comparison DEPENDENCIES/generic/include/boost/polygon/voronoi_diagram.hpp @ 16:2665513ce2d3

Add boost headers

+// Boost.Polygon library voronoi_diagram.hpp header file
+
+//          Copyright Andrii Sydorchuk 2010-2012.
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+
+// See http://www.boost.org for updates, documentation, and revision history.
+
+#ifndef BOOST_POLYGON_VORONOI_DIAGRAM
+#define BOOST_POLYGON_VORONOI_DIAGRAM
+
+#include <vector>
+#include <utility>
+
+#include "detail/voronoi_ctypes.hpp"
+#include "detail/voronoi_structures.hpp"
+
+#include "voronoi_geometry_type.hpp"
+
+namespace boost {
+namespace polygon {
+
+// Forward declarations.
+template <typename T>
+class voronoi_edge;
+
+// Represents Voronoi cell.
+// Data members:
+//   1) index of the source within the initial input set
+//   2) pointer to the incident edge
+//   3) mutable color member
+// Cell may contain point or segment site inside.
+template <typename T>
+class voronoi_cell {
+ public:
+  typedef T coordinate_type;
+  typedef std::size_t color_type;
+  typedef voronoi_edge<coordinate_type> voronoi_edge_type;
+  typedef std::size_t source_index_type;
+  typedef SourceCategory source_category_type;
+
+  voronoi_cell(source_index_type source_index,
+               source_category_type source_category) :
+      source_index_(source_index),
+      incident_edge_(NULL),
+      color_(source_category) {}
+
+  // Returns true if the cell contains point site, false else.
+  bool contains_point() const {
+    source_category_type source_category = this->source_category();
+    return belongs(source_category, GEOMETRY_CATEGORY_POINT);
+  }
+
+  // Returns true if the cell contains segment site, false else.
+  bool contains_segment() const {
+    source_category_type source_category = this->source_category();
+    return belongs(source_category, GEOMETRY_CATEGORY_SEGMENT);
+  }
+
+  source_index_type source_index() const {
+    return source_index_;
+  }
+
+  source_category_type source_category() const {
+    return static_cast<source_category_type>(color_ & SOURCE_CATEGORY_BITMASK);
+  }
+
+  // Degenerate cells don't have any incident edges.
+  bool is_degenerate() const { return incident_edge_ == NULL; }
+
+  voronoi_edge_type* incident_edge() { return incident_edge_; }
+  const voronoi_edge_type* incident_edge() const { return incident_edge_; }
+  void incident_edge(voronoi_edge_type* e) { incident_edge_ = e; }
+
+  color_type color() const { return color_ >> BITS_SHIFT; }
+  void color(color_type color) const {
+    color_ &= BITS_MASK;
+    color_ |= color << BITS_SHIFT;
+  }
+
+ private:
+  // 5 color bits are reserved.
+  enum Bits {
+    BITS_SHIFT = 0x5,
+    BITS_MASK = 0x1F
+  };
+
+  source_index_type source_index_;
+  voronoi_edge_type* incident_edge_;
+  mutable color_type color_;
+};
+
+// Represents Voronoi vertex.
+// Data members:
+//   1) vertex coordinates
+//   2) pointer to the incident edge
+//   3) mutable color member
+template <typename T>
+class voronoi_vertex {
+ public:
+  typedef T coordinate_type;
+  typedef std::size_t color_type;
+  typedef voronoi_edge<coordinate_type> voronoi_edge_type;
+
+  voronoi_vertex(const coordinate_type& x, const coordinate_type& y) :
+      x_(x),
+      y_(y),
+      incident_edge_(NULL),
+      color_(0) {}
+
+  const coordinate_type& x() const { return x_; }
+  const coordinate_type& y() const { return y_; }
+
+  bool is_degenerate() const { return incident_edge_ == NULL; }
+
+  voronoi_edge_type* incident_edge() { return incident_edge_; }
+  const voronoi_edge_type* incident_edge() const { return incident_edge_; }
+  void incident_edge(voronoi_edge_type* e) { incident_edge_ = e; }
+
+  color_type color() const { return color_ >> BITS_SHIFT; }
+  void color(color_type color) const {
+    color_ &= BITS_MASK;
+    color_ |= color << BITS_SHIFT;
+  }
+
+ private:
+  // 5 color bits are reserved.
+  enum Bits {
+    BITS_SHIFT = 0x5,
+    BITS_MASK = 0x1F
+  };
+
+  coordinate_type x_;
+  coordinate_type y_;
+  voronoi_edge_type* incident_edge_;
+  mutable color_type color_;
+};
+
+// Half-edge data structure. Represents Voronoi edge.
+// Data members:
+//   1) pointer to the corresponding cell
+//   2) pointer to the vertex that is the starting
+//      point of the half-edge
+//   3) pointer to the twin edge
+//   4) pointer to the CCW next edge
+//   5) pointer to the CCW prev edge
+//   6) mutable color member
+template <typename T>
+class voronoi_edge {
+ public:
+  typedef T coordinate_type;
+  typedef voronoi_cell<coordinate_type> voronoi_cell_type;
+  typedef voronoi_vertex<coordinate_type> voronoi_vertex_type;
+  typedef voronoi_edge<coordinate_type> voronoi_edge_type;
+  typedef std::size_t color_type;
+
+  voronoi_edge(bool is_linear, bool is_primary) :
+      cell_(NULL),
+      vertex_(NULL),
+      twin_(NULL),
+      next_(NULL),
+      prev_(NULL),
+      color_(0) {
+    if (is_linear)
+      color_ |= BIT_IS_LINEAR;
+    if (is_primary)
+      color_ |= BIT_IS_PRIMARY;
+  }
+
+  voronoi_cell_type* cell() { return cell_; }
+  const voronoi_cell_type* cell() const { return cell_; }
+  void cell(voronoi_cell_type* c) { cell_ = c; }
+
+  voronoi_vertex_type* vertex0() { return vertex_; }
+  const voronoi_vertex_type* vertex0() const { return vertex_; }
+  void vertex0(voronoi_vertex_type* v) { vertex_ = v; }
+
+  voronoi_vertex_type* vertex1() { return twin_->vertex0(); }
+  const voronoi_vertex_type* vertex1() const { return twin_->vertex0(); }
+
+  voronoi_edge_type* twin() { return twin_; }
+  const voronoi_edge_type* twin() const { return twin_; }
+  void twin(voronoi_edge_type* e) { twin_ = e; }
+
+  voronoi_edge_type* next() { return next_; }
+  const voronoi_edge_type* next() const { return next_; }
+  void next(voronoi_edge_type* e) { next_ = e; }
+
+  voronoi_edge_type* prev() { return prev_; }
+  const voronoi_edge_type* prev() const { return prev_; }
+  void prev(voronoi_edge_type* e) { prev_ = e; }
+
+  // Returns a pointer to the rotation next edge
+  // over the starting point of the half-edge.
+  voronoi_edge_type* rot_next() { return prev_->twin(); }
+  const voronoi_edge_type* rot_next() const { return prev_->twin(); }
+
+  // Returns a pointer to the rotation prev edge
+  // over the starting point of the half-edge.
+  voronoi_edge_type* rot_prev() { return twin_->next(); }
+  const voronoi_edge_type* rot_prev() const { return twin_->next(); }
+
+  // Returns true if the edge is finite (segment, parabolic arc).
+  // Returns false if the edge is infinite (ray, line).
+  bool is_finite() const { return vertex0() && vertex1(); }
+
+  // Returns true if the edge is infinite (ray, line).
+  // Returns false if the edge is finite (segment, parabolic arc).
+  bool is_infinite() const { return !vertex0() || !vertex1(); }
+
+  // Returns true if the edge is linear (segment, ray, line).
+  // Returns false if the edge is curved (parabolic arc).
+  bool is_linear() const {
+    return (color_ & BIT_IS_LINEAR) ? true : false;
+  }
+
+  // Returns true if the edge is curved (parabolic arc).
+  // Returns false if the edge is linear (segment, ray, line).
+  bool is_curved() const {
+    return (color_ & BIT_IS_LINEAR) ? false : true;
+  }
+
+  // Returns false if edge goes through the endpoint of the segment.
+  // Returns true else.
+  bool is_primary() const {
+    return (color_ & BIT_IS_PRIMARY) ? true : false;
+  }
+
+  // Returns true if edge goes through the endpoint of the segment.
+  // Returns false else.
+  bool is_secondary() const {
+    return (color_ & BIT_IS_PRIMARY) ? false : true;
+  }
+
+  color_type color() const { return color_ >> BITS_SHIFT; }
+  void color(color_type color) const {
+    color_ &= BITS_MASK;
+    color_ |= color << BITS_SHIFT;
+  }
+
+ private:
+  // 5 color bits are reserved.
+  enum Bits {
+    BIT_IS_LINEAR = 0x1,  // linear is opposite to curved
+    BIT_IS_PRIMARY = 0x2,  // primary is opposite to secondary
+
+    BITS_SHIFT = 0x5,
+    BITS_MASK = 0x1F
+  };
+
+  voronoi_cell_type* cell_;
+  voronoi_vertex_type* vertex_;
+  voronoi_edge_type* twin_;
+  voronoi_edge_type* next_;
+  voronoi_edge_type* prev_;
+  mutable color_type color_;
+};
+
+template <typename T>
+struct voronoi_diagram_traits {
+  typedef T coordinate_type;
+  typedef voronoi_cell<coordinate_type> cell_type;
+  typedef voronoi_vertex<coordinate_type> vertex_type;
+  typedef voronoi_edge<coordinate_type> edge_type;
+  typedef class {
+   public:
+    enum { ULPS = 128 };
+    bool operator()(const vertex_type& v1, const vertex_type& v2) const {
+      return (ulp_cmp(v1.x(), v2.x(), ULPS) ==
+              detail::ulp_comparison<T>::EQUAL) &&
+             (ulp_cmp(v1.y(), v2.y(), ULPS) ==
+              detail::ulp_comparison<T>::EQUAL);
+    }
+   private:
+    typename detail::ulp_comparison<T> ulp_cmp;
+  } vertex_equality_predicate_type;
+};
+
+// Voronoi output data structure.
+// CCW ordering is used on the faces perimeter and around the vertices.
+template <typename T, typename TRAITS = voronoi_diagram_traits<T> >
+class voronoi_diagram {
+ public:
+  typedef typename TRAITS::coordinate_type coordinate_type;
+  typedef typename TRAITS::cell_type cell_type;
+  typedef typename TRAITS::vertex_type vertex_type;
+  typedef typename TRAITS::edge_type edge_type;
+
+  typedef std::vector<cell_type> cell_container_type;
+  typedef typename cell_container_type::const_iterator const_cell_iterator;
+
+  typedef std::vector<vertex_type> vertex_container_type;
+  typedef typename vertex_container_type::const_iterator const_vertex_iterator;
+
+  typedef std::vector<edge_type> edge_container_type;
+  typedef typename edge_container_type::const_iterator const_edge_iterator;
+
+  voronoi_diagram() {}
+
+  void clear() {
+    cells_.clear();
+    vertices_.clear();
+    edges_.clear();
+  }
+
+  const cell_container_type& cells() const {
+    return cells_;
+  }
+
+  const vertex_container_type& vertices() const {
+    return vertices_;
+  }
+
+  const edge_container_type& edges() const {
+    return edges_;
+  }
+
+  std::size_t num_cells() const {
+    return cells_.size();
+  }
+
+  std::size_t num_edges() const {
+    return edges_.size();
+  }
+
+  std::size_t num_vertices() const {
+    return vertices_.size();
+  }
+
+  void _reserve(std::size_t num_sites) {
+    cells_.reserve(num_sites);
+    vertices_.reserve(num_sites << 1);
+    edges_.reserve((num_sites << 2) + (num_sites << 1));
+  }
+
+  template <typename CT>
+  void _process_single_site(const detail::site_event<CT>& site) {
+    cells_.push_back(cell_type(site.initial_index(), site.source_category()));
+  }
+
+  // Insert a new half-edge into the output data structure.
+  // Takes as input left and right sites that form a new bisector.
+  // Returns a pair of pointers to a new half-edges.
+  template <typename CT>
+  std::pair<void*, void*> _insert_new_edge(
+      const detail::site_event<CT>& site1,
+      const detail::site_event<CT>& site2) {
+    // Get sites' indexes.
+    int site_index1 = site1.sorted_index();
+    int site_index2 = site2.sorted_index();
+
+    bool is_linear = is_linear_edge(site1, site2);
+    bool is_primary = is_primary_edge(site1, site2);
+
+    // Create a new half-edge that belongs to the first site.
+    edges_.push_back(edge_type(is_linear, is_primary));
+    edge_type& edge1 = edges_.back();
+
+    // Create a new half-edge that belongs to the second site.
+    edges_.push_back(edge_type(is_linear, is_primary));
+    edge_type& edge2 = edges_.back();
+
+    // Add the initial cell during the first edge insertion.
+    if (cells_.empty()) {
+      cells_.push_back(cell_type(
+          site1.initial_index(), site1.source_category()));
+    }
+
+    // The second site represents a new site during site event
+    // processing. Add a new cell to the cell records.
+    cells_.push_back(cell_type(
+        site2.initial_index(), site2.source_category()));
+
+    // Set up pointers to cells.
+    edge1.cell(&cells_[site_index1]);
+    edge2.cell(&cells_[site_index2]);
+
+    // Set up twin pointers.
+    edge1.twin(&edge2);
+    edge2.twin(&edge1);
+
+    // Return a pointer to the new half-edge.
+    return std::make_pair(&edge1, &edge2);
+  }
+
+  // Insert a new half-edge into the output data structure with the
+  // start at the point where two previously added half-edges intersect.
+  // Takes as input two sites that create a new bisector, circle event
+  // that corresponds to the intersection point of the two old half-edges,
+  // pointers to those half-edges. Half-edges' direction goes out of the
+  // new Voronoi vertex point. Returns a pair of pointers to a new half-edges.
+  template <typename CT1, typename CT2>
+  std::pair<void*, void*> _insert_new_edge(
+      const detail::site_event<CT1>& site1,
+      const detail::site_event<CT1>& site3,
+      const detail::circle_event<CT2>& circle,
+      void* data12, void* data23) {
+    edge_type* edge12 = static_cast<edge_type*>(data12);
+    edge_type* edge23 = static_cast<edge_type*>(data23);
+
+    // Add a new Voronoi vertex.
+    vertices_.push_back(vertex_type(circle.x(), circle.y()));
+    vertex_type& new_vertex = vertices_.back();
+
+    // Update vertex pointers of the old edges.
+    edge12->vertex0(&new_vertex);
+    edge23->vertex0(&new_vertex);
+
+    bool is_linear = is_linear_edge(site1, site3);
+    bool is_primary = is_primary_edge(site1, site3);
+
+    // Add a new half-edge.
+    edges_.push_back(edge_type(is_linear, is_primary));
+    edge_type& new_edge1 = edges_.back();
+    new_edge1.cell(&cells_[site1.sorted_index()]);
+
+    // Add a new half-edge.
+    edges_.push_back(edge_type(is_linear, is_primary));
+    edge_type& new_edge2 = edges_.back();
+    new_edge2.cell(&cells_[site3.sorted_index()]);
+
+    // Update twin pointers.
+    new_edge1.twin(&new_edge2);
+    new_edge2.twin(&new_edge1);
+
+    // Update vertex pointer.
+    new_edge2.vertex0(&new_vertex);
+
+    // Update Voronoi prev/next pointers.
+    edge12->prev(&new_edge1);
+    new_edge1.next(edge12);
+    edge12->twin()->next(edge23);
+    edge23->prev(edge12->twin());
+    edge23->twin()->next(&new_edge2);
+    new_edge2.prev(edge23->twin());
+
+    // Return a pointer to the new half-edge.
+    return std::make_pair(&new_edge1, &new_edge2);
+  }
+
+  void _build() {
+    // Remove degenerate edges.
+    edge_iterator last_edge = edges_.begin();
+    for (edge_iterator it = edges_.begin(); it != edges_.end(); it += 2) {
+      const vertex_type* v1 = it->vertex0();
+      const vertex_type* v2 = it->vertex1();
+      if (v1 && v2 && vertex_equality_predicate_(*v1, *v2)) {
+        remove_edge(&(*it));
+      } else {
+        if (it != last_edge) {
+          edge_type* e1 = &(*last_edge = *it);
+          edge_type* e2 = &(*(last_edge + 1) = *(it + 1));
+          e1->twin(e2);
+          e2->twin(e1);
+          if (e1->prev()) {
+            e1->prev()->next(e1);
+            e2->next()->prev(e2);
+          }
+          if (e2->prev()) {
+            e1->next()->prev(e1);
+            e2->prev()->next(e2);
+          }
+        }
+        last_edge += 2;
+      }
+    }
+    edges_.erase(last_edge, edges_.end());
+
+    // Set up incident edge pointers for cells and vertices.
+    for (edge_iterator it = edges_.begin(); it != edges_.end(); ++it) {
+      it->cell()->incident_edge(&(*it));
+      if (it->vertex0()) {
+        it->vertex0()->incident_edge(&(*it));
+      }
+    }
+
+    // Remove degenerate vertices.
+    vertex_iterator last_vertex = vertices_.begin();
+    for (vertex_iterator it = vertices_.begin(); it != vertices_.end(); ++it) {
+      if (it->incident_edge()) {
+        if (it != last_vertex) {
+          *last_vertex = *it;
+          vertex_type* v = &(*last_vertex);
+          edge_type* e = v->incident_edge();
+          do {
+            e->vertex0(v);
+            e = e->rot_next();
+          } while (e != v->incident_edge());
+        }
+        ++last_vertex;
+      }
+    }
+    vertices_.erase(last_vertex, vertices_.end());
+
+    // Set up next/prev pointers for infinite edges.
+    if (vertices_.empty()) {
+      if (!edges_.empty()) {
+        // Update prev/next pointers for the line edges.
+        edge_iterator edge_it = edges_.begin();
+        edge_type* edge1 = &(*edge_it);
+        edge1->next(edge1);
+        edge1->prev(edge1);
+        ++edge_it;
+        edge1 = &(*edge_it);
+        ++edge_it;
+
+        while (edge_it != edges_.end()) {
+          edge_type* edge2 = &(*edge_it);
+          ++edge_it;
+
+          edge1->next(edge2);
+          edge1->prev(edge2);
+          edge2->next(edge1);
+          edge2->prev(edge1);
+
+          edge1 = &(*edge_it);
+          ++edge_it;
+        }
+
+        edge1->next(edge1);
+        edge1->prev(edge1);
+      }
+    } else {
+      // Update prev/next pointers for the ray edges.
+      for (cell_iterator cell_it = cells_.begin();
+         cell_it != cells_.end(); ++cell_it) {
+        if (cell_it->is_degenerate())
+          continue;
+        // Move to the previous edge while
+        // it is possible in the CW direction.
+        edge_type* left_edge = cell_it->incident_edge();
+        while (left_edge->prev() != NULL) {
+          left_edge = left_edge->prev();
+          // Terminate if this is not a boundary cell.
+          if (left_edge == cell_it->incident_edge())
+            break;
+        }
+
+        if (left_edge->prev() != NULL)
+          continue;
+
+        edge_type* right_edge = cell_it->incident_edge();
+        while (right_edge->next() != NULL)
+          right_edge = right_edge->next();
+        left_edge->prev(right_edge);
+        right_edge->next(left_edge);
+      }
+    }
+  }
+
+ private:
+  typedef typename cell_container_type::iterator cell_iterator;
+  typedef typename vertex_container_type::iterator vertex_iterator;
+  typedef typename edge_container_type::iterator edge_iterator;
+  typedef typename TRAITS::vertex_equality_predicate_type
+    vertex_equality_predicate_type;
+
+  template <typename SEvent>
+  bool is_primary_edge(const SEvent& site1, const SEvent& site2) const {
+    bool flag1 = site1.is_segment();
+    bool flag2 = site2.is_segment();
+    if (flag1 && !flag2) {
+      return (site1.point0() != site2.point0()) &&
+             (site1.point1() != site2.point0());
+    }
+    if (!flag1 && flag2) {
+      return (site2.point0() != site1.point0()) &&
+             (site2.point1() != site1.point0());
+    }
+    return true;
+  }
+
+  template <typename SEvent>
+  bool is_linear_edge(const SEvent& site1, const SEvent& site2) const {
+    if (!is_primary_edge(site1, site2)) {
+      return true;
+    }
+    return !(site1.is_segment() ^ site2.is_segment());
+  }
+
+  // Remove degenerate edge.
+  void remove_edge(edge_type* edge) {
+    // Update the endpoints of the incident edges to the second vertex.
+    vertex_type* vertex = edge->vertex0();
+    edge_type* updated_edge = edge->twin()->rot_next();
+    while (updated_edge != edge->twin()) {
+      updated_edge->vertex0(vertex);
+      updated_edge = updated_edge->rot_next();
+    }
+
+    edge_type* edge1 = edge;
+    edge_type* edge2 = edge->twin();
+
+    edge_type* edge1_rot_prev = edge1->rot_prev();
+    edge_type* edge1_rot_next = edge1->rot_next();
+
+    edge_type* edge2_rot_prev = edge2->rot_prev();
+    edge_type* edge2_rot_next = edge2->rot_next();
+
+    // Update prev/next pointers for the incident edges.
+    edge1_rot_next->twin()->next(edge2_rot_prev);
+    edge2_rot_prev->prev(edge1_rot_next->twin());
+    edge1_rot_prev->prev(edge2_rot_next->twin());
+    edge2_rot_next->twin()->next(edge1_rot_prev);
+  }
+
+  cell_container_type cells_;
+  vertex_container_type vertices_;
+  edge_container_type edges_;
+  vertex_equality_predicate_type vertex_equality_predicate_;
+
+  // Disallow copy constructor and operator=
+  voronoi_diagram(const voronoi_diagram&);
+  void operator=(const voronoi_diagram&);
+};
+}  // polygon
+}  // boost
+
+#endif  // BOOST_POLYGON_VORONOI_DIAGRAM