bool
Surface_mesh::
is_collapse_ok(Halfedge v0v1)
{
Halfedge v1v0(opposite_halfedge(v0v1));
Vertex v0(to_vertex(v1v0));
Vertex v1(to_vertex(v0v1));
Vertex vv, vl, vr;
Halfedge h1, h2;
// the edges v1-vl and vl-v0 must not be both boundary edges
if (!is_boundary(v0v1))
{
vl = to_vertex(next_halfedge(v0v1));
h1 = next_halfedge(v0v1);
h2 = next_halfedge(h1);
if (is_boundary(opposite_halfedge(h1)) && is_boundary(opposite_halfedge(h2)))
return false;
}
// the edges v0-vr and vr-v1 must not be both boundary edges
if (!is_boundary(v1v0))
{
vr = to_vertex(next_halfedge(v1v0));
h1 = next_halfedge(v1v0);
h2 = next_halfedge(h1);
if (is_boundary(opposite_halfedge(h1)) && is_boundary(opposite_halfedge(h2)))
return false;
}
// if vl and vr are equal or both invalid -> fail
if (vl == vr) return false;
// edge between two boundary vertices should be a boundary edge
if ( is_boundary(v0) && is_boundary(v1) &&
!is_boundary(v0v1) && !is_boundary(v1v0))
return false;
// test intersection of the one-rings of v0 and v1
Vertex_around_vertex_circulator vv_it, vv_end;
vv_it = vv_end = vertices(v0);
do
{
vv = vv_it;
if (vv != v1 && vv != vl && vv != vr)
if (find_halfedge(vv, v1).is_valid())
return false;
}
while (++vv_it != vv_end);
// passed all tests
return true;
}
void
Surface_mesh::
flip(Edge e)
{
// CAUTION : Flipping a halfedge may result in
// a non-manifold mesh, hence check for yourself
// whether this operation is allowed or not!
//let's make it sure it is actually checked
assert(is_flip_ok(e));
Halfedge a0 = halfedge(e, 0);
Halfedge b0 = halfedge(e, 1);
Halfedge a1 = next_halfedge(a0);
Halfedge a2 = next_halfedge(a1);
Halfedge b1 = next_halfedge(b0);
Halfedge b2 = next_halfedge(b1);
Vertex va0 = to_vertex(a0);
Vertex va1 = to_vertex(a1);
Vertex vb0 = to_vertex(b0);
Vertex vb1 = to_vertex(b1);
Face fa = face(a0);
Face fb = face(b0);
set_vertex(a0, va1);
set_vertex(b0, vb1);
set_next_halfedge(a0, a2);
set_next_halfedge(a2, b1);
set_next_halfedge(b1, a0);
set_next_halfedge(b0, b2);
set_next_halfedge(b2, a1);
set_next_halfedge(a1, b0);
set_face(a1, fb);
set_face(b1, fa);
set_halfedge(fa, a0);
set_halfedge(fb, b0);
if (halfedge(va0) == b0)
set_halfedge(va0, a1);
if (halfedge(vb0) == a0)
set_halfedge(vb0, b1);
}
void
Surface_mesh::
split(Face f, Vertex v)
{
/*
Split an arbitrary face into triangles by connecting each vertex of fh to vh.
- fh will remain valid (it will become one of the triangles)
- the halfedge handles of the new triangles will point to the old halfeges
*/
Halfedge hend = halfedge(f);
Halfedge h = next_halfedge(hend);
Halfedge hold = new_edge(to_vertex(hend), v);
set_next_halfedge(hend, hold);
set_face(hold, f);
hold = opposite_halfedge(hold);
while (h != hend)
{
Halfedge hnext = next_halfedge(h);
Face fnew = new_face();
set_halfedge(fnew, h);
Halfedge hnew = new_edge(to_vertex(h), v);
set_next_halfedge(hnew, hold);
set_next_halfedge(hold, h);
set_next_halfedge(h, hnew);
set_face(hnew, fnew);
set_face(hold, fnew);
set_face(h, fnew);
hold = opposite_halfedge(hnew);
h = hnext;
}
set_next_halfedge(hold, hend);
set_next_halfedge(next_halfedge(hend), hold);
set_face(hold, f);
set_halfedge(v, hold);
}
void
Surface_mesh::
remove_loop(Halfedge h)
{
Halfedge h0 = h;
Halfedge h1 = next_halfedge(h0);
Halfedge o0 = opposite_halfedge(h0);
Halfedge o1 = opposite_halfedge(h1);
Vertex v0 = to_vertex(h0);
Vertex v1 = to_vertex(h1);
Face fh = face(h0);
Face fo = face(o0);
// is it a loop ?
assert ((next_halfedge(h1) == h0) && (h1 != o0));
// halfedge -> halfedge
set_next_halfedge(h1, next_halfedge(o0));
set_next_halfedge(prev_halfedge(o0), h1);
// halfedge -> face
set_face(h1, fo);
// vertex -> halfedge
set_halfedge(v0, h1); adjust_outgoing_halfedge(v0);
set_halfedge(v1, o1); adjust_outgoing_halfedge(v1);
// face -> halfedge
if (fo.is_valid() && halfedge(fo) == o0)
set_halfedge(fo, h1);
// delete stuff
if (!edeleted_) edeleted_ = edge_property<bool>("e:deleted", false);
if (!fdeleted_) fdeleted_ = face_property<bool>("f:deleted", false);
if (fh.is_valid()) { fdeleted_[fh] = true; ++deleted_faces_; }
edeleted_[edge(h0)] = true; ++deleted_edges_;
garbage_ = true;
}
void
Surface_mesh::
triangulate(Face f)
{
/*
Split an arbitrary face into triangles by connecting
each vertex of fh after its second to vh.
- fh will remain valid (it will become one of the
triangles)
- the halfedge handles of the new triangles will
point to the old halfedges
*/
Halfedge base_h = halfedge(f);
Vertex start_v = from_vertex(base_h);
Halfedge next_h = next_halfedge(base_h);
while (to_vertex(next_halfedge(next_h)) != start_v)
{
Halfedge next_next_h(next_halfedge(next_h));
Face new_f = new_face();
set_halfedge(new_f, base_h);
Halfedge new_h = new_edge(to_vertex(next_h), start_v);
set_next_halfedge(base_h, next_h);
set_next_halfedge(next_h, new_h);
set_next_halfedge(new_h, base_h);
set_face(base_h, new_f);
set_face(next_h, new_f);
set_face(new_h, new_f);
base_h = opposite_halfedge(new_h);
next_h = next_next_h;
}
set_halfedge(f, base_h); //the last face takes the handle _fh
set_next_halfedge(base_h, next_h);
set_next_halfedge(next_halfedge(next_h), base_h);
set_face(base_h, f);
}
Surface_mesh::Normal
Surface_mesh::
compute_face_normal(Face f) const
{
Halfedge h = halfedge(f);
Halfedge hend = h;
Point p0 = vpoint_[to_vertex(h)];
h = next_halfedge(h);
Point p1 = vpoint_[to_vertex(h)];
h = next_halfedge(h);
Point p2 = vpoint_[to_vertex(h)];
if (next_halfedge(h) == hend) // face is a triangle
{
p2-=p1;
p0-=p1;
return p2.cross(p0).normalized();
}
else // face is a general polygon
{
Normal n(0,0,0);
hend = h;
do
{
n += (p2-p1).cross(p0-p1);
h = next_halfedge(h);
p0 = p1;
p1 = p2;
p2 = vpoint_[to_vertex(h)];
}
while (h != hend);
return n.normalized();
}
}
bool
Surface_mesh::
is_flip_ok(Edge e) const
{
// boundary edges cannot be flipped
if (is_boundary(e)) return false;
// check if the flipped edge is already present in the mesh
Halfedge h0 = halfedge(e, 0);
Halfedge h1 = halfedge(e, 1);
Vertex v0 = to_vertex(next_halfedge(h0));
Vertex v1 = to_vertex(next_halfedge(h1));
if (v0 == v1) // this is generally a bad sign !!!
return false;
if (find_halfedge(v0, v1).is_valid())
return false;
return true;
}
Surface_mesh::Normal
Surface_mesh::
compute_vertex_normal(Vertex v) const
{
Point nn(0,0,0);
Halfedge h = halfedge(v);
if (h.is_valid())
{
const Halfedge hend = h;
const Point p0 = vpoint_[v];
Point n, p1, p2;
Scalar cosine, angle;
do
{
if (!is_boundary(h))
{
p1 = vpoint_[to_vertex(h)];
p1 -= p0;
p1.normalize();
p2 = vpoint_[from_vertex(prev_halfedge(h))];
p2 -= p0;
p2.normalize();
cosine = p1.dot(p2) / sqrt(p1.dot(p1)*p2.dot(p2));
if (cosine < -1.0) cosine = -1.0;
else if (cosine > 1.0) cosine = 1.0;
angle = acos(cosine);
n = p1.cross(p2).normalized();
n *= angle;
nn += n;
}
h = cw_rotated_halfedge(h);
}
while (h != hend);
nn.normalize();
}
return nn;
}
Surface_mesh::Halfedge
Surface_mesh::
find_halfedge(Vertex start, Vertex end) const
{
assert(is_valid(start) && is_valid(end));
Halfedge h = halfedge(start);
const Halfedge hh = h;
if (h.is_valid())
{
do
{
if (to_vertex(h) == end)
return h;
h = cw_rotated_halfedge(h);
}
while (h != hh);
}
return Halfedge();
}
void
Surface_mesh::
split(Edge e, Vertex v)
{
Halfedge h0 = halfedge(e, 0);
Halfedge o0 = halfedge(e, 1);
Vertex v2 = to_vertex(o0);
Halfedge e1 = new_edge(v, v2);
Halfedge t1 = opposite_halfedge(e1);
Face f0 = face(h0);
Face f3 = face(o0);
set_halfedge(v, h0);
set_vertex(o0, v);
if (!is_boundary(h0))
{
Halfedge h1 = next_halfedge(h0);
Halfedge h2 = next_halfedge(h1);
Vertex v1 = to_vertex(h1);
Halfedge e0 = new_edge(v, v1);
Halfedge t0 = opposite_halfedge(e0);
Face f1 = new_face();
set_halfedge(f0, h0);
set_halfedge(f1, h2);
set_face(h1, f0);
set_face(t0, f0);
set_face(h0, f0);
set_face(h2, f1);
set_face(t1, f1);
set_face(e0, f1);
set_next_halfedge(h0, h1);
set_next_halfedge(h1, t0);
set_next_halfedge(t0, h0);
set_next_halfedge(e0, h2);
set_next_halfedge(h2, t1);
set_next_halfedge(t1, e0);
}
else
{
set_next_halfedge(prev_halfedge(h0), t1);
set_next_halfedge(t1, h0);
// halfedge handle of _vh already is h0
}
if (!is_boundary(o0))
{
Halfedge o1 = next_halfedge(o0);
Halfedge o2 = next_halfedge(o1);
Vertex v3 = to_vertex(o1);
Halfedge e2 = new_edge(v, v3);
Halfedge t2 = opposite_halfedge(e2);
Face f2 = new_face();
set_halfedge(f2, o1);
set_halfedge(f3, o0);
set_face(o1, f2);
set_face(t2, f2);
set_face(e1, f2);
set_face(o2, f3);
set_face(o0, f3);
set_face(e2, f3);
set_next_halfedge(e1, o1);
set_next_halfedge(o1, t2);
set_next_halfedge(t2, e1);
set_next_halfedge(o0, e2);
set_next_halfedge(e2, o2);
set_next_halfedge(o2, o0);
}
else
{
set_next_halfedge(e1, next_halfedge(o0));
set_next_halfedge(o0, e1);
set_halfedge(v, e1);
}
if (halfedge(v2) == h0)
set_halfedge(v2, t1);
}
void
Surface_mesh::
garbage_collection()
{
if (!garbage_) return;
int i, i0, i1,
nV(vertices_size()),
nE(edges_size()),
nH(halfedges_size()),
nF(faces_size());
Vertex v;
Halfedge h;
Face f;
if (!vdeleted_) vdeleted_ = vertex_property<bool>("v:deleted", false);
if (!edeleted_) edeleted_ = edge_property<bool>("e:deleted", false);
if (!fdeleted_) fdeleted_ = face_property<bool>("f:deleted", false);
// setup handle mapping
Vertex_property<Vertex> vmap = add_vertex_property<Vertex>("v:garbage-collection");
Halfedge_property<Halfedge> hmap = add_halfedge_property<Halfedge>("h:garbage-collection");
Face_property<Face> fmap = add_face_property<Face>("f:garbage-collection");
for (i=0; i<nV; ++i)
vmap[Vertex(i)] = Vertex(i);
for (i=0; i<nH; ++i)
hmap[Halfedge(i)] = Halfedge(i);
for (i=0; i<nF; ++i)
fmap[Face(i)] = Face(i);
// remove deleted vertices
if (nV > 0)
{
i0=0; i1=nV-1;
while (1)
{
// find first deleted and last un-deleted
while (!vdeleted_[Vertex(i0)] && i0 < i1) ++i0;
while ( vdeleted_[Vertex(i1)] && i0 < i1) --i1;
if (i0 >= i1) break;
// swap
vprops_.swap(i0, i1);
//add
for(unsigned int j = 0;j<map_2skel.size();j++)
{
if(map_2skel[j] == i0)
map_2skel[j] = i1;
else if(map_2skel[j] == i1)
map_2skel[j] = i0;
}
//end
};
// remember new size
nV = vdeleted_[Vertex(i0)] ? i0 : i0+1;
}
// remove deleted edges
if (nE > 0)
{
i0=0; i1=nE-1;
while (1)
{
// find first deleted and last un-deleted
while (!edeleted_[Edge(i0)] && i0 < i1) ++i0;
while ( edeleted_[Edge(i1)] && i0 < i1) --i1;
if (i0 >= i1) break;
// swap
eprops_.swap(i0, i1);
hprops_.swap(2*i0, 2*i1);
hprops_.swap(2*i0+1, 2*i1+1);
};
// remember new size
nE = edeleted_[Edge(i0)] ? i0 : i0+1;
nH = 2*nE;
}
// remove deleted faces
if (nF > 0)
{
i0=0; i1=nF-1;
while (1)
{
// find 1st deleted and last un-deleted
while (!fdeleted_[Face(i0)] && i0 < i1) ++i0;
while ( fdeleted_[Face(i1)] && i0 < i1) --i1;
if (i0 >= i1) break;
// swap
fprops_.swap(i0, i1);
};
// remember new size
nF = fdeleted_[Face(i0)] ? i0 : i0+1;
}
// update vertex connectivity
for (i=0; i<nV; ++i)
{
v = Vertex(i);
if (!is_isolated(v))
set_halfedge(v, hmap[halfedge(v)]);
}
// update halfedge connectivity
for (i=0; i<nH; ++i)
{
h = Halfedge(i);
set_vertex(h, vmap[to_vertex(h)]);
set_next_halfedge(h, hmap[next_halfedge(h)]);
if (!is_boundary(h))
set_face(h, fmap[face(h)]);
}
// update handles of faces
for (i=0; i<nF; ++i)
{
f = Face(i);
set_halfedge(f, hmap[halfedge(f)]);
}
// remove handle maps
remove_vertex_property(vmap);
remove_halfedge_property(hmap);
remove_face_property(fmap);
// finally resize arrays
vprops_.resize(nV); vprops_.free_memory();
hprops_.resize(nH); hprops_.free_memory();
eprops_.resize(nE); eprops_.free_memory();
fprops_.resize(nF); fprops_.free_memory();
deleted_vertices_ = deleted_edges_ = deleted_faces_ = 0;
garbage_ = false;
}
void
Surface_mesh::
remove_edge(Halfedge h)
{
Halfedge hn = next_halfedge(h);
Halfedge hp = prev_halfedge(h);
Halfedge o = opposite_halfedge(h);
Halfedge on = next_halfedge(o);
Halfedge op = prev_halfedge(o);
Face fh = face(h);
Face fo = face(o);
Vertex vh = to_vertex(h);
Vertex vo = to_vertex(o);
// halfedge -> vertex
Halfedge_around_vertex_circulator vh_it, vh_end;
vh_it = vh_end = halfedges(vo);
do
{
set_vertex(opposite_halfedge(vh_it), vh);
}
while (++vh_it != vh_end);
// halfedge -> halfedge
set_next_halfedge(hp, hn);
set_next_halfedge(op, on);
// face -> halfedge
if (fh.is_valid()) set_halfedge(fh, hn);
if (fo.is_valid()) set_halfedge(fo, on);
// vertex -> halfedge
if (halfedge(vh) == o) set_halfedge(vh, hn);
adjust_outgoing_halfedge(vh);
set_halfedge(vo, Halfedge());
// delete stuff
if (!vdeleted_) vdeleted_ = vertex_property<bool>("v:deleted", false);
if (!edeleted_) edeleted_ = edge_property<bool>("e:deleted", false);
vdeleted_[vo] = true; ++deleted_vertices_;
edeleted_[edge(h)] = true; ++deleted_edges_;
garbage_ = true;
//add
for(unsigned int j = 0;j < map_2skel.size();j++)
{
if(map_2skel[j] == vo.idx())
{
//unsigned int tem = map_2skel[j];
map_2skel[j] = vh.idx();
//qDebug("vertex:[%d],change %d to %d",j,tem,vh.idx());
}
}
//end
}
void draw_it(const std::vector<std::vector<sf::Vertex>> & sims, float time, float height, std::string title)
{
//http://www.sfml-dev.org/tutorials/2.1/start-vc.php
//nb -s for static libs
const float edge = 30.0f;
const float lineWidth = 5.0f;
const float width = 500.0f;
const float x_scale = width/time;
const auto bagColour = sf::Color(180, 120, 60);
sf::RenderWindow window(sf::VideoMode(static_cast<int>(width + 2*edge), static_cast<int>(height + 2*edge)), title);
window.clear(sf::Color::Black);
sf::RectangleShape left(sf::Vector2f(lineWidth, static_cast<float>(height)));
left.setFillColor(bagColour);
left.setPosition(edge, edge);
window.draw(left);
sf::RectangleShape right(sf::Vector2f(lineWidth, static_cast<float>(height)));
right.setFillColor(bagColour);
right.setPosition(edge + width, edge);
window.draw(right);
sf::RectangleShape base(sf::Vector2f(static_cast<float>(width) + lineWidth, lineWidth));
base.setFillColor(bagColour);
base.setPosition(edge, edge + height);
window.draw(base);
assert(sims.begin()->size());
//TODO - and they are all the same
size_t penultimate = sims.begin()->size() - 1;
size_t last = 1;
while (window.isOpen())
{
// check all the window's events that were triggered since the last iteration of the loop
sf::Event event;
while (window.pollEvent(event))
{
// "close requested" event: we close the window
if (event.type == sf::Event::Closed)
window.close();
break;
}
window.clear();
window.draw(left);
window.draw(right);
window.draw(base);
last = std::min(++last, sims.begin()->size() - 1);
for(const auto & points: sims)
{
bool out = false;
for(size_t i=0; i < last; ++i)
{
out |= (points[i].position.y > height);//what about the edge?
sf::Color colour = out ? sf::Color::Green: sf::Color::White;
auto scaled_start = to_vertex(points[i], colour, edge + lineWidth, x_scale, height);
auto scaled_point = to_vertex(points[i+1], colour, edge + lineWidth, x_scale, height);
sf::Vertex line[] = {scaled_start, scaled_point};
window.draw(line, 2, sf::Lines);
}
}
window.display();
std::this_thread::sleep_for(std::chrono::milliseconds(50));//set render rate... or whatever it's called
}
}
