draco/docs/spec/corner.table.md

Corner Table

Opposite()

Opposite(corner) {
  return opposite_corners_[corner];
}

Next()

Next(corner) {
  return LocalIndex(++corner) ? corner : corner - 3;
}

Previous()

Previous(corner) {
  return LocalIndex(corner) ? corner - 1 : corner + 2;
}

Vertex()

Vertex(corner) {
  faces_[Face(corner)][LocalIndex(corner)];
}

Face()

Face(corner) {
  return corner / 3;
}

LocalIndex()

LocalIndex(corner) {
  return corner % 3;
}

num_vertices()

num_vertices() {
  return vertex_corners_.size();
}

num_corners()

num_corners() {
  return faces_.size() * 3;
}

num_faces()

num_faces() {
  return faces_.size();
}

bool IsOnBoundary()

bool IsOnBoundary(vert) {
  corner = LeftMostCorner(vert);
  if (SwingLeft(corner) < 0)
    return true;
  return false;
}

SwingRight()

SwingRight(corner) {
  return Previous(Opposite(Previous(corner)));
}

SwingLeft()

SwingLeft(corner) {
  return Next(Opposite(Next(corner)));
}

GetLeftCorner()

GetLeftCorner(corner_id) {
  if (corner_id < 0)
     return kInvalidCornerIndex;
  return Opposite(Previous(corner_id));
}

GetRightCorner()

GetRightCorner(corner_id) {
  if (corner_id < 0)
     return kInvalidCornerIndex;
  return Opposite(Next(corner_id));
}

SetOppositeCorner()

SetOppositeCorner(corner_id, pp_corner_id) {
  opposite_corners_[corner_id] = opp_corner_id;
}

MapCornerToVertex()

MapCornerToVertex(corner_id, vert_id) {
  face = Face(corner_id);
  faces_[face][LocalIndex(corner_id)] = vert_id;
  if (vert_id >= 0) {
    vertex_corners_[vert_id] = corner_id;
  }
}

UpdateVertexToCornerMap()

UpdateVertexToCornerMap(vert) {
  first_c = vertex_corners_[vert];
  if (first_c < 0)
    return;
  act_c = SwingLeft(first_c);
  c = first_c;
  while (act_c >= 0 && act_c != first_c) {
    c = act_c;
    act_c = SwingLeft(act_c);
  }
  if (act_c != first_c) {
    vertex_corners_[vert] = c;
  }
}

LeftMostCorner()

LeftMostCorner(v) {
  return vertex_corners_[v];
}

MakeVertexIsolated()

MakeVertexIsolated(vert) {
  vertex_corners_[vert] = kInvalidCornerIndex;
}