//  polygon.h
//
//  by John D. de Boer


typedef struct {
long h,v;  //  e.g. longitude & latitude, respectively
} polypoint;


typedef struct {
bool      open;   //  whether polygon is open or closed
string    name;   //  name of polygon
short     num;    //  number of points in polygon
polypoint pt[0];  //  vertex coordinates
} polygon;


typedef struct {
short   num;        //  number of polygons
bool    changed;    //  whether editing has been done
polygon **poly[0];  //  references to individual polygons
} polygons;


typedef struct {
real  slop,    //  used by macpoly.c
      slop2;   //  ditto
short poly,    //  selected polygon; -1 if not polygon selected
      pt;      //  selected point of selected polygon
bool  vertex;  //  to denote whether a drag is a vertex, or a midpoint
} polyselect;


//  Writing & reading polygons

void writetextpoly(const polygon **P);
void writetextpolys(const polygons **Py);
polygon **parsetextpoly(char **T);
bool parsetextpolys(const char *S, polygons **Py);
bool readrespolys(polygons **Py, const char *Name);


//  Allocating polygons

polygon **newpoly(const polypoint *L);
void oldpoly(polygon **P);
polygons **newpolys(void);
void oldpolys(polygons **Py);


//  Modifying polygons

void movecorner(polygons **Py, int POLY, int PT, const polypoint *L);
void insertcorner(polygons **Py, int POLY, int PREV, const polypoint *L);
void removecorner(polygons **Py, int POLY, int PT);
void addpoly(polygons **Py, const polypoint *L, long DLAT);
void removepoly(polygons **Py, int POLY);
void insertpoly(polygons **Py, polygon **P);
void namepolygon(polygons **Py, int POLY, const char *S);
bool polyisopen(const polygons **Py, int POLY);
void changepolyopenness(polygons **Py, int POLY);
void reversepoly(polygons **Py, int POLY, short *SEL);