poly2tri/poly2tri/sweep/sweep_context.cc

/*
 * Poly2Tri Copyright (c) 2009-2018, Poly2Tri Contributors
 * https://github.com/jhasse/poly2tri
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 */
#include "sweep_context.h"
#include <algorithm>
#include "advancing_front.h"

namespace p2t {

SweepContext::SweepContext(const std::vector<Point*>& polyline) : points_(polyline),
  front_(nullptr),
  head_(nullptr),
  tail_(nullptr),
  af_head_(nullptr),
  af_middle_(nullptr),
  af_tail_(nullptr)
{
  InitEdges(points_);
}

void SweepContext::AddHole(const std::vector<Point*>& polyline)
{
  InitEdges(polyline);
  for(unsigned int i = 0; i < polyline.size(); i++) {
    points_.push_back(polyline[i]);
  }
}

void SweepContext::AddPoint(Point* point) {
  points_.push_back(point);
}

std::vector<Triangle*> &SweepContext::GetTriangles()
{
  return triangles_;
}

std::list<Triangle*> &SweepContext::GetMap()
{
  return map_;
}

void SweepContext::InitTriangulation()
{
  double xmax(points_[0]->x), xmin(points_[0]->x);
  double ymax(points_[0]->y), ymin(points_[0]->y);

  // Calculate bounds.
  for (unsigned int i = 0; i < points_.size(); i++) {
    Point& p = *points_[i];
    if (p.x > xmax)
      xmax = p.x;
    if (p.x < xmin)
      xmin = p.x;
    if (p.y > ymax)
      ymax = p.y;
    if (p.y < ymin)
      ymin = p.y;
  }

  double dx = kAlpha * (xmax - xmin);
  double dy = kAlpha * (ymax - ymin);
  head_ = new Point(xmin - dx, ymin - dy);
  tail_ = new Point(xmax + dx, ymin - dy);

  // Sort points along y-axis
  std::sort(points_.begin(), points_.end(), cmp);

}

void SweepContext::InitEdges(const std::vector<Point*>& polyline)
{
  size_t num_points = polyline.size();
  for (size_t i = 0; i < num_points; i++) {
    size_t j = i < num_points - 1 ? i + 1 : 0;
    edge_list.push_back(new Edge(*polyline[i], *polyline[j]));
  }
}

Point* SweepContext::GetPoint(size_t index)
{
  return points_[index];
}

void SweepContext::AddToMap(Triangle* triangle)
{
  map_.push_back(triangle);
}

Node* SweepContext::LocateNode(const Point& point)
{
  // TODO implement search tree
  return front_->LocateNode(point.x);
}

void SweepContext::CreateAdvancingFront()
{

  // Initial triangle
  Triangle* triangle = new Triangle(*points_[0], *head_, *tail_);

  map_.push_back(triangle);

  af_head_ = new Node(*triangle->GetPoint(1), *triangle);
  af_middle_ = new Node(*triangle->GetPoint(0), *triangle);
  af_tail_ = new Node(*triangle->GetPoint(2));
  front_ = new AdvancingFront(*af_head_, *af_tail_);

  // TODO: More intuitive if head is middles next and not previous?
  //       so swap head and tail
  af_head_->next = af_middle_;
  af_middle_->next = af_tail_;
  af_middle_->prev = af_head_;
  af_tail_->prev = af_middle_;
}

void SweepContext::RemoveNode(Node* node)
{
  delete node;
}

void SweepContext::MapTriangleToNodes(Triangle& t)
{
  for (int i = 0; i < 3; i++) {
    if (!t.GetNeighbor(i)) {
      Node* n = front_->LocatePoint(t.PointCW(*t.GetPoint(i)));
      if (n)
        n->triangle = &t;
    }
  }
}

void SweepContext::RemoveFromMap(Triangle* triangle)
{
  map_.remove(triangle);
}

void SweepContext::MeshClean(Triangle& triangle)
{
  std::vector<Triangle *> triangles;
  triangles.push_back(&triangle);

  while(!triangles.empty()){
	Triangle *t = triangles.back();
	triangles.pop_back();

    if (t != nullptr && !t->IsInterior()) {
      t->IsInterior(true);
      triangles_.push_back(t);
      for (int i = 0; i < 3; i++) {
        if (!t->constrained_edge[i])
          triangles.push_back(t->GetNeighbor(i));
      }
    }
  }
}

SweepContext::~SweepContext()
{

    // Clean up memory

    delete head_;
    delete tail_;
    delete front_;
    delete af_head_;
    delete af_middle_;
    delete af_tail_;

    typedef std::list<Triangle*> type_list;

    for(type_list::iterator iter = map_.begin(); iter != map_.end(); ++iter) {
        Triangle* ptr = *iter;
        delete ptr;
    }

     for(unsigned int i = 0; i < edge_list.size(); i++) {
        delete edge_list[i];
    }

}

} // namespace p2t