update to stable version

This commit is contained in:
张壹 2021-09-19 09:21:11 +08:00
parent b3367003d0
commit 2a69d72aec
10 changed files with 153 additions and 896 deletions

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@ -9,10 +9,5 @@ g++ demo.cpp
### run ### run
```shell ```shell
./a.out > demo.off ./a.out
``` ```

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@ -12,8 +12,6 @@
#include "cmath" #include "cmath"
#include "vector" #include "vector"
#include "iostream"
#define ZERO 1e-5 #define ZERO 1e-5
// Start vertex definition // Start vertex definition
@ -39,63 +37,55 @@ bool operator ==(const vertex2dc &a, const vertex2dc &b) // overload the == oper
} }
return false; return false;
} }
void circumcircle(vertex2dc *v0, vertex2dc *v1, vertex2dc *v2, double &cx, double &cy, double &cr) // calculate the circumcircle from three points
{
double s = 0.5 / ((v1->x - v0->x) * (v2->y - v0->y) - (v1->y - v0->y) * (v2->x - v0->x));
double m = v1->x*v1->x - v0->x*v0->x + v1->y*v1->y - v0->y*v0->y;
double u = v2->x*v2->x - v0->x*v0->x + v2->y*v2->y - v0->y*v0->y;
cx = ((v2->y - v0->y)*m + (v0->y - v1->y)*u)*s;
cy = ((v0->x - v2->x)*m + (v1->x - v0->x)*u)*s;
cr = (v0->x - cx)*(v0->x - cx) + (v0->y - cy)*(v0->y - cy); // not need to calculate the squared root here
return;
}
// End vertex definition // End vertex definition
// Start edge definition
struct edge
{
vertex2dc *vert[2]; // vertex of the edge
edge() {vert[0] = vert[1] = nullptr;}
edge(vertex2dc *v0ptr, vertex2dc *v1ptr) {set(v0ptr, v1ptr);}
void set(vertex2dc *v0ptr, vertex2dc *v1ptr)
{
vert[0] = v0ptr; vert[1] = v1ptr;
return;
}
};
bool operator ==(const edge &a, const edge &b) // overload the == operator for edge type
{
if((a.vert[0] == b.vert[0] && a.vert[1] == b.vert[1]) ||
(a.vert[0] == b.vert[1] && a.vert[1] == b.vert[0]))
{
return true;
}
return false;
}
// End edge definition
// Start triangle definition // Start triangle definition
struct triangle struct triangle
{ {
int id;
vertex2dc *vert[3]; // vertex of the triangle vertex2dc *vert[3]; // vertex of the triangle
triangle *neigh[3]; // neighbors of the triangle
double cx, cy; // center of the triangle's circumcircle double cx, cy; // center of the triangle's circumcircle
double cr; // radius of the circumcircle double cr; // radius of the circumcircle
triangle() {vert[0] = vert[1] = vert[2] = nullptr; neigh[0] = neigh[1] = neigh[2] = nullptr;} triangle() {vert[0] = vert[1] = vert[2] = nullptr;}
triangle(vertex2dc *v0ptr, vertex2dc *v1ptr, vertex2dc *v2ptr) {set(v0ptr, v1ptr, v2ptr);} triangle(vertex2dc *v0ptr, vertex2dc *v1ptr, vertex2dc *v2ptr) {set(v0ptr, v1ptr, v2ptr);}
void set(vertex2dc *v0ptr, vertex2dc *v1ptr, vertex2dc *v2ptr) void set(vertex2dc *v0ptr, vertex2dc *v1ptr, vertex2dc *v2ptr)
{ {
vert[0] = v0ptr; vert[1] = v1ptr; vert[2] = v2ptr; vert[0] = v0ptr; vert[1] = v1ptr; vert[2] = v2ptr;
neigh[0] = neigh[1] = neigh[2] = nullptr;
circumcircle(vert[0], vert[1], vert[2], cx, cy, cr); double s = 0.5 / ((vert[1]->x - vert[0]->x) * (vert[2]->y - vert[0]->y) - (vert[1]->y - vert[0]->y) * (vert[2]->x - vert[0]->x));
double m = vert[1]->x * vert[1]->x - vert[0]->x * vert[0]->x + vert[1]->y * vert[1]->y - vert[0]->y * vert[0]->y;
double u = vert[2]->x * vert[2]->x - vert[0]->x * vert[0]->x + vert[2]->y * vert[2]->y - vert[0]->y * vert[0]->y;
cx = ((vert[2]->y - vert[0]->y) * m + (vert[0]->y - vert[1]->y) * u) * s;
cy = ((vert[0]->x - vert[2]->x) * m + (vert[1]->x - vert[0]->x) * u) * s;
cr = (vert[0]->x - cx) * (vert[0]->x - cx) + (vert[0]->y - cy) * (vert[0]->y - cy); // not need to sqrt() here
return; return;
} }
void set_neighbor(triangle *n0ptr, triangle *n1ptr, triangle *n2ptr)
{
neigh[0] = n0ptr; neigh[1] = n1ptr; neigh[2] = n2ptr;
return;
}
bool bound_location(double inx, double iny) // Test if the location is inside the triangle
{
double l1x, l1y, l2x, l2y;
for (int i = 0; i < 3; i++)
{
l1x = vert[(i+1)%3]->x - vert[i]->x;
l1y = vert[(i+1)%3]->y - vert[i]->y;
l2x = inx - vert[i]->x;
l2y = iny - vert[i]->y;
if ((l1x*l2y - l1y*l2x) < 0) // This condition includes points on the triangle's edge
{
return false;
}
}
return true;
}
}; };
// End triangle definition // End triangle definition
@ -105,7 +95,7 @@ struct triangle
* @param in_verts Input vertexes. Defined by the user. * @param in_verts Input vertexes. Defined by the user.
* @param out_tris Output triangles. Compute by the function. * @param out_tris Output triangles. Compute by the function.
*/ */
void triangulation(std::vector<vertex2dc> &in_verts, std::vector<triangle*> &out_tris) void triangulation(std::vector<vertex2dc> &in_verts, std::vector<triangle> &out_tris)
{ {
if (!out_tris.empty()) out_tris.clear(); if (!out_tris.empty()) out_tris.clear();
if (in_verts.size() < 3) return; if (in_verts.size() < 3) return;
@ -128,261 +118,119 @@ void triangulation(std::vector<vertex2dc> &in_verts, std::vector<triangle*> &out
vertex2dc *tmp_vert = nullptr; vertex2dc *tmp_vert = nullptr;
std::vector<vertex2dc*> assit_vert; std::vector<vertex2dc*> assit_vert;
tmp_vert = new vertex2dc(midx - maxi_s, midy - maxi_s, 99990); // lower left corner tmp_vert = new vertex2dc(midx - maxi_s, midy - maxi_s); // lower left corner
assit_vert.push_back(tmp_vert); assit_vert.push_back(tmp_vert);
tmp_vert = new vertex2dc(midx + maxi_s, midy - maxi_s, 99991); // lower right corner tmp_vert = new vertex2dc(midx + maxi_s, midy - maxi_s); // lower right corner
assit_vert.push_back(tmp_vert); assit_vert.push_back(tmp_vert);
tmp_vert = new vertex2dc(midx + maxi_s, midy + maxi_s, 99992); // upper right corner tmp_vert = new vertex2dc(midx + maxi_s, midy + maxi_s); // upper right corner
assit_vert.push_back(tmp_vert); assit_vert.push_back(tmp_vert);
tmp_vert = new vertex2dc(midx - maxi_s, midy + maxi_s, 99993); // upper left corner tmp_vert = new vertex2dc(midx - maxi_s, midy + maxi_s); // upper left corner
assit_vert.push_back(tmp_vert); assit_vert.push_back(tmp_vert);
triangle *old_tri = nullptr, *tmp_tri = nullptr; triangle *tmp_tri = nullptr;
triangle *cnst_tri[3], *old_neigh[6]; std::vector<triangle*> exist_tri, cnst_tri;
std::vector<triangle*>::iterator t_iter; std::vector<triangle*>::iterator t_iter;
tmp_tri = new triangle(assit_vert[0], assit_vert[1], assit_vert[2]); // order the vertex anti-clock wise tmp_tri = new triangle(assit_vert[0], assit_vert[1], assit_vert[2]); // order the vertex anti-clock wise
out_tris.push_back(tmp_tri); exist_tri.push_back(tmp_tri);
tmp_tri = new triangle(assit_vert[0], assit_vert[2], assit_vert[3]); // order the vertex anti-clock wise tmp_tri = new triangle(assit_vert[0], assit_vert[2], assit_vert[3]); // order the vertex anti-clock wise
out_tris.push_back(tmp_tri); exist_tri.push_back(tmp_tri);
out_tris[0]->set_neighbor(nullptr, nullptr, out_tris[1]);
out_tris[1]->set_neighbor(out_tris[0], nullptr, nullptr);
// loop all input vertice // loop all input vertice
bool removed;
double dist; double dist;
edge tmp_edge;
std::vector<edge> cnst_edge;
std::vector<edge>::iterator e_iter;
for (int i = 0; i < in_verts.size(); ++i) for (int i = 0; i < in_verts.size(); ++i)
{ {
// determine the triangle that includes the new vertex and remove it from out_tris // determine triangles that include the point and add the triangle to the cnst_tri and remove the triangle from exist_tri
for (t_iter = out_tris.begin(); t_iter != out_tris.end(); ) // this is the part that could take a lot of time if we are working with a large amount of points. We will fix this later
cnst_tri.clear();
for (t_iter = exist_tri.begin(); t_iter != exist_tri.end(); )
{ {
old_tri = *t_iter; tmp_tri = *t_iter;
if (old_tri->bound_location(in_verts[i].x, in_verts[i].y))
dist = (tmp_tri->cx - in_verts[i].x) * (tmp_tri->cx - in_verts[i].x) +
(tmp_tri->cy - in_verts[i].y) * (tmp_tri->cy - in_verts[i].y);
if ((dist - tmp_tri->cr) <= ZERO) // Points on the circumcircle are also included
{ {
t_iter = out_tris.erase(t_iter); t_iter = exist_tri.erase(t_iter);
break; cnst_tri.push_back(tmp_tri);
} }
else t_iter++; else t_iter++;
} }
// build three new triangles // loop to remove duplicate edges
for (int n = 0; n < 3; ++n) cnst_edge.clear();
for (int c = 0; c < cnst_tri.size(); ++c)
{ {
tmp_tri = new triangle(old_tri->vert[n], old_tri->vert[(n+1)%3], &in_verts[i]); for (int e = 0; e < 3; ++e)
cnst_tri[n] = tmp_tri; {
out_tris.push_back(tmp_tri); tmp_edge.set(cnst_tri[c]->vert[e], cnst_tri[c]->vert[(e+1)%3]);
}
// sort neighbors removed = false;
for (int n = 0; n < 3; ++n) for (e_iter = cnst_edge.begin(); e_iter != cnst_edge.end(); )
{
if (old_tri->neigh[n] == nullptr)
{
cnst_tri[n]->set_neighbor(nullptr, cnst_tri[(n+1)%3], cnst_tri[(n+2)%3]);
}
else
{
cnst_tri[n]->set_neighbor(old_tri->neigh[n], cnst_tri[(n+1)%3], cnst_tri[(n+2)%3]);
for (int k = 0; k < 3; ++k) // replace neighbor for the oppositing triangle
{ {
if (old_tri->neigh[n]->neigh[k] == old_tri) if (tmp_edge == *e_iter) // duplicate edge, remove from cnst_edge
{ {
old_tri->neigh[n]->neigh[k] = cnst_tri[n]; e_iter = cnst_edge.erase(e_iter);
break; removed = true;
break; // no need to search more
} }
else e_iter++;
}
if (!removed) // not a duplicate edge, add to the cnst_edge
{
cnst_edge.push_back(tmp_edge);
} }
} }
} }
// delete the old triangle // construct new triangles and add to exist_tri
delete old_tri; old_tri = nullptr; for (int c = 0; c < cnst_edge.size(); ++c)
// test if the cnst_tri need to be flipped
for (int n = 0; n < 3; ++n)
{ {
if (cnst_tri[n]->neigh[0] != nullptr) // must has neighbor on this side tmp_tri = new triangle(cnst_edge[c].vert[0], cnst_edge[c].vert[1], &in_verts[i]); // order the vertex anti-clock wise
{ exist_tri.push_back(tmp_tri);
old_tri = cnst_tri[n]->neigh[0];
for (int v = 0; v < 3; ++v)
{
tmp_vert = old_tri->vert[v];
if (tmp_vert != cnst_tri[n]->vert[0] && tmp_vert != cnst_tri[n]->vert[1]) // find the opposite vertex
{
//dist = (cnst_tri[n]->cx - tmp_vert->x) * (cnst_tri[n]->cx - tmp_vert->x) +
// (cnst_tri[n]->cy - tmp_vert->y) * (cnst_tri[n]->cy - tmp_vert->y);
//if ((dist - cnst_tri[n]->cr) <= ZERO) // need to be flipped
dist = (old_tri->cx - cnst_tri[n]->vert[2]->x) * (old_tri->cx - cnst_tri[n]->vert[2]->x) +
(old_tri->cy - cnst_tri[n]->vert[2]->y) * (old_tri->cy - cnst_tri[n]->vert[2]->y);
if ((dist - old_tri->cr) <= ZERO) // need to be flipped
{
// record the original neighbors
old_neigh[0] = cnst_tri[n]->neigh[0];
old_neigh[1] = cnst_tri[n]->neigh[1];
old_neigh[2] = cnst_tri[n]->neigh[2];
old_neigh[3] = old_tri->neigh[0];
old_neigh[4] = old_tri->neigh[1];
old_neigh[5] = old_tri->neigh[2];
cnst_tri[n]->set(cnst_tri[n]->vert[0], tmp_vert, cnst_tri[n]->vert[2]); // flip
if (v == 0)
{
old_tri->set(old_tri->vert[0], old_tri->vert[1], cnst_tri[n]->vert[2]); //flip
// Sort neighbors
cnst_tri[n]->set_neighbor(old_neigh[5], old_tri, old_neigh[2]);
old_tri->set_neighbor(old_neigh[3], old_neigh[1], cnst_tri[n]);
for (int k = 0; k < 3; ++k)
{
if (cnst_tri[n]->neigh[0] != nullptr && cnst_tri[n]->neigh[0]->neigh[k] == old_tri)
{
cnst_tri[n]->neigh[0]->neigh[k] = cnst_tri[n];
break;
}
}
for (int k = 0; k < 3; ++k)
{
if (old_tri->neigh[1] != nullptr && old_tri->neigh[1]->neigh[k] == cnst_tri[n])
{
old_tri->neigh[1]->neigh[k] = old_tri;
break;
}
}
}
else if (v == 1)
{
old_tri->set(cnst_tri[n]->vert[2], old_tri->vert[1], old_tri->vert[2]); //flip
// Sort neighbors
cnst_tri[n]->set_neighbor(old_neigh[3], old_tri, old_neigh[2]);
old_tri->set_neighbor(cnst_tri[n], old_neigh[4], old_neigh[1]);
for (int k = 0; k < 3; ++k)
{
if (cnst_tri[n]->neigh[0] != nullptr && cnst_tri[n]->neigh[0]->neigh[k] == old_tri)
{
cnst_tri[n]->neigh[0]->neigh[k] = cnst_tri[n];
break;
}
}
for (int k = 0; k < 3; ++k)
{
if (old_tri->neigh[2] != nullptr && old_tri->neigh[2]->neigh[k] == cnst_tri[n])
{
old_tri->neigh[2]->neigh[k] = old_tri;
break;
}
}
}
else
{
old_tri->set(old_tri->vert[0], cnst_tri[n]->vert[2], old_tri->vert[2]); //flip
// Sort neighbors
cnst_tri[n]->set_neighbor(old_neigh[4], old_tri, old_neigh[2]);
old_tri->set_neighbor(old_neigh[1], cnst_tri[n], old_neigh[5]);
for (int k = 0; k < 3; ++k)
{
if (cnst_tri[n]->neigh[0] != nullptr && cnst_tri[n]->neigh[0]->neigh[k] == old_tri)
{
cnst_tri[n]->neigh[0]->neigh[k] = cnst_tri[n];
break;
}
}
for (int k = 0; k < 3; ++k)
{
if (old_tri->neigh[0] != nullptr && old_tri->neigh[0]->neigh[k] == cnst_tri[n])
{
old_tri->neigh[0]->neigh[k] = old_tri;
break;
}
}
}
}
break;
}
}
}
} }
std::cout << "Insert time: " << i + 1 << std::endl; // destroy memories used by cnst_edge
for (int e = 0; e < out_tris.size(); ++e) for (int c = 0; c < cnst_tri.size(); ++c)
{ {
std::cout << out_tris[e]->vert[0]->id << " " << out_tris[e]->vert[1]->id << " " << out_tris[e]->vert[2]->id << std::endl; tmp_tri = cnst_tri[c];
delete tmp_tri; tmp_tri = nullptr;
} }
std::cout << "===================\n";
} }
// remove any triangles has an assistant vertex from out_tris // remove any triangles has an assistant vertex from exist_tri
for (t_iter = out_tris.begin(); t_iter != out_tris.end(); ) for (t_iter = exist_tri.begin(); t_iter != exist_tri.end(); )
{ {
tmp_tri = *t_iter; tmp_tri = *t_iter;
if (tmp_tri->vert[0] == assit_vert[0] || tmp_tri->vert[0] == assit_vert[1] || tmp_tri->vert[0] == assit_vert[2] || tmp_tri->vert[0] == assit_vert[3]) if (tmp_tri->vert[0] == assit_vert[0] || tmp_tri->vert[0] == assit_vert[1] || tmp_tri->vert[0] == assit_vert[2] || tmp_tri->vert[0] == assit_vert[3] ||
tmp_tri->vert[1] == assit_vert[0] || tmp_tri->vert[1] == assit_vert[1] || tmp_tri->vert[1] == assit_vert[2] || tmp_tri->vert[1] == assit_vert[3] ||
tmp_tri->vert[2] == assit_vert[0] || tmp_tri->vert[2] == assit_vert[1] || tmp_tri->vert[2] == assit_vert[2] || tmp_tri->vert[2] == assit_vert[3])
{ {
for (int k = 0; k < 3; ++k)
{
if (tmp_tri->neigh[1] != nullptr && tmp_tri->neigh[1]->neigh[k] == tmp_tri)
{
tmp_tri->neigh[1]->neigh[k] = nullptr;
break;
}
}
// destroy the memories located and remove from the vector // destroy the memories located and remove from the vector
t_iter = out_tris.erase(t_iter); t_iter = exist_tri.erase(t_iter);
delete tmp_tri; tmp_tri = nullptr;
}
else if (tmp_tri->vert[1] == assit_vert[0] || tmp_tri->vert[1] == assit_vert[1] || tmp_tri->vert[1] == assit_vert[2] || tmp_tri->vert[1] == assit_vert[3])
{
for (int k = 0; k < 3; ++k)
{
if (tmp_tri->neigh[2] != nullptr && tmp_tri->neigh[2]->neigh[k] == tmp_tri)
{
tmp_tri->neigh[2]->neigh[k] = nullptr;
break;
}
}
// destroy the memories located and remove from the vector
t_iter = out_tris.erase(t_iter);
delete tmp_tri; tmp_tri = nullptr;
}
else if (tmp_tri->vert[2] == assit_vert[0] || tmp_tri->vert[2] == assit_vert[1] || tmp_tri->vert[2] == assit_vert[2] || tmp_tri->vert[2] == assit_vert[3])
{
for (int k = 0; k < 3; ++k)
{
if (tmp_tri->neigh[0] != nullptr && tmp_tri->neigh[0]->neigh[k] == tmp_tri)
{
tmp_tri->neigh[0]->neigh[k] = nullptr;
break;
}
}
// destroy the memories located and remove from the vector
t_iter = out_tris.erase(t_iter);
delete tmp_tri; tmp_tri = nullptr; delete tmp_tri; tmp_tri = nullptr;
} }
else t_iter++; else t_iter++;
} }
// assign triangles index // copy exist_tri to out_tris and destroy memories located
for (int i = 0; i < out_tris.size(); i++) out_tris.resize(exist_tri.size());
for (int i = 0; i < exist_tri.size(); ++i)
{ {
out_tris[i]->id = i; out_tris[i].set(exist_tri[i]->vert[0], exist_tri[i]->vert[1], exist_tri[i]->vert[2]);
delete exist_tri[i]; exist_tri[i] = nullptr;
} }
// destroy memories located for assit_vert // destroy memories located for assit_vert
for (int i = 0; i < 4; ++i) for (int i = 0; i < 4; ++i)
{ {
@ -406,7 +254,7 @@ bool duplicated_vertex(const std::vector<vertex2dc> &in_verts)
{ {
for (int j = i+1; j < in_verts.size(); ++j) for (int j = i+1; j < in_verts.size(); ++j)
{ {
if (in_verts[i] == in_verts[j]) if (in_verts[i] == in_verts[j] && in_verts[i].id != in_verts[j].id)
{ {
return true; return true;
} }
@ -423,9 +271,9 @@ bool duplicated_vertex(const std::vector<vertex2dc> &in_verts)
* *
* @return If the triangulation is fully delaunay * @return If the triangulation is fully delaunay
*/ */
bool fully_delaunay(const std::vector<triangle*> &in_tris, const std::vector<vertex2dc> &in_verts) bool fully_delaunay(const std::vector<triangle> &in_tris, const std::vector<vertex2dc> &in_verts)
{ {
if (in_tris.empty()) return false; if (in_tris.empty()) return true;
int count; int count;
double dist; double dist;
@ -434,10 +282,10 @@ bool fully_delaunay(const std::vector<triangle*> &in_tris, const std::vector<ver
count = 0; count = 0;
for (int j = 0; j < in_verts.size(); ++j) for (int j = 0; j < in_verts.size(); ++j)
{ {
dist = (in_tris[i]->cx - in_verts[j].x) * (in_tris[i]->cx - in_verts[j].x) + dist = (in_tris[i].cx - in_verts[j].x) * (in_tris[i].cx - in_verts[j].x) +
(in_tris[i]->cy - in_verts[j].y) * (in_tris[i]->cy - in_verts[j].y); (in_tris[i].cy - in_verts[j].y) * (in_tris[i].cy - in_verts[j].y);
if ((dist - in_tris[i]->cr) <= ZERO) if ((dist - in_tris[i].cr) <= ZERO)
{ {
count++; count++;
} }

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@ -1,312 +0,0 @@
/**
* @defgroup DELAUNAY
*
* @brief An implementation of the 2D Delaunay triangulation using the Bowyer-Watson algorithm.
*
* @author Yi Zhang
* @date 2021-09-12
*/
#ifndef _BW_2D_DELAUNAY_H
#define _BW_2D_DELAUNAY_H
#include "cmath"
#include "vector"
#include "iostream"
#define ZERO 1e-5
// Start vertex definition
struct vertex2dc
{
unsigned int id; // index of the vertex
double x, y; // position of the vertex
vertex2dc() : x(NAN), y(NAN), id(0) {}
vertex2dc(double inx, double iny, unsigned int inid = 0) {set(inx, iny, inid);}
void set(double inx, double iny, unsigned int inid = 0)
{
x = inx; y = iny; id = inid;
return;
}
};
bool operator ==(const vertex2dc &a, const vertex2dc &b) // overload the == operator for vertex2dc type
{
if(fabs(a.x - b.x) <= ZERO && fabs(a.y - b.y) <= ZERO)
{
return true;
}
return false;
}
// End vertex definition
// Start edge definition
struct edge
{
vertex2dc *vert[2]; // vertex of the edge
edge() {vert[0] = vert[1] = nullptr;}
edge(vertex2dc *v0ptr, vertex2dc *v1ptr) {set(v0ptr, v1ptr);}
void set(vertex2dc *v0ptr, vertex2dc *v1ptr)
{
vert[0] = v0ptr; vert[1] = v1ptr;
return;
}
};
bool operator ==(const edge &a, const edge &b) // overload the == operator for edge type
{
if((a.vert[0] == b.vert[0] && a.vert[1] == b.vert[1]) ||
(a.vert[0] == b.vert[1] && a.vert[1] == b.vert[0]))
{
return true;
}
return false;
}
// End edge definition
// Start triangle definition
struct triangle
{
vertex2dc *vert[3]; // vertex of the triangle
double cx, cy; // center of the triangle's circumcircle
double cr; // radius of the circumcircle
triangle() {vert[0] = vert[1] = vert[2] = nullptr;}
triangle(vertex2dc *v0ptr, vertex2dc *v1ptr, vertex2dc *v2ptr) {set(v0ptr, v1ptr, v2ptr);}
void set(vertex2dc *v0ptr, vertex2dc *v1ptr, vertex2dc *v2ptr)
{
vert[0] = v0ptr; vert[1] = v1ptr; vert[2] = v2ptr;
double s = 0.5 / ((vert[1]->x - vert[0]->x) * (vert[2]->y - vert[0]->y) - (vert[1]->y - vert[0]->y) * (vert[2]->x - vert[0]->x));
double m = vert[1]->x * vert[1]->x - vert[0]->x * vert[0]->x + vert[1]->y * vert[1]->y - vert[0]->y * vert[0]->y;
double u = vert[2]->x * vert[2]->x - vert[0]->x * vert[0]->x + vert[2]->y * vert[2]->y - vert[0]->y * vert[0]->y;
cx = ((vert[2]->y - vert[0]->y) * m + (vert[0]->y - vert[1]->y) * u) * s;
cy = ((vert[0]->x - vert[2]->x) * m + (vert[1]->x - vert[0]->x) * u) * s;
cr = (vert[0]->x - cx) * (vert[0]->x - cx) + (vert[0]->y - cy) * (vert[0]->y - cy); // not need to sqrt() here
return;
}
};
// End triangle definition
/**
* @brief 2D Delaunay triangulation of some given points using the Bowyer-Watson algorithm.
*
* @param in_verts Input vertexes. Defined by the user.
* @param out_tris Output triangles. Compute by the function.
*/
void triangulation(std::vector<vertex2dc> &in_verts, std::vector<triangle> &out_tris)
{
if (!out_tris.empty()) out_tris.clear();
if (in_verts.size() < 3) return;
// locate the surrounding box and initiate the staring two triangles
double xmin = in_verts[0].x, xmax = in_verts[0].x;
double ymin = in_verts[0].y, ymax = in_verts[0].y;
for (int i = 0; i < in_verts.size(); ++i)
{
xmin = std::min(xmin, in_verts[i].x);
xmax = std::max(xmax, in_verts[i].x);
ymin = std::min(ymin, in_verts[i].y);
ymax = std::max(ymax, in_verts[i].y);
}
double midx = 0.5*(xmin + xmax);
double midy = 0.5*(ymin + ymax);
double maxi_s = std::max(xmax - xmin, ymax - ymin); // use an four times bigger rectangle to include all points
vertex2dc *tmp_vert = nullptr;
std::vector<vertex2dc*> assit_vert;
tmp_vert = new vertex2dc(midx - maxi_s, midy - maxi_s, 99990); // lower left corner
assit_vert.push_back(tmp_vert);
tmp_vert = new vertex2dc(midx + maxi_s, midy - maxi_s, 99991); // lower right corner
assit_vert.push_back(tmp_vert);
tmp_vert = new vertex2dc(midx + maxi_s, midy + maxi_s, 99992); // upper right corner
assit_vert.push_back(tmp_vert);
tmp_vert = new vertex2dc(midx - maxi_s, midy + maxi_s, 99993); // upper left corner
assit_vert.push_back(tmp_vert);
triangle *tmp_tri = nullptr;
std::vector<triangle*> exist_tri, cnst_tri;
std::vector<triangle*>::iterator t_iter;
tmp_tri = new triangle(assit_vert[0], assit_vert[1], assit_vert[2]); // order the vertex anti-clock wise
exist_tri.push_back(tmp_tri);
tmp_tri = new triangle(assit_vert[0], assit_vert[2], assit_vert[3]); // order the vertex anti-clock wise
exist_tri.push_back(tmp_tri);
// loop all input vertice
bool removed;
double dist;
edge tmp_edge;
std::vector<edge> cnst_edge;
std::vector<edge>::iterator e_iter;
for (int i = 0; i < in_verts.size(); ++i)
{
// determine triangles that include the point and add the triangle to the cnst_tri and remove the triangle from exist_tri
// this is the part that could take a lot of time if we are working with a large amount of points. We will fix this later
cnst_tri.clear();
for (t_iter = exist_tri.begin(); t_iter != exist_tri.end(); )
{
tmp_tri = *t_iter;
dist = (tmp_tri->cx - in_verts[i].x) * (tmp_tri->cx - in_verts[i].x) +
(tmp_tri->cy - in_verts[i].y) * (tmp_tri->cy - in_verts[i].y);
if ((dist - tmp_tri->cr) <= ZERO) // Points on the circumcircle are also included
{
t_iter = exist_tri.erase(t_iter);
cnst_tri.push_back(tmp_tri);
}
else t_iter++;
}
// loop to remove duplicate edges
cnst_edge.clear();
for (int c = 0; c < cnst_tri.size(); ++c)
{
for (int e = 0; e < 3; ++e)
{
tmp_edge.set(cnst_tri[c]->vert[e], cnst_tri[c]->vert[(e+1)%3]);
removed = false;
for (e_iter = cnst_edge.begin(); e_iter != cnst_edge.end(); )
{
if (tmp_edge == *e_iter) // duplicate edge, remove from cnst_edge
{
e_iter = cnst_edge.erase(e_iter);
removed = true;
break; // no need to search more
}
else e_iter++;
}
if (!removed) // not a duplicate edge, add to the cnst_edge
{
cnst_edge.push_back(tmp_edge);
}
}
}
// construct new triangles and add to exist_tri
for (int c = 0; c < cnst_edge.size(); ++c)
{
tmp_tri = new triangle(cnst_edge[c].vert[0], cnst_edge[c].vert[1], &in_verts[i]); // order the vertex anti-clock wise
exist_tri.push_back(tmp_tri);
}
// destroy memories used by cnst_edge
for (int c = 0; c < cnst_tri.size(); ++c)
{
tmp_tri = cnst_tri[c];
delete tmp_tri; tmp_tri = nullptr;
}
std::cout << "Insert time: " << i + 1 << std::endl;
for (int e = 0; e < exist_tri.size(); ++e)
{
std::cout << exist_tri[e]->vert[0]->id << " " << exist_tri[e]->vert[1]->id << " " << exist_tri[e]->vert[2]->id << std::endl;
}
std::cout << "===================\n";
}
// remove any triangles has an assistant vertex from exist_tri
for (t_iter = exist_tri.begin(); t_iter != exist_tri.end(); )
{
tmp_tri = *t_iter;
if (tmp_tri->vert[0] == assit_vert[0] || tmp_tri->vert[0] == assit_vert[1] || tmp_tri->vert[0] == assit_vert[2] || tmp_tri->vert[0] == assit_vert[3] ||
tmp_tri->vert[1] == assit_vert[0] || tmp_tri->vert[1] == assit_vert[1] || tmp_tri->vert[1] == assit_vert[2] || tmp_tri->vert[1] == assit_vert[3] ||
tmp_tri->vert[2] == assit_vert[0] || tmp_tri->vert[2] == assit_vert[1] || tmp_tri->vert[2] == assit_vert[2] || tmp_tri->vert[2] == assit_vert[3])
{
// destroy the memories located and remove from the vector
t_iter = exist_tri.erase(t_iter);
delete tmp_tri; tmp_tri = nullptr;
}
else t_iter++;
}
// copy exist_tri to out_tris and destroy memories located
out_tris.resize(exist_tri.size());
for (int i = 0; i < exist_tri.size(); ++i)
{
out_tris[i].set(exist_tri[i]->vert[0], exist_tri[i]->vert[1], exist_tri[i]->vert[2]);
delete exist_tri[i]; exist_tri[i] = nullptr;
}
// destroy memories located for assit_vert
for (int i = 0; i < 4; ++i)
{
delete assit_vert[i]; assit_vert[i] = nullptr;
}
return;
}
/**
* @brief Check for duplicated vertex
*
* @param[in] in_verts Input vertexes
*
* @return If there is duplicated vertex
*/
bool duplicated_vertex(const std::vector<vertex2dc> &in_verts)
{
if (in_verts.empty()) return false;
for (int i = 0; i < in_verts.size()-1; ++i)
{
for (int j = i+1; j < in_verts.size(); ++j)
{
if (in_verts[i] == in_verts[j])
{
return true;
}
}
}
return false;
}
/**
* @brief Check to see if the triangulation is fully delaunay
*
* @param[in] in_tris Input triangles
* @param[in] in_verts Input vertexes
*
* @return If the triangulation is fully delaunay
*/
bool fully_delaunay(const std::vector<triangle> &in_tris, const std::vector<vertex2dc> &in_verts)
{
if (in_tris.empty()) return true;
int count;
double dist;
for (int i = 0; i < in_tris.size(); ++i)
{
count = 0;
for (int j = 0; j < in_verts.size(); ++j)
{
dist = (in_tris[i].cx - in_verts[j].x) * (in_tris[i].cx - in_verts[j].x) +
(in_tris[i].cy - in_verts[j].y) * (in_tris[i].cy - in_verts[j].y);
if ((dist - in_tris[i].cr) <= ZERO)
{
count++;
}
}
if (count > 3)
{
return false;
}
}
return true;
}
#endif // _BW_2D_DELAUNAY_H

View File

@ -5,7 +5,7 @@
int main(int argc, char const *argv[]) int main(int argc, char const *argv[])
{ {
std::vector<vertex2dc> points(7); std::vector<vertex2dc> points(21);
points[0].set(-0.8, -0.8, 0); points[0].set(-0.8, -0.8, 0);
points[1].set(0.4, -1.2, 1); points[1].set(0.4, -1.2, 1);
points[2].set(1.2, -0.9, 2); points[2].set(1.2, -0.9, 2);
@ -13,7 +13,6 @@ int main(int argc, char const *argv[])
points[4].set(2.5, 0.5, 4); points[4].set(2.5, 0.5, 4);
points[5].set(4.1, 0.7, 5); points[5].set(4.1, 0.7, 5);
points[6].set(5.7, 1.8, 6); points[6].set(5.7, 1.8, 6);
/*
points[7].set(5.1, 3.4, 7); points[7].set(5.1, 3.4, 7);
points[8].set(2.5, 4.4, 8); points[8].set(2.5, 4.4, 8);
points[9].set(1.2, 3.7, 9); points[9].set(1.2, 3.7, 9);
@ -28,26 +27,14 @@ int main(int argc, char const *argv[])
points[18].set(2.4, 2.8, 18); points[18].set(2.4, 2.8, 18);
points[19].set(3.5, 1.8, 19); points[19].set(3.5, 1.8, 19);
points[20].set(3.6, 3.1, 20); points[20].set(3.6, 3.1, 20);
*/
/*
std::vector<vertex2dc> points(7);
points[0].set(-0.8, -0.8, 0);
points[1].set(0.4, -1.2, 1);
points[2].set(1.2, 0.9, 2);
points[3].set(-0.4, 0.5, 3);
points[4].set(0.2, -0.15, 4);
points[5].set(0.5, 0.375, 5);
points[6].set(0.7, -0.15, 6);
*/
if (duplicated_vertex(points)) if (duplicated_vertex(points))
{ {
std::cerr << "Duplicated vertice detected.\n"; std::cerr << "Duplicated vertexes detected.\n";
return 0; return 0;
} }
std::vector<triangle*> elements; std::vector<triangle> elements;
triangulation(points, elements); triangulation(points, elements);
if (fully_delaunay(elements, points)) if (fully_delaunay(elements, points))
@ -72,36 +59,12 @@ int main(int argc, char const *argv[])
outfile << i + 1 << " 2 0"; outfile << i + 1 << " 2 0";
for (int j = 0; j < 3; j++) for (int j = 0; j < 3; j++)
{ {
outfile << " " << elements[i]->vert[j]->id + 1; outfile << " " << elements[i].vert[j]->id + 1;
} }
outfile << std::endl; outfile << std::endl;
} }
outfile << "$EndElements"<< std::endl; outfile << "$EndElements"<< std::endl;
outfile.close(); outfile.close();
// write a neighbor file
outfile.open("demo.neigh");
outfile << elements.size() << std::endl;
for (int i = 0; i < elements.size(); i++)
{
outfile << i + 1;
for (int j = 0; j < 3; j++)
{
if (elements[i]->neigh[j] != nullptr)
{
outfile << " " << elements[i]->neigh[j]->id + 1;
}
else outfile << " -1";
}
outfile << std::endl;
}
outfile.close();
// destroy allocated memories
for (int i = 0; i < elements.size(); i++)
{
delete elements[i];
}
return 0; return 0;
} }

View File

@ -2,7 +2,7 @@ $MeshFormat
2.2 0 8 2.2 0 8
$EndMeshFormat $EndMeshFormat
$Nodes $Nodes
7 21
1 -0.8 -0.8 0.0 1 -0.8 -0.8 0.0
2 0.4 -1.2 0.0 2 0.4 -1.2 0.0
3 1.2 -0.9 0.0 3 1.2 -0.9 0.0
@ -10,11 +10,51 @@ $Nodes
5 2.5 0.5 0.0 5 2.5 0.5 0.0
6 4.1 0.7 0.0 6 4.1 0.7 0.0
7 5.7 1.8 0.0 7 5.7 1.8 0.0
8 5.1 3.4 0.0
9 2.5 4.4 0.0
10 1.2 3.7 0.0
11 -1.2 3.9 0.0
12 -3.2 5.1 0.0
13 -4.3 2.9 0.0
14 -3.1 0.7 0.0
15 -1.3 0.6 0.0
16 -2.1 2.9 0.0
17 0.6 1.2 0.0
18 0.1 2.4 0.0
19 2.4 2.8 0.0
20 3.5 1.8 0.0
21 3.6 3.1 0.0
$EndNodes $EndNodes
$Elements $Elements
4 30
1 2 0 3 4 2 1 2 0 2 3 4
2 2 0 4 3 5 2 2 0 4 3 5
3 2 0 7 5 6 3 2 0 5 3 6
4 2 0 5 3 6 4 2 0 10 9 11
5 2 0 11 9 12
6 2 0 14 1 15
7 2 0 11 12 16
8 2 0 12 13 16
9 2 0 13 14 16
10 2 0 14 15 16
11 2 0 1 2 17
12 2 0 2 4 17
13 2 0 4 5 17
14 2 0 15 1 17
15 2 0 10 11 18
16 2 0 11 16 18
17 2 0 16 15 18
18 2 0 15 17 18
19 2 0 9 10 19
20 2 0 17 5 19
21 2 0 10 18 19
22 2 0 18 17 19
23 2 0 6 7 20
24 2 0 7 8 20
25 2 0 5 6 20
26 2 0 19 5 20
27 2 0 8 9 21
28 2 0 9 19 21
29 2 0 19 20 21
30 2 0 20 8 21
$EndElements $EndElements

View File

@ -1,5 +0,0 @@
4
1 2 -1 -1
2 1 4 -1
3 -1 4 -1
4 2 -1 3

View File

@ -1,14 +0,0 @@
OFF
7 5 0
-0.8 -0.8 0.0
0.4 -1.2 0.0
1.2 -0.9 0.0
1.6 0.1 0.0
2.5 0.5 0.0
4.1 0.7 0.0
5.7 1.8 0.0
3 0 1 3
3 1 2 3
3 3 2 4
3 4 2 5
3 4 5 6

View File

@ -1,76 +0,0 @@
#include "delaunay_backup.h"
#include "iostream"
#include "fstream"
#include "iomanip"
int main(int argc, char const *argv[])
{
std::vector<vertex2dc> points(7);
points[0].set(-0.8, -0.8, 0);
points[1].set(0.4, -1.2, 1);
points[2].set(1.2, -0.9, 2);
points[3].set(1.6, 0.1, 3);
points[4].set(2.5, 0.5, 4);
points[5].set(4.1, 0.7, 5);
points[6].set(5.7, 1.8, 6);
/*
points[7].set(5.1, 3.4, 7);
points[8].set(2.5, 4.4, 8);
points[9].set(1.2, 3.7, 9);
points[10].set(-1.2, 3.9, 10);
points[11].set(-3.2, 5.1, 11);
points[12].set(-4.3, 2.9, 12);
points[13].set(-3.1, 0.7, 13);
points[14].set(-1.3, 0.6, 14);
points[15].set(-2.1, 2.9, 15);
points[16].set(0.6, 1.2, 16);
points[17].set(0.1, 2.4, 17);
points[18].set(2.4, 2.8, 18);
points[19].set(3.5, 1.8, 19);
points[20].set(3.6, 3.1, 20);
*/
/*
std::vector<vertex2dc> points(7);
points[0].set(-0.8, -0.8, 0);
points[1].set(0.4, -1.2, 1);
points[2].set(1.2, 0.9, 2);
points[3].set(-0.4, 0.5, 3);
points[4].set(0.2, -0.15, 4);
points[5].set(0.5, 0.375, 5);
points[6].set(0.7, -0.15, 6);
*/
if (duplicated_vertex(points))
{
std::cerr << "Duplicated vertice detected.\n";
return 0;
}
std::vector<triangle> elements;
triangulation(points, elements);
if (fully_delaunay(elements, points))
{
std::clog << "The triangulation is fully delaunay.\n";
}
else std::clog << "The triangulation is not fully delaunay\n";
// Write a OFF file
std::cout << "OFF\n";
std::cout << points.size() << " " << elements.size() << " 0\n";
for (int i = 0; i < points.size(); i++)
{
std::cout << std::setprecision(16) << points[i].x << " " << points[i].y << " 0.0" << std::endl;
}
for (int i = 0; i < elements.size(); i++)
{
std::cout << "3 " << elements[i].vert[0]->id << " " << elements[i].vert[1]->id
<< " " << elements[i].vert[2]->id << std::endl;
}
return 0;
}

84
log.txt
View File

@ -1,84 +0,0 @@
Insert time: 1
0 99991 99992
99990 99991 0
99992 99993 0
99993 99990 0
===================
Insert time: 2
99990 99991 1
1 99993 0
99993 99990 0
0 99990 1
99991 99992 1
99992 99993 1
===================
Insert time: 3
99990 99991 1
1 99993 0
99993 99990 0
0 99990 1
2 99993 1
99991 99992 2
99992 99993 2
1 99991 2
===================
Insert time: 4
99990 99991 1
1 99993 0
99993 99990 0
0 99990 1
2 3 1
99991 99992 3
1 99991 2
99992 99993 3
99993 1 3
2 99991 3
===================
Insert time: 5
99990 99991 1
1 99993 0
99993 99990 0
0 99990 1
2 3 1
1 99991 2
4 99993 3
99993 1 3
2 99991 4
99991 99992 4
99992 99993 4
3 2 4
===================
Insert time: 6
99990 99991 1
1 99993 0
99993 99990 0
0 99990 1
2 3 1
1 99991 2
4 99993 3
99993 1 3
2 99991 5
99992 99993 4
3 2 4
99991 99992 5
99992 4 5
4 2 5
===================
Insert time: 7
99990 99991 1
1 99993 0
99993 99990 0
0 99990 1
2 3 1
1 99991 2
4 99993 3
99993 1 3
2 99991 5
99992 99993 4
3 2 4
6 4 5
4 2 5
99991 99992 6
99992 4 6
5 99991 6
===================

View File

@ -1,98 +0,0 @@
Insert time: 1
99990 99991 0
99991 99992 0
99992 99993 0
99993 99990 0
===================
Insert time: 2
99993 99990 0
99990 99991 1
0 99990 1
99991 99992 1
99992 99993 1
99993 0 1
===================
Insert time: 3
99993 99990 0
99990 99991 1
0 99990 1
99991 99992 2
1 99991 2
99992 99993 2
99993 0 2
0 1 2
===================
Insert time: 4
99993 99990 0
99990 99991 1
0 99990 1
1 99991 2
99991 99992 3
2 99991 3
99992 99993 3
99993 0 3
0 1 3
1 2 3
===================
Insert time: 5
99993 99990 0
99990 99991 1
0 99990 1
1 99991 2
99993 0 3
0 1 3
1 2 3
99991 99992 4
2 99991 4
3 2 4
99992 99993 4
99993 3 4
===================
Insert time: 6
99993 99990 0
99990 99991 1
0 99990 1
1 99991 2
99993 0 3
0 1 3
1 2 3
3 2 4
99992 99993 4
99993 3 4
99991 99992 5
99992 4 5
2 99991 5
4 2 5
===================
Insert time: 7
99993 99990 0
99990 99991 1
0 99990 1
1 99991 2
99993 0 3
0 1 3
1 2 3
3 2 4
99993 3 4
2 99991 5
4 2 5
99992 99993 6
99993 4 6
99991 99992 6
5 99991 6
4 5 6
===================
OFF
7 5 0
-0.8 -0.8 0.0
0.4 -1.2 0.0
1.2 -0.9 0.0
1.6 0.1 0.0
2.5 0.5 0.0
4.1 0.7 0.0
5.7 1.8 0.0
3 0 1 3
3 1 2 3
3 3 2 4
3 4 2 5
3 4 5 6