1 // Copyright (C) 2007-2024 CEA, EDF
3 // This library is free software; you can redistribute it and/or
4 // modify it under the terms of the GNU Lesser General Public
5 // License as published by the Free Software Foundation; either
6 // version 2.1 of the License, or (at your option) any later version.
8 // This library is distributed in the hope that it will be useful,
9 // but WITHOUT ANY WARRANTY; without even the implied warranty of
10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 // Lesser General Public License for more details.
13 // You should have received a copy of the GNU Lesser General Public
14 // License along with this library; if not, write to the Free Software
15 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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20 #include "TransformedTriangle.hxx"
21 #include "VectorUtils.hxx"
22 #include "TetraAffineTransform.hxx"
32 namespace INTERP_KERNEL
36 * \brief Class representing a circular order of a set of points around their barycenter.
37 * It is used with the STL sort() algorithm to sort the point of the two polygons
40 class ProjectedCentralCircularSortOrder
44 /// Enumeration of different planes to project on when calculating order
45 enum CoordType { XY, XZ, YZ };
50 * @param barycenter double[3] containing the barycenter of the points to be compared
51 * @param type plane to project on when comparing. The comparison will not work if all the points are in a plane perpendicular
52 * to the plane being projected on
54 ProjectedCentralCircularSortOrder(const double* barycenter, const CoordType type)
55 : _aIdx((type == YZ) ? 1 : 0),
56 _bIdx((type == XY) ? 1 : 2),
57 _a(barycenter[_aIdx]),
63 * Comparison operator.
64 * Compares the relative position between two points in their ordering around the barycenter.
66 * @param pt1 a double[3] representing a point
67 * @param pt2 a double[3] representing a point
68 * @return true if the angle of the difference vector between pt1 and the barycenter is greater than that
69 * of the difference vector between pt2 and the barycenter.
71 bool operator()(const double* pt1, const double* pt2)
73 // calculate angles with the axis
74 // const double ang1 = atan2(pt1[_aIdx] - _a, pt1[_bIdx] - _b);
75 // const double ang2 = atan2(pt2[_aIdx] - _a, pt2[_bIdx] - _b);
77 // A ***much*** faster alternative to atan2 to get a pseudo-angle suitable for sorting:
78 // https://stackoverflow.com/questions/16542042/fastest-way-to-sort-vectors-by-angle-without-actually-computing-that-angle
79 const double dy1 = pt1[_aIdx] - _a, dx1 = pt1[_bIdx] - _b,
80 dy2 = pt2[_aIdx] - _a, dx2 = pt2[_bIdx] - _b;
81 const double ang1 = std::copysign(1. - dx1/(std::fabs(dx1)+fabs(dy1)),dy1);
82 const double ang2 = std::copysign(1. - dx2/(std::fabs(dx2)+fabs(dy2)),dy2);
88 /// index corresponding to first coordinate of plane on which points are projected
91 /// index corresponding to second coordinate of plane on which points are projected
94 /// value of first projected coordinate of the barycenter
97 /// value of second projected coordinate of the barycenter
101 // ----------------------------------------------------------------------------------
102 // TransformedTriangle PUBLIC
103 // ----------------------------------------------------------------------------------
108 * The coordinates are copied to the internal member variables
110 * @param p array of three doubles containing coordinates of P
111 * @param q array of three doubles containing coordinates of Q
112 * @param r array of three doubles containing coordinates of R
114 TransformedTriangle::TransformedTriangle(double* p, double* q, double* r)
115 : _is_double_products_calculated(false), _is_triple_products_calculated(false), _volume(0)
118 for(int i = 0 ; i < 3 ; ++i)
121 _coords[5*P + i] = p[i];
122 _coords[5*Q + i] = q[i];
123 _coords[5*R + i] = r[i];
128 _coords[5*P + 3] = 1 - p[0] - p[1] - p[2];
129 _coords[5*Q + 3] = 1 - q[0] - q[1] - q[2];
130 _coords[5*R + 3] = 1 - r[0] - r[1] - r[2];
132 // Handle degenerated case where one of the seg of PQR is (almost) inside XYZ plane,
133 // and hence by extension when the whole PQR triangle is in the XYZ plane
134 handleDegenerateCases();
137 _coords[5*P + 4] = 1 - p[0] - p[1];
138 _coords[5*Q + 4] = 1 - q[0] - q[1];
139 _coords[5*R + 4] = 1 - r[0] - r[1];
141 // initialise rest of data
142 preCalculateDoubleProducts();
144 preCalculateTriangleSurroundsEdge();
146 preCalculateTripleProducts();
153 * Deallocates the memory used to store the points of the polygons.
154 * This memory is allocated in calculateIntersectionAndProjectionPolygons().
156 TransformedTriangle::~TransformedTriangle()
158 // delete elements of polygons
159 for(auto& it: _polygonA)
161 for(auto& it: _polygonB)
166 * Calculates the volume of intersection between the triangle and the
169 * @return volume of intersection of this triangle with unit tetrahedron,
170 * as described in Grandy
173 double TransformedTriangle::calculateIntersectionVolume()
175 // check first that we are not below z - plane
176 if(isTriangleBelowTetraeder())
178 LOG(2, " --- Triangle is below tetraeder - V = 0.0");
182 // get the sign of the volume - equal to the sign of the z-component of the normal
183 // of the triangle, u_x * v_y - u_y * v_x, where u = q - p and v = r - p
184 // if it is zero, the triangle is perpendicular to the z - plane and so the volume is zero
185 // const double uv_xy[4] =
187 // _coords[5*Q] - _coords[5*P], _coords[5*Q + 1] - _coords[5*P + 1], // u_x, u_y
188 // _coords[5*R] - _coords[5*P], _coords[5*R + 1] - _coords[5*P + 1] // v_x, v_y
191 // double sign = uv_xy[0] * uv_xy[3] - uv_xy[1] * uv_xy[2];
192 int sign = isTriangleInclinedToFacet( OXY );
196 LOG(2, " --- Triangle is perpendicular to z-plane - V = 0.0");
197 return _volume = 0.0;
202 //sign = sign > 0.0 ? 1.0 : -1.0;
204 LOG(2, "-- Calculating intersection polygons ... ");
205 calculateIntersectionAndProjectionPolygons();
207 double barycenter[3];
209 // calculate volume under A
211 if(_polygonA.size() > 2)
213 LOG(2, "---- Treating polygon A ... ");
215 LOG(3, " --- Final points in polygon A");
216 for(const auto& pt: _polygonA)
219 calculatePolygonBarycenter(A, barycenter);
220 sortIntersectionPolygon(A, barycenter);
221 volA = calculateVolumeUnderPolygon(A, barycenter);
222 LOG(2, "Volume is " << sign * volA);
226 // if triangle is not in h = 0 plane, calculate volume under B
227 if(_polygonB.size() > 2 && !isTriangleInPlaneOfFacet(XYZ)) // second condition avoids double counting in case triangle fully included in h=0 facet
229 LOG(2, "---- Treating polygon B ... ");
231 LOG(3, " --- Final points in polygon B");
232 for(const auto& pt: _polygonB)
235 calculatePolygonBarycenter(B, barycenter);
236 sortIntersectionPolygon(B, barycenter);
237 volB = calculateVolumeUnderPolygon(B, barycenter);
238 LOG(2, "Volume is " << sign * volB);
242 LOG(2, "############ Triangle :")
244 LOG(2, "vol A = " << volA);
245 LOG(2, "vol B = " << volB);
246 LOG(2, "TOTAL = " << sign*(volA+volB));
249 return _volume = sign * (volA + volB);
254 * Calculates the volume of intersection between the triangle and the
257 * @return volume of intersection of this triangle with unit tetrahedron,
258 * as described in Grandy
261 double TransformedTriangle::calculateIntersectionSurface(TetraAffineTransform* tat)
263 // check first that we are not below z - plane
264 if(isTriangleBelowTetraeder())
266 LOG(2, " --- Triangle is below tetraeder - V = 0.0");
270 LOG(2, "-- Calculating intersection polygon ... ");
271 calculateIntersectionPolygon();
274 if(_polygonA.size() > 2) {
275 double barycenter[3];
276 calculatePolygonBarycenter(A, barycenter);
277 sortIntersectionPolygon(A, barycenter);
278 const std::size_t nbPoints = _polygonA.size();
279 for(std::size_t i = 0 ; i < nbPoints ; ++i)
280 tat->reverseApply(_polygonA[i], _polygonA[i]);
281 _volume = calculateSurfacePolygon();
287 // ----------------------------------------------------------------------------------
288 // TransformedTriangle PROTECTED
289 // ----------------------------------------------------------------------------------
292 * Calculates the intersection polygons A and B, performing the intersection tests
293 * and storing the corresponding points in the vectors _polygonA and _polygonB.
295 * @post _polygonA contains the intersection polygon A and _polygonB contains the
296 * intersection polygon B.
299 void TransformedTriangle::calculateIntersectionAndProjectionPolygons()
302 std::cout << " @@@@@@@@ COORDS @@@@@@ " << std::endl;
306 assert(_polygonA.size() == 0);
307 assert(_polygonB.size() == 0);
308 // avoid reallocations in push_back() by pre-allocating enough memory
309 // we should never have more than 20 points
310 _polygonA.reserve(20);
311 _polygonB.reserve(20);
312 // -- surface intersections
314 for(TetraEdge edge = OX ; edge <= ZX ; edge = TetraEdge(edge + 1))
316 if(testSurfaceEdgeIntersection(edge))
318 double* ptA = new double[3];
319 calcIntersectionPtSurfaceEdge(edge, ptA);
320 _polygonA.push_back(ptA);
321 LOG(3,"Surface-edge (edge " << strTE(edge) << "): " << vToStr(ptA) << " added to A ");
324 double* ptB = new double[3];
325 copyVector3(ptA, ptB);
326 _polygonB.push_back(ptB);
327 LOG(3,"Surface-edge (edge " << strTE(edge) << "): " << vToStr(ptB) << " added to B ");
334 for(TetraCorner corner = X ; corner < NO_TET_CORNER ; corner = TetraCorner(corner + 1))
336 if(testSurfaceRayIntersection(corner))
338 double* ptB = new double[3];
339 copyVector3(&COORDS_TET_CORNER[3 * corner], ptB);
340 _polygonB.push_back(ptB);
341 LOG(3,"Surface-ray (corner " << strTC(corner) << "): " << vToStr(ptB) << " added to B");
345 // -- segment intersections
346 for(TriSegment seg = PQ ; seg < NO_TRI_SEGMENT ; seg = TriSegment(seg + 1))
351 // check beforehand which double-products are zero.
352 for(DoubleProduct dp = C_YZ; dp < NO_DP; dp = DoubleProduct(dp + 1))
353 isZero[dp] = (calcStableC(seg, dp) == 0.0);
356 for(TetraFacet facet = OYZ ; facet < NO_TET_FACET ; facet = TetraFacet(facet + 1))
358 // is this test worth it?
360 !isZero[DP_FOR_SEG_FACET_INTERSECTION[3*facet]] &&
361 !isZero[DP_FOR_SEG_FACET_INTERSECTION[3*facet + 1]] &&
362 !isZero[DP_FOR_SEG_FACET_INTERSECTION[3*facet + 2]];
364 if(doTest && testSegmentFacetIntersection(seg, facet))
366 double* ptA = new double[3];
367 calcIntersectionPtSegmentFacet(seg, facet, ptA);
368 _polygonA.push_back(ptA);
369 LOG(3,"Segment-facet (facet " << strTF(facet) << ", seg " << strTriS(seg) << "): " << vToStr(ptA) << " added to A");
372 double* ptB = new double[3];
373 copyVector3(ptA, ptB);
374 _polygonB.push_back(ptB);
375 LOG(3,"Segment-facet (facet " << strTF(facet) << ", seg " << strTriS(seg) << "): " << vToStr(ptB) << " added to B");
382 for(TetraEdge edge = OX ; edge <= ZX ; edge = TetraEdge(edge + 1))
384 const DoubleProduct edge_dp = DoubleProduct(edge);
386 if(isZero[edge_dp] && testSegmentEdgeIntersection(seg, edge))
388 double* ptA = new double[3];
389 calcIntersectionPtSegmentEdge(seg, edge, ptA);
390 _polygonA.push_back(ptA);
391 LOG(3,"Segment-edge (edge " << strTE(edge) << ", seg " << strTriS(seg) << "): " << vToStr(ptA) << " added to A");
394 double* ptB = new double[3];
395 copyVector3(ptA, ptB);
396 _polygonB.push_back(ptB);
397 LOG(3,"Segment-edge (edge " << strTE(edge) << ", seg " << strTriS(seg) << "): " << vToStr(ptA) << " added to B");
403 for(TetraCorner corner = O ; corner < NO_TET_CORNER ; corner = TetraCorner(corner + 1))
406 isZero[DoubleProduct( EDGES_FOR_CORNER[3*corner] )] &&
407 isZero[DoubleProduct( EDGES_FOR_CORNER[3*corner+1] )] &&
408 isZero[DoubleProduct( EDGES_FOR_CORNER[3*corner+2] )];
410 if(doTest && testSegmentCornerIntersection(seg, corner))
412 double* ptA = new double[3];
413 copyVector3(&COORDS_TET_CORNER[3 * corner], ptA);
414 _polygonA.push_back(ptA);
415 LOG(3,"Segment-corner (corner " << strTC(corner) << ", seg " << strTriS(seg) << "): " << vToStr(ptA) << " added to A");
418 double* ptB = new double[3];
419 _polygonB.push_back(ptB);
420 copyVector3(&COORDS_TET_CORNER[3 * corner], ptB);
421 LOG(3,"Segment-corner (corner " << strTC(corner) << ", seg " << strTriS(seg) << "): " << vToStr(ptB) << " added to B");
427 for(TetraCorner corner = X ; corner < NO_TET_CORNER ; corner = TetraCorner(corner + 1))
429 if(isZero[DP_SEGMENT_RAY_INTERSECTION[7*(corner-1)]] && testSegmentRayIntersection(seg, corner))
431 double* ptB = new double[3];
432 copyVector3(&COORDS_TET_CORNER[3 * corner], ptB);
433 _polygonB.push_back(ptB);
434 LOG(3,"Segment-ray (corner " << strTC(corner) << ", seg " << strTriS(seg) << "): " << vToStr(ptB) << " added to B");
438 // segment - halfstrip
439 for(TetraEdge edge = XY ; edge <= ZX ; edge = TetraEdge(edge + 1))
443 const int edgeIdx = int(edge) - 3; // offset since we only care for edges XY - ZX
445 !isZero[DP_FOR_HALFSTRIP_INTERSECTION[4*edgeIdx]] &&
446 !isZero[DP_FOR_HALFSTRIP_INTERSECTION[4*edgeIdx+1]];
449 if(doTest && testSegmentHalfstripIntersection(seg, edge))
451 if(testSegmentHalfstripIntersection(seg, edge))
453 double* ptB = new double[3];
454 calcIntersectionPtSegmentHalfstrip(seg, edge, ptB);
455 _polygonB.push_back(ptB);
456 LOG(3,"Segment-halfstrip : " << vToStr(ptB) << " added to B");
462 for(TriCorner corner = P ; corner < NO_TRI_CORNER ; corner = TriCorner(corner + 1))
464 // { XYZ - inclusion only possible if in Tetrahedron?
466 if(testCornerInTetrahedron(corner))
468 double* ptA = new double[3];
469 copyVector3(&_coords[5*corner], ptA);
470 _polygonA.push_back(ptA);
471 LOG(3,"Inclusion tetrahedron (corner " << strTriC(corner) << "): " << vToStr(ptA) << " added to A");
475 if(testCornerOnXYZFacet(corner))
477 double* ptB = new double[3];
478 copyVector3(&_coords[5*corner], ptB);
479 _polygonB.push_back(ptB);
480 LOG(3,"Inclusion XYZ-plane (corner " << strTriC(corner) << "): " << vToStr(ptB) << " added to B");
483 // projection on XYZ - facet
484 if(testCornerAboveXYZFacet(corner))
486 double* ptB = new double[3];
487 copyVector3(&_coords[5*corner], ptB);
488 ptB[2] = 1 - ptB[0] - ptB[1]; // lower z to project on XYZ
489 assert(epsilonEqual(ptB[0]+ptB[1]+ptB[2] - 1, 0.0));
490 _polygonB.push_back(ptB);
491 LOG(3,"Projection XYZ-plane (corner " << strTriC(corner) << "): " << vToStr(ptB) << " added to B");
499 * Calculates the intersection polygon A, performing the intersection tests
500 * and storing the corresponding point in the vector _polygonA.
502 * @post _polygonA contains the intersection polygon A.
505 void TransformedTriangle::calculateIntersectionPolygon()
507 assert(_polygonA.size() == 0);
508 // avoid reallocations in push_back() by pre-allocating enough memory
509 // we should never have more than 20 points
510 _polygonA.reserve(20);
511 // -- surface intersections
513 for(TetraEdge edge = OX ; edge <= ZX ; edge = TetraEdge(edge + 1))
515 if(testSurfaceEdgeIntersection(edge))
517 double* ptA = new double[3];
518 calcIntersectionPtSurfaceEdge(edge, ptA);
519 _polygonA.push_back(ptA);
520 LOG(3,"Surface-edge : " << vToStr(ptA) << " added to A ");
524 // -- segment intersections
525 for(TriSegment seg = PQ ; seg < NO_TRI_SEGMENT ; seg = TriSegment(seg + 1))
530 // check beforehand which double-products are zero
531 // Test for "== 0.0" here is OK since doubleProduct has been fixed for rounding to zero already.
532 for(DoubleProduct dp = C_YZ; dp < NO_DP; dp = DoubleProduct(dp + 1))
533 isZero[dp] = (calcStableC(seg, dp) == 0.0);
536 for(TetraFacet facet = OYZ ; facet < NO_TET_FACET ; facet = TetraFacet(facet + 1))
538 // is this test worth it?
540 !isZero[DP_FOR_SEG_FACET_INTERSECTION[3*facet]] &&
541 !isZero[DP_FOR_SEG_FACET_INTERSECTION[3*facet + 1]] &&
542 !isZero[DP_FOR_SEG_FACET_INTERSECTION[3*facet + 2]];
544 if(doTest && testSegmentFacetIntersection(seg, facet))
546 double* ptA = new double[3];
547 calcIntersectionPtSegmentFacet(seg, facet, ptA);
548 _polygonA.push_back(ptA);
549 LOG(3,"Segment-facet : " << vToStr(ptA) << " added to A");
554 for(TetraEdge edge = OX ; edge <= ZX ; edge = TetraEdge(edge + 1))
556 const DoubleProduct edge_dp = DoubleProduct(edge);
558 if(isZero[edge_dp] && testSegmentEdgeIntersection(seg, edge))
560 double* ptA = new double[3];
561 calcIntersectionPtSegmentEdge(seg, edge, ptA);
562 _polygonA.push_back(ptA);
563 LOG(3,"Segment-edge : " << vToStr(ptA) << " added to A");
568 for(TetraCorner corner = O ; corner < NO_TET_CORNER ; corner = TetraCorner(corner + 1))
571 isZero[DoubleProduct( EDGES_FOR_CORNER[3*corner] )] &&
572 isZero[DoubleProduct( EDGES_FOR_CORNER[3*corner+1] )] &&
573 isZero[DoubleProduct( EDGES_FOR_CORNER[3*corner+2] )];
575 if(doTest && testSegmentCornerIntersection(seg, corner))
577 double* ptA = new double[3];
578 copyVector3(&COORDS_TET_CORNER[3 * corner], ptA);
579 _polygonA.push_back(ptA);
580 LOG(3,"Segment-corner : " << vToStr(ptA) << " added to A");
587 for(TriCorner corner = P ; corner < NO_TRI_CORNER ; corner = TriCorner(corner + 1))
589 // { XYZ - inclusion only possible if in Tetrahedron?
591 if(testCornerInTetrahedron(corner))
593 double* ptA = new double[3];
594 copyVector3(&_coords[5*corner], ptA);
595 _polygonA.push_back(ptA);
596 LOG(3,"Inclusion tetrahedron : " << vToStr(ptA) << " added to A");
605 * Returns the surface of polygon A.
607 * @return the surface of polygon A.
609 double TransformedTriangle::calculateSurfacePolygon()
611 const std::size_t nbPoints = _polygonA.size();
613 double sum[3] = {0., 0., 0.};
615 for(std::size_t i = 0 ; i < nbPoints ; ++i)
617 const double *const ptCurr = _polygonA[i]; // pt "i"
618 const double *const ptNext = _polygonA[(i + 1) % nbPoints]; // pt "i+1" (pt nbPoints == pt 0)
620 cross(ptCurr, ptNext, pdt);
624 const double surface = norm(sum) * 0.5;
625 LOG(2,"Surface is " << surface);
630 * Calculates the barycenters of the given intersection polygon.
632 * @pre the intersection polygons have been calculated with calculateIntersectionAndProjectionPolygons()
634 * @param poly one of the two intersection polygons
635 * @param barycenter array of three doubles where barycenter is stored
638 void TransformedTriangle::calculatePolygonBarycenter(const IntersectionPolygon poly, double* barycenter)
640 LOG(3,"--- Calculating polygon barycenter");
642 // get the polygon points
643 std::vector<double*>& polygon = (poly == A) ? _polygonA : _polygonB;
645 // calculate barycenter
646 const std::size_t m = polygon.size();
648 for(int j = 0 ; j < 3 ; ++j)
655 for(std::size_t i = 0 ; i < m ; ++i)
657 const double* pt = polygon[i];
658 for(int j = 0 ; j < 3 ; ++j)
660 barycenter[j] += pt[j] / double(m);
664 LOG(3,"Barycenter is " << vToStr(barycenter));
668 * Sorts the given intersection polygon in circular order around its barycenter.
669 * @pre the intersection polygons have been calculated with calculateIntersectionAndProjectionPolygons()
670 * @post the vertices in _polygonA and _polygonB are sorted in circular order around their
671 * respective barycenters
673 * @param poly one of the two intersection polygons
674 * @param barycenter array of three doubles with the coordinates of the barycenter
677 void TransformedTriangle::sortIntersectionPolygon(const IntersectionPolygon poly, const double* barycenter)
679 LOG(3,"--- Sorting polygon ...");
681 using INTERP_KERNEL::ProjectedCentralCircularSortOrder;
682 typedef ProjectedCentralCircularSortOrder SortOrder; // change is only necessary here and in constructor
683 typedef SortOrder::CoordType CoordType;
685 // get the polygon points
686 std::vector<double*>& polygon = (poly == A) ? _polygonA : _polygonB;
688 if(polygon.size() == 0)
691 // determine type of sorting
692 CoordType type = SortOrder::XY;
693 if(poly == A && !isTriangleInclinedToFacet( OXY )) // B is on h = 0 plane -> ok
695 // NB : the following test is never true if we have eliminated the
696 // triangles parallel to x == 0 and y == 0 in calculateIntersectionVolume().
697 // We keep the test here anyway, to avoid interdependency.
699 // is triangle inclined to x == 0 ?
700 type = isTriangleInclinedToFacet(OZX) ? SortOrder::XZ : SortOrder::YZ;
703 // create order object
704 SortOrder order(barycenter, type);
706 // sort vector with this object
707 // NB : do not change place of first object, with respect to which the order
709 sort((polygon.begin()), polygon.end(), order);
711 LOG(3,"Sorted polygon is ");
712 for(size_t i = 0 ; i < polygon.size() ; ++i)
714 LOG(3,vToStr(polygon[i]));
720 * Calculates the volume between the given polygon and the z = 0 plane.
722 * @pre the intersection polygones have been calculated with calculateIntersectionAndProjectionPolygons(),
723 * and they have been sorted in circular order with sortIntersectionPolygons(void)
725 * @param poly one of the two intersection polygons
726 * @param barycenter array of three doubles with the coordinates of the barycenter
727 * @return the volume between the polygon and the z = 0 plane
730 double TransformedTriangle::calculateVolumeUnderPolygon(IntersectionPolygon poly, const double* barycenter)
732 LOG(2,"--- Calculating volume under polygon");
734 // get the polygon points
735 std::vector<double*>& polygon = (poly == A) ? _polygonA : _polygonB;
738 const std::size_t m = polygon.size();
740 for(std::size_t i = 0 ; i < m ; ++i)
742 const double* ptCurr = polygon[i]; // pt "i"
743 const double* ptNext = polygon[(i + 1) % m]; // pt "i+1" (pt m == pt 0)
745 const double factor1 = ptCurr[2] + ptNext[2] + barycenter[2];
746 const double factor2 =
747 ptCurr[0]*(ptNext[1] - barycenter[1])
748 + ptNext[0]*(barycenter[1] - ptCurr[1])
749 + barycenter[0]*(ptCurr[1] - ptNext[1]);
750 vol += (factor1 * factor2) / 6.0;
753 LOG(2,"Abs. Volume is " << vol);
758 ////////////////////////////////////////////////////////////////////////////////////
759 // Detection of (very) degenerate cases /////////////
760 ////////////////////////////////////////////////////////////////////////////////////
763 * Checks if the triangle lies in the plane of a given facet
765 * @param facet one of the facets of the tetrahedron
766 * @return true if PQR lies in the plane of the facet, false if not
768 bool TransformedTriangle::isTriangleInPlaneOfFacet(const TetraFacet facet) const
770 // coordinate to check
771 const int coord = static_cast<int>(facet);
773 for(TriCorner c = P ; c < NO_TRI_CORNER ; c = TriCorner(c + 1))
774 if(_coords[5*c + coord] != 0.0)
781 * Checks if the triangle is parallel to the given facet
783 * @param facet one of the facets of the unit tetrahedron
784 * @return true if triangle is parallel to facet, false if not
786 bool TransformedTriangle::isTriangleParallelToFacet(const TetraFacet facet) const
788 // coordinate to check
789 const int coord = static_cast<int>(facet);
790 return (epsilonEqual(_coords[5*P + coord], _coords[5*Q + coord])) && (epsilonEqual(_coords[5*P + coord], _coords[5*R + coord]));
794 * Checks if the triangle is not perpedicular to the given facet
796 * @param facet one of the facets of the unit tetrahedron
797 * @return zero if the triangle is perpendicular to the facet,
798 * else 1 or -1 depending on the sign of cross product of facet edges
800 int TransformedTriangle::isTriangleInclinedToFacet(const TetraFacet facet) const
802 // coordinate to check
803 const int coord = static_cast<int>(facet);
804 const int ind1 = ( coord+1 ) % 3, ind2 = ( coord+2 ) % 3;
805 const double uv_xy[4] =
808 _coords[5*Q+ind1] - _coords[5*P+ind1], _coords[5*Q+ind2] - _coords[5*P+ind2],
810 _coords[5*R+ind1] - _coords[5*P+ind1], _coords[5*R+ind2] - _coords[5*P+ind2]
813 double sign = uv_xy[0] * uv_xy[3] - uv_xy[1] * uv_xy[2];
814 if(epsilonEqual(sign, 0.))
816 return (sign < 0.) ? -1 : (sign > 0.) ? 1 : 0;
820 * Determines whether the triangle is below the z-plane.
822 * @return true if the z-coordinate of the three corners of the triangle are all less than 0, false otherwise.
824 bool TransformedTriangle::isTriangleBelowTetraeder() const
826 for(TriCorner c = P ; c < NO_TRI_CORNER ; c = TriCorner(c + 1))
827 // check z-coords for all points
828 if(_coords[5*c + 2] >= 0.0)
835 * Prints the coordinates of the triangle to std::cout
838 void TransformedTriangle::dumpCoords() const
840 std::cout << "Coords : ";
841 for(int i = 0 ; i < 3; ++i)
842 std::cout << vToStr(&_coords[5*i]) << ",";
844 std::cout << std::endl;