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netgen/libsrc/meshing/boundarylayer.cpp
Matthias Hochsteger 92fb557314 fix boundarylayer 2d bug
2022-10-03 17:22:44 +02:00

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#include <mystdlib.h>
#include "meshing.hpp"
#include "meshing2.hpp"
#include "delaunay2d.hpp"
#include "debugging.hpp"
#include "global.hpp"
#include "../geom2d/csg2d.hpp"
#include <set>
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)
{
auto n = Cross(trig[1]-trig[0], trig[2]-trig[0]);
auto v0n = (seg[0]-trig[0])*n;
auto v1n = (seg[1]-trig[0])*n;
if(v0n * v1n >= 0)
return false;
lam = -v0n/(v1n-v0n);
lam *= 0.9;
if(lam < -1e-8 || lam>1+1e-8)
return false;
return true;
}
bool isIntersectingPlane ( const array<Point<3>, 2> & seg, const ArrayMem<Point<3>, 4> & face, double & lam)
{
lam = 1.0;
bool intersect0 = isIntersectingPlane( seg, array<Point<3>, 3>{face[0], face[1], face[2]}, lam );
if(face.Size()==3)
return intersect0;
double lam1 = 1.0;
bool intersect1 = isIntersectingPlane( seg, array<Point<3>, 3>{face[2], face[3], face[0]}, lam1 );
lam = min(lam, lam1);
return intersect0 || intersect1;
}
bool isIntersectingTrig ( const array<Point<3>, 2> & seg, const array<Point<3>, 3> & trig, double & lam)
{
if(!isIntersectingPlane(seg, trig, lam))
return false;
auto p = seg[0] + lam/0.9*(seg[1]-seg[0]);
auto n_trig = Cross(trig[1]-trig[0], trig[2]-trig[0]).Normalize();
for(auto i : Range(3))
{
// check if p0 and p are on same side of segment p1-p2
auto p0 = trig[i];
auto p1 = trig[(i+1)%3];
auto p2 = trig[(i+2)%3];
auto n = Cross(p2-p1, n_trig);
auto v0 = (p2-p1).Normalize();
auto v1 = (p0-p1).Normalize();
auto inside_dir = (v1 - (v1*v0) * v0).Normalize();
auto v2 = (p-p1).Normalize();
if(inside_dir * v1 < 0)
inside_dir = -inside_dir;
if( (inside_dir*v2) < 0 )
return false;
}
return true;
};
bool isIntersectingFace( const array<Point<3>, 2> & seg, const ArrayMem<Point<3>, 4> & face, double & lam )
{
lam = 1.0;
double lam0 = 1.0;
bool intersect0 = isIntersectingTrig( seg, {face[0], face[1], face[2]}, lam0 );
if(intersect0)
lam = min(lam, lam0);
if(face.Size()==3)
return intersect0;
double lam1 = 1.0;
bool intersect1 = isIntersectingTrig( seg, {face[2], face[3], face[0]}, lam1 );
if(intersect1)
lam = min(lam, lam1);
return intersect0 || intersect1;
}
array<Point<3>, 2> BoundaryLayerTool :: GetMappedSeg( PointIndex pi )
{
return { mesh[pi], mesh[pi] + height*limits[pi]*growthvectors[pi] };
}
ArrayMem<Point<3>, 4> BoundaryLayerTool :: GetFace( SurfaceElementIndex sei )
{
const auto & sel = mesh[sei];
ArrayMem<Point<3>, 4> points(sel.GetNP());
for(auto i : Range(sel.GetNP()))
points[i] = mesh[sel[i]];
return points;
}
ArrayMem<Point<3>, 4> BoundaryLayerTool :: GetMappedFace( SurfaceElementIndex sei )
{
const auto & sel = mesh[sei];
ArrayMem<Point<3>, 4> points(sel.GetNP());
for(auto i : Range(sel.GetNP()))
points[i] = mesh[sel[i]] + height * limits[sel[i]]*growthvectors[sel[i]];
return points;
}
ArrayMem<Point<3>, 4> BoundaryLayerTool :: GetMappedFace( SurfaceElementIndex sei, int face )
{
if(face == -1) return GetFace(sei);
if(face == -2) return GetMappedFace(sei);
const auto & sel = mesh[sei];
auto np = sel.GetNP();
auto pi0 = sel[face % np];
auto pi1 = sel[(face+1) % np];
ArrayMem<Point<3>, 4> points(4);
points[0] = points[3] = mesh[pi0];
points[1] = points[2] = mesh[pi1];
points[3] += height * limits[pi0]*growthvectors[pi0];
points[2] += height * limits[pi1]*growthvectors[pi1];
return points;
}
Vec<3> BoundaryLayerTool :: getEdgeTangent(PointIndex pi, int edgenr)
{
Vec<3> tangent = 0.0;
ArrayMem<PointIndex,2> pts;
for(auto segi : topo.GetVertexSegments(pi))
{
auto & seg = mesh[segi];
if(seg.edgenr != edgenr+1)
continue;
PointIndex other = seg[0]+seg[1]-pi;
if(!pts.Contains(other))
pts.Append(other);
}
if(pts.Size() != 2)
throw Exception("Something went wrong in getEdgeTangent!");
tangent = mesh[pts[1]] - mesh[pts[0]];
return tangent.Normalize();
}
void BoundaryLayerTool :: LimitGrowthVectorLengths()
{
static Timer tall("BoundaryLayerTool::LimitGrowthVectorLengths"); RegionTimer rtall(tall);
limits.SetSize(np);
limits = 1.0;
auto smooth = [&] (size_t nsteps) {
for(auto i : Range(nsteps))
for(const auto & sel : mesh.SurfaceElements())
{
double min_limit = 999;
for(auto pi : sel.PNums())
min_limit = min(min_limit, limits[pi]);
for(auto pi : sel.PNums())
limits[pi] = min(limits[pi], 1.4*min_limit);
}
};
// check for self-intersection within new elements (prisms/hexes)
auto self_intersection = [&] () {
for(SurfaceElementIndex sei : mesh.SurfaceElements().Range())
{
auto facei = mesh[sei].GetIndex();
if(facei < nfd_old && !params.surfid.Contains(facei))
continue;
auto sel = mesh[sei];
auto np = sel.GetNP();
// check if a new edge intesects the plane of any opposing face
double lam;
for(auto i : Range(np))
for(auto fi : Range(np-2))
if(isIntersectingPlane(GetMappedSeg(sel[i]), GetMappedFace(sei, i+fi+1), lam))
if(lam < 1.0)
limits[sel[i]] *= lam;
}
};
// first step: intersect with other surface elements that are boundary of domain the layer is grown into
// second (and subsequent) steps: intersect with other boundary layers, allow restriction by 20% in each step
auto changed_domains = domains;
if(!params.outside)
changed_domains.Invert();
bool limit_reached = true;
double lam_lower_limit = 1.0;
int step = 0;
while(limit_reached || step<2)
{
if(step>0)
lam_lower_limit *= 0.8;
limit_reached = false;
// build search tree with all surface elements (bounding box of a surface element also covers the generated boundary layer)
Box<3> bbox(Box<3>::EMPTY_BOX);
for(auto pi : mesh.Points().Range())
{
bbox.Add(mesh[pi]);
bbox.Add(mesh[pi]+limits[pi]*height*growthvectors[pi]);
}
BoxTree<3> tree(bbox);
for(auto sei : mesh.SurfaceElements().Range())
{
const auto & sel = mesh[sei];
Box<3> box(Box<3>::EMPTY_BOX);
const auto& fd = mesh.GetFaceDescriptor(sel.GetIndex());
if(!changed_domains.Test(fd.DomainIn()) &&
!changed_domains.Test(fd.DomainOut()))
continue;
for(auto pi : sel.PNums())
box.Add(mesh[pi]);
// also add moved points to bounding box
if(params.surfid.Contains(sel.GetIndex()))
for(auto pi : sel.PNums())
box.Add(mesh[pi]+limits[pi]*height*growthvectors[pi]);
tree.Insert(box, sei);
}
for(auto pi : mesh.Points().Range())
{
if(mesh[pi].Type() == INNERPOINT)
continue;
if(growthvectors[pi].Length2() == 0.0)
continue;
Box<3> box(Box<3>::EMPTY_BOX);
auto seg = GetMappedSeg(pi);
box.Add(seg[0]);
box.Add(seg[1]);
double lam = 1.0;
tree.GetFirstIntersecting(box.PMin(), box.PMax(), [&](SurfaceElementIndex sei)
{
const auto & sel = mesh[sei];
if(sel.PNums().Contains(pi))
return false;
auto face = GetMappedFace(sei, -2);
double lam_ = 999;
bool is_bl_sel = params.surfid.Contains(sel.GetIndex());
if(step==0)
{
if(isIntersectingFace(seg, face, lam_))
{
if(is_bl_sel) // allow only half the distance if the opposing surface element has a boundary layer too
lam_ *= 0.5;
lam = min(lam, lam_);
}
}
// if the opposing surface element has a boundary layer, we need to additionally intersect with the new faces
if(step>0 && is_bl_sel)
{
for(auto facei : Range(-1, sel.GetNP()))
{
auto face = GetMappedFace(sei, facei);
if(isIntersectingFace(seg, face, lam_)) // && lam_ > other_limit)
{
lam = min(lam, lam_);
}
}
}
return false;
});
if(lam<1)
{
if(lam<lam_lower_limit && step>0)
{
limit_reached = true;
lam = lam_lower_limit;
}
limits[pi] = min(limits[pi], lam);
}
}
step++;
}
self_intersection();
smooth(3);
for(auto pi : Range(growthvectors))
growthvectors[pi] *= limits[pi];
}
// depending on the geometry type, the mesh contains segments multiple times (once for each face)
bool HaveSingleSegments( const Mesh & mesh )
{
auto& topo = mesh.GetTopology();
NgArray<SurfaceElementIndex> surf_els;
for(auto segi : Range(mesh.LineSegments()))
{
mesh.GetTopology().GetSegmentSurfaceElements(segi+1, surf_els);
if(surf_els.Size()<2)
continue;
auto seg = mesh[segi];
auto pi0 = min(seg[0], seg[1]);
auto pi1 = max(seg[0], seg[1]);
auto p0_segs = topo.GetVertexSegments(seg[0]);
for(auto segi_other : p0_segs)
{
if(segi_other == segi)
continue;
auto seg_other = mesh[segi_other];
auto pi0_other = min(seg_other[0], seg_other[1]);
auto pi1_other = max(seg_other[0], seg_other[1]);
if( pi0_other == pi0 && pi1_other == pi1 )
return false;
}
// found segment with multiple adjacent surface elements but no other segments with same points -> have single segments
return true;
}
return true;
}
// duplicates segments (and sets seg.si accordingly) to have a unified data structure for all geometry types
Array<Segment> BuildSegments( Mesh & mesh )
{
Array<Segment> segments;
auto& topo = mesh.GetTopology();
NgArray<SurfaceElementIndex> surf_els;
for(auto segi : Range(mesh.LineSegments()))
{
auto seg = mesh[segi];
mesh.GetTopology().GetSegmentSurfaceElements(segi+1, surf_els);
for(auto seli : surf_els)
{
const auto & sel = mesh[seli];
seg.si = sel.GetIndex();
auto np = sel.GetNP();
for(auto i : Range(np))
{
if(sel[i] == seg[0])
{
if(sel[(i+1)%np] != seg[1])
swap(seg[0], seg[1]);
break;
}
}
segments.Append(seg);
}
}
return segments;
}
void MergeAndAddSegments( Mesh & mesh, FlatArray<Segment> new_segments)
{
INDEX_2_HASHTABLE<bool> already_added( 2*new_segments.Size() );
for(auto & seg : new_segments)
{
INDEX_2 i2 (seg[0], seg[1]);
i2.Sort();
if(!already_added.Used(i2))
{
mesh.AddSegment(seg);
already_added.Set(i2, true);
}
}
}
void BoundaryLayerTool :: InterpolateSurfaceGrowthVectors()
{
static Timer tall("InterpolateSurfaceGrowthVectors"); RegionTimer rtall(tall);
static Timer tsmooth("InterpolateSurfaceGrowthVectors-Smoothing");
auto np = mesh.GetNP();
BitArray is_point_on_bl_surface(np+1);
is_point_on_bl_surface.Clear();
BitArray is_point_on_other_surface(np+1);
is_point_on_other_surface.Clear();
Array<Vec<3>, PointIndex> normals(np);
for(auto pi : Range(growthvectors))
normals[pi] = growthvectors[pi];
ParallelForRange( mesh.SurfaceElements().Range(), [&] ( auto myrange )
{
for(SurfaceElementIndex sei : myrange)
{
auto facei = mesh[sei].GetIndex();
if(facei < nfd_old && !params.surfid.Contains(facei))
{
for(auto pi : mesh[sei].PNums())
if(mesh[pi].Type() == SURFACEPOINT)
is_point_on_other_surface.SetBitAtomic(pi);
}
else
{
for(auto pi : mesh[sei].PNums())
if(mesh[pi].Type() == SURFACEPOINT)
is_point_on_bl_surface.SetBitAtomic(pi);
}
}
});
Array<PointIndex> points;
for(PointIndex pi : mesh.Points().Range())
{
if(is_point_on_bl_surface[pi])
{
points.Append(pi);
growthvectors[pi] = 0.0;
}
if(is_point_on_other_surface[pi])
{
points.Append(pi);
}
}
// smooth tangential part of growth vectors from edges to surface elements
RegionTimer rtsmooth(tsmooth);
for(auto i : Range(10))
{
for(auto pi : points)
{
auto sels = p2sel[pi];
Vec<3> new_gw = growthvectors[pi];
int cnt = 1;
std::set<PointIndex> suround;
suround.insert(pi);
auto normal = normals[pi];
for(auto sei: sels)
{
const auto & sel = mesh[sei];
for(auto pi1 : sel.PNums())
if(suround.count(pi1)==0)
{
suround.insert(pi1);
auto gw_other = growthvectors[pi1];
auto normal_other = getNormal(mesh[sei]);
auto tangent_part = gw_other - (gw_other*normal_other)*normal_other;
if(is_point_on_bl_surface[pi])
new_gw += tangent_part;
else
new_gw += gw_other;
}
}
growthvectors[pi] = 1.0/suround.size() * new_gw;
}
}
for(auto pi : points)
growthvectors[pi] += normals[pi];
}
BoundaryLayerTool::BoundaryLayerTool(Mesh & mesh_, const BoundaryLayerParameters & params_)
: mesh(mesh_), topo(mesh_.GetTopology()), params(params_)
{
static Timer timer("BoundaryLayerTool::ctor");
RegionTimer regt(timer);
//for(auto & seg : mesh.LineSegments())
//seg.edgenr = seg.epgeominfo[1].edgenr;
height = 0.0;
for (auto h : params.heights)
height += h;
max_edge_nr = -1;
for(const auto& seg : mesh.LineSegments())
if(seg.edgenr > max_edge_nr)
max_edge_nr = seg.edgenr;
new_mat_nr = mesh.GetNDomains() +1;
mesh.SetMaterial(new_mat_nr, params.new_mat);
domains = params.domains;
if(!params.outside)
domains.Invert();
topo.SetBuildVertex2Element(true);
mesh.UpdateTopology();
have_single_segments = HaveSingleSegments(mesh);
if(have_single_segments)
segments = BuildSegments(mesh);
else
segments = mesh.LineSegments();
np = mesh.GetNP();
ne = mesh.GetNE();
nse = mesh.GetNSE();
nseg = segments.Size();
p2sel = mesh.CreatePoint2SurfaceElementTable();
nfd_old = mesh.GetNFD();
si_map.SetSize(nfd_old+1);
si_map = -1;
}
void BoundaryLayerTool :: CreateNewFaceDescriptors()
{
surfacefacs.SetSize(nfd_old+1);
surfacefacs = 0.0;
// create new FaceDescriptors
for(auto i : Range(1, nfd_old+1))
{
const auto& fd = mesh.GetFaceDescriptor(i);
string name = fd.GetBCName();
if(params.surfid.Contains(i))
{
if(auto isIn = domains.Test(fd.DomainIn()); isIn != domains.Test(fd.DomainOut()))
{
int new_si = mesh.GetNFD()+1;
surfacefacs[i] = isIn ? 1. : -1.;
// -1 surf nr is so that curving does not do anything
FaceDescriptor new_fd(-1, isIn ? new_mat_nr : fd.DomainIn(),
isIn ? fd.DomainOut() : new_mat_nr, -1);
new_fd.SetBCProperty(new_si);
mesh.AddFaceDescriptor(new_fd);
si_map[i] = new_si;
mesh.SetBCName(new_si-1, "mapped_" + name);
}
}
}
}
void BoundaryLayerTool :: CalculateGrowthVectors()
{
growthvectors.SetSize(np);
growthvectors = 0.;
for(auto pi : mesh.Points().Range())
{
const auto & p = mesh[pi];
if(p.Type() == INNERPOINT)
continue;
std::map<int, Vec<3>> normals;
// calculate one normal vector per face (average with angles as weights for multiple surface elements within a face)
for(auto sei : p2sel[pi])
{
const auto & sel = mesh[sei];
auto facei = sel.GetIndex();
if(!params.surfid.Contains(facei))
continue;
auto n = surfacefacs[sel.GetIndex()] * getNormal(sel);
int itrig = sel.PNums().Pos(pi);
itrig += sel.GetNP();
auto v0 = (mesh[sel.PNumMod(itrig+1)] - mesh[pi]).Normalize();
auto v1 = (mesh[sel.PNumMod(itrig-1)] - mesh[pi]).Normalize();
if(normals.count(facei)==0)
normals[facei] = {0.,0.,0.};
normals[facei] += acos(v0*v1)*n;
}
for(auto & [facei, n] : normals)
n *= 1.0/n.Length();
// combine normal vectors for each face to keep uniform distances
auto & np = growthvectors[pi];
for(auto & [facei, n] : normals)
{
if(np.Length() == 0) { np = n; continue; }
auto npn = np * n;
auto npnp = np * np;
auto nn = n * n;
if(nn-npn*npn/npnp == 0) { np = n; continue; }
np += (nn - npn)/(nn - npn*npn/npnp) * (n - npn/npnp * np);
}
}
}
Array<Array<pair<SegmentIndex, int>>, SegmentIndex> BoundaryLayerTool :: BuildSegMap()
{
// Bit array to keep track of segments already processed
BitArray segs_done(nseg+1);
segs_done.Clear();
// map for all segments with same points
// points to pair of SegmentIndex, int
// int is type of other segment, either:
// 0 == adjacent surface grows layer
// 1 == adjacent surface doesn't grow layer, but layer ends on it
// 2 == adjacent surface is interior surface that ends on layer
// 3 == adjacent surface is exterior surface that ends on layer (not allowed yet)
Array<Array<pair<SegmentIndex, int>>, SegmentIndex> segmap(segments.Size());
// moved segments
is_edge_moved.SetSize(max_edge_nr+1);
is_edge_moved = false;
// boundaries to project endings to
is_boundary_projected.SetSize(nfd_old+1);
is_boundary_projected.Clear();
is_boundary_moved.SetSize(nfd_old+1);
is_boundary_moved.Clear();
for(auto si : Range(segments))
{
if(segs_done[si]) continue;
const auto& segi = segments[si];
if(si_map[segi.si] == -1) continue;
segs_done.SetBit(si);
segmap[si].Append(make_pair(si, 0));
moved_segs.Append(si);
is_edge_moved.SetBit(segi.edgenr);
for(auto sj : Range(segments))
{
if(segs_done.Test(sj)) continue;
const auto& segj = segments[sj];
if((segi[0] == segj[0] && segi[1] == segj[1]) ||
(segi[0] == segj[1] && segi[1] == segj[0]))
{
segs_done.SetBit(sj);
int type;
if(si_map[segj.si] != -1)
type = 0;
else if(const auto& fd = mesh.GetFaceDescriptor(segj.si); domains.Test(fd.DomainIn()) && domains.Test(fd.DomainOut()))
{
type = 2;
if(fd.DomainIn() == 0 || fd.DomainOut() == 0)
is_boundary_projected.SetBit(segj.si);
}
else if(const auto& fd = mesh.GetFaceDescriptor(segj.si); !domains.Test(fd.DomainIn()) && !domains.Test(fd.DomainOut()))
{
type = 3;
is_boundary_moved.SetBit(segj.si);
}
else
{
type = 1;
// in case 1 we project the growthvector onto the surface
is_boundary_projected.SetBit(segj.si);
}
segmap[si].Append(make_pair(sj, type));
}
}
}
return segmap;
}
BitArray BoundaryLayerTool :: ProjectGrowthVectorsOnSurface()
{
BitArray in_surface_direction(nfd_old+1);
in_surface_direction.Clear();
// project growthvector on surface for inner angles
if(params.grow_edges)
{
for(const auto& sel : mesh.SurfaceElements())
if(is_boundary_projected.Test(sel.GetIndex()))
{
auto n = getNormal(sel);
for(auto i : Range(sel.PNums()))
{
auto pi = sel.PNums()[i];
if(growthvectors[pi].Length2() == 0.)
continue;
auto next = sel.PNums()[(i+1)%sel.GetNV()];
auto prev = sel.PNums()[i == 0 ? sel.GetNV()-1 : i-1];
auto v1 = (mesh[next] - mesh[pi]).Normalize();
auto v2 = (mesh[prev] - mesh[pi]).Normalize();
auto v3 = growthvectors[pi];
v3.Normalize();
auto tol = v1.Length() * 1e-12;
if((v1 * v3 > -tol) && (v2 * v3 > -tol))
in_surface_direction.SetBit(sel.GetIndex());
else
continue;
if(!params.project_boundaries.Contains(sel.GetIndex()))
continue;
auto& g = growthvectors[pi];
auto ng = n * g;
auto gg = g * g;
auto nn = n * n;
// if(fabs(ng*ng-nn*gg) < 1e-12 || fabs(ng) < 1e-12) continue;
auto a = -ng*ng/(ng*ng-nn * gg);
auto b = ng*gg/(ng*ng-nn*gg);
g += a*g + b*n;
}
}
}
else
{
for(const auto& seg : segments)
{
int count = 0;
for(const auto& seg2 : segments)
if(((seg[0] == seg2[0] && seg[1] == seg2[1]) || (seg[0] == seg2[1] && seg[1] == seg2[0])) && params.surfid.Contains(seg2.si))
count++;
if(count == 1)
{
growthvectors[seg[0]] = {0., 0., 0.};
growthvectors[seg[1]] = {0., 0., 0.};
}
}
}
return in_surface_direction;
}
void BoundaryLayerTool :: InterpolateGrowthVectors()
{
// interpolate tangential component of growth vector along edge
for(auto edgenr : Range(max_edge_nr))
{
// if(!is_edge_moved[edgenr+1]) continue;
// build sorted list of edge
Array<PointIndex> points;
// find first vertex on edge
double edge_len = 0.;
auto is_end_point = [&] (PointIndex pi)
{
// if(mesh[pi].Type() == FIXEDPOINT)
// return true;
// return false;
auto segs = topo.GetVertexSegments(pi);
auto first_edgenr = mesh[segs[0]].edgenr;
for(auto segi : segs)
if(mesh[segi].edgenr != first_edgenr)
return true;
return false;
};
bool any_grows = false;
for(const auto& seg : segments)
{
if(seg.edgenr-1 == edgenr)
{
if(growthvectors[seg[0]].Length2() != 0 ||
growthvectors[seg[1]].Length2() != 0)
any_grows = true;
if(points.Size() == 0 && is_end_point(seg[0]))
{
points.Append(seg[0]);
points.Append(seg[1]);
edge_len += (mesh[seg[1]] - mesh[seg[0]]).Length();
}
}
}
if(!any_grows)
continue;
if(!points.Size())
throw Exception("Could not find startpoint for edge " + ToString(edgenr));
while(true)
{
bool point_found = false;
for(auto si : topo.GetVertexSegments(points.Last()))
{
const auto& seg = mesh[si];
if(seg.edgenr-1 != edgenr)
continue;
if(seg[0] == points.Last() && points[points.Size()-2] !=seg[1])
{
edge_len += (mesh[points.Last()] - mesh[seg[1]]).Length();
points.Append(seg[1]);
point_found = true;
break;
}
else if(seg[1] == points.Last() &&
points[points.Size()-2] != seg[0])
{
edge_len += (mesh[points.Last()] - mesh[seg[0]]).Length();
points.Append(seg[0]);
point_found = true;
break;
}
}
if(is_end_point(points.Last()))
break;
if(!point_found)
{
throw Exception(string("Could not find connected list of line segments for edge ") + edgenr);
}
}
if(growthvectors[points[0]].Length2() == 0 &&
growthvectors[points.Last()].Length2() == 0)
continue;
// tangential part of growth vectors
auto t1 = (mesh[points[1]]-mesh[points[0]]).Normalize();
auto gt1 = growthvectors[points[0]] * t1 * t1;
auto t2 = (mesh[points.Last()]-mesh[points[points.Size()-2]]).Normalize();
auto gt2 = growthvectors[points.Last()] * t2 * t2;
if(!is_edge_moved[edgenr+1])
{
if(growthvectors[points[0]] * (mesh[points[1]] - mesh[points[0]]) < 0)
gt1 = 0.;
if(growthvectors[points.Last()] * (mesh[points[points.Size()-2]] - mesh[points.Last()]) < 0)
gt2 = 0.;
}
double len = 0.;
for(size_t i = 1; i < points.Size()-1; i++)
{
auto pi = points[i];
len += (mesh[pi] - mesh[points[i-1]]).Length();
auto t = getEdgeTangent(pi, edgenr);
auto lam = len/edge_len;
auto interpol = (1-lam) * (gt1 * t) * t + lam * (gt2 * t) * t;
growthvectors[pi] += interpol;
}
}
InterpolateSurfaceGrowthVectors();
}
void BoundaryLayerTool :: InsertNewElements( FlatArray<Array<pair<SegmentIndex, int>>, SegmentIndex> segmap, const BitArray & in_surface_direction )
{
static Timer timer("BoundaryLayerTool::InsertNewElements"); RegionTimer rt(timer);
Array<Array<PointIndex>, PointIndex> mapto(np);
// insert new points
for (PointIndex pi = 1; pi <= np; pi++)
if (growthvectors[pi].Length2() != 0)
{
Point<3> p = mesh[pi];
for(auto i : Range(params.heights))
{
p += params.heights[i] * growthvectors[pi];
mapto[pi].Append(mesh.AddPoint(p));
}
}
// add 2d quads on required surfaces
map<pair<PointIndex, PointIndex>, int> seg2edge;
if(params.grow_edges)
{
for(auto sei : moved_segs)
{
// copy here since we will add segments and this would
// invalidate a reference!
auto segi = segments[sei];
for(auto [sej, type] : segmap[sei])
{
auto segj = segments[sej];
if(type == 0)
{
Segment s;
s[0] = mapto[segj[0]].Last();
s[1] = mapto[segj[1]].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 = si_map[segj.si];
new_segments.Append(s);
}
// here we need to grow the quad elements
else if(type == 1)
{
PointIndex pp1 = segj[1];
PointIndex pp2 = segj[0];
if(in_surface_direction.Test(segj.si))
{
Swap(pp1, pp2);
is_boundary_moved.SetBit(segj.si);
}
PointIndex p1 = pp1;
PointIndex p2 = pp2;
PointIndex p3, p4;
Segment s0;
s0[0] = p1;
s0[1] = p2;
s0[2] = PointIndex::INVALID;
s0.edgenr = segj.edgenr;
s0.si = segj.si;
new_segments.Append(s0);
for(auto i : Range(params.heights))
{
Element2d sel(QUAD);
p3 = mapto[pp2][i];
p4 = mapto[pp1][i];
sel[0] = p1;
sel[1] = p2;
sel[2] = p3;
sel[3] = p4;
for(auto i : Range(4))
{
sel.GeomInfo()[i].u = 0.0;
sel.GeomInfo()[i].v = 0.0;
}
sel.SetIndex(segj.si);
mesh.AddSurfaceElement(sel);
// TODO: Too many, would be enough to only add outermost ones
Segment s1;
s1[0] = p2;
s1[1] = p3;
s1[2] = PointIndex::INVALID;
auto pair = make_pair(p2, p3);
if(seg2edge.find(pair) == seg2edge.end())
seg2edge[pair] = ++max_edge_nr;
s1.edgenr = seg2edge[pair];
s1.si = segj.si;
new_segments.Append(s1);
Segment s2;
s2[0] = p4;
s2[1] = p1;
s2[2] = PointIndex::INVALID;
pair = make_pair(p1, p4);
if(seg2edge.find(pair) == seg2edge.end())
seg2edge[pair] = ++max_edge_nr;
s2.edgenr = seg2edge[pair];
s2.si = segj.si;
new_segments.Append(s2);
p1 = p4;
p2 = p3;
}
Segment s3;
s3[0] = p3;
s3[1] = p4;
s3[2] = PointIndex::INVALID;
auto pair = p3 < p4 ? make_pair(p3, p4) : make_pair(p4, p3);
if(seg2edge.find(pair) == seg2edge.end())
seg2edge[pair] = ++max_edge_nr;
s3.edgenr = seg2edge[pair];
s3.si = segj.si;
new_segments.Append(s3);
}
}
}
}
BitArray fixed_points(np+1);
fixed_points.Clear();
BitArray moveboundarypoint(np+1);
moveboundarypoint.Clear();
for(SurfaceElementIndex si = 0; si < nse; si++)
{
// copy because surfaceels array will be resized!
auto sel = mesh[si];
if(si_map[sel.GetIndex()] != -1)
{
Array<PointIndex> points(sel.PNums());
if(surfacefacs[sel.GetIndex()] > 0) Swap(points[0], points[2]);
for(auto j : Range(params.heights))
{
auto eltype = points.Size() == 3 ? PRISM : HEX;
Element el(eltype);
for(auto i : Range(points))
el[i] = points[i];
for(auto i : Range(points))
points[i] = mapto[sel.PNums()[i]][j];
if(surfacefacs[sel.GetIndex()] > 0) Swap(points[0], points[2]);
for(auto i : Range(points))
el[sel.PNums().Size() + i] = points[i];
el.SetIndex(new_mat_nr);
mesh.AddVolumeElement(el);
}
Element2d newel = sel;
for(auto& p : newel.PNums())
p = mapto[p].Last();
newel.SetIndex(si_map[sel.GetIndex()]);
mesh.AddSurfaceElement(newel);
}
else
{
bool has_moved = false;
for(auto p : sel.PNums())
if(mapto[p].Size())
has_moved = true;
if(has_moved)
for(auto p : sel.PNums())
{
if(!mapto[p].Size())
{
fixed_points.SetBit(p);
if(is_boundary_moved.Test(sel.GetIndex()))
moveboundarypoint.SetBit(p);
}
}
}
if(is_boundary_moved.Test(sel.GetIndex()))
{
for(auto& p : mesh[si].PNums())
if(mapto[p].Size())
p = mapto[p].Last();
}
}
for(SegmentIndex sei = 0; sei < nseg; sei++)
{
auto& seg = segments[sei];
if(is_boundary_moved.Test(seg.si))
for(auto& p : seg.PNums())
if(mapto[p].Size())
p = mapto[p].Last();
}
for(ElementIndex ei = 0; ei < ne; ei++)
{
auto el = mesh[ei];
ArrayMem<PointIndex,4> fixed;
ArrayMem<PointIndex,4> moved;
bool moved_bnd = false;
for(const auto& p : el.PNums())
{
if(fixed_points.Test(p))
fixed.Append(p);
if(mapto[p].Size())
moved.Append(p);
if(moveboundarypoint.Test(p))
moved_bnd = true;
}
bool do_move, do_insert;
if(domains.Test(el.GetIndex()))
{
do_move = fixed.Size() && moved_bnd;
do_insert = do_move;
}
else
{
do_move = !fixed.Size() || moved_bnd;
do_insert = !do_move;
}
if(do_move)
{
for(auto& p : mesh[ei].PNums())
if(mapto[p].Size())
p = mapto[p].Last();
}
if(do_insert)
{
if(el.GetType() == TET)
{
if(moved.Size() == 3) // inner corner
{
PointIndex p1 = moved[0];
PointIndex p2 = moved[1];
PointIndex p3 = moved[2];
auto v1 = mesh[p1];
auto n = Cross(mesh[p2]-v1, mesh[p3]-v1);
auto d = mesh[mapto[p1][0]] - v1;
if(n*d > 0)
Swap(p2,p3);
PointIndex p4 = p1;
PointIndex p5 = p2;
PointIndex p6 = p3;
for(auto i : Range(params.heights))
{
Element nel(PRISM);
nel[0] = p4; nel[1] = p5; nel[2] = p6;
p4 = mapto[p1][i]; p5 = mapto[p2][i]; p6 = mapto[p3][i];
nel[3] = p4; nel[4] = p5; nel[5] = p6;
nel.SetIndex(el.GetIndex());
mesh.AddVolumeElement(nel);
}
}
if(moved.Size() == 2)
{
if(fixed.Size() == 1)
{
PointIndex p1 = moved[0];
PointIndex p2 = moved[1];
for(auto i : Range(params.heights))
{
PointIndex p3 = mapto[moved[1]][i];
PointIndex p4 = mapto[moved[0]][i];
Element nel(PYRAMID);
nel[0] = p1;
nel[1] = p2;
nel[2] = p3;
nel[3] = p4;
nel[4] = el[0] + el[1] + el[2] + el[3] - fixed[0] - moved[0] - moved[1];
if(Cross(mesh[p2]-mesh[p1], mesh[p4]-mesh[p1]) * (mesh[nel[4]]-mesh[nel[1]]) > 0)
Swap(nel[1], nel[3]);
nel.SetIndex(el.GetIndex());
mesh.AddVolumeElement(nel);
p1 = p4;
p2 = p3;
}
}
}
if(moved.Size() == 1 && fixed.Size() == 1)
{
PointIndex p1 = moved[0];
for(auto i : Range(params.heights))
{
Element nel = el;
PointIndex p2 = mapto[moved[0]][i];
for(auto& p : nel.PNums())
{
if(p == moved[0])
p = p1;
else if(p == fixed[0])
p = p2;
}
p1 = p2;
mesh.AddVolumeElement(nel);
}
}
}
else if(el.GetType() == PYRAMID)
{
if(moved.Size() == 2)
{
if(fixed.Size() != 2)
throw Exception("This case is not implemented yet! Fixed size = " + ToString(fixed.Size()));
PointIndex p1 = moved[0];
PointIndex p2 = moved[1];
for(auto i : Range(params.heights))
{
PointIndex p3 = mapto[moved[1]][i];
PointIndex p4 = mapto[moved[0]][i];
Element nel(PYRAMID);
nel[0] = p1;
nel[1] = p2;
nel[2] = p3;
nel[3] = p4;
nel[4] = el[0] + el[1] + el[2] + el[3] + el[4] - fixed[0] - fixed[1] - moved[0] - moved[1];
if(Cross(mesh[p2] - mesh[p1], mesh[p4]-mesh[p1]) * (mesh[nel[4]]-mesh[nel[1]]) > 0)
Swap(nel[1], nel[3]);
nel.SetIndex(el.GetIndex());
mesh.AddVolumeElement(nel);
p1 = p4;
p2 = p3;
}
}
else if(moved.Size() == 1)
throw Exception("This case is not implemented yet!");
}
else
throw Exception("Boundarylayer only implemented for tets and pyramids outside yet!");
}
}
}
void BoundaryLayerTool :: SetDomInOut()
{
for(auto i : Range(1, nfd_old+1))
if(si_map[i] != -1)
{
if(mesh.GetFaceDescriptor(mesh.GetNFD()).DomainIn() == new_mat_nr)
mesh.GetFaceDescriptor(i).SetDomainOut(new_mat_nr);
else
mesh.GetFaceDescriptor(i).SetDomainIn(new_mat_nr);
}
}
void BoundaryLayerTool :: AddSegments()
{
if(have_single_segments)
MergeAndAddSegments(mesh, new_segments);
else
{
for(auto & seg : new_segments)
mesh.AddSegment(seg);
}
}
void BoundaryLayerTool :: FixVolumeElements()
{
static Timer timer("BoundaryLayerTool::FixVolumeElements"); RegionTimer rt(timer);
BitArray is_inner_point(mesh.GetNP()+1);
is_inner_point.Clear();
auto changed_domains = domains;
if(!params.outside)
changed_domains.Invert();
for(ElementIndex ei : Range(ne))
if(changed_domains.Test(mesh[ei].GetIndex()))
for(auto pi : mesh[ei].PNums())
if(mesh[pi].Type() == INNERPOINT)
is_inner_point.SetBit(pi);
Array<PointIndex> points;
for(auto pi : mesh.Points().Range())
if(is_inner_point.Test(pi))
points.Append(pi);
auto p2el = mesh.CreatePoint2ElementTable(is_inner_point);
// smooth growth vectors to shift additional element layers to the inside and fix flipped tets
for(auto step : Range(10))
{
for(auto pi : points)
{
Vec<3> average_gw = 0.0;
auto & els = p2el[pi];
size_t cnt = 0;
for(auto ei : els)
if(ei<ne)
for(auto pi1 : mesh[ei].PNums())
if(pi1<=np)
{
average_gw += growthvectors[pi1];
cnt++;
}
growthvectors[pi] = 1.0/cnt * average_gw;
}
}
for(auto pi : points)
{
mesh[pi] += height * growthvectors[pi];
growthvectors[pi] = 0.0;
}
}
void BoundaryLayerTool :: Perform()
{
CreateNewFaceDescriptors();
CalculateGrowthVectors();
auto segmap = BuildSegMap();
auto in_surface_direction = ProjectGrowthVectorsOnSurface();
InterpolateGrowthVectors();
if(params.limit_growth_vectors)
LimitGrowthVectorLengths();
FixVolumeElements();
InsertNewElements(segmap, in_surface_direction);
SetDomInOut();
AddSegments();
mesh.GetTopology().ClearEdges();
mesh.SetNextMajorTimeStamp();
mesh.UpdateTopology();
MeshingParameters mp;
mp.optimize3d ="m";
mp.optsteps3d = 4;
OptimizeVolume(mp, mesh);
}
void GenerateBoundaryLayer(Mesh& mesh, const BoundaryLayerParameters& blp)
{
static Timer timer("Create Boundarylayers");
RegionTimer regt(timer);
BoundaryLayerTool tool(mesh, blp);
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;
}
}
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