void triangulate(const Vertices& vertices, PolygonMesh& output)
{
const int n_vertices = vertices.vertices.size();
if (n_vertices <= 3)
{
output.polygons.push_back(vertices);
return;
}
std::vector<uint32_t> remaining_vertices(n_vertices);
if (area(vertices.vertices) > 0) // clockwise?
{
remaining_vertices = vertices.vertices;
}
else
{
for (int v = 0; v < n_vertices; v++)
remaining_vertices[v] = vertices.vertices[n_vertices - 1 - v];
}
// Avoid closed loops.
if (remaining_vertices.front() == remaining_vertices.back())
remaining_vertices.erase(remaining_vertices.end()-1);
// null_iterations avoids infinite loops if the polygon is not simple.
for (int u = remaining_vertices.size() - 1, null_iterations = 0;
remaining_vertices.size() > 2 && null_iterations < remaining_vertices.size()*2;
++null_iterations, u=(u+1)%remaining_vertices.size())
{
int v = (u + 1) % remaining_vertices.size();
int w = (u + 2) % remaining_vertices.size();
if (isEar(u, v, w, remaining_vertices))
{
Vertices triangle;
triangle.vertices.resize(3);
triangle.vertices[0] = remaining_vertices[u];
triangle.vertices[1] = remaining_vertices[v];
triangle.vertices[2] = remaining_vertices[w];
output.polygons.push_back(triangle);
remaining_vertices.erase(remaining_vertices.begin()+v);
null_iterations = 0;
}
}
for (int i = 0; i < remaining_vertices.size(); ++i)
ntk_dbg_print(remaining_vertices[i], 1);
}
void
pcl::EarClipping::triangulate (const Vertices& vertices, PolygonMesh& output)
{
const int n_vertices = static_cast<const int> (vertices.vertices.size ());
if (n_vertices <= 3)
return;
std::vector<uint32_t> remaining_vertices (n_vertices);
if (area (vertices.vertices) > 0) // clockwise?
remaining_vertices = vertices.vertices;
else
for (int v = 0; v < n_vertices; v++)
remaining_vertices[v] = vertices.vertices[n_vertices - 1 - v];
// Avoid closed loops.
if (remaining_vertices.front () == remaining_vertices.back ())
remaining_vertices.erase (remaining_vertices.end () - 1);
// null_iterations avoids infinite loops if the polygon is not simple.
for (int u = static_cast<int> (remaining_vertices.size ()) - 1, null_iterations = 0;
remaining_vertices.size () > 2 && null_iterations < static_cast<int >(remaining_vertices.size () * 2);
++null_iterations, u = (u+1) % static_cast<int> (remaining_vertices.size ()))
{
int v = (u + 1) % static_cast<int> (remaining_vertices.size ());
int w = (u + 2) % static_cast<int> (remaining_vertices.size ());
if (isEar (u, v, w, remaining_vertices))
{
Vertices triangle;
triangle.vertices.resize (3);
triangle.vertices[0] = remaining_vertices[u];
triangle.vertices[1] = remaining_vertices[v];
triangle.vertices[2] = remaining_vertices[w];
output.polygons.push_back (triangle);
remaining_vertices.erase (remaining_vertices.begin () + v);
null_iterations = 0;
}
}
}
