/**********************************************************************
 * $Id$
 *
 * PostGIS - Spatial Types for PostgreSQL
 * Copyright 2009 Paul Ramsey <pramsey@cleverelephant.ca>
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU General Public Licence. See the COPYING file.
 *
 **********************************************************************/

#ifndef _LWGEODETIC_H
#define _LWGEODETIC_H 1

/* For NAN */
#define _GNU_SOURCE
#include <math.h>

#ifndef NAN
#define NAN 0.0/0.0
#endif

extern int gbox_geocentric_slow;

#define POW2(x) ((x)*(x))

/**
* Point in spherical coordinates on the world. Units of radians.
*/
typedef struct
{
	double lon;
	double lat;
} GEOGRAPHIC_POINT;

/**
* Two-point great circle segment from a to b.
*/
typedef struct
{
	GEOGRAPHIC_POINT start;
	GEOGRAPHIC_POINT end;
} GEOGRAPHIC_EDGE;

/**
* Holder for sorting points in distance algorithm
*/
typedef struct
{
	double measure;
	uint32_t index;
} DISTANCE_ORDER;

/**
* Conversion functions
*/
#define deg2rad(d) (PI * (d) / 180.0)
#define rad2deg(r) (180.0 * (r) / PI)

/**
* Ape a java function
*/
#define signum(a) ((a) < 0 ? -1 : ((a) > 0 ? 1 : (a)))

/*
* Geodetic calculations
*/
void geog2cart(const GEOGRAPHIC_POINT *g, POINT3D *p);
void cart2geog(const POINT3D *p, GEOGRAPHIC_POINT *g);
void robust_cross_product(const GEOGRAPHIC_POINT *p, const GEOGRAPHIC_POINT *q, POINT3D *a);
void x_to_z(POINT3D *p);
void y_to_z(POINT3D *p);
int edge_point_on_plane(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p);
int edge_point_in_cone(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p);
int edge_contains_coplanar_point(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p);
int edge_contains_point(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p);
double z_to_latitude(double z, int top);
int clairaut_cartesian(const POINT3D *start, const POINT3D *end, GEOGRAPHIC_POINT *g_top, GEOGRAPHIC_POINT *g_bottom);
int clairaut_geographic(const GEOGRAPHIC_POINT *start, const GEOGRAPHIC_POINT *end, GEOGRAPHIC_POINT *g_top, GEOGRAPHIC_POINT *g_bottom);
double sphere_distance(const GEOGRAPHIC_POINT *s, const GEOGRAPHIC_POINT *e);
double sphere_distance_cartesian(const POINT3D *s, const POINT3D *e);
int sphere_project(const GEOGRAPHIC_POINT *r, double distance, double azimuth, GEOGRAPHIC_POINT *n);
int edge_calculate_gbox(const GEOGRAPHIC_EDGE *e, GBOX *gbox);
int edge_calculate_gbox_slow(const GEOGRAPHIC_EDGE *e, GBOX *gbox);
int edge_intersection(const GEOGRAPHIC_EDGE *e1, const GEOGRAPHIC_EDGE *e2, GEOGRAPHIC_POINT *g);
double edge_distance_to_point(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *gp, GEOGRAPHIC_POINT *closest);
double edge_distance_to_edge(const GEOGRAPHIC_EDGE *e1, const GEOGRAPHIC_EDGE *e2, GEOGRAPHIC_POINT *closest1, GEOGRAPHIC_POINT *closest2);
void geographic_point_init(double lon, double lat, GEOGRAPHIC_POINT *g);
int ptarray_point_in_ring_winding(const POINTARRAY *pa, const POINT2D *pt_to_test);
int lwpoly_covers_point2d(const LWPOLY *poly, const POINT2D *pt_to_test);
int ptarray_point_in_ring(const POINTARRAY *pa, const POINT2D *pt_outside, const POINT2D *pt_to_test);
double ptarray_area_sphere(const POINTARRAY *pa, const POINT2D *pt_outside);
double latitude_degrees_normalize(double lat);
double longitude_degrees_normalize(double lon);
double ptarray_length_spheroid(const POINTARRAY *pa, const SPHEROID *s);
int geographic_point_equals(const GEOGRAPHIC_POINT *g1, const GEOGRAPHIC_POINT *g2);
int crosses_dateline(const GEOGRAPHIC_POINT *s, const GEOGRAPHIC_POINT *e);
void point_shift(GEOGRAPHIC_POINT *p, double shift);
double longitude_radians_normalize(double lon);
double latitude_radians_normalize(double lat);
void vector_sum(const POINT3D *a, const POINT3D *b, POINT3D *n);
void normalize(POINT3D *p);
double sphere_direction(const GEOGRAPHIC_POINT *s, const GEOGRAPHIC_POINT *e, double d);

/*
** Prototypes for spheroid functions.
*/
double spheroid_distance(const GEOGRAPHIC_POINT *a, const GEOGRAPHIC_POINT *b, const SPHEROID *spheroid);
double spheroid_direction(const GEOGRAPHIC_POINT *r, const GEOGRAPHIC_POINT *s, const SPHEROID *spheroid);
int spheroid_project(const GEOGRAPHIC_POINT *r, const SPHEROID *spheroid, double distance, double azimuth, GEOGRAPHIC_POINT *g);

#endif /* _LWGEODETIC_H */