160 lines
4.5 KiB
C++
160 lines
4.5 KiB
C++
/*---------------------------------------------------------------------------*\
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========= |
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\\ / F ield | foam-extend: Open Source CFD
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\\ / O peration | Version: 4.1
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\\ / A nd | Web: http://www.foam-extend.org
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\\/ M anipulation | For copyright notice see file Copyright
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-------------------------------------------------------------------------------
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License
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This file is part of foam-extend.
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foam-extend is free software: you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation, either version 3 of the License, or (at your
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option) any later version.
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foam-extend is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with foam-extend. If not, see <http://www.gnu.org/licenses/>.
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\*---------------------------------------------------------------------------*/
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#include "collapseEdge.H"
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//- Sets point neighbours of face to val
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static void markPointNbrs
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(
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const triSurface& surf,
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const label faceI,
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const bool val,
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boolList& okToCollapse
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)
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{
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const labelledTri& f = surf.localFaces()[faceI];
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forAll(f, fp)
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{
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const labelList& pFaces = surf.pointFaces()[f[fp]];
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forAll(pFaces, i)
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{
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okToCollapse[pFaces[i]] = false;
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}
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}
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}
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static triSurface pack
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(
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const triSurface& surf,
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const pointField& localPoints,
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const labelList& pointMap
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)
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{
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List<labelledTri> newTriangles(surf.size());
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label newTriangleI = 0;
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forAll(surf, faceI)
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{
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const labelledTri& f = surf.localFaces()[faceI];
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label newA = pointMap[f[0]];
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label newB = pointMap[f[1]];
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label newC = pointMap[f[2]];
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if ((newA != newB) && (newA != newC) && (newB != newC))
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{
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newTriangles[newTriangleI++] =
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labelledTri(newA, newB, newC, f.region());
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}
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}
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newTriangles.setSize(newTriangleI);
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return triSurface(newTriangles, surf.patches(), localPoints);
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}
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// Collapses small edge to point, thus removing triangle.
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label collapseEdge(triSurface& surf, const scalar minLen)
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{
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label nTotalCollapsed = 0;
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while (true)
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{
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const pointField& localPoints = surf.localPoints();
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const List<labelledTri>& localFaces = surf.localFaces();
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// Mapping from old to new points
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labelList pointMap(surf.nPoints());
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forAll(pointMap, i)
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{
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pointMap[i] = i;
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}
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// Storage for new points.
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pointField newPoints(localPoints);
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// To protect neighbours of collapsed faces.
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boolList okToCollapse(surf.size(), true);
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label nCollapsed = 0;
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forAll(localFaces, faceI)
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{
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if (okToCollapse[faceI])
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{
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// Check edge lengths.
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const labelledTri& f = localFaces[faceI];
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forAll(f, fp)
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{
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label v = f[fp];
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label v1 = f[(fp+1) % 3];
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if (mag(localPoints[v1] - localPoints[v]) < minLen)
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{
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// Collapse f[fp1] onto f[fp].
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pointMap[v1] = v;
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newPoints[v] = 0.5*(localPoints[v1] + localPoints[v]);
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Pout<< "Collapsing triange " << faceI << " to edge mid "
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<< newPoints[v] << endl;
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nCollapsed++;
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okToCollapse[faceI] = false;
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// Protect point neighbours from collapsing.
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markPointNbrs(surf, faceI, false, okToCollapse);
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break;
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}
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}
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}
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}
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Pout<< "collapseEdge : collapsing " << nCollapsed << " triangles"
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<< endl;
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nTotalCollapsed += nCollapsed;
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if (nCollapsed == 0)
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{
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break;
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}
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// Pack the triangles
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surf = pack(surf, newPoints, pointMap);
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}
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// Remove any unused vertices
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surf = triSurface(surf.localFaces(), surf.patches(), surf.localPoints());
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return nTotalCollapsed;
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}
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// ************************************************************************* //
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