New BoxTree for Delaunay

This commit is contained in:
Matthias Hochsteger 2019-09-25 15:04:27 +02:00
parent 206aa3a6bd
commit b2808109b6

View File

@ -2,10 +2,231 @@
#include "meshing.hpp"
namespace netgen
{
template<int dim, typename T=INDEX>
class BTree
{
// Number of entries per leaf
static constexpr int N = 100;
struct Node;
struct Leaf
{
Point<2*dim> p[N];
T index[N];
int n_elements;
Leaf() : n_elements(0) {}
void Add( Array<Leaf*, INDEX> &leaf_index, const Point<2*dim> &ap, T aindex )
{
p[n_elements] = ap;
index[n_elements] = aindex;
n_elements++;
if(leaf_index.Size()<=aindex)
leaf_index.SetSize(2*aindex);
leaf_index[aindex] = this;
}
};
struct Node
{
double sep;
Node *left, *right;
Leaf *leaf;
int level;
Node() = default;
~Node()
{
delete leaf;
delete left;
delete right;
}
};
Node root;
Array<Leaf*, INDEX> leaf_index;
Point<dim> global_min, global_max;
double tol;
public:
BTree (const Point<dim> & pmin, const Point<dim> & pmax)
: global_min(pmin), global_max(pmax)
{
root.leaf = new Leaf();
root.level = 0;
tol = 1e-7 * Dist(pmax, pmin);
}
void GetIntersecting (const Point<dim> & pmin, const Point<dim> & pmax,
NgArray<T> & pis) const
{
static Array<const Node*> stack(1000);
static Array<int> dir_stack(1000);
static NgArray<T> ref_pis;
pis.SetSize(0);
Point<2*dim> tpmin, tpmax;
for (size_t i : IntRange(dim))
{
tpmin(i) = global_min(i);
tpmax(i) = pmax(i)+tol;
tpmin(i+dim) = pmin(i)-tol;
tpmax(i+dim) = global_max(i);
}
stack.SetSize(0);
stack.Append(&root);
dir_stack.SetSize(0);
dir_stack.Append(0);
while(stack.Size())
{
const Node *node = stack.Last();
stack.DeleteLast();
int dir = dir_stack.Last();
dir_stack.DeleteLast();
if(Leaf *leaf=node->leaf)
{
for (auto i : IntRange(leaf->n_elements))
{
bool intersect = true;
const auto p = leaf->p[i];
for (int d = 0; d < dim; d++)
if (p[d] > tpmax[d])
continue;
for (int d = dim; d < 2*dim; d++)
if (p[d] < tpmin[d])
continue;
pis.Append (leaf->index[i]);
}
}
else
{
int newdir = dir+1;
if(newdir==2*dim) newdir = 0;
if (tpmin[dir] <= node->sep)
{
stack.Append(node->left);
dir_stack.Append(newdir);
}
if (tpmax[dir] >= node->sep)
{
stack.Append(node->right);
dir_stack.Append(newdir);
}
}
}
}
void Insert (const Point<dim> & pmin, const Point<dim> & pmax, T pi)
{
int dir = 0;
Point<2*dim> p;
for (auto i : IntRange(dim))
{
p(i) = pmin[i];
p(i+dim) = pmax[i];
}
Node * node = &root;
Leaf * leaf = node->leaf;
// search correct leaf to add point
while(!leaf)
{
node = p[dir] < node->sep ? node->left : node->right;
dir++;
if(dir==2*dim) dir = 0;
leaf = node->leaf;
}
// add point to leaf
if(leaf->n_elements < N)
leaf->Add(leaf_index, p,pi);
else // assume leaf->n_elements == N
{
// add two new nodes and one new leaf
int n_elements = leaf->n_elements;
ArrayMem<double, N> coords(n_elements);
ArrayMem<int, N> order(n_elements);
// separate points in two halves, first sort all coordinates in direction dir
for (auto i : IntRange(n_elements))
{
order[i] = i;
coords[i] = leaf->p[i][dir];
}
QuickSortI(coords, order);
int isplit = N/2;
Leaf *leaf1 = new Leaf();
Leaf *leaf2 = new Leaf();
for (auto i : order.Range(isplit))
leaf1->Add(leaf_index, leaf->p[i], leaf->index[i] );
for (auto i : order.Range(isplit, N))
leaf2->Add(leaf_index, leaf->p[i], leaf->index[i] );
Node *node1 = new Node();
node1->leaf = leaf1;
node1->level = node->level+1;
Node *node2 = new Node();
node2->leaf = leaf2;
node2->level = node->level+1;
node->left = node1;
node->right = node2;
node->leaf = nullptr;
node->sep = 0.5 * (leaf->p[order[isplit-1]][dir] + leaf->p[order[isplit]][dir]);
// add new point to one of the new leaves
if (p[dir] < node->sep)
leaf1->Add( leaf_index, p, pi );
else
leaf2->Add( leaf_index, p, pi );
delete leaf;
}
}
void DeleteElement (T pi)
{
Leaf *leaf = leaf_index[pi];
auto & n_elements = leaf->n_elements;
auto & index = leaf->index;
auto & p = leaf->p;
for (auto i : IntRange(n_elements))
{
if(index[i] == pi)
{
n_elements--;
if(i!=n_elements)
{
index[i] = index[n_elements];
p[i] = p[n_elements];
}
return;
}
}
}
};
typedef BTree<3> TBoxTree;
// typedef BoxTree<3> TBoxTree;
static const int deltetfaces[][3] =
{ { 1, 2, 3 },
{ 2, 0, 3 },
@ -214,7 +435,7 @@ namespace netgen
void AddDelaunayPoint (PointIndex newpi, const Point3d & newp,
NgArray<DelaunayTet> & tempels,
Mesh & mesh,
BoxTree<3> & tettree,
TBoxTree & tettree,
MeshNB & meshnb,
NgArray<Point<3> > & centers, NgArray<double> & radi2,
NgArray<int> & connected, NgArray<int> & treesearch,
@ -586,7 +807,7 @@ namespace netgen
pmin2 = pmin2 + 0.1 * (pmin2 - pmax2);
pmax2 = pmax2 + 0.1 * (pmax2 - pmin2);
BoxTree<3> tettree(pmin2, pmax2);
TBoxTree tettree(pmin2, pmax2);
tempels.Append (startel);