navigation2d.h

#ifndef NAVIGATION_2D_H
#define NAVIGATION_2D_H

#include "scene/2d/node_2d.h"
#include "scene/2d/navigation_polygon.h"

class Navigation2D : public Node2D {

    OBJ_TYPE( Navigation2D, Node2D);


    union Point {

        struct {
            int64_t x:32;
            int64_t y:32;
        };

        uint64_t key;
        bool operator<(const Point& p_key) const { return key < p_key.key; }
    };


    struct EdgeKey {

        Point a;
        Point b;

        bool operator<(const EdgeKey& p_key) const {
            return (a.key==p_key.a.key)?(b.key<p_key.b.key):(a.key<p_key.a.key);
        };

        EdgeKey(const Point& p_a=Point(),const Point& p_b=Point()) {
            a=p_a;
            b=p_b;
            if (a.key > b.key) {
                SWAP(a,b);
            }
        }
    };


    struct NavMesh;
    struct Polygon;

    struct ConnectionPending {

        Polygon *polygon;
        int edge;
    };

    struct Polygon {

        struct Edge {
            Point point;
            Polygon *C; //connection
            int C_edge;
            List<ConnectionPending>::Element *P;
            Edge() { C=NULL; C_edge=-1; P=NULL; }
        };

        Vector<Edge> edges;

        Vector2 center;
        Vector2 entry;

        float distance;
        int prev_edge;

        bool clockwise;

        NavMesh *owner;
    };


    struct Connection {

        Polygon *A;
        int A_edge;
        Polygon *B;
        int B_edge;

        List<ConnectionPending> pending;

        Connection() { A=NULL; B=NULL; A_edge=-1; B_edge=-1;}
    };

    Map<EdgeKey,Connection> connections;


    struct NavMesh {

        Object *owner;
        Matrix32 xform;
        bool linked;
        Ref<NavigationPolygon> navpoly;
        List<Polygon> polygons;

    };



    _FORCE_INLINE_ Point _get_point(const Vector2& p_pos) const {

        int x = int(Math::floor(p_pos.x/cell_size));
        int y = int(Math::floor(p_pos.y/cell_size));

        Point p;
        p.key=0;
        p.x=x;
        p.y=y;
        return p;

    }

    _FORCE_INLINE_ Vector2 _get_vertex(const Point& p_point) const {

        return Vector2(p_point.x,p_point.y)*cell_size;
    }



    void _navpoly_link(int p_id);
    void _navpoly_unlink(int p_id);

    float cell_size;
    Map<int,NavMesh> navpoly_map;
    int last_id;
#if 0
    void _clip_path(Vector<Vector2>& path,Polygon *from_poly, const Vector2& p_to_point, Polygon* p_to_poly);
#endif
protected:

    static void _bind_methods();

public:

    //API should be as dynamic as possible
    int navpoly_create(const Ref<NavigationPolygon>& p_mesh,const Matrix32& p_xform,Object* p_owner=NULL);
    void navpoly_set_transform(int p_id, const Matrix32& p_xform);
    void navpoly_remove(int p_id);

    Vector<Vector2> get_simple_path(const Vector2& p_start, const Vector2& p_end,bool p_optimize=true);
    Vector2 get_closest_point(const Vector2& p_point);
    Object* get_closest_point_owner(const Vector2& p_point);

    Navigation2D();
};


#endif // Navigation2D2D_H