sweep_context.h

Go to the documentation of this file.

/*
 * 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.
 */

#ifndef SWEEP_CONTEXT_H
#define SWEEP_CONTEXT_H

#include <list>
#include <vector>
#include <cstddef>

namespace p2t {
// Inital triangle factor, seed triangle will extend 30% of
// PointSet width to both left and right.
const double kAlpha = 0.3;

struct Point;
class Triangle;
struct Node;
struct Edge;
class AdvancingFront;

class SweepContext
{
public:

    SweepContext( std::vector<Point*> polyline );
    ~SweepContext();

    void set_head( Point* p1 );

    Point* head();

    void set_tail( Point* p1 );

    Point* tail();

    int point_count();

    Node& LocateNode( Point& point );

    void RemoveNode( Node* node );

    void CreateAdvancingFront( std::vector<Node*> nodes );

    void MapTriangleToNodes( Triangle& t );

    void AddToMap( Triangle* triangle );

    Point* GetPoint( const int& index );

    Point* GetPoints();

    void RemoveFromMap( Triangle* triangle );

    void AddHole( std::vector<Point*> polyline );

    void AddPoint( Point* point );

    AdvancingFront* front();

    void MeshClean( Triangle& triangle );

    std::vector<Triangle*> GetTriangles();

    std::list<Triangle*> GetMap();

    std::vector<Edge*> edge_list;

    struct Basin
    {
        Node* left_node;
        Node* bottom_node;
        Node* right_node;
        double width;
        bool left_highest;

        Basin() : left_node( NULL ), bottom_node( NULL ), right_node( NULL ), width( 0.0 ),
            left_highest( false )
        {
        }

        void Clear()
        {
            left_node = NULL;
            bottom_node = NULL;
            right_node  = NULL;
            width = 0.0;
            left_highest = false;
        }
    };

    struct EdgeEvent
    {
        Edge* constrained_edge;
        bool right;

        EdgeEvent() : constrained_edge( NULL ), right( false )
        {
        }
    };

    Basin basin;
    EdgeEvent edge_event;

private:

    friend class Sweep;

    std::vector<Triangle*> triangles_;
    std::list<Triangle*>    map_;
    std::vector<Point*>     points_;

// Advancing front
    AdvancingFront* front_;
// head point used with advancing front
    Point* head_;
// tail point used with advancing front
    Point* tail_;

    Node* af_head_, * af_middle_, * af_tail_;

    void    InitTriangulation();
    void    InitEdges( std::vector<Point*> polyline );
};

inline AdvancingFront* SweepContext::front()
{
    return front_;
}


inline int SweepContext::point_count()
{
    return points_.size();
}


inline void SweepContext::set_head( Point* p1 )
{
    head_ = p1;
}


inline Point* SweepContext::head()
{
    return head_;
}


inline void SweepContext::set_tail( Point* p1 )
{
    tail_ = p1;
}


inline Point* SweepContext::tail()
{
    return tail_;
}
}

#endif