOOLS_LEVEL_SET_ADVECT_HAS_BEEN_INCLUDED
11 #define OPENVDB_TOOLS_LEVEL_SET_ADVECT_HAS_BEEN_INCLUDED
12
13 #include <tbb/parallel_for.h>
14 #include <tbb/parallel_reduce.h>
15 #include <openvdb/Platform.h>
16 #include "LevelSetTracker.h"
17 #include "VelocityFields.h" // for EnrightField
18 #include <openvdb/math/FiniteDifference.h>
19 //#include <openvdb/util/CpuTimer.h>
20 #include <functional>
21
22
23 namespace openvdb {
24 OPENVDB_USE_VERSION_NAMESPACE
25 namespace OPENVDB_VERSION_NAME {
26 namespace tools {
27
28 /// @brief Hyperbolic advection of narrow-band level sets in an
29 /// external velocity field
30 ///
31 /// The @c FieldType template argument below refers to any functor
32 /// with the following interface (see tools/VelocityFields.h
33 /// for examples):
34 ///
35 /// @code
36 /// class VelocityField {
37 /// ...
38 /// public:
39 /// openvdb::VectorType operator() (const openvdb::Coord& xyz, ValueType time) const;
40 /// ...
41 /// };
42 /// @endcode
43 ///
44 /// @note The functor method returns the velocity field at coordinate
45 /// position xyz of the advection grid, and for the specified
46 /// time. Note that since the velocity is returned in the local
47 /// coordinate space of the grid that is being advected, the functor
48 /// typically depends on the transformation of that grid. This design
49 /// is chosen for performance reasons. Finally we will assume that the
50 /// functor method is NOT threadsafe (typically uses a ValueAccessor)
51 /// and that its lightweight enough that we can copy it per thread.
52 ///
53 /// The @c InterruptType template argument below refers to any class
54 /// with the following interface:
55 /// @code
56 /// class Interrupter {
57 /// ...
58 /// public:
59 /// void start(const char* name = nullptr) // called when computations begin
60 /// void end() // called when computations end
61 /// bool wasInterrupted(int percent=-1) // return true to break computation
62 ///};
63 /// @endcode
64 ///
65 /// @note If no template argument is provided for this InterruptType
66 /// the util::NullInterrupter is used which implies that all
67 /// interrupter calls are no-ops (i.e. incurs no computational overhead).
68 ///
69
70 template<typename GridT,
71 typename FieldT = EnrightField<typename GridT::ValueType>,
72 typename InterruptT = util::NullInterrupter>
73 class LevelSetAdvection
74 {
75 public:
76 using GridType = GridT;
77 using TrackerT = LevelSetTracker<GridT, InterruptT>;
78 using LeafRange = typename TrackerT::LeafRange;
79 using LeafType = typename TrackerT::LeafType;
80 using BufferType = typename TrackerT::BufferType;
81 using ValueType = typename TrackerT::ValueType;
82 using VectorType = typename FieldT::VectorType;
83
84 /// Main constructor
85 LevelSetAdvection(GridT& grid, const FieldT& field, InterruptT* interrupt = nullptr):
86 mTracker(grid, interrupt), mField(field),
87 mSpatialScheme(math::HJWENO5_BIAS),
88 mTemporalScheme(math::TVD_RK2) {}
89
90 virtual ~LevelSetAdvection() {}
91
92 /// @brief Return the spatial finite difference scheme
93 math::BiasedGradientScheme getSpatialScheme() const { return mSpatialScheme; }
94 /// @brief Set the spatial finite difference scheme
95 void setSpatialScheme(math::BiasedGradientScheme scheme) { mSpatialScheme = scheme; }
96
97 /// @brief Return the temporal integration scheme
98 math::TemporalIntegrationScheme getTemporalScheme() const { return mTemporalScheme; }
99 /// @brief Set the spatial finite difference scheme
100 void setTemporalScheme(math::TemporalIntegrationScheme scheme) { mTemporalScheme = scheme; }
101
102 /// @brief Return the spatial finite difference scheme
103 math::BiasedGradientScheme getTrackerSpatialScheme() const {
104 return mTracker.getSpatialScheme();
105 }
106 /// @brief Set the spatial finite difference scheme
107 void setTrackerSpatialScheme(math::BiasedGradientScheme scheme) {
108 mTracker.setSpatialScheme(scheme);
109 }
110 /// @brief Return the temporal integration scheme
111 math::TemporalIntegrationScheme getTrackerTemporalScheme() const {
112 return mTracker.getTemporalScheme();
113 }
114 /// @brief Set the spatial finite difference scheme
115 void setTrackerTemporalScheme(math::TemporalIntegrationScheme scheme) {
116 mTracker.setTemporalScheme(scheme);
117 }
118
119 /// @brief Return The number of normalizations performed per track or
120 /// normalize call.
121 int getNormCount() const { return mTracker.getNormCount(); }
122 /// @brief Set the number of normalizations performed per track or
123 /// normalize call.
124 void setNormCount(int n) { mTracker.setNormCount(n); }
125
126 /// @brief Return the grain-size used for multi-threading
127 int getGrainSize() const { return mTracker.getGrainSize(); }
128 /// @brief Set the grain-size used for multi-threading.
129 /// @note A grain size of 0 or less disables multi-threading!
130 void setGrainSize(int grainsize) { mTracker.setGrainSize(grainsize); }
131
132 /// Advect the level set from its current time, time0, to its
133 /// final time, time1. If time0>time1 backward advection is performed.
134 ///
135 /// @return number of CFL iterations used to advect from time0 to time1
136 size_t advect(ValueType time0, ValueType time1);
137
138 private:
139 // disallow copy construction and copy by assignment!
140 LevelSetAdvection(const LevelSetAdvection&);// not implemented
141 LevelSetAdvection& operator=(const LevelSetAdvection&);// not implemented
142
143 // This templated private struct implements all the level set magic.
144 template<typename MapT, math::BiasedGradientScheme SpatialScheme,
145 math::TemporalIntegrationScheme TemporalScheme>
146 struct Advect
147 {
148 /// Main constructor
149 Advect(LevelSetAdvection& parent);
150 /// Shallow copy constructor called by tbb::parallel_for() threads
151 Advect(const Advect& other);
152 /// Destructor
153 virtual ~Advect() { if (mIsMaster) this->clearField(); }
154 /// Advect the level set from its current time, time0, to its final time, time1.
155 /// @return number of CFL iterations
156 size_t advect(ValueType time0, ValueType time1);
157 /// Used internally by tbb::parallel_for()
158 void operator()(const LeafRange& r) const
159 {
160 if (mTask) mTask(const_cast<Advect*>(this), r);
161 else OPENVDB_THROW(ValueError, "task is undefined - don\'t call this method directly");
162 }
163 /// method calling tbb
164 void cook(const char* msg, size_t swapBuffer = 0);
165 /// Sample field and return the CFL time step
166 typename GridT::ValueType sampleField(ValueType time0, ValueType time1);
167 template <bool Aligned> void sample(const LeafRange& r, ValueType t0, ValueType t1);
168 inline void sampleXformed(const LeafRange& r, ValueType t0, ValueType t1)
169 {
170 this->sample<false>(r, t0, t1);
171 }
172 inline void sampleAligned(const LeafRange& r, ValueType t0, ValueType t1)
173 {
174 this->sample<true>(r, t0, t1);
175 }
176 void clearField();
177 // Convex combination of Phi and a forward Euler advection steps:
178 // Phi(result) = alpha * Phi(phi) + (1-alpha) * (Phi(0) - dt * Speed(speed)*|Grad[Phi(0)]|);
179 template <int Nominator, int Denominator>
180 void euler(const LeafRange&, ValueType, Index, Index);
181 inline void euler01(const LeafRange& r, ValueType t) {this->euler<0,1>(r, t, 0, 1);}
182 inline void euler12(const LeafRange& r, ValueType t) {this->euler<1,2>(r, t, 1, 1);}
183 inline void euler34(const LeafRange& r, ValueType t) {this->euler<3,4>(r, t, 1, 2);}
184 inline void euler13(const LeafRange& r, ValueType t) {this->euler<1,3>(r, t, 1, 2);}
185
186 LevelSetAdvection& mParent;
187 VectorType* mVelocity;
188 size_t* mOffsets;
189 const MapT* mMap;
190 typename std::function<void (Advect*, const LeafRange&)> mTask;
191 const bool mIsMaster;
192 }; // end of private Advect struct
193
194 template<math::BiasedGradientScheme SpatialScheme>
195 size_t advect1(ValueType time0, ValueType time1);
196
197 template<math::BiasedGradientScheme SpatialScheme,
198 math::TemporalIntegrationScheme TemporalScheme>
199 size_t advect2(ValueType time0, ValueType time1);
200
201 template<math::BiasedGradientScheme SpatialScheme,
202 math::TemporalIntegrationScheme TemporalScheme,
203 typename MapType>
204 size_t advect3(ValueType time0, ValueType time1);
205
206 TrackerT mTracker;
207 //each thread needs a deep copy of the field since it might contain a ValueAccessor
208 const FieldT mField;
209 math::BiasedGradientScheme mSpatialScheme;
210 math::TemporalIntegrationScheme mTemporalScheme;
211
212 };//end of LevelSetAdvection
213
214
215 template<typename GridT, typename FieldT, typename InterruptT>
216 size_t
217 LevelSetAdvection<GridT, FieldT, InterruptT>::advect(ValueType time0, ValueType time1)
218 {
219 switch (mSpatialScheme) {
220 case math::FIRST_BIAS:
221 return this->advect1<math::FIRST_BIAS >(time0, time1);
222 case math::SECOND_BIAS:
223 return this->advect1<math::SECOND_BIAS >(time0, time1);
224 case math::THIRD_BIAS:
225 return this->advect1<math::THIRD_BIAS >(time0, time1);
226 case math::WENO5_BIAS:
227 return this->advect1<math::WENO5_BIAS >(time0, time1);
228 case math::HJWENO5_BIAS:
229 return this->advect1<math::HJWENO5_BIAS>(time0, time1);
230 default:
231 OPENVDB_THROW(ValueError, "Spatial difference scheme not supported!");
232 }
233 return 0;
234 }
235
236
237 template<typename GridT, typename FieldT, typename InterruptT>
238 template<math::BiasedGradientScheme SpatialScheme>
239 size_t
240 LevelSetAdvection<GridT, FieldT, InterruptT>::advect1(ValueType time0, ValueType time1)
241 {
242 switch (mTemporalScheme) {
243 case math::TVD_RK1:
244 return this->advect2<SpatialScheme, math::TVD_RK1>(time0, time1);
245 case math::TVD_RK2:
246 return this->advect2<SpatialScheme, math::TVD_RK2>(time0, time1);
247 case math::TVD_RK3:
248 return this->advect2<SpatialScheme, math::TVD_RK3>(time0, time1);
249 default:
250 OPENVDB_THROW(ValueError, "Temporal integration scheme not supported!");
251 }
252 return 0;
253 }
254
255
256 template<typename GridT, typename FieldT, typename InterruptT>
257 template<math::BiasedGradientScheme SpatialScheme, math::TemporalIntegrationScheme TemporalScheme>
258 size_t
259 LevelSetAdvection<GridT, FieldT, InterruptT>::advect2(ValueType time0, ValueType time1)
260 {
261 const math::Transform& trans = mTracker.grid().transform();
262 if (trans.mapType() == math::UniformScaleMap::mapType()) {
263 return this->advect3<SpatialScheme, TemporalScheme, math::UniformScaleMap>(time0, time1);
264 } else if (trans.mapType() == math::UniformScaleTranslateMap::mapType()) {
265 return this->advect3<SpatialScheme, TemporalScheme, math::UniformScaleTranslateMap>(
266 time0, time1);
267 } else if (trans.mapType() == math::UnitaryMap::mapType()) {
268 return this->advect3<SpatialScheme, TemporalScheme, math::UnitaryMap >(time0, time1);
269 } else if (trans.mapType() == math::TranslationMap::mapType()) {
270 return this->advect3<SpatialScheme, TemporalScheme, math::TranslationMap>(time0, time1);
271 } else {
272 OPENVDB_THROW(ValueError, "MapType not supported!");
273 }
274 return 0;
275 }
276
277
278 template<typename GridT, typename FieldT, typename InterruptT>
279 template<
280 math::BiasedGradientScheme SpatialScheme,
281 math::TemporalIntegrationScheme TemporalScheme,
282 typename MapT>
283 size_t
284 LevelSetAdvection<GridT, FieldT, InterruptT>::advect3(ValueType time0, ValueType time1)
285 {
286 Advect<MapT, SpatialScheme, TemporalScheme> tmp(*this);
287 return tmp.advect(time0, time1);
288 }
289
290
291 ///////////////////////////////////////////////////////////////////////
292
293
294 template<typename GridT, typename FieldT, typename InterruptT>
295 template<
296 typename MapT,
297 math::BiasedGradientScheme SpatialScheme,
298 math::TemporalIntegrationScheme TemporalScheme>
299 inline
300 LevelSetAdvection<GridT, FieldT, InterruptT>::
301 Advect<MapT, SpatialScheme, TemporalScheme>::
302 Advect(LevelSetAdvection& parent)
303 : mParent(parent)
304 , mVelocity(nullptr)
305 , mOffsets(nullptr)
306 , mMap(parent.mTracker.grid().transform().template constMap<MapT>().get())
307 , mTask(0)
308 , mIsMaster(true)
309 {
310 }
311
312
313 template<typename GridT, typename FieldT, typename InterruptT>
314 template<
315 typename MapT,
316 math::BiasedGradientScheme SpatialScheme,
317 math::TemporalIntegrationScheme TemporalScheme>
318 inline
319 LevelSetAdvection<GridT, FieldT, InterruptT>::
320 Advect<MapT, SpatialScheme, TemporalScheme>::
321 Advect(const Advect& other)
322 : mParent(other.mParent)
323 , mVelocity(other.mVelocity)
324 , mOffsets(other.mOffsets)
325 , mMap(other.mMap)
326 , mTask(other.mTask)
327 , mIsMaster(false)
328 {
329 }
330
331
332 template<typename GridT, typename FieldT, typename InterruptT>
333 template<
334 typename MapT,
335 math::BiasedGradientScheme SpatialScheme,
336 math::TemporalIntegrationScheme TemporalScheme>
337 inline size_t
338 LevelSetAdvection<GridT, FieldT, InterruptT>::
339 Advect<MapT, SpatialScheme, TemporalScheme>::
340 advect(ValueType time0, ValueType time1)
341 {
342 namespace ph = std::placeholders;
343
344 //util::CpuTimer timer;
345 size_t countCFL = 0;
346 if ( math::isZero(time0 - time1) ) return countCFL;
347 const bool isForward = time0 < time1;
348 while ((isForward ? time0<time1 : time0>time1) && mParent.mTracker.checkInterrupter()) {
349 /// Make sure we have enough temporal auxiliary buffers
350 //timer.start( "\nallocate buffers" );
351 mParent.mTracker.leafs().rebuildAuxBuffers(TemporalScheme == math::TVD_RK3 ? 2 : 1);
352 //timer.stop();
353
354 const ValueType dt = this->sampleField(time0, time1);
355 if ( math::isZero(dt) ) break;//V is essentially zero so terminate
356
357 OPENVDB_NO_UNREACHABLE_CODE_WARNING_BEGIN //switch is resolved at compile-time
358 switch(TemporalScheme) {
359 case math::TVD_RK1:
360 // Perform one explicit Euler step: t1 = t0 + dt
361 // Phi_t1(1) = Phi_t0(0) - dt * VdotG_t0(0)
362 mTask = std::bind(&Advect::euler01, ph::_1, ph::_2, dt);
363
364 // Cook and swap buffer 0 and 1 such that Phi_t1(0) and Phi_t0(1)
365 this->cook("Advecting level set using TVD_RK1", 1);
366 break;
367 case math::TVD_RK2:
368 // Perform one explicit Euler step: t1 = t0 + dt
369 // Phi_t1(1) = Phi_t0(0) - dt * VdotG_t0(0)
370 mTask = std::bind(&Advect::euler01, ph::_1, ph::_2, dt);
371
372 // Cook and swap buffer 0 and 1 such that Phi_t1(0) and Phi_t0(1)
373 this->cook("Advecting level set using TVD_RK1 (step 1 of 2)", 1);
374
375 // Convex combine explict Euler step: t2 = t0 + dt
376 // Phi_t2(1) = 1/2 * Phi_t0(1) + 1/2 * (Phi_t1(0) - dt * V.Grad_t1(0))
377 mTask = std::bind(&Advect::euler12, ph::_1, ph::_2, dt);
378
379 // Cook and swap buffer 0 and 1 such that Phi_t2(0) and Phi_t1(1)
380 this->cook("Advecting level set using TVD_RK1 (step 2 of 2)", 1);
381 break;
382 case math::TVD_RK3:
383 // Perform one explicit Euler step: t1 = t0 + dt
384 // Phi_t1(1) = Phi_t0(0) - dt * VdotG_t0(0)
385 mTask = std::bind(&Advect::euler01, ph::_1, ph::_2, dt);
386
387 // Cook and swap buffer 0 and 1 such that Phi_t1(0) and Phi_t0(1)
388 this->cook("Advecting level set using TVD_RK3 (step 1 of 3)", 1);
389
390 // Convex combine explict Euler step: t2 = t0 + dt/2
391 // Phi_t2(2) = 3/4 * Phi_t0(1) + 1/4 * (Phi_t1(0) - dt * V.Grad_t1(0))
392 mTask = std::bind(&Advect::euler34, ph::_1, ph::_2, dt);
393
394 // Cook and swap buffer 0 and 2 such that Phi_t2(0) and Phi_t1(2)
395 this->cook("Advecting level set using TVD_RK3 (step 2 of 3)", 2);
396
397 // Convex combine explict Euler step: t3 = t0 + dt
398 // Phi_t3(2) = 1/3 * Phi_t0(1) + 2/3 * (Phi_t2(0) - dt * V.Grad_t2(0)
399 mTask = std::bind(&Advect::euler13, ph::_1, ph::_2, dt);
400
401 // Cook and swap buffer 0 and 2 such that Phi_t3(0) and Phi_t2(2)
402 this->cook("Advecting level set using TVD_RK3 (step 3 of 3)", 2);
403 break;
404 default:
405 OPENVDB_THROW(ValueError, "Temporal integration scheme not supported!");
406 }//end of compile-time resolved switch
407 OPENVDB_NO_UNREACHABLE_CODE_WARNING_END
408
409 time0 += isForward ? dt : -dt;
410 ++countCFL;
411 mParent.mTracker.leafs().removeAuxBuffers();
412 this->clearField();
413 /// Track the narrow band
414 mParent.mTracker.track();
415 }//end wile-loop over time
416 return countCFL;//number of CLF propagation steps
417 }
418
419
420 template<typename GridT, typename FieldT, typename InterruptT>
421 template<
422 typename MapT,
423 math::BiasedGradientScheme SpatialScheme,
424 math::TemporalIntegrationScheme TemporalScheme>
425 inline typename GridT::ValueType
426 LevelSetAdvection<GridT, FieldT, InterruptT>::
427 Advect<MapT, SpatialScheme, TemporalScheme>::
428 sampleField(ValueType time0, ValueType time1)
429 {
430 namespace ph = std::placeholders;
431
432 const int grainSize = mParent.mTracker.getGrainSize();
433 const size_t leafCount = mParent.mTracker.leafs().leafCount();
434 if (leafCount==0) return ValueType(0.0);
435
436 // Compute the prefix sum of offsets to active voxels
437 size_t size=0, voxelCount=mParent.mTracker.leafs().getPrefixSum(mOffsets, size, grainSize);
438
439 // Sample the velocity field
440 if (mParent.mField.transform() == mParent.mTracker.grid().transform()) {
441 mTask = std::bind(&Advect::sampleAligned, ph::_1, ph::_2, time0, time1);
442 } else {
443 mTask = std::bind(&Advect::sampleXformed, ph::_1, ph::_2, time0, time1);
444 }
445 assert(voxelCount == mParent.mTracker.grid().activeVoxelCount());
446 mVelocity = new VectorType[ voxelCount ];
447 this->cook("Sampling advection field");
448
449 // Find the extrema of the magnitude of the velocities
450 ValueType maxAbsV = 0;
451 VectorType* v = mVelocity;
452 for (size_t i = 0; i < voxelCount; ++i, ++v) {
453 maxAbsV = math::Max(maxAbsV, ValueType(v->lengthSqr()));
454 }
455
456 // Compute the CFL number
457 if (math::isApproxZero(maxAbsV, math::Delta<ValueType>::value())) return ValueType(0);
458 static const ValueType CFL = (TemporalScheme == math::TVD_RK1 ? ValueType(0.3) :
459 TemporalScheme == math::TVD_RK2 ? ValueType(0.9) :
460 ValueType(1.0))/math::Sqrt(ValueType(3.0));
461 const ValueType dt = math::Abs(time1 - time0), dx = mParent.mTracker.voxelSize();
462 return math::Min(dt, ValueType(CFL*dx/math::Sqrt(maxAbsV)));
463 }
464
465
466 template<typename GridT, typename FieldT, typename InterruptT>
467 template<
468 typename MapT,
469 math::BiasedGradientScheme SpatialScheme,
470 math::TemporalIntegrationScheme TemporalScheme>
471 template<bool Aligned>
472 inline void
473 LevelSetAdvection<GridT, FieldT, InterruptT>::
474 Advect<MapT, SpatialScheme, TemporalScheme>::
475 sample(const LeafRange& range, ValueType time0, ValueType time1)
476 {
477 const bool isForward = time0 < time1;
478 using VoxelIterT = typename LeafType::ValueOnCIter;
479 const MapT& map = *mMap;
480 const FieldT field( mParent.mField );
481 mParent.mTracker.checkInterrupter();
482 for (typename LeafRange::Iterator leafIter = range.begin(); leafIter; ++leafIter) {
483 VectorType* vel = mVelocity + mOffsets[ leafIter.pos() ];
484 for (VoxelIterT iter = leafIter->cbeginValueOn(); iter; ++iter, ++vel) {
485 OPENVDB_NO_TYPE_CONVERSION_WARNING_BEGIN
486 const VectorType v = Aligned ? field(iter.getCoord(), time0) ://resolved at compile time
487 field(map.applyMap(iter.getCoord().asVec3d()), time0);
488 *vel = isForward ? v : -v;
489 OPENVDB_NO_TYPE_CONVERSION_WARNING_END
490 }
491 }
492 }
493
494
495 template<typename GridT, typename FieldT, typename InterruptT>
496 template<
497 typename MapT,
498 math::BiasedGradientScheme SpatialScheme,
499 math::TemporalIntegrationScheme TemporalScheme>
500 inline void
501 LevelSetAdvection<GridT, FieldT, InterruptT>::
502 Advect<MapT, SpatialScheme, TemporalScheme>::
503 clearField()
504 {
505 delete [] mOffsets;
506 delete [] mVelocity;
507 mOffsets = nullptr;
508 mVelocity = nullptr;
509 }
510
511
512 template<typename GridT, typename FieldT, typename InterruptT>
513 template<
514 typename MapT,
515 math::BiasedGradientScheme SpatialScheme,
516 math::TemporalIntegrationScheme TemporalScheme>
517 inline void
518 LevelSetAdvection<GridT, FieldT, InterruptT>::
519 Advect<MapT, SpatialScheme, TemporalScheme>::
520 cook(const char* msg, size_t swapBuffer)
521 {
522 mParent.mTracker.startInterrupter( msg );
523
524 const int grainSize = mParent.mTracker.getGrainSize();
525 const LeafRange range = mParent.mTracker.leafs().leafRange(grainSize);
526
527 grainSize == 0 ? (*this)(range) : tbb::parallel_for(range, *this);
528
529 mParent.mTracker.leafs().swapLeafBuffer(swapBuffer, grainSize == 0);
530
531 mParent.mTracker.endInterrupter();
532 }
533
534
535 // Convex combination of Phi and a forward Euler advection steps:
536 // Phi(result) = alpha * Phi(phi) + (1-alpha) * (Phi(0) - dt * V.Grad(0));
537 template<typename GridT, typename FieldT, typename InterruptT>
538 template<
539 typename MapT,
540 math::BiasedGradientScheme SpatialScheme,
541 math::TemporalIntegrationScheme TemporalScheme>
542 template <int Nominator, int Denominator>
543 inline void
544 LevelSetAdvection<GridT, FieldT, InterruptT>::
545 Advect<MapT, SpatialScheme, TemporalScheme>::
546 euler(const LeafRange& range, ValueType dt, Index phiBuffer, Index resultBuffer)
547 {
548 using SchemeT = math::BIAS_SCHEME<SpatialScheme>;
549 using StencilT = typename SchemeT::template ISStencil<GridType>::StencilType;
550 using VoxelIterT = typename LeafType::ValueOnCIter;
551 using GradT = math::GradientBiased<MapT, SpatialScheme>;
552
553 static const ValueType Alpha = ValueType(Nominator)/ValueType(Denominator);
554 static const ValueType Beta = ValueType(1) - Alpha;
555
556 mParent.mTracker.checkInterrupter();
557 const MapT& map = *mMap;
558 StencilT stencil(mParent.mTracker.grid());
559 for (typename LeafRange::Iterator leafIter = range.begin(); leafIter; ++leafIter) {
560 const VectorType* vel = mVelocity + mOffsets[ leafIter.pos() ];
561 const ValueType* phi = leafIter.buffer(phiBuffer).data();
562 ValueType* result = leafIter.buffer(resultBuffer).data();
563 for (VoxelIterT voxelIter = leafIter->cbeginValueOn(); voxelIter; ++voxelIter, ++vel) {
564 const Index i = voxelIter.pos();
565 stencil.moveTo(voxelIter);
566 const ValueType a =
567 stencil.getValue() - dt * vel->dot(GradT::result(map, stencil, *vel));
568 result[i] = Nominator ? Alpha * phi[i] + Beta * a : a;
569 }//loop over active voxels in the leaf of the mask
570 }//loop over leafs of the level set
571 }
572
573
574 ////////////////////////////////////////
575
576
577 // Explicit Template Instantiation
578
579 #ifdef OPENVDB_USE_EXPLICIT_INSTANTIATION
580
581 #ifdef OPENVDB_INSTANTIATE_LEVELSETADVECT
582 #include <openvdb/util/ExplicitInstantiation.h>
583 #endif
584
585 OPENVDB_INSTANTIATE_CLASS LevelSetAdvection<FloatGrid, DiscreteField<Vec3SGrid, BoxSampler>, util::NullInterrupter>;
586 OPENVDB_INSTANTIATE_CLASS LevelSetAdvection<DoubleGrid, DiscreteField<Vec3SGrid, BoxSampler>, util::NullInterrupter>;
587
588 #endif // OPENVDB_USE_EXPLICIT_INSTANTIATION
589
590
591 } // namespace tools
592 } // namespace OPENVDB_VERSION_NAME
593 } // namespace openvdb
594
595 #endif // OPENVDB_TOOLS_LEVEL_SET_ADVECT_HAS_BEEN_INCLUDED
596