boundarylayer 2d code in separate file

This commit is contained in:
Matthias Hochsteger 2023-04-27 15:25:15 +02:00
parent 96268d6691
commit 875da8ee45
3 changed files with 757 additions and 751 deletions

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@ -12,6 +12,7 @@ target_sources(nglib PRIVATE
parallelmesh.cpp paralleltop.cpp basegeom.cpp
python_mesh.cpp surfacegeom.cpp
debugging.cpp fieldlines.cpp visual_interface.cpp
boundarylayer2d.cpp
)
target_link_libraries( nglib PRIVATE netgen_metis "$<BUILD_INTERFACE:netgen_python>" ${ZLIB_LIBRARIES} )

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@ -1,100 +1,13 @@
#include <mystdlib.h>
#include "meshing.hpp"
#include "meshing2.hpp"
#include "delaunay2d.hpp"
#include "debugging.hpp"
#include "global.hpp"
#include "../geom2d/csg2d.hpp"
#include <set>
#include <regex>
namespace netgen
{
void InsertVirtualBoundaryLayer (Mesh & mesh)
{
cout << "Insert virt. b.l." << endl;
int surfid;
cout << "Boundary Nr:";
cin >> surfid;
int i;
int np = mesh.GetNP();
cout << "Old NP: " << mesh.GetNP() << endl;
cout << "Trigs: " << mesh.GetNSE() << endl;
NgBitArray bndnodes(np);
NgArray<int> mapto(np);
bndnodes.Clear();
for (i = 1; i <= mesh.GetNSeg(); i++)
{
int snr = mesh.LineSegment(i).edgenr;
cout << "snr = " << snr << endl;
if (snr == surfid)
{
bndnodes.Set (mesh.LineSegment(i)[0]);
bndnodes.Set (mesh.LineSegment(i)[1]);
}
}
for (i = 1; i <= mesh.GetNSeg(); i++)
{
int snr = mesh.LineSegment(i).edgenr;
if (snr != surfid)
{
bndnodes.Clear (mesh.LineSegment(i)[0]);
bndnodes.Clear (mesh.LineSegment(i)[1]);
}
}
for (i = 1; i <= np; i++)
{
if (bndnodes.Test(i))
mapto.Elem(i) = mesh.AddPoint (mesh.Point (i));
else
mapto.Elem(i) = 0;
}
for (i = 1; i <= mesh.GetNSE(); i++)
{
Element2d & el = mesh.SurfaceElement(i);
for (int j = 1; j <= el.GetNP(); j++)
if (mapto.Get(el.PNum(j)))
el.PNum(j) = mapto.Get(el.PNum(j));
}
int nq = 0;
for (i = 1; i <= mesh.GetNSeg(); i++)
{
int snr = mesh.LineSegment(i).edgenr;
if (snr == surfid)
{
int p1 = mesh.LineSegment(i)[0];
int p2 = mesh.LineSegment(i)[1];
int p3 = mapto.Get (p1);
if (!p3) p3 = p1;
int p4 = mapto.Get (p2);
if (!p4) p4 = p2;
Element2d el(QUAD);
el.PNum(1) = p1;
el.PNum(2) = p2;
el.PNum(3) = p3;
el.PNum(4) = p4;
el.SetIndex (2);
mesh.AddSurfaceElement (el);
nq++;
}
}
cout << "New NP: " << mesh.GetNP() << endl;
cout << "Quads: " << nq << endl;
}
// checks if a segment is intersecting a plane, spanned by three points, lam will be set s.t. p_intersect = seg[0] + lam * (seg[1]-seg[0])
bool isIntersectingPlane ( const array<Point<3>, 2> & seg, const array<Point<3>, 3> & trig, double & lam)
{
@ -1482,7 +1395,6 @@ namespace netgen
OptimizeVolume(mp, mesh);
}
void GenerateBoundaryLayer(Mesh& mesh, const BoundaryLayerParameters& blp)
{
static Timer timer("Create Boundarylayers");
@ -1492,666 +1404,4 @@ namespace netgen
tool.Perform();
}
void AddDirection( Vec<3> & a, Vec<3> b )
{
if(a.Length2()==0.)
{
a = b;
return;
}
if(b.Length2()==0.)
return;
auto ab = a * b;
if(fabs(ab)>1-1e-8)
return;
Mat<2> m;
m(0,0) = a[0];
m(0,1) = a[1];
m(1,0) = b[0];
m(1,1) = b[1];
Vec<2> lam;
Vec<2> rhs;
rhs[0] = a[0]-b[0];
rhs[1] = a[1]-b[1];
const auto Dot = [](Vec<3> a, Vec<3> b)
{ return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; };
rhs[0] = Dot(a,a);
rhs[1] = Dot(b,b);
m.Solve(rhs, lam);
a[0] = lam[0];
a[1] = lam[1];
a[2] = 0.0;
return;
}
static void Generate2dMesh( Mesh & mesh, int domain )
{
Box<3> box{Box<3>::EMPTY_BOX};
for(const auto & seg : mesh.LineSegments())
if (seg.domin == domain || seg.domout == domain)
for (auto pi : {seg[0], seg[1]})
box.Add(mesh[pi]);
MeshingParameters mp;
Meshing2 meshing (*mesh.GetGeometry(), mp, box);
Array<PointIndex, PointIndex> compress(mesh.GetNP());
compress = PointIndex::INVALID;
PointIndex cnt = PointIndex::BASE;
auto p2sel = mesh.CreatePoint2SurfaceElementTable();
PointGeomInfo gi;
gi.u = 0.0;
gi.v = 0.0;
gi.trignum = domain;
for(auto seg : mesh.LineSegments())
{
if(seg.domin == domain || seg.domout == domain)
for (auto pi : {seg[0], seg[1]})
if (compress[pi]==PointIndex{PointIndex::INVALID})
{
meshing.AddPoint(mesh[pi], pi);
compress[pi] = cnt++;
}
if(seg.domin == domain)
meshing.AddBoundaryElement (compress[seg[0]], compress[seg[1]], gi, gi);
if(seg.domout == domain)
meshing.AddBoundaryElement (compress[seg[1]], compress[seg[0]], gi, gi);
}
auto oldnf = mesh.GetNSE();
auto res = meshing.GenerateMesh (mesh, mp, mp.maxh, domain);
for (SurfaceElementIndex sei : Range(oldnf, mesh.GetNSE()))
mesh[sei].SetIndex (domain);
int hsteps = mp.optsteps2d;
const char * optstr = mp.optimize2d.c_str();
MeshOptimize2d meshopt(mesh);
meshopt.SetFaceIndex(domain);
meshopt.SetMetricWeight (mp.elsizeweight);
for (size_t j = 1; j <= strlen(optstr); j++)
{
switch (optstr[j-1])
{
case 's':
{ // topological swap
meshopt.EdgeSwapping (0);
break;
}
case 'S':
{ // metric swap
meshopt.EdgeSwapping (1);
break;
}
case 'm':
{
meshopt.ImproveMesh(mp);
break;
}
case 'c':
{
meshopt.CombineImprove();
break;
}
default:
cerr << "Optimization code " << optstr[j-1] << " not defined" << endl;
}
}
mesh.Compress();
mesh.CalcSurfacesOfNode();
mesh.OrderElements();
mesh.SetNextMajorTimeStamp();
}
int GenerateBoundaryLayer2 (Mesh & mesh, int domain, const Array<double> & thicknesses, bool should_make_new_domain, const Array<int> & boundaries)
{
mesh.GetTopology().SetBuildVertex2Element(true);
mesh.UpdateTopology();
const auto & line_segments = mesh.LineSegments();
SegmentIndex first_new_seg = mesh.LineSegments().Range().Next();
int np = mesh.GetNP();
int nseg = line_segments.Size();
int ne = mesh.GetNSE();
mesh.UpdateTopology();
double total_thickness = 0.0;
for(auto thickness : thicknesses)
total_thickness += thickness;
Array<Array<PointIndex>, PointIndex> mapto(np);
// Bit array to keep track of segments already processed
BitArray segs_done(nseg);
segs_done.Clear();
// moved segments
Array<SegmentIndex> moved_segs;
Array<Vec<3>, PointIndex> growthvectors(np);
growthvectors = 0.;
auto & meshtopo = mesh.GetTopology();
Array<SegmentIndex> segments;
// surface index map
Array<int> si_map(mesh.GetNFD()+2);
si_map = -1;
int fd_old = mesh.GetNFD();
int max_edge_nr = -1;
int max_domain = -1;
for(const auto& seg : line_segments)
{
if(seg.epgeominfo[0].edgenr > max_edge_nr)
max_edge_nr = seg.epgeominfo[0].edgenr;
if(seg.domin > max_domain)
max_domain = seg.domin;
if(seg.domout > max_domain)
max_domain = seg.domout;
}
int new_domain = max_domain+1;
BitArray active_boundaries(max_edge_nr+1);
BitArray active_segments(nseg);
active_boundaries.Clear();
active_segments.Clear();
if(boundaries.Size() == 0)
active_boundaries.Set();
else
for(auto edgenr : boundaries)
active_boundaries.SetBit(edgenr);
for(auto segi : Range(line_segments))
{
const auto seg = line_segments[segi];
if(active_boundaries.Test(seg.epgeominfo[0].edgenr) && (seg.domin==domain || seg.domout==domain))
active_segments.SetBit(segi);
}
{
FaceDescriptor new_fd(0, 0, 0, -1);
new_fd.SetBCProperty(new_domain);
int new_fd_index = mesh.AddFaceDescriptor(new_fd);
if(should_make_new_domain)
mesh.SetBCName(new_domain-1, "mapped_" + mesh.GetBCName(domain-1));
}
for(auto segi : Range(line_segments))
{
if(segs_done[segi]) continue;
segs_done.SetBit(segi);
const auto& seg = line_segments[segi];
if(seg.domin != domain && seg.domout != domain) continue;
if(!active_boundaries.Test(seg.epgeominfo[0].edgenr))
continue;
moved_segs.Append(segi);
}
// calculate growth vectors (average normal vectors of adjacent segments at each point)
for (auto si : moved_segs)
{
auto & seg = line_segments[si];
auto n = mesh[seg[1]] - mesh[seg[0]];
n = {-n[1], n[0], 0};
n.Normalize();
if(seg.domout == domain)
n = -n;
AddDirection(growthvectors[seg[0]], n);
AddDirection(growthvectors[seg[1]], n);
}
//////////////////////////////////////////////////////////////////////////
// average growthvectors along straight lines to avoid overlaps in corners
BitArray points_done(np+1);
points_done.Clear();
for(auto si : moved_segs)
{
auto current_seg = line_segments[si];
auto current_si = si;
auto first = current_seg[0];
auto current = -1;
auto next = current_seg[1];
if(points_done.Test(first))
continue;
Array<PointIndex> chain;
chain.Append(first);
// first find closed loops of segments
while(next != current && next != first)
{
current = next;
points_done.SetBit(current);
chain.Append(current);
for(auto sj : meshtopo.GetVertexSegments( current ))
{
if(!active_segments.Test(sj))
continue;
if(sj!=current_si)
{
current_si = sj;
current_seg = mesh[sj];
next = current_seg[0] + current_seg[1] - current;
break;
}
}
}
auto ifirst = 0;
auto n = chain.Size();
// angle of adjacent segments at points a[i-1], a[i], a[i+1]
auto getAngle = [&mesh, &growthvectors] (FlatArray<PointIndex> a, size_t i)
{
auto n = a.Size();
auto v0 = growthvectors[a[(i+n-1)%n]];
auto v1 = growthvectors[a[i]];
auto v2 = growthvectors[a[(i+1)%n]];
auto p0 = mesh[a[(i+n-1)%n]];
auto p1 = mesh[a[i]];
auto p2 = mesh[a[(i+1)%n]];
v0 = p1-p0;
v1 = p2-p1;
auto angle = abs(atan2(v1[0], v1[1]) - atan2(v0[0], v0[1]));
if(angle>M_PI)
angle = 2*M_PI-angle;
return angle;
};
// find first corner point
while(getAngle(chain, ifirst) < 1e-5 )
ifirst = (ifirst+1)%n;
// Copy points of closed loop in correct order, starting with a corner
Array<PointIndex> pis(n+1);
pis.Range(0, n-ifirst) = chain.Range(ifirst, n);
pis.Range(n-ifirst, n) = chain.Range(0, n-ifirst);
pis[n] = pis[0];
Array<double> lengths(n);
for(auto i : Range(n))
lengths[i] = (mesh[pis[(i+1)%n]] - mesh[pis[i]]).Length();
auto averageGrowthVectors = [&] (size_t first, size_t last)
{
if(first+1 >= last)
return;
double total_len = 0.0;
for(auto l : lengths.Range(first, last))
total_len += l;
double len = lengths[first];
auto v0 = growthvectors[pis[first]];
auto v1 = growthvectors[pis[last]];
for(auto i : Range(first+1, last))
{
auto pi = pis[i];
growthvectors[pi] = (len/total_len)*v1 + (1.0-len/total_len)*v0;
len += lengths[i];
}
};
auto icurrent = 0;
while(icurrent<n)
{
auto ilast = icurrent+1;
while(getAngle(pis, ilast) < 1e-5 && ilast < n)
ilast++;
// found straight line -> average growth vectors between end points
if(icurrent!=ilast)
averageGrowthVectors(icurrent, ilast);
icurrent = ilast;
}
}
//////////////////////////////////////////////////////////////////////
// reduce growthvectors where necessary to avoid overlaps/slim regions
const auto getSegmentBox = [&] (SegmentIndex segi)
{
PointIndex pi0=mesh[segi][0], pi1=mesh[segi][1];
Box<3> box( mesh[pi0], mesh[pi1] );
box.Add( mesh[pi0]+growthvectors[pi0] );
box.Add( mesh[pi1]+growthvectors[pi1] );
return box;
};
Array<double, PointIndex> growth(np);
growth = 1.0;
const auto Dot = [](auto a, auto b)
{ return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; };
const auto restrictGrowthVectors = [&] (SegmentIndex segi0, SegmentIndex segi1)
{
if(!active_segments.Test(segi0))
return;
const auto & seg0 = mesh[segi0];
const auto & seg1 = mesh[segi1];
if( (seg0.domin != domain && seg0.domout != domain) ||
(seg1.domin != domain && seg1.domout != domain) )
return;
if(segi0 == segi1)
return;
if(seg0[0]==seg1[0] || seg0[0]==seg1[1] || seg0[1]==seg1[0] || seg0[1] == seg1[1])
return;
auto n = mesh[seg0[0]] - mesh[seg0[1]];
n = {-n[1], n[0], 0};
n.Normalize();
if(Dot(n, growthvectors[seg0[0]])<0) n = -n;
if(Dot(n, growthvectors[seg0[1]])<0) n = -n;
auto n1 = mesh[seg1[0]] - mesh[seg1[1]];
n1 = {-n1[1], n1[0], 0};
n1.Normalize();
if(Dot(n1, growthvectors[seg1[0]])<0) n1 = -n;
if(Dot(n1, growthvectors[seg1[1]])<0) n1 = -n;
auto p10 = mesh[seg1[0]];
auto p11 = mesh[seg1[1]];
for ( auto pi : {seg0[0], seg0[1]} )
{
if(growthvectors[pi] == 0.0)
continue;
PointIndex pi1 = seg0[0] + seg0[1] - pi;
auto p1 = mesh[pi1];
auto p = mesh[pi];
Point<3> points[] = { p10, p11, p10+total_thickness*growthvectors[seg1[0]], p11+total_thickness*growthvectors[seg1[1]], p1+total_thickness*growthvectors[pi1] };
Vec<3> gn{ growthvectors[pi][1], -growthvectors[pi][0], 0.0 };
if(Dot(gn, p1-p) < 0)
gn = -gn;
double d0 = Dot(gn, p);
double d1 = Dot(gn, p1);
if(d0>d1)
Swap(d0,d1);
bool all_left=true, all_right=true;
for (auto i: Range(4))
{
auto p_other = points[i];
auto dot = Dot(gn,p_other);
if(dot>d0) all_left = false;
if(dot<d1) all_right = false;
}
if(all_left || all_right)
return;
//for ( auto pi : {seg0[0], seg0[1]} )
{
double safety = 1.3;
double t = safety*total_thickness;
if(growthvectors[pi] == 0.0)
continue;
Point<3> points[] = { p10, p10+t*growthvectors[seg1[0]], p11, p11+t*growthvectors[seg1[1]] };
auto p0 = mesh[pi];
auto p1 = p0 + t*growthvectors[pi];
auto P2 = [](Point<3> p) { return Point<2>{p[0], p[1]}; };
ArrayMem<pair<double, double>, 4> intersections;
double alpha, beta;
if(X_INTERSECTION == intersect( P2(p0), P2(p1), P2(points[0]), P2(points[2]), alpha, beta ))
intersections.Append({alpha, 0.0});
if(X_INTERSECTION == intersect( P2(p0), P2(p1), P2(points[1]), P2(points[3]), alpha, beta ))
intersections.Append({alpha, 1.0});
if(X_INTERSECTION == intersect( P2(p0), P2(p1), P2(points[0]), P2(points[1]), alpha, beta ))
intersections.Append({alpha, beta});
if(X_INTERSECTION == intersect( P2(p0), P2(p1), P2(points[2]), P2(points[3]), alpha, beta ))
intersections.Append({alpha, beta});
QuickSort(intersections);
for(auto [alpha,beta] : intersections)
{
if(!active_segments.Test(segi1))
growth[pi] = min(growth[pi], alpha);
else
{
double mean = 0.5*(alpha+beta);
growth[pi] = min(growth[pi], mean);
growth[seg1[0]] = min(growth[seg1[0]], mean);
growth[seg1[1]] = min(growth[seg1[1]], mean);
}
}
}
}
};
Box<3> box(Box<3>::EMPTY_BOX);
for (auto segi : Range(mesh.LineSegments()))
{
auto segbox = getSegmentBox( segi );
box.Add(segbox.PMin());
box.Add(segbox.PMax());
}
BoxTree<3> segtree(box);
for (auto segi : Range(mesh.LineSegments()))
{
auto p2 = [](Point<3> p) { return Point<2>{p[0], p[1]}; };
auto seg = line_segments[segi];
double alpha,beta;
intersect( p2(mesh[seg[0]]), p2(mesh[seg[0]]+total_thickness*growthvectors[seg[0]]), p2(mesh[seg[1]]), p2(mesh[seg[1]]+total_thickness*growthvectors[seg[1]]), alpha, beta );
if(beta>0 && alpha>0 && alpha<1.1)
growth[seg[0]] = min(growth[seg[0]], 0.8*alpha);
if(alpha>0 && beta>0 && beta<1.1)
growth[seg[1]] = min(growth[seg[1]], 0.8*beta);
for (auto segj : Range(mesh.LineSegments()))
if(segi!=segj)
restrictGrowthVectors(segi, segj);
}
for( auto pi : Range(growthvectors))
growthvectors[pi] *= growth[pi];
// insert new points
for(PointIndex pi : Range(mesh.Points()))
if(growthvectors[pi].Length2()!=0)
{
auto & pnew = mapto[pi];
auto dist = 0.0;
for(auto t : thicknesses)
{
dist+=t;
pnew.Append( mesh.AddPoint( mesh[pi] + dist*growthvectors[pi] ) );
mesh[pnew.Last()].SetType(FIXEDPOINT);
}
}
map<pair<PointIndex, PointIndex>, int> seg2edge;
// insert new elements ( and move old ones )
for(auto si : moved_segs)
{
auto seg = line_segments[si];
bool swap = false;
auto & pm0 = mapto[seg[0]];
auto & pm1 = mapto[seg[1]];
auto newindex = si_map[domain];
Segment s = seg;
s.geominfo[0] = {};
s.geominfo[1] = {};
s[0] = pm0.Last();
s[1] = pm1.Last();
s[2] = PointIndex::INVALID;
auto pair = s[0] < s[1] ? make_pair(s[0], s[1]) : make_pair(s[1], s[0]);
if(seg2edge.find(pair) == seg2edge.end())
seg2edge[pair] = ++max_edge_nr;
s.edgenr = seg2edge[pair];
s.si = seg.si;
mesh.AddSegment(s);
for ( auto i : Range(thicknesses))
{
PointIndex pi0, pi1, pi2, pi3;
if(i==0)
{
pi0 = seg[0];
pi1 = seg[1];
}
else
{
pi0 = pm0[i-1];
pi1 = pm1[i-1];
}
pi2 = pm1[i];
pi3 = pm0[i];
if(i==0)
{
auto p0 = mesh[pi0];
auto p1 = mesh[pi1];
auto q0 = mesh[pi2];
auto q1 = mesh[pi3];
Vec<2> n = {-p1[1]+p0[1], p1[0]-p0[0]};
Vec<2> v = { q0[0]-p0[0], q0[1]-p0[1]};
if(n[0]*v[0]+n[1]*v[1]<0)
swap = true;
}
Element2d newel;
newel.SetType(QUAD);
newel[0] = pi0;
newel[1] = pi1;
newel[2] = pi2;
newel[3] = pi3;
newel.SetIndex(new_domain);
newel.GeomInfo() = PointGeomInfo{};
if(swap)
{
Swap(newel[0], newel[1]);
Swap(newel[2], newel[3]);
}
for(auto i : Range(4))
{
newel.GeomInfo()[i].u = 0.0;
newel.GeomInfo()[i].v = 0.0;
}
mesh.AddSurfaceElement(newel);
}
// segment now adjacent to new 2d-domain!
if(line_segments[si].domin == domain)
line_segments[si].domin = new_domain;
if(line_segments[si].domout == domain)
line_segments[si].domout = new_domain;
}
for(auto pi : Range(mapto))
{
if(mapto[pi].Size() == 0)
continue;
auto pnew = mapto[pi].Last();
for(auto old_sei : meshtopo.GetVertexSurfaceElements( pi ))
{
if(mesh[old_sei].GetIndex() == domain)
{
auto & old_el = mesh[old_sei];
for(auto i : IntRange(old_el.GetNP()))
if(old_el[i]==pi)
old_el[i] = pnew;
}
}
}
for(auto & sel : mesh.SurfaceElements())
if(sel.GetIndex() == domain)
sel.Delete();
mesh.Compress();
mesh.CalcSurfacesOfNode();
Generate2dMesh(mesh, domain);
// even without new domain, we need temporarily a new domain to mesh the remaining area, without confusing the meshes with quads -> add segments temporarily and reset domain number and segments afterwards
if(!should_make_new_domain)
{
// map new domain back to old one
for(auto & sel : mesh.SurfaceElements())
if(sel.GetIndex()==new_domain)
sel.SetIndex(domain);
// remove (temporary) inner segments
for(auto segi : Range(first_new_seg, mesh.LineSegments().Range().Next()))
{
mesh[segi][0].Invalidate();
mesh[segi][1].Invalidate();
}
for(auto segi : moved_segs)
{
if(mesh[segi].domin == new_domain)
mesh[segi].domin = domain;
if(mesh[segi].domout == new_domain)
mesh[segi].domout = domain;
}
mesh.Compress();
mesh.CalcSurfacesOfNode();
}
return new_domain;
}
}
} // namespace netgen

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@ -0,0 +1,755 @@
#include <mystdlib.h>
#include "meshing.hpp"
#include "meshing2.hpp"
#include "../geom2d/csg2d.hpp"
namespace netgen
{
void InsertVirtualBoundaryLayer (Mesh & mesh)
{
cout << "Insert virt. b.l." << endl;
int surfid;
cout << "Boundary Nr:";
cin >> surfid;
int i;
int np = mesh.GetNP();
cout << "Old NP: " << mesh.GetNP() << endl;
cout << "Trigs: " << mesh.GetNSE() << endl;
NgBitArray bndnodes(np);
NgArray<int> mapto(np);
bndnodes.Clear();
for (i = 1; i <= mesh.GetNSeg(); i++)
{
int snr = mesh.LineSegment(i).edgenr;
cout << "snr = " << snr << endl;
if (snr == surfid)
{
bndnodes.Set (mesh.LineSegment(i)[0]);
bndnodes.Set (mesh.LineSegment(i)[1]);
}
}
for (i = 1; i <= mesh.GetNSeg(); i++)
{
int snr = mesh.LineSegment(i).edgenr;
if (snr != surfid)
{
bndnodes.Clear (mesh.LineSegment(i)[0]);
bndnodes.Clear (mesh.LineSegment(i)[1]);
}
}
for (i = 1; i <= np; i++)
{
if (bndnodes.Test(i))
mapto.Elem(i) = mesh.AddPoint (mesh.Point (i));
else
mapto.Elem(i) = 0;
}
for (i = 1; i <= mesh.GetNSE(); i++)
{
Element2d & el = mesh.SurfaceElement(i);
for (int j = 1; j <= el.GetNP(); j++)
if (mapto.Get(el.PNum(j)))
el.PNum(j) = mapto.Get(el.PNum(j));
}
int nq = 0;
for (i = 1; i <= mesh.GetNSeg(); i++)
{
int snr = mesh.LineSegment(i).edgenr;
if (snr == surfid)
{
int p1 = mesh.LineSegment(i)[0];
int p2 = mesh.LineSegment(i)[1];
int p3 = mapto.Get (p1);
if (!p3) p3 = p1;
int p4 = mapto.Get (p2);
if (!p4) p4 = p2;
Element2d el(QUAD);
el.PNum(1) = p1;
el.PNum(2) = p2;
el.PNum(3) = p3;
el.PNum(4) = p4;
el.SetIndex (2);
mesh.AddSurfaceElement (el);
nq++;
}
}
cout << "New NP: " << mesh.GetNP() << endl;
cout << "Quads: " << nq << endl;
}
void AddDirection( Vec<3> & a, Vec<3> b )
{
if(a.Length2()==0.)
{
a = b;
return;
}
if(b.Length2()==0.)
return;
auto ab = a * b;
if(fabs(ab)>1-1e-8)
return;
Mat<2> m;
m(0,0) = a[0];
m(0,1) = a[1];
m(1,0) = b[0];
m(1,1) = b[1];
Vec<2> lam;
Vec<2> rhs;
rhs[0] = a[0]-b[0];
rhs[1] = a[1]-b[1];
const auto Dot = [](Vec<3> a, Vec<3> b)
{ return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; };
rhs[0] = Dot(a,a);
rhs[1] = Dot(b,b);
m.Solve(rhs, lam);
a[0] = lam[0];
a[1] = lam[1];
a[2] = 0.0;
return;
}
static void Generate2dMesh( Mesh & mesh, int domain )
{
Box<3> box{Box<3>::EMPTY_BOX};
for(const auto & seg : mesh.LineSegments())
if (seg.domin == domain || seg.domout == domain)
for (auto pi : {seg[0], seg[1]})
box.Add(mesh[pi]);
MeshingParameters mp;
Meshing2 meshing (*mesh.GetGeometry(), mp, box);
Array<PointIndex, PointIndex> compress(mesh.GetNP());
compress = PointIndex::INVALID;
PointIndex cnt = PointIndex::BASE;
auto p2sel = mesh.CreatePoint2SurfaceElementTable();
PointGeomInfo gi;
gi.u = 0.0;
gi.v = 0.0;
gi.trignum = domain;
for(auto seg : mesh.LineSegments())
{
if(seg.domin == domain || seg.domout == domain)
for (auto pi : {seg[0], seg[1]})
if (compress[pi]==PointIndex{PointIndex::INVALID})
{
meshing.AddPoint(mesh[pi], pi);
compress[pi] = cnt++;
}
if(seg.domin == domain)
meshing.AddBoundaryElement (compress[seg[0]], compress[seg[1]], gi, gi);
if(seg.domout == domain)
meshing.AddBoundaryElement (compress[seg[1]], compress[seg[0]], gi, gi);
}
auto oldnf = mesh.GetNSE();
auto res = meshing.GenerateMesh (mesh, mp, mp.maxh, domain);
for (SurfaceElementIndex sei : Range(oldnf, mesh.GetNSE()))
mesh[sei].SetIndex (domain);
int hsteps = mp.optsteps2d;
const char * optstr = mp.optimize2d.c_str();
MeshOptimize2d meshopt(mesh);
meshopt.SetFaceIndex(domain);
meshopt.SetMetricWeight (mp.elsizeweight);
for (size_t j = 1; j <= strlen(optstr); j++)
{
switch (optstr[j-1])
{
case 's':
{ // topological swap
meshopt.EdgeSwapping (0);
break;
}
case 'S':
{ // metric swap
meshopt.EdgeSwapping (1);
break;
}
case 'm':
{
meshopt.ImproveMesh(mp);
break;
}
case 'c':
{
meshopt.CombineImprove();
break;
}
default:
cerr << "Optimization code " << optstr[j-1] << " not defined" << endl;
}
}
mesh.Compress();
mesh.CalcSurfacesOfNode();
mesh.OrderElements();
mesh.SetNextMajorTimeStamp();
}
int GenerateBoundaryLayer2 (Mesh & mesh, int domain, const Array<double> & thicknesses, bool should_make_new_domain, const Array<int> & boundaries)
{
mesh.GetTopology().SetBuildVertex2Element(true);
mesh.UpdateTopology();
const auto & line_segments = mesh.LineSegments();
SegmentIndex first_new_seg = mesh.LineSegments().Range().Next();
int np = mesh.GetNP();
int nseg = line_segments.Size();
int ne = mesh.GetNSE();
mesh.UpdateTopology();
double total_thickness = 0.0;
for(auto thickness : thicknesses)
total_thickness += thickness;
Array<Array<PointIndex>, PointIndex> mapto(np);
// Bit array to keep track of segments already processed
BitArray segs_done(nseg);
segs_done.Clear();
// moved segments
Array<SegmentIndex> moved_segs;
Array<Vec<3>, PointIndex> growthvectors(np);
growthvectors = 0.;
auto & meshtopo = mesh.GetTopology();
Array<SegmentIndex> segments;
// surface index map
Array<int> si_map(mesh.GetNFD()+2);
si_map = -1;
int fd_old = mesh.GetNFD();
int max_edge_nr = -1;
int max_domain = -1;
for(const auto& seg : line_segments)
{
if(seg.epgeominfo[0].edgenr > max_edge_nr)
max_edge_nr = seg.epgeominfo[0].edgenr;
if(seg.domin > max_domain)
max_domain = seg.domin;
if(seg.domout > max_domain)
max_domain = seg.domout;
}
int new_domain = max_domain+1;
BitArray active_boundaries(max_edge_nr+1);
BitArray active_segments(nseg);
active_boundaries.Clear();
active_segments.Clear();
if(boundaries.Size() == 0)
active_boundaries.Set();
else
for(auto edgenr : boundaries)
active_boundaries.SetBit(edgenr);
for(auto segi : Range(line_segments))
{
const auto seg = line_segments[segi];
if(active_boundaries.Test(seg.epgeominfo[0].edgenr) && (seg.domin==domain || seg.domout==domain))
active_segments.SetBit(segi);
}
{
FaceDescriptor new_fd(0, 0, 0, -1);
new_fd.SetBCProperty(new_domain);
int new_fd_index = mesh.AddFaceDescriptor(new_fd);
if(should_make_new_domain)
mesh.SetBCName(new_domain-1, "mapped_" + mesh.GetBCName(domain-1));
}
for(auto segi : Range(line_segments))
{
if(segs_done[segi]) continue;
segs_done.SetBit(segi);
const auto& seg = line_segments[segi];
if(seg.domin != domain && seg.domout != domain) continue;
if(!active_boundaries.Test(seg.epgeominfo[0].edgenr))
continue;
moved_segs.Append(segi);
}
// calculate growth vectors (average normal vectors of adjacent segments at each point)
for (auto si : moved_segs)
{
auto & seg = line_segments[si];
auto n = mesh[seg[1]] - mesh[seg[0]];
n = {-n[1], n[0], 0};
n.Normalize();
if(seg.domout == domain)
n = -n;
AddDirection(growthvectors[seg[0]], n);
AddDirection(growthvectors[seg[1]], n);
}
//////////////////////////////////////////////////////////////////////////
// average growthvectors along straight lines to avoid overlaps in corners
BitArray points_done(np+1);
points_done.Clear();
for(auto si : moved_segs)
{
auto current_seg = line_segments[si];
auto current_si = si;
auto first = current_seg[0];
auto current = -1;
auto next = current_seg[1];
if(points_done.Test(first))
continue;
Array<PointIndex> chain;
chain.Append(first);
// first find closed loops of segments
while(next != current && next != first)
{
current = next;
points_done.SetBit(current);
chain.Append(current);
for(auto sj : meshtopo.GetVertexSegments( current ))
{
if(!active_segments.Test(sj))
continue;
if(sj!=current_si)
{
current_si = sj;
current_seg = mesh[sj];
next = current_seg[0] + current_seg[1] - current;
break;
}
}
}
auto ifirst = 0;
auto n = chain.Size();
// angle of adjacent segments at points a[i-1], a[i], a[i+1]
auto getAngle = [&mesh, &growthvectors] (FlatArray<PointIndex> a, size_t i)
{
auto n = a.Size();
auto v0 = growthvectors[a[(i+n-1)%n]];
auto v1 = growthvectors[a[i]];
auto v2 = growthvectors[a[(i+1)%n]];
auto p0 = mesh[a[(i+n-1)%n]];
auto p1 = mesh[a[i]];
auto p2 = mesh[a[(i+1)%n]];
v0 = p1-p0;
v1 = p2-p1;
auto angle = abs(atan2(v1[0], v1[1]) - atan2(v0[0], v0[1]));
if(angle>M_PI)
angle = 2*M_PI-angle;
return angle;
};
// find first corner point
while(getAngle(chain, ifirst) < 1e-5 )
ifirst = (ifirst+1)%n;
// Copy points of closed loop in correct order, starting with a corner
Array<PointIndex> pis(n+1);
pis.Range(0, n-ifirst) = chain.Range(ifirst, n);
pis.Range(n-ifirst, n) = chain.Range(0, n-ifirst);
pis[n] = pis[0];
Array<double> lengths(n);
for(auto i : Range(n))
lengths[i] = (mesh[pis[(i+1)%n]] - mesh[pis[i]]).Length();
auto averageGrowthVectors = [&] (size_t first, size_t last)
{
if(first+1 >= last)
return;
double total_len = 0.0;
for(auto l : lengths.Range(first, last))
total_len += l;
double len = lengths[first];
auto v0 = growthvectors[pis[first]];
auto v1 = growthvectors[pis[last]];
for(auto i : Range(first+1, last))
{
auto pi = pis[i];
growthvectors[pi] = (len/total_len)*v1 + (1.0-len/total_len)*v0;
len += lengths[i];
}
};
auto icurrent = 0;
while(icurrent<n)
{
auto ilast = icurrent+1;
while(getAngle(pis, ilast) < 1e-5 && ilast < n)
ilast++;
// found straight line -> average growth vectors between end points
if(icurrent!=ilast)
averageGrowthVectors(icurrent, ilast);
icurrent = ilast;
}
}
//////////////////////////////////////////////////////////////////////
// reduce growthvectors where necessary to avoid overlaps/slim regions
const auto getSegmentBox = [&] (SegmentIndex segi)
{
PointIndex pi0=mesh[segi][0], pi1=mesh[segi][1];
Box<3> box( mesh[pi0], mesh[pi1] );
box.Add( mesh[pi0]+growthvectors[pi0] );
box.Add( mesh[pi1]+growthvectors[pi1] );
return box;
};
Array<double, PointIndex> growth(np);
growth = 1.0;
const auto Dot = [](auto a, auto b)
{ return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; };
const auto restrictGrowthVectors = [&] (SegmentIndex segi0, SegmentIndex segi1)
{
if(!active_segments.Test(segi0))
return;
const auto & seg0 = mesh[segi0];
const auto & seg1 = mesh[segi1];
if( (seg0.domin != domain && seg0.domout != domain) ||
(seg1.domin != domain && seg1.domout != domain) )
return;
if(segi0 == segi1)
return;
if(seg0[0]==seg1[0] || seg0[0]==seg1[1] || seg0[1]==seg1[0] || seg0[1] == seg1[1])
return;
auto n = mesh[seg0[0]] - mesh[seg0[1]];
n = {-n[1], n[0], 0};
n.Normalize();
if(Dot(n, growthvectors[seg0[0]])<0) n = -n;
if(Dot(n, growthvectors[seg0[1]])<0) n = -n;
auto n1 = mesh[seg1[0]] - mesh[seg1[1]];
n1 = {-n1[1], n1[0], 0};
n1.Normalize();
if(Dot(n1, growthvectors[seg1[0]])<0) n1 = -n;
if(Dot(n1, growthvectors[seg1[1]])<0) n1 = -n;
auto p10 = mesh[seg1[0]];
auto p11 = mesh[seg1[1]];
for ( auto pi : {seg0[0], seg0[1]} )
{
if(growthvectors[pi] == 0.0)
continue;
PointIndex pi1 = seg0[0] + seg0[1] - pi;
auto p1 = mesh[pi1];
auto p = mesh[pi];
Point<3> points[] = { p10, p11, p10+total_thickness*growthvectors[seg1[0]], p11+total_thickness*growthvectors[seg1[1]], p1+total_thickness*growthvectors[pi1] };
Vec<3> gn{ growthvectors[pi][1], -growthvectors[pi][0], 0.0 };
if(Dot(gn, p1-p) < 0)
gn = -gn;
double d0 = Dot(gn, p);
double d1 = Dot(gn, p1);
if(d0>d1)
Swap(d0,d1);
bool all_left=true, all_right=true;
for (auto i: Range(4))
{
auto p_other = points[i];
auto dot = Dot(gn,p_other);
if(dot>d0) all_left = false;
if(dot<d1) all_right = false;
}
if(all_left || all_right)
return;
//for ( auto pi : {seg0[0], seg0[1]} )
{
double safety = 1.3;
double t = safety*total_thickness;
if(growthvectors[pi] == 0.0)
continue;
Point<3> points[] = { p10, p10+t*growthvectors[seg1[0]], p11, p11+t*growthvectors[seg1[1]] };
auto p0 = mesh[pi];
auto p1 = p0 + t*growthvectors[pi];
auto P2 = [](Point<3> p) { return Point<2>{p[0], p[1]}; };
ArrayMem<pair<double, double>, 4> intersections;
double alpha, beta;
if(X_INTERSECTION == intersect( P2(p0), P2(p1), P2(points[0]), P2(points[2]), alpha, beta ))
intersections.Append({alpha, 0.0});
if(X_INTERSECTION == intersect( P2(p0), P2(p1), P2(points[1]), P2(points[3]), alpha, beta ))
intersections.Append({alpha, 1.0});
if(X_INTERSECTION == intersect( P2(p0), P2(p1), P2(points[0]), P2(points[1]), alpha, beta ))
intersections.Append({alpha, beta});
if(X_INTERSECTION == intersect( P2(p0), P2(p1), P2(points[2]), P2(points[3]), alpha, beta ))
intersections.Append({alpha, beta});
QuickSort(intersections);
for(auto [alpha,beta] : intersections)
{
if(!active_segments.Test(segi1))
growth[pi] = min(growth[pi], alpha);
else
{
double mean = 0.5*(alpha+beta);
growth[pi] = min(growth[pi], mean);
growth[seg1[0]] = min(growth[seg1[0]], mean);
growth[seg1[1]] = min(growth[seg1[1]], mean);
}
}
}
}
};
Box<3> box(Box<3>::EMPTY_BOX);
for (auto segi : Range(mesh.LineSegments()))
{
auto segbox = getSegmentBox( segi );
box.Add(segbox.PMin());
box.Add(segbox.PMax());
}
BoxTree<3> segtree(box);
for (auto segi : Range(mesh.LineSegments()))
{
auto p2 = [](Point<3> p) { return Point<2>{p[0], p[1]}; };
auto seg = line_segments[segi];
double alpha,beta;
intersect( p2(mesh[seg[0]]), p2(mesh[seg[0]]+total_thickness*growthvectors[seg[0]]), p2(mesh[seg[1]]), p2(mesh[seg[1]]+total_thickness*growthvectors[seg[1]]), alpha, beta );
if(beta>0 && alpha>0 && alpha<1.1)
growth[seg[0]] = min(growth[seg[0]], 0.8*alpha);
if(alpha>0 && beta>0 && beta<1.1)
growth[seg[1]] = min(growth[seg[1]], 0.8*beta);
for (auto segj : Range(mesh.LineSegments()))
if(segi!=segj)
restrictGrowthVectors(segi, segj);
}
for( auto pi : Range(growthvectors))
growthvectors[pi] *= growth[pi];
// insert new points
for(PointIndex pi : Range(mesh.Points()))
if(growthvectors[pi].Length2()!=0)
{
auto & pnew = mapto[pi];
auto dist = 0.0;
for(auto t : thicknesses)
{
dist+=t;
pnew.Append( mesh.AddPoint( mesh[pi] + dist*growthvectors[pi] ) );
mesh[pnew.Last()].SetType(FIXEDPOINT);
}
}
map<pair<PointIndex, PointIndex>, int> seg2edge;
// insert new elements ( and move old ones )
for(auto si : moved_segs)
{
auto seg = line_segments[si];
bool swap = false;
auto & pm0 = mapto[seg[0]];
auto & pm1 = mapto[seg[1]];
auto newindex = si_map[domain];
Segment s = seg;
s.geominfo[0] = {};
s.geominfo[1] = {};
s[0] = pm0.Last();
s[1] = pm1.Last();
s[2] = PointIndex::INVALID;
auto pair = s[0] < s[1] ? make_pair(s[0], s[1]) : make_pair(s[1], s[0]);
if(seg2edge.find(pair) == seg2edge.end())
seg2edge[pair] = ++max_edge_nr;
s.edgenr = seg2edge[pair];
s.si = seg.si;
mesh.AddSegment(s);
for ( auto i : Range(thicknesses))
{
PointIndex pi0, pi1, pi2, pi3;
if(i==0)
{
pi0 = seg[0];
pi1 = seg[1];
}
else
{
pi0 = pm0[i-1];
pi1 = pm1[i-1];
}
pi2 = pm1[i];
pi3 = pm0[i];
if(i==0)
{
auto p0 = mesh[pi0];
auto p1 = mesh[pi1];
auto q0 = mesh[pi2];
auto q1 = mesh[pi3];
Vec<2> n = {-p1[1]+p0[1], p1[0]-p0[0]};
Vec<2> v = { q0[0]-p0[0], q0[1]-p0[1]};
if(n[0]*v[0]+n[1]*v[1]<0)
swap = true;
}
Element2d newel;
newel.SetType(QUAD);
newel[0] = pi0;
newel[1] = pi1;
newel[2] = pi2;
newel[3] = pi3;
newel.SetIndex(new_domain);
newel.GeomInfo() = PointGeomInfo{};
if(swap)
{
Swap(newel[0], newel[1]);
Swap(newel[2], newel[3]);
}
for(auto i : Range(4))
{
newel.GeomInfo()[i].u = 0.0;
newel.GeomInfo()[i].v = 0.0;
}
mesh.AddSurfaceElement(newel);
}
// segment now adjacent to new 2d-domain!
if(line_segments[si].domin == domain)
line_segments[si].domin = new_domain;
if(line_segments[si].domout == domain)
line_segments[si].domout = new_domain;
}
for(auto pi : Range(mapto))
{
if(mapto[pi].Size() == 0)
continue;
auto pnew = mapto[pi].Last();
for(auto old_sei : meshtopo.GetVertexSurfaceElements( pi ))
{
if(mesh[old_sei].GetIndex() == domain)
{
auto & old_el = mesh[old_sei];
for(auto i : IntRange(old_el.GetNP()))
if(old_el[i]==pi)
old_el[i] = pnew;
}
}
}
for(auto & sel : mesh.SurfaceElements())
if(sel.GetIndex() == domain)
sel.Delete();
mesh.Compress();
mesh.CalcSurfacesOfNode();
Generate2dMesh(mesh, domain);
// even without new domain, we need temporarily a new domain to mesh the remaining area, without confusing the meshes with quads -> add segments temporarily and reset domain number and segments afterwards
if(!should_make_new_domain)
{
// map new domain back to old one
for(auto & sel : mesh.SurfaceElements())
if(sel.GetIndex()==new_domain)
sel.SetIndex(domain);
// remove (temporary) inner segments
for(auto segi : Range(first_new_seg, mesh.LineSegments().Range().Next()))
{
mesh[segi][0].Invalidate();
mesh[segi][1].Invalidate();
}
for(auto segi : moved_segs)
{
if(mesh[segi].domin == new_domain)
mesh[segi].domin = domain;
if(mesh[segi].domout == new_domain)
mesh[segi].domout = domain;
}
mesh.Compress();
mesh.CalcSurfacesOfNode();
}
return new_domain;
}
} // namespace netgen