text: /*
   * Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
   * http://code.google.com/p/poly2tri/
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
   *
   * * Redistributions of source code must retain the above copyright notice,
   *   this list of conditions and the following disclaimer.
   * * Redistributions in binary form must reproduce the above copyright notice,
   *   this list of conditions and the following disclaimer in the documentation
   *   and/or other materials provided with the distribution.
   * * Neither the name of Poly2Tri nor the names of its contributors may be
   *   used to endorse or promote products derived from this software without specific
   *   prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  #include "advancing_front.h"
  
  namespace p2t {
  
  AdvancingFront::AdvancingFront(Node& head, Node& tail)
  {
    head_ = &head;
    tail_ = &tail;
    search_node_ = &head;
  }
  
  Node* AdvancingFront::LocateNode(const double& x)
  {
    Node* node = search_node_;
  
    if (x < node->value) {
      while ((node = node->prev) != NULL) {
        if (x >= node->value) {
          search_node_ = node;
          return node;
        }
      }
    } else {
      while ((node = node->next) != NULL) {
        if (x < node->value) {
          search_node_ = node->prev;
          return node->prev;
        }
      }
    }
    return NULL;
  }
  
  Node* AdvancingFront::FindSearchNode(const double& x)
  {
    (void)x; // suppress compiler warnings "unused parameter 'x'"
    // TODO: implement BST index
    return search_node_;
  }
  
  Node* AdvancingFront::LocatePoint(const Point* point)
  {
    const double px = point->x;
    Node* node = FindSearchNode(px);
    const double nx = node->point->x;
  
    if (px == nx) {
      if (point != node->point) {
        // We might have two nodes with same x value for a short time
        if (point == node->prev->point) {
          node = node->prev;
        } else if (point == node->next->point) {
          node = node->next;
        } else {
          return NULL;
        }
      }
    } else if (px < nx) {
      while ((node = node->prev) != NULL) {
        if (point == node->point) {
          break;
        }
      }
    } else {
      while ((node = node->next) != NULL) {
        if (point == node->point)
          break;
      }
    }
    if(node) search_node_ = node;
    return node;
  }
  
  AdvancingFront::~AdvancingFront()
  {
  }
  
  }
  
  