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postgis/liblwgeom/lwgeodetic.c

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/**********************************************************************
*
* PostGIS - Spatial Types for PostgreSQL
* http://postgis.net
*
* PostGIS is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* PostGIS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with PostGIS. If not, see <http://www.gnu.org/licenses/>.
*
**********************************************************************
*
* Copyright 2009 Paul Ramsey <pramsey@cleverelephant.ca>
* Copyright 2009 David Skea <David.Skea@gov.bc.ca>
*
**********************************************************************/
#include "liblwgeom_internal.h"
#include "lwgeodetic.h"
#include "lwgeom_log.h"
/**
* For testing geodetic bounding box, we have a magic global variable.
* When this is true (when the cunit tests set it), use the slow, but
* guaranteed correct, algorithm. Otherwise use the regular one.
*/
int gbox_geocentric_slow = LW_FALSE;
/**
* Utility function for ptarray_contains_point_sphere()
*/
static int
point3d_equals(const POINT3D *p1, const POINT3D *p2)
{
return FP_EQUALS(p1->x, p2->x) && FP_EQUALS(p1->y, p2->y) && FP_EQUALS(p1->z, p2->z);
}
/**
* Convert a longitude to the range of -PI,PI
*/
double longitude_radians_normalize(double lon)
{
if ( lon == -1.0 * M_PI )
return M_PI;
if ( lon == -2.0 * M_PI )
return 0.0;
if ( lon > 2.0 * M_PI )
lon = remainder(lon, 2.0 * M_PI);
if ( lon < -2.0 * M_PI )
lon = remainder(lon, -2.0 * M_PI);
if ( lon > M_PI )
lon = -2.0 * M_PI + lon;
if ( lon < -1.0 * M_PI )
lon = 2.0 * M_PI + lon;
if ( lon == -2.0 * M_PI )
lon *= -1.0;
return lon;
}
/**
* Convert a latitude to the range of -PI/2,PI/2
*/
double latitude_radians_normalize(double lat)
{
if ( lat > 2.0 * M_PI )
lat = remainder(lat, 2.0 * M_PI);
if ( lat < -2.0 * M_PI )
lat = remainder(lat, -2.0 * M_PI);
if ( lat > M_PI )
lat = M_PI - lat;
if ( lat < -1.0 * M_PI )
lat = -1.0 * M_PI - lat;
if ( lat > M_PI_2 )
lat = M_PI - lat;
if ( lat < -1.0 * M_PI_2 )
lat = -1.0 * M_PI - lat;
return lat;
}
/**
* Convert a longitude to the range of -180,180
* @param lon longitude in degrees
*/
double longitude_degrees_normalize(double lon)
{
if ( lon > 360.0 )
lon = remainder(lon, 360.0);
if ( lon < -360.0 )
lon = remainder(lon, -360.0);
if ( lon > 180.0 )
lon = -360.0 + lon;
if ( lon < -180.0 )
lon = 360 + lon;
if ( lon == -180.0 )
return 180.0;
if ( lon == -360.0 )
return 0.0;
return lon;
}
/**
* Convert a latitude to the range of -90,90
* @param lat latitude in degrees
*/
double latitude_degrees_normalize(double lat)
{
if ( lat > 360.0 )
lat = remainder(lat, 360.0);
if ( lat < -360.0 )
lat = remainder(lat, -360.0);
if ( lat > 180.0 )
lat = 180.0 - lat;
if ( lat < -180.0 )
lat = -180.0 - lat;
if ( lat > 90.0 )
lat = 180.0 - lat;
if ( lat < -90.0 )
lat = -180.0 - lat;
return lat;
}
/**
* Shift a point around by a number of radians
*/
void point_shift(GEOGRAPHIC_POINT *p, double shift)
{
double lon = p->lon + shift;
if ( lon > M_PI )
p->lon = -1.0 * M_PI + (lon - M_PI);
else
p->lon = lon;
return;
}
int geographic_point_equals(const GEOGRAPHIC_POINT *g1, const GEOGRAPHIC_POINT *g2)
{
return FP_EQUALS(g1->lat, g2->lat) && FP_EQUALS(g1->lon, g2->lon);
}
/**
* Initialize a geographic point
* @param lon longitude in degrees
* @param lat latitude in degrees
*/
void geographic_point_init(double lon, double lat, GEOGRAPHIC_POINT *g)
{
g->lat = latitude_radians_normalize(deg2rad(lat));
g->lon = longitude_radians_normalize(deg2rad(lon));
}
/** Returns the angular height (latitudinal span) of the box in radians */
double
gbox_angular_height(const GBOX* gbox)
{
double d[6];
int i;
double zmin = FLT_MAX;
double zmax = -1 * FLT_MAX;
POINT3D pt;
/* Take a copy of the box corners so we can treat them as a list */
/* Elements are xmin, xmax, ymin, ymax, zmin, zmax */
memcpy(d, &(gbox->xmin), 6*sizeof(double));
/* Generate all 8 corner vectors of the box */
for ( i = 0; i < 8; i++ )
{
pt.x = d[i / 4];
pt.y = d[2 + (i % 4) / 2];
pt.z = d[4 + (i % 2)];
normalize(&pt);
if ( pt.z < zmin ) zmin = pt.z;
if ( pt.z > zmax ) zmax = pt.z;
}
return asin(zmax) - asin(zmin);
}
/** Returns the angular width (longitudinal span) of the box in radians */
double
gbox_angular_width(const GBOX* gbox)
{
double d[6];
int i, j;
POINT3D pt[3];
double maxangle;
double magnitude;
/* Take a copy of the box corners so we can treat them as a list */
/* Elements are xmin, xmax, ymin, ymax, zmin, zmax */
memcpy(d, &(gbox->xmin), 6*sizeof(double));
/* Start with the bottom corner */
pt[0].x = gbox->xmin;
pt[0].y = gbox->ymin;
magnitude = sqrt(pt[0].x*pt[0].x + pt[0].y*pt[0].y);
pt[0].x /= magnitude;
pt[0].y /= magnitude;
/* Generate all 8 corner vectors of the box */
/* Find the vector furthest from our seed vector */
for ( j = 0; j < 2; j++ )
{
maxangle = -1 * FLT_MAX;
for ( i = 0; i < 4; i++ )
{
double angle, dotprod;
POINT3D pt_n;
pt_n.x = d[i / 2];
pt_n.y = d[2 + (i % 2)];
magnitude = sqrt(pt_n.x*pt_n.x + pt_n.y*pt_n.y);
pt_n.x /= magnitude;
pt_n.y /= magnitude;
pt_n.z = 0.0;
dotprod = pt_n.x*pt[j].x + pt_n.y*pt[j].y;
angle = acos(dotprod > 1.0 ? 1.0 : dotprod);
if ( angle > maxangle )
{
pt[j+1] = pt_n;
maxangle = angle;
}
}
}
/* Return the distance between the two furthest vectors */
return maxangle;
}
/** Computes the average(ish) center of the box and returns success. */
int
gbox_centroid(const GBOX* gbox, POINT2D* out)
{
double d[6];
GEOGRAPHIC_POINT g;
POINT3D pt;
int i;
/* Take a copy of the box corners so we can treat them as a list */
/* Elements are xmin, xmax, ymin, ymax, zmin, zmax */
memcpy(d, &(gbox->xmin), 6*sizeof(double));
/* Zero out our return vector */
pt.x = pt.y = pt.z = 0.0;
for ( i = 0; i < 8; i++ )
{
POINT3D pt_n;
pt_n.x = d[i / 4];
pt_n.y = d[2 + ((i % 4) / 2)];
pt_n.z = d[4 + (i % 2)];
normalize(&pt_n);
pt.x += pt_n.x;
pt.y += pt_n.y;
pt.z += pt_n.z;
}
pt.x /= 8.0;
pt.y /= 8.0;
pt.z /= 8.0;
normalize(&pt);
cart2geog(&pt, &g);
out->x = longitude_degrees_normalize(rad2deg(g.lon));
out->y = latitude_degrees_normalize(rad2deg(g.lat));
return LW_SUCCESS;
}
/**
* Check to see if this geocentric gbox is wrapped around a pole.
* Only makes sense if this gbox originated from a polygon, as it's assuming
* the box is generated from external edges and there's an "interior" which
* contains the pole.
*
* This function is overdetermined, for very large polygons it might add an
* unwarranted pole. STILL NEEDS WORK!
*/
static int gbox_check_poles(GBOX *gbox)
{
int rv = LW_FALSE;
#if POSTGIS_DEBUG_LEVEL >= 4
char *gbox_str = gbox_to_string(gbox);
LWDEBUG(4, "checking poles");
LWDEBUGF(4, "gbox %s", gbox_str);
lwfree(gbox_str);
#endif
/* Z axis */
if (gbox->xmin < 0.0 && gbox->xmax > 0.0 &&
gbox->ymin < 0.0 && gbox->ymax > 0.0)
{
/* Extrema lean positive */
if ((gbox->zmin > 0.0) && (gbox->zmax > 0.0))
{
LWDEBUG(4, "enclosed positive z axis");
gbox->zmax = 1.0;
}
/* Extrema lean negative */
else if ((gbox->zmin < 0.0) && (gbox->zmax < 0.0))
{
LWDEBUG(4, "enclosed negative z axis");
gbox->zmin = -1.0;
}
/* Extrema both sides! */
else
{
LWDEBUG(4, "enclosed both z axes");
gbox->zmin = -1.0;
gbox->zmax = 1.0;
}
rv = LW_TRUE;
}
/* Y axis */
if (gbox->xmin < 0.0 && gbox->xmax > 0.0 &&
gbox->zmin < 0.0 && gbox->zmax > 0.0)
{
if ((gbox->ymin > 0.0) && (gbox->ymax > 0.0))
{
LWDEBUG(4, "enclosed positive y axis");
gbox->ymax = 1.0;
}
else if ((gbox->ymin < 0.0) && (gbox->ymax < 0.0))
{
LWDEBUG(4, "enclosed negative y axis");
gbox->ymin = -1.0;
}
else
{
LWDEBUG(4, "enclosed both y axes");
gbox->ymax = 1.0;
gbox->ymin = -1.0;
}
rv = LW_TRUE;
}
/* X axis */
if (gbox->ymin < 0.0 && gbox->ymax > 0.0 &&
gbox->zmin < 0.0 && gbox->zmax > 0.0)
{
if ((gbox->xmin > 0.0) && (gbox->xmax > 0.0))
{
LWDEBUG(4, "enclosed positive x axis");
gbox->xmax = 1.0;
}
else if ((gbox->xmin < 0.0) && (gbox->xmax < 0.0))
{
LWDEBUG(4, "enclosed negative x axis");
gbox->xmin = -1.0;
}
else
{
LWDEBUG(4, "enclosed both x axes");
gbox->xmax = 1.0;
gbox->xmin = -1.0;
}
rv = LW_TRUE;
}
return rv;
}
/**
* Convert spherical coordinates to cartesian coordinates on unit sphere
*/
void geog2cart(const GEOGRAPHIC_POINT *g, POINT3D *p)
{
p->x = cos(g->lat) * cos(g->lon);
p->y = cos(g->lat) * sin(g->lon);
p->z = sin(g->lat);
}
/**
* Convert cartesian coordinates on unit sphere to spherical coordinates
*/
void cart2geog(const POINT3D *p, GEOGRAPHIC_POINT *g)
{
g->lon = atan2(p->y, p->x);
g->lat = asin(p->z);
}
/**
* Convert lon/lat coordinates to cartesian coordinates on unit sphere
*/
void ll2cart(const POINT2D *g, POINT3D *p)
{
double x_rad = M_PI * g->x / 180.0;
double y_rad = M_PI * g->y / 180.0;
double cos_y_rad = cos(y_rad);
p->x = cos_y_rad * cos(x_rad);
p->y = cos_y_rad * sin(x_rad);
p->z = sin(y_rad);
}
/**
* Convert cartesian coordinates on unit sphere to lon/lat coordinates
static void cart2ll(const POINT3D *p, POINT2D *g)
{
g->x = longitude_degrees_normalize(180.0 * atan2(p->y, p->x) / M_PI);
g->y = latitude_degrees_normalize(180.0 * asin(p->z) / M_PI);
}
*/
/**
* Calculate the dot product of two unit vectors
* (-1 == opposite, 0 == orthogonal, 1 == identical)
*/
static double dot_product(const POINT3D *p1, const POINT3D *p2)
{
return (p1->x*p2->x) + (p1->y*p2->y) + (p1->z*p2->z);
}
/**
* Calculate the cross product of two vectors
*/
static void cross_product(const POINT3D *a, const POINT3D *b, POINT3D *n)
{
n->x = a->y * b->z - a->z * b->y;
n->y = a->z * b->x - a->x * b->z;
n->z = a->x * b->y - a->y * b->x;
return;
}
/**
* Calculate the sum of two vectors
*/
void vector_sum(const POINT3D *a, const POINT3D *b, POINT3D *n)
{
n->x = a->x + b->x;
n->y = a->y + b->y;
n->z = a->z + b->z;
return;
}
/**
* Calculate the difference of two vectors
*/
static void vector_difference(const POINT3D *a, const POINT3D *b, POINT3D *n)
{
n->x = a->x - b->x;
n->y = a->y - b->y;
n->z = a->z - b->z;
return;
}
/**
* Scale a vector out by a factor
*/
void vector_scale(POINT3D *n, double scale)
{
n->x *= scale;
n->y *= scale;
n->z *= scale;
return;
}
/*
* static inline double vector_magnitude(const POINT3D* v)
* {
* return sqrt(v->x*v->x + v->y*v->y + v->z*v->z);
* }
*/
/**
* Angle between two unit vectors
*/
double vector_angle(const POINT3D* v1, const POINT3D* v2)
{
POINT3D v3, normal;
double angle, x, y;
cross_product(v1, v2, &normal);
normalize(&normal);
cross_product(&normal, v1, &v3);
x = dot_product(v1, v2);
y = dot_product(v2, &v3);
angle = atan2(y, x);
return angle;
}
/**
* Normalize to a unit vector.
*/
static void normalize2d(POINT2D *p)
{
double d = sqrt(p->x*p->x + p->y*p->y);
if (FP_IS_ZERO(d))
{
p->x = p->y = 0.0;
return;
}
p->x = p->x / d;
p->y = p->y / d;
return;
}
/**
* Calculates the unit normal to two vectors, trying to avoid
* problems with over-narrow or over-wide cases.
*/
void unit_normal(const POINT3D *P1, const POINT3D *P2, POINT3D *normal)
{
double p_dot = dot_product(P1, P2);
POINT3D P3;
/* If edge is really large, calculate a narrower equivalent angle A1/A3. */
if ( p_dot < 0 )
{
vector_sum(P1, P2, &P3);
normalize(&P3);
}
/* If edge is narrow, calculate a wider equivalent angle A1/A3. */
else if ( p_dot > 0.95 )
{
vector_difference(P2, P1, &P3);
normalize(&P3);
}
/* Just keep the current angle in A1/A3. */
else
{
P3 = *P2;
}
/* Normals to the A-plane and B-plane */
cross_product(P1, &P3, normal);
normalize(normal);
}
/**
* Rotates v1 through an angle (in radians) within the plane defined by v1/v2, returns
* the rotated vector in n.
*/
void vector_rotate(const POINT3D* v1, const POINT3D* v2, double angle, POINT3D* n)
{
POINT3D u;
double cos_a = cos(angle);
double sin_a = sin(angle);
double uxuy, uyuz, uxuz;
double ux2, uy2, uz2;
double rxx, rxy, rxz, ryx, ryy, ryz, rzx, rzy, rzz;
/* Need a unit vector normal to rotate around */
unit_normal(v1, v2, &u);
uxuy = u.x * u.y;
uxuz = u.x * u.z;
uyuz = u.y * u.z;
ux2 = u.x * u.x;
uy2 = u.y * u.y;
uz2 = u.z * u.z;
rxx = cos_a + ux2 * (1 - cos_a);
rxy = uxuy * (1 - cos_a) - u.z * sin_a;
rxz = uxuz * (1 - cos_a) + u.y * sin_a;
ryx = uxuy * (1 - cos_a) + u.z * sin_a;
ryy = cos_a + uy2 * (1 - cos_a);
ryz = uyuz * (1 - cos_a) - u.x * sin_a;
rzx = uxuz * (1 - cos_a) - u.y * sin_a;
rzy = uyuz * (1 - cos_a) + u.x * sin_a;
rzz = cos_a + uz2 * (1 - cos_a);
n->x = rxx * v1->x + rxy * v1->y + rxz * v1->z;
n->y = ryx * v1->x + ryy * v1->y + ryz * v1->z;
n->z = rzx * v1->x + rzy * v1->y + rzz * v1->z;
normalize(n);
}
/**
* Normalize to a unit vector.
*/
void normalize(POINT3D *p)
{
double d = sqrt(p->x*p->x + p->y*p->y + p->z*p->z);
if (FP_IS_ZERO(d))
{
p->x = p->y = p->z = 0.0;
return;
}
p->x = p->x / d;
p->y = p->y / d;
p->z = p->z / d;
return;
}
/**
* Computes the cross product of two vectors using their lat, lng representations.
* Good even for small distances between p and q.
*/
void robust_cross_product(const GEOGRAPHIC_POINT *p, const GEOGRAPHIC_POINT *q, POINT3D *a)
{
double lon_qpp = (q->lon + p->lon) / -2.0;
double lon_qmp = (q->lon - p->lon) / 2.0;
double sin_p_lat_minus_q_lat = sin(p->lat-q->lat);
double sin_p_lat_plus_q_lat = sin(p->lat+q->lat);
double sin_lon_qpp = sin(lon_qpp);
double sin_lon_qmp = sin(lon_qmp);
double cos_lon_qpp = cos(lon_qpp);
double cos_lon_qmp = cos(lon_qmp);
a->x = sin_p_lat_minus_q_lat * sin_lon_qpp * cos_lon_qmp -
sin_p_lat_plus_q_lat * cos_lon_qpp * sin_lon_qmp;
a->y = sin_p_lat_minus_q_lat * cos_lon_qpp * cos_lon_qmp +
sin_p_lat_plus_q_lat * sin_lon_qpp * sin_lon_qmp;
a->z = cos(p->lat) * cos(q->lat) * sin(q->lon-p->lon);
}
void x_to_z(POINT3D *p)
{
double tmp = p->z;
p->z = p->x;
p->x = tmp;
}
void y_to_z(POINT3D *p)
{
double tmp = p->z;
p->z = p->y;
p->y = tmp;
}
int crosses_dateline(const GEOGRAPHIC_POINT *s, const GEOGRAPHIC_POINT *e)
{
double sign_s = SIGNUM(s->lon);
double sign_e = SIGNUM(e->lon);
double ss = fabs(s->lon);
double ee = fabs(e->lon);
if ( sign_s == sign_e )
{
return LW_FALSE;
}
else
{
double dl = ss + ee;
if ( dl < M_PI )
return LW_FALSE;
else if ( FP_EQUALS(dl, M_PI) )
return LW_FALSE;
else
return LW_TRUE;
}
}
/**
* Returns -1 if the point is to the left of the plane formed
* by the edge, 1 if the point is to the right, and 0 if the
* point is on the plane.
*/
static int
edge_point_side(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p)
{
POINT3D normal, pt;
double w;
/* Normal to the plane defined by e */
robust_cross_product(&(e->start), &(e->end), &normal);
normalize(&normal);
geog2cart(p, &pt);
/* We expect the dot product of with normal with any vector in the plane to be zero */
w = dot_product(&normal, &pt);
LWDEBUGF(4,"dot product %.9g",w);
if ( FP_IS_ZERO(w) )
{
LWDEBUG(4, "point is on plane (dot product is zero)");
return 0;
}
if ( w < 0 )
return -1;
else
return 1;
}
/**
* Returns the angle in radians at point B of the triangle formed by A-B-C
*/
static double
sphere_angle(const GEOGRAPHIC_POINT *a, const GEOGRAPHIC_POINT *b, const GEOGRAPHIC_POINT *c)
{
POINT3D normal1, normal2;
robust_cross_product(b, a, &normal1);
robust_cross_product(b, c, &normal2);
normalize(&normal1);
normalize(&normal2);
return sphere_distance_cartesian(&normal1, &normal2);
}
/**
* Computes the spherical area of a triangle. If C is to the left of A/B,
* the area is negative. If C is to the right of A/B, the area is positive.
*
* @param a The first triangle vertex.
* @param b The second triangle vertex.
* @param c The last triangle vertex.
* @return the signed area in radians.
*/
static double
sphere_signed_area(const GEOGRAPHIC_POINT *a, const GEOGRAPHIC_POINT *b, const GEOGRAPHIC_POINT *c)
{
double angle_a, angle_b, angle_c;
double area_radians = 0.0;
int side;
GEOGRAPHIC_EDGE e;
angle_a = sphere_angle(b,a,c);
angle_b = sphere_angle(a,b,c);
angle_c = sphere_angle(b,c,a);
area_radians = angle_a + angle_b + angle_c - M_PI;
/* What's the direction of the B/C edge? */
e.start = *a;
e.end = *b;
side = edge_point_side(&e, c);
/* Co-linear points implies no area */
if ( side == 0 )
return 0.0;
/* Add the sign to the area */
return side * area_radians;
}
/**
* Returns true if the point p is on the great circle plane.
* Forms the scalar triple product of A,B,p and if the volume of the
* resulting parallelepiped is near zero the point p is on the
* great circle plane.
*/
int edge_point_on_plane(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p)
{
int side = edge_point_side(e, p);
if ( side == 0 )
return LW_TRUE;
return LW_FALSE;
}
/**
* Returns true if the point p is inside the cone defined by the
* two ends of the edge e.
*/
int edge_point_in_cone(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p)
{
POINT3D vcp, vs, ve, vp;
double vs_dot_vcp, vp_dot_vcp;
geog2cart(&(e->start), &vs);
geog2cart(&(e->end), &ve);
/* Antipodal case, everything is inside. */
if ( vs.x == -1.0 * ve.x && vs.y == -1.0 * ve.y && vs.z == -1.0 * ve.z )
return LW_TRUE;
geog2cart(p, &vp);
/* The normalized sum bisects the angle between start and end. */
vector_sum(&vs, &ve, &vcp);
normalize(&vcp);
/* The projection of start onto the center defines the minimum similarity */
vs_dot_vcp = dot_product(&vs, &vcp);
LWDEBUGF(4,"vs_dot_vcp %.19g",vs_dot_vcp);
/* The projection of candidate p onto the center */
vp_dot_vcp = dot_product(&vp, &vcp);
LWDEBUGF(4,"vp_dot_vcp %.19g",vp_dot_vcp);
/* If p is more similar than start then p is inside the cone */
LWDEBUGF(4,"fabs(vp_dot_vcp - vs_dot_vcp) %.39g",fabs(vp_dot_vcp - vs_dot_vcp));
/*
** We want to test that vp_dot_vcp is >= vs_dot_vcp but there are
** numerical stability issues for values that are very very nearly
** equal. Unfortunately there are also values of vp_dot_vcp that are legitimately
** very close to but still less than vs_dot_vcp which we also need to catch.
** The tolerance of 10-17 seems to do the trick on 32-bit and 64-bit architectures,
** for the test cases here.
** However, tuning the tolerance value feels like a dangerous hack.
** Fundamentally, the problem is that this test is so sensitive.
*/
/* 1.1102230246251565404236316680908203125e-16 */
if ( vp_dot_vcp > vs_dot_vcp || fabs(vp_dot_vcp - vs_dot_vcp) < 2e-16 )
{
LWDEBUG(4, "point is in cone");
return LW_TRUE;
}
LWDEBUG(4, "point is not in cone");
return LW_FALSE;
}
/**
* True if the longitude of p is within the range of the longitude of the ends of e
*/
int edge_contains_coplanar_point(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p)
{
GEOGRAPHIC_EDGE g;
GEOGRAPHIC_POINT q;
double slon = fabs((e->start).lon) + fabs((e->end).lon);
double dlon = fabs(fabs((e->start).lon) - fabs((e->end).lon));
double slat = (e->start).lat + (e->end).lat;
LWDEBUGF(4, "e.start == GPOINT(%.6g %.6g) ", (e->start).lat, (e->start).lon);
LWDEBUGF(4, "e.end == GPOINT(%.6g %.6g) ", (e->end).lat, (e->end).lon);
LWDEBUGF(4, "p == GPOINT(%.6g %.6g) ", p->lat, p->lon);
/* Copy values into working registers */
g = *e;
q = *p;
/* Vertical plane, we need to do this calculation in latitude */
if ( FP_EQUALS( g.start.lon, g.end.lon ) )
{
LWDEBUG(4, "vertical plane, we need to do this calculation in latitude");
/* Supposed to be co-planar... */
if ( ! FP_EQUALS( q.lon, g.start.lon ) )
return LW_FALSE;
if ( ( g.start.lat <= q.lat && q.lat <= g.end.lat ) ||
( g.end.lat <= q.lat && q.lat <= g.start.lat ) )
{
return LW_TRUE;
}
else
{
return LW_FALSE;
}
}
/* Over the pole, we need normalize latitude and do this calculation in latitude */
if ( FP_EQUALS( slon, M_PI ) && ( SIGNUM(g.start.lon) != SIGNUM(g.end.lon) || FP_EQUALS(dlon, M_PI) ) )
{
LWDEBUG(4, "over the pole...");
/* Antipodal, everything (or nothing?) is inside */
if ( FP_EQUALS( slat, 0.0 ) )
return LW_TRUE;
/* Point *is* the north pole */
if ( slat > 0.0 && FP_EQUALS(q.lat, M_PI_2 ) )
return LW_TRUE;
/* Point *is* the south pole */
if ( slat < 0.0 && FP_EQUALS(q.lat, -1.0 * M_PI_2) )
return LW_TRUE;
LWDEBUG(4, "coplanar?...");
/* Supposed to be co-planar... */
if ( ! FP_EQUALS( q.lon, g.start.lon ) )
return LW_FALSE;
LWDEBUG(4, "north or south?...");
/* Over north pole, test based on south pole */
if ( slat > 0.0 )
{
LWDEBUG(4, "over the north pole...");
if ( q.lat > FP_MIN(g.start.lat, g.end.lat) )
return LW_TRUE;
else
return LW_FALSE;
}
else
/* Over south pole, test based on north pole */
{
LWDEBUG(4, "over the south pole...");
if ( q.lat < FP_MAX(g.start.lat, g.end.lat) )
return LW_TRUE;
else
return LW_FALSE;
}
}
/* Dateline crossing, flip everything to the opposite hemisphere */
else if ( slon > M_PI && ( SIGNUM(g.start.lon) != SIGNUM(g.end.lon) ) )
{
LWDEBUG(4, "crosses dateline, flip longitudes...");
if ( g.start.lon > 0.0 )
g.start.lon -= M_PI;
else
g.start.lon += M_PI;
if ( g.end.lon > 0.0 )
g.end.lon -= M_PI;
else
g.end.lon += M_PI;
if ( q.lon > 0.0 )
q.lon -= M_PI;
else
q.lon += M_PI;
}
if ( ( g.start.lon <= q.lon && q.lon <= g.end.lon ) ||
( g.end.lon <= q.lon && q.lon <= g.start.lon ) )
{
LWDEBUG(4, "true, this edge contains point");
return LW_TRUE;
}
LWDEBUG(4, "false, this edge does not contain point");
return LW_FALSE;
}
/**
* Given two points on a unit sphere, calculate their distance apart in radians.
*/
double sphere_distance(const GEOGRAPHIC_POINT *s, const GEOGRAPHIC_POINT *e)
{
double d_lon, cos_d_lon, cos_lat_e, sin_lat_e, cos_lat_s, sin_lat_s;
double a1, a2, a, b;
if (FP_EQUALS(s->lat, e->lat) && FP_EQUALS(s->lon, e->lon)) return 0.0;
d_lon = e->lon - s->lon;
cos_d_lon = cos(d_lon);
cos_lat_e = cos(e->lat);
sin_lat_e = sin(e->lat);
cos_lat_s = cos(s->lat);
sin_lat_s = sin(s->lat);
a1 = POW2(cos_lat_e * sin(d_lon));
a2 = POW2(cos_lat_s * sin_lat_e - sin_lat_s * cos_lat_e * cos_d_lon);
a = sqrt(a1 + a2);
b = sin_lat_s * sin_lat_e + cos_lat_s * cos_lat_e * cos_d_lon;
return atan2(a, b);
}
/**
* Given two unit vectors, calculate their distance apart in radians.
*/
double sphere_distance_cartesian(const POINT3D *s, const POINT3D *e)
{
return acos(FP_MIN(1.0, dot_product(s, e)));
}
/**
* Given two points on a unit sphere, calculate the direction from s to e.
*/
double sphere_direction(const GEOGRAPHIC_POINT *s, const GEOGRAPHIC_POINT *e, double d)
{
double heading = 0.0;
double f;
/* Starting from the poles? Special case. */
if ( FP_IS_ZERO(cos(s->lat)) )
return (s->lat > 0.0) ? M_PI : 0.0;
f = (sin(e->lat) - sin(s->lat) * cos(d)) / (sin(d) * cos(s->lat));
if ( FP_EQUALS(f, 1.0) )
heading = 0.0;
else if ( FP_EQUALS(f, -1.0) )
heading = M_PI;
else if ( fabs(f) > 1.0 )
{
LWDEBUGF(4, "f = %g", f);
heading = acos(f);
}
else
heading = acos(f);
if ( sin(e->lon - s->lon) < 0.0 )
heading = -1 * heading;
return heading;
}
#if 0 /* unused */
/**
* Computes the spherical excess of a spherical triangle defined by
* the three vertices A, B, C. Computes on the unit sphere (i.e., divides
* edge lengths by the radius, even if the radius is 1.0). The excess is
* signed based on the sign of the delta longitude of A and B.
*
* @param a The first triangle vertex.
* @param b The second triangle vertex.
* @param c The last triangle vertex.
* @return the signed spherical excess.
*/
static double sphere_excess(const GEOGRAPHIC_POINT *a, const GEOGRAPHIC_POINT *b, const GEOGRAPHIC_POINT *c)
{
double a_dist = sphere_distance(b, c);
double b_dist = sphere_distance(c, a);
double c_dist = sphere_distance(a, b);
double hca = sphere_direction(c, a, b_dist);
double hcb = sphere_direction(c, b, a_dist);
double sign = SIGNUM(hcb-hca);
double ss = (a_dist + b_dist + c_dist) / 2.0;
double E = tan(ss/2.0)*tan((ss-a_dist)/2.0)*tan((ss-b_dist)/2.0)*tan((ss-c_dist)/2.0);
return 4.0 * atan(sqrt(fabs(E))) * sign;
}
#endif
/**
* Returns true if the point p is on the minor edge defined by the
* end points of e.
*/
int edge_contains_point(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *p)
{
if ( edge_point_in_cone(e, p) && edge_point_on_plane(e, p) )
/* if ( edge_contains_coplanar_point(e, p) && edge_point_on_plane(e, p) ) */
{
LWDEBUG(4, "point is on edge");
return LW_TRUE;
}
LWDEBUG(4, "point is not on edge");
return LW_FALSE;
}
/**
* Used in great circle to compute the pole of the great circle.
*/
double z_to_latitude(double z, int top)
{
double sign = SIGNUM(z);
double tlat = acos(z);
LWDEBUGF(4, "inputs: z(%.8g) sign(%.8g) tlat(%.8g)", z, sign, tlat);
if (FP_IS_ZERO(z))
{
if (top) return M_PI_2;
else return -1.0 * M_PI_2;
}
if (fabs(tlat) > M_PI_2 )
{
tlat = sign * (M_PI - fabs(tlat));
}
else
{
tlat = sign * tlat;
}
LWDEBUGF(4, "output: tlat(%.8g)", tlat);
return tlat;
}
/**
* Computes the pole of the great circle disk which is the intersection of
* the great circle with the line of maximum/minimum gradient that lies on
* the great circle plane.
*/
int clairaut_cartesian(const POINT3D *start, const POINT3D *end, GEOGRAPHIC_POINT *g_top, GEOGRAPHIC_POINT *g_bottom)
{
POINT3D t1, t2;
GEOGRAPHIC_POINT vN1, vN2;
LWDEBUG(4,"entering function");
unit_normal(start, end, &t1);
unit_normal(end, start, &t2);
LWDEBUGF(4, "unit normal t1 == POINT(%.8g %.8g %.8g)", t1.x, t1.y, t1.z);
LWDEBUGF(4, "unit normal t2 == POINT(%.8g %.8g %.8g)", t2.x, t2.y, t2.z);
cart2geog(&t1, &vN1);
cart2geog(&t2, &vN2);
g_top->lat = z_to_latitude(t1.z,LW_TRUE);
g_top->lon = vN2.lon;
g_bottom->lat = z_to_latitude(t2.z,LW_FALSE);
g_bottom->lon = vN1.lon;
LWDEBUGF(4, "clairaut top == GPOINT(%.6g %.6g)", g_top->lat, g_top->lon);
LWDEBUGF(4, "clairaut bottom == GPOINT(%.6g %.6g)", g_bottom->lat, g_bottom->lon);
return LW_SUCCESS;
}
/**
* Computes the pole of the great circle disk which is the intersection of
* the great circle with the line of maximum/minimum gradient that lies on
* the great circle plane.
*/
int clairaut_geographic(const GEOGRAPHIC_POINT *start, const GEOGRAPHIC_POINT *end, GEOGRAPHIC_POINT *g_top, GEOGRAPHIC_POINT *g_bottom)
{
POINT3D t1, t2;
GEOGRAPHIC_POINT vN1, vN2;
LWDEBUG(4,"entering function");
robust_cross_product(start, end, &t1);
normalize(&t1);
robust_cross_product(end, start, &t2);
normalize(&t2);
LWDEBUGF(4, "unit normal t1 == POINT(%.8g %.8g %.8g)", t1.x, t1.y, t1.z);
LWDEBUGF(4, "unit normal t2 == POINT(%.8g %.8g %.8g)", t2.x, t2.y, t2.z);
cart2geog(&t1, &vN1);
cart2geog(&t2, &vN2);
g_top->lat = z_to_latitude(t1.z,LW_TRUE);
g_top->lon = vN2.lon;
g_bottom->lat = z_to_latitude(t2.z,LW_FALSE);
g_bottom->lon = vN1.lon;
LWDEBUGF(4, "clairaut top == GPOINT(%.6g %.6g)", g_top->lat, g_top->lon);
LWDEBUGF(4, "clairaut bottom == GPOINT(%.6g %.6g)", g_bottom->lat, g_bottom->lon);
return LW_SUCCESS;
}
/**
* Returns true if an intersection can be calculated, and places it in *g.
* Returns false otherwise.
*/
int edge_intersection(const GEOGRAPHIC_EDGE *e1, const GEOGRAPHIC_EDGE *e2, GEOGRAPHIC_POINT *g)
{
POINT3D ea, eb, v;
LWDEBUGF(4, "e1 start(%.20g %.20g) end(%.20g %.20g)", e1->start.lat, e1->start.lon, e1->end.lat, e1->end.lon);
LWDEBUGF(4, "e2 start(%.20g %.20g) end(%.20g %.20g)", e2->start.lat, e2->start.lon, e2->end.lat, e2->end.lon);
LWDEBUGF(4, "e1 start(%.20g %.20g) end(%.20g %.20g)", rad2deg(e1->start.lon), rad2deg(e1->start.lat), rad2deg(e1->end.lon), rad2deg(e1->end.lat));
LWDEBUGF(4, "e2 start(%.20g %.20g) end(%.20g %.20g)", rad2deg(e2->start.lon), rad2deg(e2->start.lat), rad2deg(e2->end.lon), rad2deg(e2->end.lat));
if ( geographic_point_equals(&(e1->start), &(e2->start)) )
{
*g = e1->start;
return LW_TRUE;
}
if ( geographic_point_equals(&(e1->end), &(e2->end)) )
{
*g = e1->end;
return LW_TRUE;
}
if ( geographic_point_equals(&(e1->end), &(e2->start)) )
{
*g = e1->end;
return LW_TRUE;
}
if ( geographic_point_equals(&(e1->start), &(e2->end)) )
{
*g = e1->start;
return LW_TRUE;
}
robust_cross_product(&(e1->start), &(e1->end), &ea);
normalize(&ea);
robust_cross_product(&(e2->start), &(e2->end), &eb);
normalize(&eb);
LWDEBUGF(4, "e1 cross product == POINT(%.12g %.12g %.12g)", ea.x, ea.y, ea.z);
LWDEBUGF(4, "e2 cross product == POINT(%.12g %.12g %.12g)", eb.x, eb.y, eb.z);
LWDEBUGF(4, "fabs(dot_product(ea, eb)) == %.14g", fabs(dot_product(&ea, &eb)));
if ( FP_EQUALS(fabs(dot_product(&ea, &eb)), 1.0) )
{
LWDEBUGF(4, "parallel edges found! dot_product = %.12g", dot_product(&ea, &eb));
/* Parallel (maybe equal) edges! */
/* Hack alert, only returning ONE end of the edge right now, most do better later. */
/* Hack alert #2, returning a value of 2 to indicate a co-linear crossing event. */
if ( edge_contains_point(e1, &(e2->start)) )
{
*g = e2->start;
return 2;
}
if ( edge_contains_point(e1, &(e2->end)) )
{
*g = e2->end;
return 2;
}
if ( edge_contains_point(e2, &(e1->start)) )
{
*g = e1->start;
return 2;
}
if ( edge_contains_point(e2, &(e1->end)) )
{
*g = e1->end;
return 2;
}
}
unit_normal(&ea, &eb, &v);
LWDEBUGF(4, "v == POINT(%.12g %.12g %.12g)", v.x, v.y, v.z);
g->lat = atan2(v.z, sqrt(v.x * v.x + v.y * v.y));
g->lon = atan2(v.y, v.x);
LWDEBUGF(4, "g == GPOINT(%.12g %.12g)", g->lat, g->lon);
LWDEBUGF(4, "g == POINT(%.12g %.12g)", rad2deg(g->lon), rad2deg(g->lat));
if ( edge_contains_point(e1, g) && edge_contains_point(e2, g) )
{
return LW_TRUE;
}
else
{
LWDEBUG(4, "flipping point to other side of sphere");
g->lat = -1.0 * g->lat;
g->lon = g->lon + M_PI;
if ( g->lon > M_PI )
{
g->lon = -1.0 * (2.0 * M_PI - g->lon);
}
if ( edge_contains_point(e1, g) && edge_contains_point(e2, g) )
{
return LW_TRUE;
}
}
return LW_FALSE;
}
double edge_distance_to_point(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *gp, GEOGRAPHIC_POINT *closest)
{
double d1 = 1000000000.0, d2, d3, d_nearest;
POINT3D n, p, k;
GEOGRAPHIC_POINT gk, g_nearest;
/* Zero length edge, */
if ( geographic_point_equals(&(e->start), &(e->end)) )
{
if (closest)
*closest = e->start;
return sphere_distance(&(e->start), gp);
}
robust_cross_product(&(e->start), &(e->end), &n);
normalize(&n);
geog2cart(gp, &p);
vector_scale(&n, dot_product(&p, &n));
vector_difference(&p, &n, &k);
normalize(&k);
cart2geog(&k, &gk);
if ( edge_point_in_cone(e, &gk) )
{
d1 = sphere_distance(gp, &gk);
}
d2 = sphere_distance(gp, &(e->start));
d3 = sphere_distance(gp, &(e->end));
d_nearest = d1;
g_nearest = gk;
if ( d2 < d_nearest )
{
d_nearest = d2;
g_nearest = e->start;
}
if ( d3 < d_nearest )
{
d_nearest = d3;
g_nearest = e->end;
}
if (closest)
*closest = g_nearest;
return d_nearest;
}
/**
* Calculate the distance between two edges.
* IMPORTANT: this test does not check for edge intersection!!! (distance == 0)
* You have to check for intersection before calling this function.
*/
double edge_distance_to_edge(const GEOGRAPHIC_EDGE *e1, const GEOGRAPHIC_EDGE *e2, GEOGRAPHIC_POINT *closest1, GEOGRAPHIC_POINT *closest2)
{
double d;
GEOGRAPHIC_POINT gcp1s, gcp1e, gcp2s, gcp2e, c1, c2;
double d1s = edge_distance_to_point(e1, &(e2->start), &gcp1s);
double d1e = edge_distance_to_point(e1, &(e2->end), &gcp1e);
double d2s = edge_distance_to_point(e2, &(e1->start), &gcp2s);
double d2e = edge_distance_to_point(e2, &(e1->end), &gcp2e);
d = d1s;
c1 = gcp1s;
c2 = e2->start;
if ( d1e < d )
{
d = d1e;
c1 = gcp1e;
c2 = e2->end;
}
if ( d2s < d )
{
d = d2s;
c1 = e1->start;
c2 = gcp2s;
}
if ( d2e < d )
{
d = d2e;
c1 = e1->end;
c2 = gcp2e;
}
if ( closest1 ) *closest1 = c1;
if ( closest2 ) *closest2 = c2;
return d;
}
/**
* Given a starting location r, a distance and an azimuth
* to the new point, compute the location of the projected point on the unit sphere.
*/
int sphere_project(const GEOGRAPHIC_POINT *r, double distance, double azimuth, GEOGRAPHIC_POINT *n)
{
double d = distance;
double lat1 = r->lat;
double lon1 = r->lon;
double lat2, lon2;
lat2 = asin(sin(lat1)*cos(d) + cos(lat1)*sin(d)*cos(azimuth));
/* If we're going straight up or straight down, we don't need to calculate the longitude */
/* TODO: this isn't quite true, what if we're going over the pole? */
if ( FP_EQUALS(azimuth, M_PI) || FP_EQUALS(azimuth, 0.0) )
{
lon2 = r->lon;
}
else
{
lon2 = lon1 + atan2(sin(azimuth)*sin(d)*cos(lat1), cos(d)-sin(lat1)*sin(lat2));
}
if ( isnan(lat2) || isnan(lon2) )
return LW_FAILURE;
n->lat = lat2;
n->lon = lon2;
return LW_SUCCESS;
}
int edge_calculate_gbox_slow(const GEOGRAPHIC_EDGE *e, GBOX *gbox)
{
int steps = 1000000;
int i;
double dx, dy, dz;
double distance = sphere_distance(&(e->start), &(e->end));
POINT3D pn, p, start, end;
/* Edge is zero length, just return the naive box */
if ( FP_IS_ZERO(distance) )
{
LWDEBUG(4, "edge is zero length. returning");
geog2cart(&(e->start), &start);
geog2cart(&(e->end), &end);
gbox_init_point3d(&start, gbox);
gbox_merge_point3d(&end, gbox);
return LW_SUCCESS;
}
/* Edge is antipodal (one point on each side of the globe),
set the box to contain the whole world and return */
if ( FP_EQUALS(distance, M_PI) )
{
LWDEBUG(4, "edge is antipodal. setting to maximum size box, and returning");
gbox->xmin = gbox->ymin = gbox->zmin = -1.0;
gbox->xmax = gbox->ymax = gbox->zmax = 1.0;
return LW_SUCCESS;
}
/* Walk along the chord between start and end incrementally,
normalizing at each step. */
geog2cart(&(e->start), &start);
geog2cart(&(e->end), &end);
dx = (end.x - start.x)/steps;
dy = (end.y - start.y)/steps;
dz = (end.z - start.z)/steps;
p = start;
gbox->xmin = gbox->xmax = p.x;
gbox->ymin = gbox->ymax = p.y;
gbox->zmin = gbox->zmax = p.z;
for ( i = 0; i < steps; i++ )
{
p.x += dx;
p.y += dy;
p.z += dz;
pn = p;
normalize(&pn);
gbox_merge_point3d(&pn, gbox);
}
return LW_SUCCESS;
}
/**
* The magic function, given an edge in spherical coordinates, calculate a
* 3D bounding box that fully contains it, taking into account the curvature
* of the sphere on which it is inscribed.
*
* Any arc on the sphere defines a plane that bisects the sphere. In this plane,
* the arc is a portion of a unit circle.
* Projecting the end points of the axes (1,0,0), (-1,0,0) etc, into the plane
* and normalizing yields potential extrema points. Those points on the
* side of the plane-dividing line formed by the end points that is opposite
* the origin of the plane are extrema and should be added to the bounding box.
*/
int edge_calculate_gbox(const POINT3D *A1, const POINT3D *A2, GBOX *gbox)
{
POINT2D R1, R2, RX, O;
POINT3D AN, A3;
POINT3D X[6];
int i, o_side;
/* Initialize the box with the edge end points */
gbox_init_point3d(A1, gbox);
gbox_merge_point3d(A2, gbox);
/* Zero length edge, just return! */
if ( p3d_same(A1, A2) )
return LW_SUCCESS;
/* Error out on antipodal edge */
if ( FP_EQUALS(A1->x, -1*A2->x) && FP_EQUALS(A1->y, -1*A2->y) && FP_EQUALS(A1->z, -1*A2->z) )
{
lwerror("Antipodal (180 degrees long) edge detected!");
return LW_FAILURE;
}
/* Create A3, a vector in the plane of A1/A2, orthogonal to A1 */
unit_normal(A1, A2, &AN);
unit_normal(&AN, A1, &A3);
/* Project A1 and A2 into the 2-space formed by the plane A1/A3 */
R1.x = 1.0;
R1.y = 0.0;
R2.x = dot_product(A2, A1);
R2.y = dot_product(A2, &A3);
/* Initialize our 3-space axis points (x+, x-, y+, y-, z+, z-) */
memset(X, 0, sizeof(POINT3D) * 6);
X[0].x = X[2].y = X[4].z = 1.0;
X[1].x = X[3].y = X[5].z = -1.0;
/* Initialize a 2-space origin point. */
O.x = O.y = 0.0;
/* What side of the line joining R1/R2 is O? */
o_side = lw_segment_side(&R1, &R2, &O);
/* Add any extrema! */
for ( i = 0; i < 6; i++ )
{
/* Convert 3-space axis points to 2-space unit vectors */
RX.x = dot_product(&(X[i]), A1);
RX.y = dot_product(&(X[i]), &A3);
normalize2d(&RX);
/* Any axis end on the side of R1/R2 opposite the origin */
/* is an extreme point in the arc, so we add the 3-space */
/* version of the point on R1/R2 to the gbox */
if ( lw_segment_side(&R1, &R2, &RX) != o_side )
{
POINT3D Xn;
Xn.x = RX.x * A1->x + RX.y * A3.x;
Xn.y = RX.x * A1->y + RX.y * A3.y;
Xn.z = RX.x * A1->z + RX.y * A3.z;
gbox_merge_point3d(&Xn, gbox);
}
}
return LW_SUCCESS;
}
/*
* When we have a globe-covering gbox but we still want an outside
* point, we do this Very Bad Hack, which is look at the first two points
* in the ring and then nudge a point to the left of that arc.
* There is an assumption of convexity built in there, as well as that
* the shape doesn't have a sharp reversal in it. It's ugly, but
* it fixes some common cases (large selection polygons) that users
* are generating. At some point all of geodetic needs a clean-room
* rewrite.
* There is also an assumption of CCW exterior ring, which is how the
* GeoJSON spec defined geographic ring orientation.
*/
static int lwpoly_pt_outside_hack(const LWPOLY *poly, POINT2D *pt_outside)
{
GEOGRAPHIC_POINT g1, g2, gSum;
POINT4D p1, p2;
POINT3D q1, q2, qMid, qCross, qSum;
POINTARRAY *pa;
if (lwgeom_is_empty((LWGEOM*)poly))
return LW_FAILURE;
if (poly->nrings < 1)
return LW_FAILURE;
pa = poly->rings[0];
if (pa->npoints < 2)
return LW_FAILURE;
/* First two points of ring */
getPoint4d_p(pa, 0, &p1);
getPoint4d_p(pa, 1, &p2);
/* Convert to XYZ unit vectors */
geographic_point_init(p1.x, p1.y, &g1);
geographic_point_init(p2.x, p2.y, &g2);
geog2cart(&g1, &q1);
geog2cart(&g2, &q2);
/* Mid-point of first two points */
vector_sum(&q1, &q2, &qMid);
normalize(&qMid);
/* Cross product of first two points (perpendicular) */
cross_product(&q1, &q2, &qCross);
normalize(&qCross);
/* Invert it to put it outside, and scale down */
vector_scale(&qCross, -0.2);
/* Project midpoint to the right */
vector_sum(&qMid, &qCross, &qSum);
normalize(&qSum);
/* Convert back to lon/lat */
cart2geog(&qSum, &gSum);
pt_outside->x = rad2deg(gSum.lon);
pt_outside->y = rad2deg(gSum.lat);
return LW_SUCCESS;
}
int lwpoly_pt_outside(const LWPOLY *poly, POINT2D *pt_outside)
{
int rv;
/* Make sure we have boxes */
if ( poly->bbox )
{
rv = gbox_pt_outside(poly->bbox, pt_outside);
}
else
{
GBOX gbox;
lwgeom_calculate_gbox_geodetic((LWGEOM*)poly, &gbox);
rv = gbox_pt_outside(&gbox, pt_outside);
}
if (rv == LW_FALSE)
return lwpoly_pt_outside_hack(poly, pt_outside);
return rv;
}
/**
* Given a unit geocentric gbox, return a lon/lat (degrees) coordinate point point that is
* guaranteed to be outside the box (and therefore anything it contains).
*/
int gbox_pt_outside(const GBOX *gbox, POINT2D *pt_outside)
{
double grow = M_PI / 180.0 / 60.0; /* one arc-minute */
int i;
GBOX ge;
POINT3D corners[8];
POINT3D pt;
GEOGRAPHIC_POINT g;
while ( grow < M_PI )
{
/* Assign our box and expand it slightly. */
ge = *gbox;
if ( ge.xmin > -1 ) ge.xmin -= grow;
if ( ge.ymin > -1 ) ge.ymin -= grow;
if ( ge.zmin > -1 ) ge.zmin -= grow;
if ( ge.xmax < 1 ) ge.xmax += grow;
if ( ge.ymax < 1 ) ge.ymax += grow;
if ( ge.zmax < 1 ) ge.zmax += grow;
/* Build our eight corner points */
corners[0].x = ge.xmin;
corners[0].y = ge.ymin;
corners[0].z = ge.zmin;
corners[1].x = ge.xmin;
corners[1].y = ge.ymax;
corners[1].z = ge.zmin;
corners[2].x = ge.xmin;
corners[2].y = ge.ymin;
corners[2].z = ge.zmax;
corners[3].x = ge.xmax;
corners[3].y = ge.ymin;
corners[3].z = ge.zmin;
corners[4].x = ge.xmax;
corners[4].y = ge.ymax;
corners[4].z = ge.zmin;
corners[5].x = ge.xmax;
corners[5].y = ge.ymin;
corners[5].z = ge.zmax;
corners[6].x = ge.xmin;
corners[6].y = ge.ymax;
corners[6].z = ge.zmax;
corners[7].x = ge.xmax;
corners[7].y = ge.ymax;
corners[7].z = ge.zmax;
LWDEBUG(4, "trying to use a box corner point...");
for ( i = 0; i < 8; i++ )
{
normalize(&(corners[i]));
LWDEBUGF(4, "testing corner %d: POINT(%.8g %.8g %.8g)", i, corners[i].x, corners[i].y, corners[i].z);
if ( ! gbox_contains_point3d(gbox, &(corners[i])) )
{
LWDEBUGF(4, "corner %d is outside our gbox", i);
pt = corners[i];
normalize(&pt);
cart2geog(&pt, &g);
pt_outside->x = rad2deg(g.lon);
pt_outside->y = rad2deg(g.lat);
LWDEBUGF(4, "returning POINT(%.8g %.8g) as outside point", pt_outside->x, pt_outside->y);
return LW_SUCCESS;
}
}
/* Try a wider growth to push the corners outside the original box. */
grow *= 2.0;
}
/* This should never happen! */
// lwerror("BOOM! Could not generate outside point!");
return LW_FAILURE;
}
static int ptarray_segmentize_sphere_edge_recursive (
const POINT3D *p1, const POINT3D *p2, /* 3-space points we are interpolating between */
const POINT4D *v1, const POINT4D *v2, /* real values and z/m values */
double d, double max_seg_length, /* current segment length and segment limit */
POINTARRAY *pa) /* write out results here */
{
GEOGRAPHIC_POINT g;
/* Reached the terminal leaf in recursion. Add */
/* the left-most point to the pointarray here */
/* We recurse down the left side first, so outputs should */
/* end up added to the array in order this way */
if (d <= max_seg_length)
{
POINT4D p;
cart2geog(p1, &g);
p.x = v1->x;
p.y = v1->y;
p.z = v1->z;
p.m = v1->m;
return ptarray_append_point(pa, &p, LW_FALSE);
}
/* Find the mid-point and recurse on the left and then the right */
else
{
/* Calculate mid-point */
POINT3D mid;
mid.x = (p1->x + p2->x) / 2.0;
mid.y = (p1->y + p2->y) / 2.0;
mid.z = (p1->z + p2->z) / 2.0;
normalize(&mid);
/* Calculate z/m mid-values */
POINT4D midv;
cart2geog(&mid, &g);
midv.x = rad2deg(g.lon);
midv.y = rad2deg(g.lat);
midv.z = (v1->z + v2->z) / 2.0;
midv.m = (v1->m + v2->m) / 2.0;
/* Recurse on the left first */
ptarray_segmentize_sphere_edge_recursive(p1, &mid, v1, &midv, d/2.0, max_seg_length, pa);
ptarray_segmentize_sphere_edge_recursive(&mid, p2, &midv, v2, d/2.0, max_seg_length, pa);
return LW_SUCCESS;
}
}
/**
* Create a new point array with no segment longer than the input segment length (expressed in radians!)
* @param pa_in - input point array pointer
* @param max_seg_length - maximum output segment length in radians
*/
static POINTARRAY*
ptarray_segmentize_sphere(const POINTARRAY *pa_in, double max_seg_length)
{
POINTARRAY *pa_out;
int hasz = ptarray_has_z(pa_in);
int hasm = ptarray_has_m(pa_in);
POINT4D p1, p2;
POINT3D q1, q2;
GEOGRAPHIC_POINT g1, g2;
uint32_t i;
/* Just crap out on crazy input */
if ( ! pa_in )
lwerror("%s: null input pointarray", __func__);
if ( max_seg_length <= 0.0 )
lwerror("%s: maximum segment length must be positive", __func__);
/* Empty starting array */
pa_out = ptarray_construct_empty(hasz, hasm, pa_in->npoints);
/* Simple loop per edge */
for (i = 1; i < pa_in->npoints; i++)
{
getPoint4d_p(pa_in, i-1, &p1);
getPoint4d_p(pa_in, i, &p2);
geographic_point_init(p1.x, p1.y, &g1);
geographic_point_init(p2.x, p2.y, &g2);
/* Skip duplicate points (except in case of 2-point lines!) */
if ((pa_in->npoints > 2) && p4d_same(&p1, &p2))
continue;
/* How long is this edge? */
double d = sphere_distance(&g1, &g2);
if (d > max_seg_length)
{
geog2cart(&g1, &q1);
geog2cart(&g2, &q2);
/* 3-d end points, XYZM end point, current edge size, min edge size */
ptarray_segmentize_sphere_edge_recursive(&q1, &q2, &p1, &p2, d, max_seg_length, pa_out);
}
/* If we don't segmentize, we need to add first point manually */
else
{
ptarray_append_point(pa_out, &p1, LW_TRUE);
}
}
/* Always add the last point */
ptarray_append_point(pa_out, &p2, LW_TRUE);
return pa_out;
}
/**
* Create a new, densified geometry where no segment is longer than max_seg_length.
* Input geometry is not altered, output geometry must be freed by caller.
* @param lwg_in = input geometry
* @param max_seg_length = maximum segment length in radians
*/
LWGEOM*
lwgeom_segmentize_sphere(const LWGEOM *lwg_in, double max_seg_length)
{
POINTARRAY *pa_out;
LWLINE *lwline;
LWPOLY *lwpoly_in, *lwpoly_out;
LWCOLLECTION *lwcol_in, *lwcol_out;
uint32_t i;
/* Reflect NULL */
if ( ! lwg_in )
return NULL;
/* Clone empty */
if ( lwgeom_is_empty(lwg_in) )
return lwgeom_clone(lwg_in);
switch (lwg_in->type)
{
case MULTIPOINTTYPE:
case POINTTYPE:
return lwgeom_clone_deep(lwg_in);
break;
case LINETYPE:
lwline = lwgeom_as_lwline(lwg_in);
pa_out = ptarray_segmentize_sphere(lwline->points, max_seg_length);
return lwline_as_lwgeom(lwline_construct(lwg_in->srid, NULL, pa_out));
break;
case POLYGONTYPE:
lwpoly_in = lwgeom_as_lwpoly(lwg_in);
lwpoly_out = lwpoly_construct_empty(lwg_in->srid, lwgeom_has_z(lwg_in), lwgeom_has_m(lwg_in));
for ( i = 0; i < lwpoly_in->nrings; i++ )
{
pa_out = ptarray_segmentize_sphere(lwpoly_in->rings[i], max_seg_length);
lwpoly_add_ring(lwpoly_out, pa_out);
}
return lwpoly_as_lwgeom(lwpoly_out);
break;
case MULTILINETYPE:
case MULTIPOLYGONTYPE:
case COLLECTIONTYPE:
lwcol_in = lwgeom_as_lwcollection(lwg_in);
lwcol_out = lwcollection_construct_empty(lwg_in->type, lwg_in->srid, lwgeom_has_z(lwg_in), lwgeom_has_m(lwg_in));
for ( i = 0; i < lwcol_in->ngeoms; i++ )
{
lwcollection_add_lwgeom(lwcol_out, lwgeom_segmentize_sphere(lwcol_in->geoms[i], max_seg_length));
}
return lwcollection_as_lwgeom(lwcol_out);
break;
default:
lwerror("lwgeom_segmentize_sphere: unsupported input geometry type: %d - %s",
lwg_in->type, lwtype_name(lwg_in->type));
break;
}
lwerror("lwgeom_segmentize_sphere got to the end of the function, should not happen");
return NULL;
}
/**
* Returns the area of the ring (ring must be closed) in square radians (surface of
* the sphere is 4*PI).
*/
double
ptarray_area_sphere(const POINTARRAY *pa)
{
uint32_t i;
const POINT2D *p;
GEOGRAPHIC_POINT a, b, c;
double area = 0.0;
/* Return zero on nonsensical inputs */
if ( ! pa || pa->npoints < 4 )
return 0.0;
p = getPoint2d_cp(pa, 0);
geographic_point_init(p->x, p->y, &a);
p = getPoint2d_cp(pa, 1);
geographic_point_init(p->x, p->y, &b);
for ( i = 2; i < pa->npoints-1; i++ )
{
p = getPoint2d_cp(pa, i);
geographic_point_init(p->x, p->y, &c);
area += sphere_signed_area(&a, &b, &c);
b = c;
}
return fabs(area);
}
static double ptarray_distance_spheroid(const POINTARRAY *pa1, const POINTARRAY *pa2, const SPHEROID *s, double tolerance, int check_intersection)
{
GEOGRAPHIC_EDGE e1, e2;
GEOGRAPHIC_POINT g1, g2;
GEOGRAPHIC_POINT nearest1, nearest2;
POINT3D A1, A2, B1, B2;
const POINT2D *p;
double distance;
uint32_t i, j;
int use_sphere = (s->a == s->b ? 1 : 0);
/* Make result really big, so that everything will be smaller than it */
distance = FLT_MAX;
/* Empty point arrays? Return negative */
if ( pa1->npoints == 0 || pa2->npoints == 0 )
return -1.0;
/* Handle point/point case here */
if ( pa1->npoints == 1 && pa2->npoints == 1 )
{
p = getPoint2d_cp(pa1, 0);
geographic_point_init(p->x, p->y, &g1);
p = getPoint2d_cp(pa2, 0);
geographic_point_init(p->x, p->y, &g2);
/* Sphere special case, axes equal */
distance = s->radius * sphere_distance(&g1, &g2);
if ( use_sphere )
return distance;
/* Below tolerance, actual distance isn't of interest */
else if ( distance < 0.95 * tolerance )
return distance;
/* Close or greater than tolerance, get the real answer to be sure */
else
return spheroid_distance(&g1, &g2, s);
}
/* Handle point/line case here */
if ( pa1->npoints == 1 || pa2->npoints == 1 )
{
/* Handle one/many case here */
uint32_t i;
const POINTARRAY *pa_one;
const POINTARRAY *pa_many;
if ( pa1->npoints == 1 )
{
pa_one = pa1;
pa_many = pa2;
}
else
{
pa_one = pa2;
pa_many = pa1;
}
/* Initialize our point */
p = getPoint2d_cp(pa_one, 0);
geographic_point_init(p->x, p->y, &g1);
/* Initialize start of line */
p = getPoint2d_cp(pa_many, 0);
geographic_point_init(p->x, p->y, &(e1.start));
/* Iterate through the edges in our line */
for ( i = 1; i < pa_many->npoints; i++ )
{
double d;
p = getPoint2d_cp(pa_many, i);
geographic_point_init(p->x, p->y, &(e1.end));
/* Get the spherical distance between point and edge */
d = s->radius * edge_distance_to_point(&e1, &g1, &g2);
/* New shortest distance! Record this distance / location */
if ( d < distance )
{
distance = d;
nearest2 = g2;
}
/* We've gotten closer than the tolerance... */
if ( d <= tolerance )
{
/* Working on a sphere? The answer is correct, return */
if ( use_sphere )
{
return d;
}
/* Far enough past the tolerance that the spheroid calculation won't change things */
else if ( d <= tolerance * 0.95 )
{
return d;
}
/* On a spheroid and near the tolerance? Confirm that we are *actually* closer than tolerance */
else
{
d = spheroid_distance(&g1, &nearest2, s);
/* Yes, closer than tolerance, return! */
if ( d <= tolerance )
return d;
}
}
e1.start = e1.end;
}
/* On sphere, return answer */
if ( use_sphere )
return distance;
/* On spheroid, calculate final answer based on closest approach */
else
return spheroid_distance(&g1, &nearest2, s);
}
/* Initialize start of line 1 */
p = getPoint2d_cp(pa1, 0);
geographic_point_init(p->x, p->y, &(e1.start));
geog2cart(&(e1.start), &A1);
/* Handle line/line case */
for ( i = 1; i < pa1->npoints; i++ )
{
p = getPoint2d_cp(pa1, i);
geographic_point_init(p->x, p->y, &(e1.end));
geog2cart(&(e1.end), &A2);
/* Initialize start of line 2 */
p = getPoint2d_cp(pa2, 0);
geographic_point_init(p->x, p->y, &(e2.start));
geog2cart(&(e2.start), &B1);
for ( j = 1; j < pa2->npoints; j++ )
{
double d;
p = getPoint2d_cp(pa2, j);
geographic_point_init(p->x, p->y, &(e2.end));
geog2cart(&(e2.end), &B2);
LWDEBUGF(4, "e1.start == GPOINT(%.6g %.6g) ", e1.start.lat, e1.start.lon);
LWDEBUGF(4, "e1.end == GPOINT(%.6g %.6g) ", e1.end.lat, e1.end.lon);
LWDEBUGF(4, "e2.start == GPOINT(%.6g %.6g) ", e2.start.lat, e2.start.lon);
LWDEBUGF(4, "e2.end == GPOINT(%.6g %.6g) ", e2.end.lat, e2.end.lon);
if ( check_intersection && edge_intersects(&A1, &A2, &B1, &B2) )
{
LWDEBUG(4,"edge intersection! returning 0.0");
return 0.0;
}
d = s->radius * edge_distance_to_edge(&e1, &e2, &g1, &g2);
LWDEBUGF(4,"got edge_distance_to_edge %.8g", d);
if ( d < distance )
{
distance = d;
nearest1 = g1;
nearest2 = g2;
}
if ( d <= tolerance )
{
if ( use_sphere )
{
return d;
}
else
{
d = spheroid_distance(&nearest1, &nearest2, s);
if ( d <= tolerance )
return d;
}
}
/* Copy end to start to allow a new end value in next iteration */
e2.start = e2.end;
B1 = B2;
}
/* Copy end to start to allow a new end value in next iteration */
e1.start = e1.end;
A1 = A2;
LW_ON_INTERRUPT(return -1.0);
}
LWDEBUGF(4,"finished all loops, returning %.8g", distance);
if ( use_sphere )
return distance;
else
return spheroid_distance(&nearest1, &nearest2, s);
}
/**
* Calculate the area of an LWGEOM. Anything except POLYGON, MULTIPOLYGON
* and GEOMETRYCOLLECTION return zero immediately. Multi's recurse, polygons
* calculate external ring area and subtract internal ring area. A GBOX is
* required to calculate an outside point.
*/
double lwgeom_area_sphere(const LWGEOM *lwgeom, const SPHEROID *spheroid)
{
int type;
double radius2 = spheroid->radius * spheroid->radius;
assert(lwgeom);
/* No area in nothing */
if ( lwgeom_is_empty(lwgeom) )
return 0.0;
/* Read the geometry type number */
type = lwgeom->type;
/* Anything but polygons and collections returns zero */
if ( ! ( type == POLYGONTYPE || type == MULTIPOLYGONTYPE || type == COLLECTIONTYPE ) )
return 0.0;
/* Actually calculate area */
if ( type == POLYGONTYPE )
{
LWPOLY *poly = (LWPOLY*)lwgeom;
uint32_t i;
double area = 0.0;
/* Just in case there's no rings */
if ( poly->nrings < 1 )
return 0.0;
/* First, the area of the outer ring */
area += radius2 * ptarray_area_sphere(poly->rings[0]);
/* Subtract areas of inner rings */
for ( i = 1; i < poly->nrings; i++ )
{
area -= radius2 * ptarray_area_sphere(poly->rings[i]);
}
return area;
}
/* Recurse into sub-geometries to get area */
if ( type == MULTIPOLYGONTYPE || type == COLLECTIONTYPE )
{
LWCOLLECTION *col = (LWCOLLECTION*)lwgeom;
uint32_t i;
double area = 0.0;
for ( i = 0; i < col->ngeoms; i++ )
{
area += lwgeom_area_sphere(col->geoms[i], spheroid);
}
return area;
}
/* Shouldn't get here. */
return 0.0;
}
/**
* Calculate a projected point given a source point, a distance and a bearing.
* @param r - location of first point.
* @param spheroid - spheroid definition.
* @param distance - distance, in units of the spheroid def'n.
* @param azimuth - azimuth in radians.
* @return s - location of projected point.
*
*/
LWPOINT* lwgeom_project_spheroid(const LWPOINT *r, const SPHEROID *spheroid, double distance, double azimuth)
{
GEOGRAPHIC_POINT geo_source, geo_dest;
POINT4D pt_dest;
double x, y;
POINTARRAY *pa;
LWPOINT *lwp;
/* Normalize distance to be positive*/
if ( distance < 0.0 ) {
distance = -distance;
azimuth += M_PI;
}
/* Normalize azimuth */
azimuth -= 2.0 * M_PI * floor(azimuth / (2.0 * M_PI));
/* Check the distance validity */
if ( distance > (M_PI * spheroid->radius) )
{
lwerror("Distance must not be greater than %g", M_PI * spheroid->radius);
return NULL;
}
/* Convert to ta geodetic point */
x = lwpoint_get_x(r);
y = lwpoint_get_y(r);
geographic_point_init(x, y, &geo_source);
/* Try the projection */
if( spheroid_project(&geo_source, spheroid, distance, azimuth, &geo_dest) == LW_FAILURE )
{
LWDEBUGF(3, "Unable to project from (%g %g) with azimuth %g and distance %g", x, y, azimuth, distance);
lwerror("Unable to project from (%g %g) with azimuth %g and distance %g", x, y, azimuth, distance);
return NULL;
}
/* Build the output LWPOINT */
pa = ptarray_construct(0, 0, 1);
pt_dest.x = rad2deg(longitude_radians_normalize(geo_dest.lon));
pt_dest.y = rad2deg(latitude_radians_normalize(geo_dest.lat));
pt_dest.z = pt_dest.m = 0.0;
ptarray_set_point4d(pa, 0, &pt_dest);
lwp = lwpoint_construct(r->srid, NULL, pa);
lwgeom_set_geodetic(lwpoint_as_lwgeom(lwp), LW_TRUE);
return lwp;
}
/**
* Calculate a bearing (azimuth) given a source and destination point.
* @param r - location of first point.
* @param s - location of second point.
* @param spheroid - spheroid definition.
* @return azimuth - azimuth in radians.
*
*/
double lwgeom_azumith_spheroid(const LWPOINT *r, const LWPOINT *s, const SPHEROID *spheroid)
{
GEOGRAPHIC_POINT g1, g2;
double x1, y1, x2, y2, az;
/* Convert r to a geodetic point */
x1 = lwpoint_get_x(r);
y1 = lwpoint_get_y(r);
geographic_point_init(x1, y1, &g1);
/* Convert s to a geodetic point */
x2 = lwpoint_get_x(s);
y2 = lwpoint_get_y(s);
geographic_point_init(x2, y2, &g2);
/* Same point, return NaN */
if ( FP_EQUALS(x1, x2) && FP_EQUALS(y1, y2) )
{
return NAN;
}
/* Do the direction calculation */
az = spheroid_direction(&g1, &g2, spheroid);
/* Ensure result is positive */
return az < -0 ? 2*M_PI + az : az;
// return az;
}
/**
* Calculate the distance between two LWGEOMs, using the coordinates are
* longitude and latitude. Return immediately when the calculated distance drops
* below the tolerance (useful for dwithin calculations).
* Return a negative distance for incalculable cases.
*/
double lwgeom_distance_spheroid(const LWGEOM *lwgeom1, const LWGEOM *lwgeom2, const SPHEROID *spheroid, double tolerance)
{
uint8_t type1, type2;
int check_intersection = LW_FALSE;
GBOX gbox1, gbox2;
gbox_init(&gbox1);
gbox_init(&gbox2);
assert(lwgeom1);
assert(lwgeom2);
LWDEBUGF(4, "entered function, tolerance %.8g", tolerance);
/* What's the distance to an empty geometry? We don't know.
Return a negative number so the caller can catch this case. */
if ( lwgeom_is_empty(lwgeom1) || lwgeom_is_empty(lwgeom2) )
{
return -1.0;
}
type1 = lwgeom1->type;
type2 = lwgeom2->type;
/* Make sure we have boxes */
if ( lwgeom1->bbox )
gbox1 = *(lwgeom1->bbox);
else
lwgeom_calculate_gbox_geodetic(lwgeom1, &gbox1);
/* Make sure we have boxes */
if ( lwgeom2->bbox )
gbox2 = *(lwgeom2->bbox);
else
lwgeom_calculate_gbox_geodetic(lwgeom2, &gbox2);
/* If the boxes aren't disjoint, we have to check for edge intersections */
if ( gbox_overlaps(&gbox1, &gbox2) )
check_intersection = LW_TRUE;
/* Point/line combinations can all be handled with simple point array iterations */
if ( ( type1 == POINTTYPE || type1 == LINETYPE ) &&
( type2 == POINTTYPE || type2 == LINETYPE ) )
{
POINTARRAY *pa1, *pa2;
if ( type1 == POINTTYPE )
pa1 = ((LWPOINT*)lwgeom1)->point;
else
pa1 = ((LWLINE*)lwgeom1)->points;
if ( type2 == POINTTYPE )
pa2 = ((LWPOINT*)lwgeom2)->point;
else
pa2 = ((LWLINE*)lwgeom2)->points;
return ptarray_distance_spheroid(pa1, pa2, spheroid, tolerance, check_intersection);
}
/* Point/Polygon cases, if point-in-poly, return zero, else return distance. */
if ( ( type1 == POLYGONTYPE && type2 == POINTTYPE ) ||
( type2 == POLYGONTYPE && type1 == POINTTYPE ) )
{
const POINT2D *p;
LWPOLY *lwpoly;
LWPOINT *lwpt;
double distance = FLT_MAX;
uint32_t i;
if ( type1 == POINTTYPE )
{
lwpt = (LWPOINT*)lwgeom1;
lwpoly = (LWPOLY*)lwgeom2;
}
else
{
lwpt = (LWPOINT*)lwgeom2;
lwpoly = (LWPOLY*)lwgeom1;
}
p = getPoint2d_cp(lwpt->point, 0);
/* Point in polygon implies zero distance */
if ( lwpoly_covers_point2d(lwpoly, p) )
{
return 0.0;
}
/* Not inside, so what's the actual distance? */
for ( i = 0; i < lwpoly->nrings; i++ )
{
double ring_distance = ptarray_distance_spheroid(lwpoly->rings[i], lwpt->point, spheroid, tolerance, check_intersection);
if ( ring_distance < distance )
distance = ring_distance;
if ( distance <= tolerance )
return distance;
}
return distance;
}
/* Line/polygon case, if start point-in-poly, return zero, else return distance. */
if ( ( type1 == POLYGONTYPE && type2 == LINETYPE ) ||
( type2 == POLYGONTYPE && type1 == LINETYPE ) )
{
const POINT2D *p;
LWPOLY *lwpoly;
LWLINE *lwline;
double distance = FLT_MAX;
uint32_t i;
if ( type1 == LINETYPE )
{
lwline = (LWLINE*)lwgeom1;
lwpoly = (LWPOLY*)lwgeom2;
}
else
{
lwline = (LWLINE*)lwgeom2;
lwpoly = (LWPOLY*)lwgeom1;
}
p = getPoint2d_cp(lwline->points, 0);
LWDEBUG(4, "checking if a point of line is in polygon");
/* Point in polygon implies zero distance */
if ( lwpoly_covers_point2d(lwpoly, p) )
return 0.0;
LWDEBUG(4, "checking ring distances");
/* Not contained, so what's the actual distance? */
for ( i = 0; i < lwpoly->nrings; i++ )
{
double ring_distance = ptarray_distance_spheroid(lwpoly->rings[i], lwline->points, spheroid, tolerance, check_intersection);
LWDEBUGF(4, "ring[%d] ring_distance = %.8g", i, ring_distance);
if ( ring_distance < distance )
distance = ring_distance;
if ( distance <= tolerance )
return distance;
}
LWDEBUGF(4, "all rings checked, returning distance = %.8g", distance);
return distance;
}
/* Polygon/polygon case, if start point-in-poly, return zero, else
* return distance. */
if (type1 == POLYGONTYPE && type2 == POLYGONTYPE)
{
const POINT2D* p;
LWPOLY* lwpoly1 = (LWPOLY*)lwgeom1;
LWPOLY* lwpoly2 = (LWPOLY*)lwgeom2;
double distance = FLT_MAX;
uint32_t i, j;
/* Point of 2 in polygon 1 implies zero distance */
p = getPoint2d_cp(lwpoly1->rings[0], 0);
if (lwpoly_covers_point2d(lwpoly2, p)) return 0.0;
/* Point of 1 in polygon 2 implies zero distance */
p = getPoint2d_cp(lwpoly2->rings[0], 0);
if (lwpoly_covers_point2d(lwpoly1, p)) return 0.0;
/* Not contained, so what's the actual distance? */
for (i = 0; i < lwpoly1->nrings; i++)
{
for (j = 0; j < lwpoly2->nrings; j++)
{
double ring_distance =
ptarray_distance_spheroid(
lwpoly1->rings[i],
lwpoly2->rings[j],
spheroid,
tolerance,
check_intersection);
if (ring_distance < distance)
distance = ring_distance;
if (distance <= tolerance) return distance;
}
}
return distance;
}
/* Recurse into collections */
if ( lwtype_is_collection(type1) )
{
uint32_t i;
double distance = FLT_MAX;
LWCOLLECTION *col = (LWCOLLECTION*)lwgeom1;
for ( i = 0; i < col->ngeoms; i++ )
{
double geom_distance = lwgeom_distance_spheroid(
col->geoms[i], lwgeom2, spheroid, tolerance);
if ( geom_distance < distance )
distance = geom_distance;
if ( distance <= tolerance )
return distance;
}
return distance;
}
/* Recurse into collections */
if ( lwtype_is_collection(type2) )
{
uint32_t i;
double distance = FLT_MAX;
LWCOLLECTION *col = (LWCOLLECTION*)lwgeom2;
for ( i = 0; i < col->ngeoms; i++ )
{
double geom_distance = lwgeom_distance_spheroid(lwgeom1, col->geoms[i], spheroid, tolerance);
if ( geom_distance < distance )
distance = geom_distance;
if ( distance <= tolerance )
return distance;
}
return distance;
}
lwerror("arguments include unsupported geometry type (%s, %s)", lwtype_name(type1), lwtype_name(type1));
return -1.0;
}
int lwgeom_covers_lwgeom_sphere(const LWGEOM *lwgeom1, const LWGEOM *lwgeom2)
{
int type1, type2;
GBOX gbox1, gbox2;
gbox1.flags = gbox2.flags = 0;
assert(lwgeom1);
assert(lwgeom2);
type1 = lwgeom1->type;
type2 = lwgeom2->type;
/* dim(geom2) > dim(geom1) always returns false (because geom2 is bigger) */
if ( (type1 == POINTTYPE && type2 == LINETYPE)
|| (type1 == POINTTYPE && type2 == POLYGONTYPE)
|| (type1 == LINETYPE && type2 == POLYGONTYPE) )
{
LWDEBUG(4, "dimension of geom2 is bigger than geom1");
return LW_FALSE;
}
/* Make sure we have boxes */
if ( lwgeom1->bbox )
gbox1 = *(lwgeom1->bbox);
else
lwgeom_calculate_gbox_geodetic(lwgeom1, &gbox1);
/* Make sure we have boxes */
if ( lwgeom2->bbox )
gbox2 = *(lwgeom2->bbox);
else
lwgeom_calculate_gbox_geodetic(lwgeom2, &gbox2);
/* Handle the polygon/point case */
if ( type1 == POLYGONTYPE && type2 == POINTTYPE )
{
POINT2D pt_to_test;
getPoint2d_p(((LWPOINT*)lwgeom2)->point, 0, &pt_to_test);
return lwpoly_covers_point2d((LWPOLY*)lwgeom1, &pt_to_test);
}
else if ( type1 == POLYGONTYPE && type2 == LINETYPE)
{
return lwpoly_covers_lwline((LWPOLY*)lwgeom1, (LWLINE*)lwgeom2);
}
else if ( type1 == POLYGONTYPE && type2 == POLYGONTYPE)
{
return lwpoly_covers_lwpoly((LWPOLY*)lwgeom1, (LWPOLY*)lwgeom2);
}
else if ( type1 == LINETYPE && type2 == POINTTYPE)
{
return lwline_covers_lwpoint((LWLINE*)lwgeom1, (LWPOINT*)lwgeom2);
}
else if ( type1 == LINETYPE && type2 == LINETYPE)
{
return lwline_covers_lwline((LWLINE*)lwgeom1, (LWLINE*)lwgeom2);
}
else if ( type1 == POINTTYPE && type2 == POINTTYPE)
{
return lwpoint_same((LWPOINT*)lwgeom1, (LWPOINT*)lwgeom2);
}
/* If any of the first argument parts covers the second argument, it's true */
if ( lwtype_is_collection( type1 ) )
{
uint32_t i;
LWCOLLECTION *col = (LWCOLLECTION*)lwgeom1;
for ( i = 0; i < col->ngeoms; i++ )
{
if ( lwgeom_covers_lwgeom_sphere(col->geoms[i], lwgeom2) )
{
return LW_TRUE;
}
}
return LW_FALSE;
}
/* Only if all of the second arguments are covered by the first argument is the condition true */
if ( lwtype_is_collection( type2 ) )
{
uint32_t i;
LWCOLLECTION *col = (LWCOLLECTION*)lwgeom2;
for ( i = 0; i < col->ngeoms; i++ )
{
if ( ! lwgeom_covers_lwgeom_sphere(lwgeom1, col->geoms[i]) )
{
return LW_FALSE;
}
}
return LW_TRUE;
}
/* Don't get here */
lwerror("lwgeom_covers_lwgeom_sphere: reached end of function without resolution");
return LW_FALSE;
}
/**
* Given a polygon (lon/lat decimal degrees) and point (lon/lat decimal degrees) and
* a guaranteed outside point (lon/lat decimal degrees) (calculate with gbox_pt_outside())
* return LW_TRUE if point is inside or on edge of polygon.
*/
int lwpoly_covers_point2d(const LWPOLY *poly, const POINT2D *pt_to_test)
{
uint32_t i;
int in_hole_count = 0;
POINT3D p;
GEOGRAPHIC_POINT gpt_to_test;
POINT2D pt_outside;
GBOX gbox;
#if POSTGIS_DEBUG_LEVEL >= 4
char *geom_ewkt;
#endif
gbox.flags = 0;
/* Nulls and empties don't contain anything! */
if ( ! poly || lwgeom_is_empty((LWGEOM*)poly) )
{
LWDEBUG(4,"returning false, geometry is empty or null");
return LW_FALSE;
}
/* Make sure we have boxes */
if ( poly->bbox )
gbox = *(poly->bbox);
else
lwgeom_calculate_gbox_geodetic((LWGEOM*)poly, &gbox);
/* Point not in box? Done! */
geographic_point_init(pt_to_test->x, pt_to_test->y, &gpt_to_test);
geog2cart(&gpt_to_test, &p);
if ( ! gbox_contains_point3d(&gbox, &p) )
{
LWDEBUG(4, "the point is not in the box!");
return LW_FALSE;
}
/* Calculate our outside point from the gbox */
lwpoly_pt_outside(poly, &pt_outside);
LWDEBUGF(4, "pt_outside POINT(%.18g %.18g)", pt_outside.x, pt_outside.y);
LWDEBUGF(4, "pt_to_test POINT(%.18g %.18g)", pt_to_test->x, pt_to_test->y);
#if POSTGIS_DEBUG_LEVEL >= 4
geom_ewkt = lwgeom_to_ewkt((LWGEOM*)poly);
LWDEBUGF(4, "polygon %s", geom_ewkt);
lwfree(geom_ewkt);
geom_ewkt = gbox_to_string(&gbox);
LWDEBUGF(4, "gbox %s", geom_ewkt);
lwfree(geom_ewkt);
#endif
/* Not in outer ring? We're done! */
if ( ! ptarray_contains_point_sphere(poly->rings[0], &pt_outside, pt_to_test) )
{
LWDEBUG(4,"returning false, point is outside ring");
return LW_FALSE;
}
LWDEBUGF(4, "testing %d rings", poly->nrings);
/* But maybe point is in a hole... */
for ( i = 1; i < poly->nrings; i++ )
{
LWDEBUGF(4, "ring test loop %d", i);
/* Count up hole containment. Odd => outside boundary. */
if ( ptarray_contains_point_sphere(poly->rings[i], &pt_outside, pt_to_test) )
in_hole_count++;
}
LWDEBUGF(4, "in_hole_count == %d", in_hole_count);
if ( in_hole_count % 2 )
{
LWDEBUG(4,"returning false, inner ring containment count is odd");
return LW_FALSE;
}
LWDEBUG(4,"returning true, inner ring containment count is even");
return LW_TRUE;
}
/**
* Given a polygon1 check if all points of polygon2 are inside polygon1 and no
* intersections of the polygon edges occur.
* return LW_TRUE if polygon is inside or on edge of polygon.
*/
int lwpoly_covers_lwpoly(const LWPOLY *poly1, const LWPOLY *poly2)
{
uint32_t i;
/* Nulls and empties don't contain anything! */
if ( ! poly1 || lwgeom_is_empty((LWGEOM*)poly1) )
{
LWDEBUG(4,"returning false, geometry1 is empty or null");
return LW_FALSE;
}
/* Nulls and empties don't contain anything! */
if ( ! poly2 || lwgeom_is_empty((LWGEOM*)poly2) )
{
LWDEBUG(4,"returning false, geometry2 is empty or null");
return LW_FALSE;
}
/* check if all vertices of poly2 are inside poly1 */
for (i = 0; i < poly2->nrings; i++)
{
/* every other ring is a hole, check if point is inside the actual polygon */
if ( i % 2 == 0)
{
if (LW_FALSE == lwpoly_covers_pointarray(poly1, poly2->rings[i]))
{
LWDEBUG(4,"returning false, geometry2 has point outside of geometry1");
return LW_FALSE;
}
}
else
{
if (LW_TRUE == lwpoly_covers_pointarray(poly1, poly2->rings[i]))
{
LWDEBUG(4,"returning false, geometry2 has point inside a hole of geometry1");
return LW_FALSE;
}
}
}
/* check for any edge intersections, so nothing is partially outside of poly1 */
for (i = 0; i < poly2->nrings; i++)
{
if (LW_TRUE == lwpoly_intersects_line(poly1, poly2->rings[i]))
{
LWDEBUG(4,"returning false, geometry2 is partially outside of geometry1");
return LW_FALSE;
}
}
/* no abort condition found, so the poly2 should be completly inside poly1 */
return LW_TRUE;
}
/**
*
*/
int lwpoly_covers_lwline(const LWPOLY *poly, const LWLINE *line)
{
/* Nulls and empties don't contain anything! */
if ( ! poly || lwgeom_is_empty((LWGEOM*)poly) )
{
LWDEBUG(4,"returning false, geometry1 is empty or null");
return LW_FALSE;
}
/* Nulls and empties don't contain anything! */
if ( ! line || lwgeom_is_empty((LWGEOM*)line) )
{
LWDEBUG(4,"returning false, geometry2 is empty or null");
return LW_FALSE;
}
if (LW_FALSE == lwpoly_covers_pointarray(poly, line->points))
{
LWDEBUG(4,"returning false, geometry2 has point outside of geometry1");
return LW_FALSE;
}
/* check for any edge intersections, so nothing is partially outside of poly1 */
if (LW_TRUE == lwpoly_intersects_line(poly, line->points))
{
LWDEBUG(4,"returning false, geometry2 is partially outside of geometry1");
return LW_FALSE;
}
/* no abort condition found, so the poly2 should be completely inside poly1 */
return LW_TRUE;
}
/**
* return LW_TRUE if all points are inside the polygon
*/
int lwpoly_covers_pointarray(const LWPOLY* lwpoly, const POINTARRAY* pta)
{
uint32_t i;
for (i = 0; i < pta->npoints; i++) {
const POINT2D* pt_to_test = getPoint2d_cp(pta, i);
if ( LW_FALSE == lwpoly_covers_point2d(lwpoly, pt_to_test) ) {
LWDEBUG(4,"returning false, geometry2 has point outside of geometry1");
return LW_FALSE;
}
}
return LW_TRUE;
}
/**
* Checks if any edges of lwpoly intersect with the line formed by the pointarray
* return LW_TRUE if any intersection between the given polygon and the line
*/
int lwpoly_intersects_line(const LWPOLY* lwpoly, const POINTARRAY* line)
{
uint32_t i, j, k;
POINT3D pa1, pa2, pb1, pb2;
for (i = 0; i < lwpoly->nrings; i++)
{
for (j = 0; j < lwpoly->rings[i]->npoints - 1; j++)
{
const POINT2D* a1 = getPoint2d_cp(lwpoly->rings[i], j);
const POINT2D* a2 = getPoint2d_cp(lwpoly->rings[i], j+1);
/* Set up our stab line */
ll2cart(a1, &pa1);
ll2cart(a2, &pa2);
for (k = 0; k < line->npoints - 1; k++)
{
const POINT2D* b1 = getPoint2d_cp(line, k);
const POINT2D* b2 = getPoint2d_cp(line, k+1);
/* Set up our stab line */
ll2cart(b1, &pb1);
ll2cart(b2, &pb2);
int inter = edge_intersects(&pa1, &pa2, &pb1, &pb2);
/* ignore same edges */
if (inter & PIR_INTERSECTS
&& !(inter & PIR_B_TOUCH_RIGHT || inter & PIR_COLINEAR) )
{
return LW_TRUE;
}
}
}
}
return LW_FALSE;
}
/**
* return LW_TRUE if any of the line segments covers the point
*/
int lwline_covers_lwpoint(const LWLINE* lwline, const LWPOINT* lwpoint)
{
uint32_t i;
GEOGRAPHIC_POINT p;
GEOGRAPHIC_EDGE e;
for ( i = 0; i < lwline->points->npoints - 1; i++)
{
const POINT2D* a1 = getPoint2d_cp(lwline->points, i);
const POINT2D* a2 = getPoint2d_cp(lwline->points, i+1);
geographic_point_init(a1->x, a1->y, &(e.start));
geographic_point_init(a2->x, a2->y, &(e.end));
geographic_point_init(lwpoint_get_x(lwpoint), lwpoint_get_y(lwpoint), &p);
if ( edge_contains_point(&e, &p) ) {
return LW_TRUE;
}
}
return LW_FALSE;
}
/**
* Check if first and last point of line2 are covered by line1 and then each
* point in between has to be one line1 in the exact same order
* return LW_TRUE if all edge points of line2 are on line1
*/
int lwline_covers_lwline(const LWLINE* lwline1, const LWLINE* lwline2)
{
uint32_t i, j;
GEOGRAPHIC_EDGE e1, e2;
GEOGRAPHIC_POINT p1, p2;
int start = LW_FALSE;
int changed = LW_FALSE;
/* first point on line */
if ( ! lwline_covers_lwpoint(lwline1, lwline_get_lwpoint(lwline2, 0)))
{
LWDEBUG(4,"returning false, first point of line2 is not covered by line1");
return LW_FALSE;
}
/* last point on line */
if ( ! lwline_covers_lwpoint(lwline1, lwline_get_lwpoint(lwline2, lwline2->points->npoints - 1)))
{
LWDEBUG(4,"returning false, last point of line2 is not covered by line1");
return LW_FALSE;
}
j = 0;
i = 0;
while (i < lwline1->points->npoints - 1 && j < lwline2->points->npoints - 1)
{
changed = LW_FALSE;
const POINT2D* a1 = getPoint2d_cp(lwline1->points, i);
const POINT2D* a2 = getPoint2d_cp(lwline1->points, i+1);
const POINT2D* b1 = getPoint2d_cp(lwline2->points, j);
const POINT2D* b2 = getPoint2d_cp(lwline2->points, j+1);
geographic_point_init(a1->x, a1->y, &(e1.start));
geographic_point_init(a2->x, a2->y, &(e1.end));
geographic_point_init(b1->x, b1->y, &p2);
/* we already know, that the last point is on line1, so we're done */
if ( j == lwline2->points->npoints - 1)
{
return LW_TRUE;
}
else if (start == LW_TRUE)
{
/* point is on current line1 edge, check next point in line2 */
if ( edge_contains_point(&e1, &p2)) {
j++;
changed = LW_TRUE;
}
geographic_point_init(a1->x, a1->y, &(e2.start));
geographic_point_init(a2->x, b2->y, &(e2.end));
geographic_point_init(a1->x, a1->y, &p1);
/* point is on current line2 edge, check next point in line1 */
if ( edge_contains_point(&e2, &p1)) {
i++;
changed = LW_TRUE;
}
/* no edge progressed -> point left one line */
if ( changed == LW_FALSE )
{
LWDEBUG(4,"returning false, found point not covered by both lines");
return LW_FALSE;
}
else
{
continue;
}
}
/* find first edge to cover line2 */
if (edge_contains_point(&e1, &p2))
{
start = LW_TRUE;
}
/* next line1 edge */
i++;
}
/* no uncovered point found */
return LW_TRUE;
}
int ptarray_calculate_gbox_geodetic(const POINTARRAY *pa, GBOX *gbox)
{
uint32_t i;
int first = LW_TRUE;
const POINT2D *p;
POINT3D A1, A2;
GBOX edge_gbox;
assert(gbox);
assert(pa);
gbox_init(&edge_gbox);
edge_gbox.flags = gbox->flags;
if ( pa->npoints == 0 ) return LW_FAILURE;
if ( pa->npoints == 1 )
{
p = getPoint2d_cp(pa, 0);
ll2cart(p, &A1);
gbox->xmin = gbox->xmax = A1.x;
gbox->ymin = gbox->ymax = A1.y;
gbox->zmin = gbox->zmax = A1.z;
return LW_SUCCESS;
}
p = getPoint2d_cp(pa, 0);
ll2cart(p, &A1);
for ( i = 1; i < pa->npoints; i++ )
{
p = getPoint2d_cp(pa, i);
ll2cart(p, &A2);
edge_calculate_gbox(&A1, &A2, &edge_gbox);
/* Initialize the box */
if ( first )
{
gbox_duplicate(&edge_gbox, gbox);
first = LW_FALSE;
}
/* Expand the box where necessary */
else
{
gbox_merge(&edge_gbox, gbox);
}
A1 = A2;
}
return LW_SUCCESS;
}
static int lwpoint_calculate_gbox_geodetic(const LWPOINT *point, GBOX *gbox)
{
assert(point);
return ptarray_calculate_gbox_geodetic(point->point, gbox);
}
static int lwline_calculate_gbox_geodetic(const LWLINE *line, GBOX *gbox)
{
assert(line);
return ptarray_calculate_gbox_geodetic(line->points, gbox);
}
static int lwpolygon_calculate_gbox_geodetic(const LWPOLY *poly, GBOX *gbox)
{
GBOX ringbox;
uint32_t i;
int first = LW_TRUE;
assert(poly);
if ( poly->nrings == 0 )
return LW_FAILURE;
ringbox.flags = gbox->flags;
for ( i = 0; i < poly->nrings; i++ )
{
if ( ptarray_calculate_gbox_geodetic(poly->rings[i], &ringbox) == LW_FAILURE )
return LW_FAILURE;
if ( first )
{
gbox_duplicate(&ringbox, gbox);
first = LW_FALSE;
}
else
{
gbox_merge(&ringbox, gbox);
}
}
/* If the box wraps a poly, push that axis to the absolute min/max as appropriate */
gbox_check_poles(gbox);
return LW_SUCCESS;
}
static int lwtriangle_calculate_gbox_geodetic(const LWTRIANGLE *triangle, GBOX *gbox)
{
assert(triangle);
return ptarray_calculate_gbox_geodetic(triangle->points, gbox);
}
static int lwcollection_calculate_gbox_geodetic(const LWCOLLECTION *coll, GBOX *gbox)
{
GBOX subbox = {0};
uint32_t i;
int result = LW_FAILURE;
int first = LW_TRUE;
assert(coll);
if ( coll->ngeoms == 0 )
return LW_FAILURE;
subbox.flags = gbox->flags;
for ( i = 0; i < coll->ngeoms; i++ )
{
if ( lwgeom_calculate_gbox_geodetic((LWGEOM*)(coll->geoms[i]), &subbox) == LW_SUCCESS )
{
/* Keep a copy of the sub-bounding box for later */
if ( coll->geoms[i]->bbox )
lwfree(coll->geoms[i]->bbox);
coll->geoms[i]->bbox = gbox_copy(&subbox);
if ( first )
{
gbox_duplicate(&subbox, gbox);
first = LW_FALSE;
}
else
{
gbox_merge(&subbox, gbox);
}
result = LW_SUCCESS;
}
}
return result;
}
int lwgeom_calculate_gbox_geodetic(const LWGEOM *geom, GBOX *gbox)
{
int result = LW_FAILURE;
LWDEBUGF(4, "got type %d", geom->type);
/* Add a geodetic flag to the incoming gbox */
gbox->flags = lwflags(FLAGS_GET_Z(geom->flags),FLAGS_GET_M(geom->flags),1);
switch (geom->type)
{
case POINTTYPE:
result = lwpoint_calculate_gbox_geodetic((LWPOINT*)geom, gbox);
break;
case LINETYPE:
result = lwline_calculate_gbox_geodetic((LWLINE *)geom, gbox);
break;
case POLYGONTYPE:
result = lwpolygon_calculate_gbox_geodetic((LWPOLY *)geom, gbox);
break;
case TRIANGLETYPE:
result = lwtriangle_calculate_gbox_geodetic((LWTRIANGLE *)geom, gbox);
break;
case MULTIPOINTTYPE:
case MULTILINETYPE:
case MULTIPOLYGONTYPE:
case POLYHEDRALSURFACETYPE:
case TINTYPE:
case COLLECTIONTYPE:
result = lwcollection_calculate_gbox_geodetic((LWCOLLECTION *)geom, gbox);
break;
default:
lwerror("lwgeom_calculate_gbox_geodetic: unsupported input geometry type: %d - %s",
geom->type, lwtype_name(geom->type));
break;
}
return result;
}
static int ptarray_check_geodetic(const POINTARRAY *pa)
{
uint32_t t;
POINT2D pt;
assert(pa);
for (t=0; t<pa->npoints; t++)
{
getPoint2d_p(pa, t, &pt);
/* printf( "%d (%g, %g)\n", t, pt.x, pt.y); */
if ( pt.x < -180.0 || pt.y < -90.0 || pt.x > 180.0 || pt.y > 90.0 )
return LW_FALSE;
}
return LW_TRUE;
}
static int lwpoint_check_geodetic(const LWPOINT *point)
{
assert(point);
return ptarray_check_geodetic(point->point);
}
static int lwline_check_geodetic(const LWLINE *line)
{
assert(line);
return ptarray_check_geodetic(line->points);
}
static int lwpoly_check_geodetic(const LWPOLY *poly)
{
uint32_t i = 0;
assert(poly);
for ( i = 0; i < poly->nrings; i++ )
{
if ( ptarray_check_geodetic(poly->rings[i]) == LW_FALSE )
return LW_FALSE;
}
return LW_TRUE;
}
static int lwtriangle_check_geodetic(const LWTRIANGLE *triangle)
{
assert(triangle);
return ptarray_check_geodetic(triangle->points);
}
static int lwcollection_check_geodetic(const LWCOLLECTION *col)
{
uint32_t i = 0;
assert(col);
for ( i = 0; i < col->ngeoms; i++ )
{
if ( lwgeom_check_geodetic(col->geoms[i]) == LW_FALSE )
return LW_FALSE;
}
return LW_TRUE;
}
int lwgeom_check_geodetic(const LWGEOM *geom)
{
if ( lwgeom_is_empty(geom) )
return LW_TRUE;
switch (geom->type)
{
case POINTTYPE:
return lwpoint_check_geodetic((LWPOINT *)geom);
case LINETYPE:
return lwline_check_geodetic((LWLINE *)geom);
case POLYGONTYPE:
return lwpoly_check_geodetic((LWPOLY *)geom);
case TRIANGLETYPE:
return lwtriangle_check_geodetic((LWTRIANGLE *)geom);
case MULTIPOINTTYPE:
case MULTILINETYPE:
case MULTIPOLYGONTYPE:
case POLYHEDRALSURFACETYPE:
case TINTYPE:
case COLLECTIONTYPE:
return lwcollection_check_geodetic((LWCOLLECTION *)geom);
default:
lwerror("lwgeom_check_geodetic: unsupported input geometry type: %d - %s",
geom->type, lwtype_name(geom->type));
}
return LW_FALSE;
}
static int ptarray_force_geodetic(POINTARRAY *pa)
{
uint32_t t;
int changed = LW_FALSE;
POINT4D pt;
assert(pa);
for ( t=0; t < pa->npoints; t++ )
{
getPoint4d_p(pa, t, &pt);
if ( pt.x < -180.0 || pt.x > 180.0 || pt.y < -90.0 || pt.y > 90.0 )
{
pt.x = longitude_degrees_normalize(pt.x);
pt.y = latitude_degrees_normalize(pt.y);
ptarray_set_point4d(pa, t, &pt);
changed = LW_TRUE;
}
}
return changed;
}
static int lwpoint_force_geodetic(LWPOINT *point)
{
assert(point);
return ptarray_force_geodetic(point->point);
}
static int lwline_force_geodetic(LWLINE *line)
{
assert(line);
return ptarray_force_geodetic(line->points);
}
static int lwpoly_force_geodetic(LWPOLY *poly)
{
uint32_t i = 0;
int changed = LW_FALSE;
assert(poly);
for ( i = 0; i < poly->nrings; i++ )
{
if ( ptarray_force_geodetic(poly->rings[i]) == LW_TRUE )
changed = LW_TRUE;
}
return changed;
}
static int lwcollection_force_geodetic(LWCOLLECTION *col)
{
uint32_t i = 0;
int changed = LW_FALSE;
assert(col);
for ( i = 0; i < col->ngeoms; i++ )
{
if ( lwgeom_force_geodetic(col->geoms[i]) == LW_TRUE )
changed = LW_TRUE;
}
return changed;
}
int lwgeom_force_geodetic(LWGEOM *geom)
{
switch ( lwgeom_get_type(geom) )
{
case POINTTYPE:
return lwpoint_force_geodetic((LWPOINT *)geom);
case LINETYPE:
return lwline_force_geodetic((LWLINE *)geom);
case POLYGONTYPE:
return lwpoly_force_geodetic((LWPOLY *)geom);
case MULTIPOINTTYPE:
case MULTILINETYPE:
case MULTIPOLYGONTYPE:
case COLLECTIONTYPE:
return lwcollection_force_geodetic((LWCOLLECTION *)geom);
default:
lwerror("unsupported input geometry type: %d", lwgeom_get_type(geom));
}
return LW_FALSE;
}
double ptarray_length_spheroid(const POINTARRAY *pa, const SPHEROID *s)
{
GEOGRAPHIC_POINT a, b;
double za = 0.0, zb = 0.0;
POINT4D p;
uint32_t i;
int hasz = LW_FALSE;
double length = 0.0;
double seglength = 0.0;
/* Return zero on non-sensical inputs */
if ( ! pa || pa->npoints < 2 )
return 0.0;
/* See if we have a third dimension */
hasz = FLAGS_GET_Z(pa->flags);
/* Initialize first point */
getPoint4d_p(pa, 0, &p);
geographic_point_init(p.x, p.y, &a);
if ( hasz )
za = p.z;
/* Loop and sum the length for each segment */
for ( i = 1; i < pa->npoints; i++ )
{
seglength = 0.0;
getPoint4d_p(pa, i, &p);
geographic_point_init(p.x, p.y, &b);
if ( hasz )
zb = p.z;
/* Special sphere case */
if ( s->a == s->b )
seglength = s->radius * sphere_distance(&a, &b);
/* Spheroid case */
else
seglength = spheroid_distance(&a, &b, s);
/* Add in the vertical displacement if we're in 3D */
if ( hasz )
seglength = sqrt( (zb-za)*(zb-za) + seglength*seglength );
/* Add this segment length to the total */
length += seglength;
/* B gets incremented in the next loop, so we save the value here */
a = b;
za = zb;
}
return length;
}
double lwgeom_length_spheroid(const LWGEOM *geom, const SPHEROID *s)
{
int type;
uint32_t i = 0;
double length = 0.0;
assert(geom);
/* No area in nothing */
if ( lwgeom_is_empty(geom) )
return 0.0;
type = geom->type;
if ( type == POINTTYPE || type == MULTIPOINTTYPE )
return 0.0;
if ( type == LINETYPE )
return ptarray_length_spheroid(((LWLINE*)geom)->points, s);
if ( type == POLYGONTYPE )
{
LWPOLY *poly = (LWPOLY*)geom;
for ( i = 0; i < poly->nrings; i++ )
{
length += ptarray_length_spheroid(poly->rings[i], s);
}
return length;
}
if ( type == TRIANGLETYPE )
return ptarray_length_spheroid(((LWTRIANGLE*)geom)->points, s);
if ( lwtype_is_collection( type ) )
{
LWCOLLECTION *col = (LWCOLLECTION*)geom;
for ( i = 0; i < col->ngeoms; i++ )
{
length += lwgeom_length_spheroid(col->geoms[i], s);
}
return length;
}
lwerror("unsupported type passed to lwgeom_length_sphere");
return 0.0;
}
/**
* When features are snapped or sometimes they are just this way, they are very close to
* the geodetic bounds but slightly over. This routine nudges those points, and only
* those points, back over to the bounds.
* http://trac.osgeo.org/postgis/ticket/1292
*/
static int
ptarray_nudge_geodetic(POINTARRAY *pa)
{
uint32_t i;
POINT4D p;
int altered = LW_FALSE;
int rv = LW_FALSE;
static double tolerance = 1e-10;
if ( ! pa )
lwerror("ptarray_nudge_geodetic called with null input");
for(i = 0; i < pa->npoints; i++ )
{
getPoint4d_p(pa, i, &p);
if ( p.x < -180.0 && (-180.0 - p.x <= tolerance) )
{
p.x = -180.0;
altered = LW_TRUE;
}
if ( p.x > 180.0 && (p.x - 180.0 <= tolerance) )
{
p.x = 180.0;
altered = LW_TRUE;
}
if ( p.y < -90.0 && (-90.0 - p.y <= tolerance) )
{
p.y = -90.0;
altered = LW_TRUE;
}
if ( p.y > 90.0 && (p.y - 90.0 <= tolerance) )
{
p.y = 90.0;
altered = LW_TRUE;
}
if ( altered == LW_TRUE )
{
ptarray_set_point4d(pa, i, &p);
altered = LW_FALSE;
rv = LW_TRUE;
}
}
return rv;
}
/**
* When features are snapped or sometimes they are just this way, they are very close to
* the geodetic bounds but slightly over. This routine nudges those points, and only
* those points, back over to the bounds.
* http://trac.osgeo.org/postgis/ticket/1292
*/
int
lwgeom_nudge_geodetic(LWGEOM *geom)
{
int type;
uint32_t i = 0;
int rv = LW_FALSE;
assert(geom);
/* No points in nothing */
if ( lwgeom_is_empty(geom) )
return LW_FALSE;
type = geom->type;
if ( type == POINTTYPE )
return ptarray_nudge_geodetic(((LWPOINT*)geom)->point);
if ( type == LINETYPE )
return ptarray_nudge_geodetic(((LWLINE*)geom)->points);
if ( type == POLYGONTYPE )
{
LWPOLY *poly = (LWPOLY*)geom;
for ( i = 0; i < poly->nrings; i++ )
{
int n = ptarray_nudge_geodetic(poly->rings[i]);
rv = (rv == LW_TRUE ? rv : n);
}
return rv;
}
if ( type == TRIANGLETYPE )
return ptarray_nudge_geodetic(((LWTRIANGLE*)geom)->points);
if ( lwtype_is_collection( type ) )
{
LWCOLLECTION *col = (LWCOLLECTION*)geom;
for ( i = 0; i < col->ngeoms; i++ )
{
int n = lwgeom_nudge_geodetic(col->geoms[i]);
rv = (rv == LW_TRUE ? rv : n);
}
return rv;
}
lwerror("unsupported type (%s) passed to lwgeom_nudge_geodetic", lwtype_name(type));
return rv;
}
/**
* Utility function for checking if P is within the cone defined by A1/A2.
*/
static int
point_in_cone(const POINT3D *A1, const POINT3D *A2, const POINT3D *P)
{
POINT3D AC; /* Center point of A1/A2 */
double min_similarity, similarity;
/* Boundary case */
if (point3d_equals(A1, P) || point3d_equals(A2, P))
return LW_TRUE;
/* The normalized sum bisects the angle between start and end. */
vector_sum(A1, A2, &AC);
normalize(&AC);
/* The projection of start onto the center defines the minimum similarity */
min_similarity = dot_product(A1, &AC);
/* If the edge is sufficiently curved, use the dot product test */
if (fabs(1.0 - min_similarity) > 1e-10)
{
/* The projection of candidate p onto the center */
similarity = dot_product(P, &AC);
/* If the projection of the candidate is larger than */
/* the projection of the start point, the candidate */
/* must be closer to the center than the start, so */
/* therefor inside the cone */
if (similarity > min_similarity)
{
return LW_TRUE;
}
else
{
return LW_FALSE;
}
}
else
{
/* Where the edge is very narrow, the dot product test */
/* fails, but we can use the almost-planar nature of the */
/* problem space then to test if the vector from the */
/* candidate to the start point in a different direction */
/* to the vector from candidate to end point */
/* If so, then candidate is between start and end */
POINT3D PA1, PA2;
vector_difference(P, A1, &PA1);
vector_difference(P, A2, &PA2);
normalize(&PA1);
normalize(&PA2);
if (dot_product(&PA1, &PA2) < 0.0)
{
return LW_TRUE;
}
else
{
return LW_FALSE;
}
}
return LW_FALSE;
}
/**
* Utility function for edge_intersects(), signum with a tolerance
* in determining if the value is zero.
*/
static int
dot_product_side(const POINT3D *p, const POINT3D *q)
{
double dp = dot_product(p, q);
if ( FP_IS_ZERO(dp) )
return 0;
return dp < 0.0 ? -1 : 1;
}
/**
* Returns non-zero if edges A and B interact. The type of interaction is given in the
* return value with the bitmask elements defined above.
*/
uint32_t
edge_intersects(const POINT3D *A1, const POINT3D *A2, const POINT3D *B1, const POINT3D *B2)
{
POINT3D AN, BN, VN; /* Normals to plane A and plane B */
double ab_dot;
int a1_side, a2_side, b1_side, b2_side;
int rv = PIR_NO_INTERACT;
/* Normals to the A-plane and B-plane */
unit_normal(A1, A2, &AN);
unit_normal(B1, B2, &BN);
/* Are A-plane and B-plane basically the same? */
ab_dot = dot_product(&AN, &BN);
if ( FP_EQUALS(fabs(ab_dot), 1.0) )
{
/* Co-linear case */
if ( point_in_cone(A1, A2, B1) || point_in_cone(A1, A2, B2) ||
point_in_cone(B1, B2, A1) || point_in_cone(B1, B2, A2) )
{
rv |= PIR_INTERSECTS;
rv |= PIR_COLINEAR;
}
return rv;
}
/* What side of plane-A and plane-B do the end points */
/* of A and B fall? */
a1_side = dot_product_side(&BN, A1);
a2_side = dot_product_side(&BN, A2);
b1_side = dot_product_side(&AN, B1);
b2_side = dot_product_side(&AN, B2);
/* Both ends of A on the same side of plane B. */
if ( a1_side == a2_side && a1_side != 0 )
{
/* No intersection. */
return PIR_NO_INTERACT;
}
/* Both ends of B on the same side of plane A. */
if ( b1_side == b2_side && b1_side != 0 )
{
/* No intersection. */
return PIR_NO_INTERACT;
}
/* A straddles B and B straddles A, so... */
if ( a1_side != a2_side && (a1_side + a2_side) == 0 &&
b1_side != b2_side && (b1_side + b2_side) == 0 )
{
/* Have to check if intersection point is inside both arcs */
unit_normal(&AN, &BN, &VN);
if ( point_in_cone(A1, A2, &VN) && point_in_cone(B1, B2, &VN) )
{
return PIR_INTERSECTS;
}
/* Have to check if intersection point is inside both arcs */
vector_scale(&VN, -1);
if ( point_in_cone(A1, A2, &VN) && point_in_cone(B1, B2, &VN) )
{
return PIR_INTERSECTS;
}
return PIR_NO_INTERACT;
}
/* The rest are all intersects variants... */
rv |= PIR_INTERSECTS;
/* A touches B */
if ( a1_side == 0 )
{
/* Touches at A1, A2 is on what side? */
rv |= (a2_side < 0 ? PIR_A_TOUCH_RIGHT : PIR_A_TOUCH_LEFT);
}
else if ( a2_side == 0 )
{
/* Touches at A2, A1 is on what side? */
rv |= (a1_side < 0 ? PIR_A_TOUCH_RIGHT : PIR_A_TOUCH_LEFT);
}
/* B touches A */
if ( b1_side == 0 )
{
/* Touches at B1, B2 is on what side? */
rv |= (b2_side < 0 ? PIR_B_TOUCH_RIGHT : PIR_B_TOUCH_LEFT);
}
else if ( b2_side == 0 )
{
/* Touches at B2, B1 is on what side? */
rv |= (b1_side < 0 ? PIR_B_TOUCH_RIGHT : PIR_B_TOUCH_LEFT);
}
return rv;
}
/**
* This routine returns LW_TRUE if the stabline joining the pt_outside and pt_to_test
* crosses the ring an odd number of times, or if the pt_to_test is on the ring boundary itself,
* returning LW_FALSE otherwise.
* The pt_outside *must* be guaranteed to be outside the ring (use the geography_pt_outside() function
* to derive one in postgis, or the gbox_pt_outside() function if you don't mind burning CPU cycles
* building a gbox first).
*/
int ptarray_contains_point_sphere(const POINTARRAY *pa, const POINT2D *pt_outside, const POINT2D *pt_to_test)
{
POINT3D S1, S2; /* Stab line end points */
POINT3D E1, E2; /* Edge end points (3-space) */
POINT2D p; /* Edge end points (lon/lat) */
uint32_t count = 0, i, inter;
/* Null input, not enough points for a ring? You ain't closed! */
if ( ! pa || pa->npoints < 4 )
return LW_FALSE;
/* Set up our stab line */
ll2cart(pt_to_test, &S1);
ll2cart(pt_outside, &S2);
/* Initialize first point */
getPoint2d_p(pa, 0, &p);
ll2cart(&p, &E1);
/* Walk every edge and see if the stab line hits it */
for ( i = 1; i < pa->npoints; i++ )
{
LWDEBUGF(4, "testing edge (%d)", i);
LWDEBUGF(4, " start point == POINT(%.12g %.12g)", p.x, p.y);
/* Read next point. */
getPoint2d_p(pa, i, &p);
ll2cart(&p, &E2);
/* Skip over too-short edges. */
if ( point3d_equals(&E1, &E2) )
{
continue;
}
/* Our test point is on an edge end! Point is "in ring" by our definition */
if ( point3d_equals(&S1, &E1) )
{
return LW_TRUE;
}
/* Calculate relationship between stab line and edge */
inter = edge_intersects(&S1, &S2, &E1, &E2);
/* We have some kind of interaction... */
if ( inter & PIR_INTERSECTS )
{
/* If the stabline is touching the edge, that implies the test point */
/* is on the edge, so we're done, the point is in (on) the ring. */
if ( (inter & PIR_A_TOUCH_RIGHT) || (inter & PIR_A_TOUCH_LEFT) )
{
return LW_TRUE;
}
/* It's a touching interaction, disregard all the left-side ones. */
/* It's a co-linear intersection, ignore those. */
if ( inter & PIR_B_TOUCH_RIGHT || inter & PIR_COLINEAR )
{
/* Do nothing, to avoid double counts. */
LWDEBUGF(4," edge (%d) crossed, disregarding to avoid double count", i, count);
}
else
{
/* Increment crossingn count. */
count++;
LWDEBUGF(4," edge (%d) crossed, count == %d", i, count);
}
}
else
{
LWDEBUGF(4," edge (%d) did not cross", i);
}
/* Increment to next edge */
E1 = E2;
}
LWDEBUGF(4,"final count == %d", count);
/* An odd number of crossings implies containment! */
if ( count % 2 )
{
return LW_TRUE;
}
return LW_FALSE;
}
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