added attach and fill functions

src/polymesh/Mesh.hh

@@ -170,6 +170,12 @@ private:
     /// splits a half-edge
     vertex_index halfedge_split(halfedge_index h);
 
+    /// fills a face
+    face_index face_fill(halfedge_index h);
+
+    /// attaches a given vertex to the to-vertex of a given half-edge
+    void halfedge_attach(halfedge_index h, vertex_index v);
+
     /// collapse a vertex
     void vertex_collapse(vertex_index v);
     /// collapse a half-edge
@@ -197,6 +203,8 @@ private:
     void fix_boundary_state_of(vertex_index v_idx);
     /// choses a new half-edge for a given face, prefers boundary ones
     void fix_boundary_state_of(face_index f_idx);
+    /// choses a new half-edge for all vertices of a face, prefers boundary ones
+    void fix_boundary_state_of_vertices(face_index f_idx);
 
     // attributes
     bool is_boundary(vertex_index idx) const;
@@ -409,5 +417,5 @@ private:
 #include "impl/impl_cursors.hh"
 #include "impl/impl_iterators.hh"
 #include "impl/impl_mesh.hh"
-#include "impl/impl_ranges.hh"
 #include "impl/impl_primitive.hh"
+#include "impl/impl_ranges.hh"

src/polymesh/impl/impl_mesh.hh

@@ -406,6 +406,24 @@ inline void Mesh::fix_boundary_state_of(face_index f_idx)
     } while (he != he_begin);
 }
 
+inline void Mesh::fix_boundary_state_of_vertices(face_index f_idx)
+{
+    auto &f = face(f_idx);
+
+    auto he_begin = f.halfedge;
+    auto he = he_begin;
+    do
+    {
+        auto &h_ref = halfedge(he);
+
+        // fix vertex
+        fix_boundary_state_of(h_ref.to_vertex);
+
+        // advance
+        he = h_ref.next_halfedge;
+    } while (he != he_begin);
+}
+
 inline halfedge_index Mesh::find_free_incident(halfedge_index in_begin, halfedge_index in_end) const
 {
     assert(halfedge(in_begin).to_vertex == halfedge(in_end).to_vertex);
@@ -703,6 +721,65 @@ inline vertex_index Mesh::halfedge_split(halfedge_index h)
     return v;
 }
 
+inline face_index Mesh::face_fill(halfedge_index h)
+{
+    assert(is_boundary(h));
+
+    auto f = alloc_face();
+    auto &f_ref = face(f);
+
+    f_ref.halfedge = h;
+
+    auto h_begin = h;
+    do
+    {
+        auto &h_ref = halfedge(h);
+
+        // set face
+        h_ref.face = f;
+
+        // set boundary
+        if (is_boundary(opposite(h)))
+            f_ref.halfedge = h;
+
+        // advance
+        h = h_ref.next_halfedge;
+    } while (h != h_begin);
+
+    // fix vertex boundaries
+    fix_boundary_state_of_vertices(f);
+
+    return f;
+}
+
+inline void Mesh::halfedge_attach(halfedge_index h, vertex_index v)
+{
+    assert(vertex(v).is_isolated());
+
+    auto &h_ref = halfedge(h);
+    auto h_next = h_ref.next_halfedge;
+    auto v_to = h_ref.to_vertex;
+
+    auto f = h_ref.face;
+
+    auto e = alloc_edge();
+    auto h0 = halfedge_of(e, 0);
+    auto h1 = halfedge_of(e, 1);
+
+    auto &h0_ref = halfedge(h0);
+    auto &h1_ref = halfedge(h1);
+
+    h0_ref.face = f;
+    h0_ref.to_vertex = v;
+
+    h1_ref.face = f;
+    h1_ref.to_vertex = v_to;
+
+    connect_prev_next(h, h0);
+    connect_prev_next(h0, h1);
+    connect_prev_next(h1, h_next);
+}
+
 inline void Mesh::vertex_collapse(vertex_index v)
 {
     auto &v_ref = vertex(v);

src/polymesh/impl/impl_ranges.hh

@@ -650,6 +650,12 @@ vertex_handle face_collection<iterator>::split(face_handle f) const
     return this->mesh->handle_of(this->mesh->face_split(f.idx));
 }
 
+template <class iterator>
+face_handle face_collection<iterator>::fill(halfedge_handle h) const
+{
+    return this->mesh->handle_of(this->mesh->face_fill(h.idx));
+}
+
 template <class iterator>
 vertex_handle edge_collection<iterator>::split(edge_handle e) const
 {
@@ -686,6 +692,12 @@ vertex_handle halfedge_collection<iterator>::split(halfedge_handle h) const
     return this->mesh->handle_of(this->mesh->halfedge_split(h.idx));
 }
 
+template <class iterator>
+void halfedge_collection<iterator>::attach(halfedge_handle h, vertex_handle v) const
+{
+    this->mesh->halfedge_attach(h.idx, v.idx);
+}
+
 template <class iterator>
 void halfedge_collection<iterator>::rotate_next(halfedge_handle h) const
 {

src/polymesh/ranges.hh

@@ -212,6 +212,10 @@ struct face_collection : smart_collection<Mesh*, face_tag, iterator>
     /// The face itself is deleted and multiple new ones are created
     vertex_handle split(face_handle f) const;
 
+    /// Fills the half-edge ring of a given boundary half-edge
+    /// Returns the new face
+    face_handle fill(halfedge_handle h) const;
+
     /// Removes a face (adjacent edges and vertices are NOT removed)
     /// (marks it as removed, compactify mesh to actually remove it)
     void remove(face_handle f) const;
@@ -274,6 +278,9 @@ struct halfedge_collection : smart_collection<Mesh*, halfedge_tag, iterator>
     /// (thus h->next() is the newly inserted edge and h->vertex_to() is the returned vertex)
     vertex_handle split(halfedge_handle h) const;
 
+    /// Given an isolated vertex v, inserts a self-adjacent edge at the to-vertex to v
+    void attach(halfedge_handle h, vertex_handle v) const;
+
     /// Moves the to-vertex of this half-edge to the same as the next half-edge
     /// Preserves all attributes
     /// NOTE: does not work on boundaries!