double
circ_tree_distance_tree(const CIRC_NODE* n1, const CIRC_NODE* n2, const SPHEROID* spheroid, double threshold)
{
double min_dist = MAXFLOAT;
double max_dist = MAXFLOAT;
GEOGRAPHIC_POINT closest1, closest2;
double distance1, distance2;
double threshold_radians = threshold / spheroid->radius;
distance1 = circ_tree_distance_tree_internal(n1, n2, threshold_radians, &min_dist, &max_dist, &closest1, &closest2);
distance2 = spheroid_distance(&closest1, &closest2, spheroid);
return distance2;
}
static double ptarray_area_spheroid(const POINTARRAY *pa, const SPHEROID *spheroid)
{
GEOGRAPHIC_POINT a, b;
POINT2D p;
int i;
double area = 0.0;
GBOX gbox2d;
int in_south = LW_FALSE;
double delta_lon_tolerance;
double latitude_min;
gbox2d.flags = gflags(0, 0, 0);
/* Return zero on non-sensical inputs */
if ( ! pa || pa->npoints < 4 )
return 0.0;
/* Get the raw min/max values for the latitudes */
ptarray_calculate_gbox(pa, &gbox2d);
if ( signum(gbox2d.ymin) != signum(gbox2d.ymax) )
lwerror("ptarray_area_spheroid: cannot handle ptarray that crosses equator");
/* Geodetic bbox < 0.0 implies geometry is entirely in southern hemisphere */
if ( gbox2d.ymax < 0.0 )
in_south = LW_TRUE;
LWDEBUGF(4, "gbox2d.ymax %.12g", gbox2d.ymax);
/* Tolerance for strip area calculation */
if ( in_south )
{
delta_lon_tolerance = (90.0 / (fabs(gbox2d.ymin) / 8.0) - 2.0) / 10000.0;
latitude_min = deg2rad(fabs(gbox2d.ymax));
}
else
{
delta_lon_tolerance = (90.0 / (fabs(gbox2d.ymax) / 8.0) - 2.0) / 10000.0;
latitude_min = deg2rad(gbox2d.ymin);
}
/* Initialize first point */
getPoint2d_p(pa, 0, &p);
geographic_point_init(p.x, p.y, &a);
for ( i = 1; i < pa->npoints; i++ )
{
GEOGRAPHIC_POINT a1, b1;
double strip_area = 0.0;
double delta_lon = 0.0;
LWDEBUGF(4, "edge #%d", i);
getPoint2d_p(pa, i, &p);
geographic_point_init(p.x, p.y, &b);
a1 = a;
b1 = b;
/* Flip into north if in south */
if ( in_south )
{
a1.lat = -1.0 * a1.lat;
b1.lat = -1.0 * b1.lat;
}
LWDEBUGF(4, "in_south %d", in_south);
LWDEBUGF(4, "crosses_dateline(a, b) %d", crosses_dateline(&a, &b) );
if ( crosses_dateline(&a, &b) )
{
double shift;
if ( a1.lon > 0.0 )
shift = (M_PI - a1.lon) + 0.088; /* About 5deg more */
else
shift = (M_PI - b1.lon) + 0.088; /* About 5deg more */
LWDEBUGF(4, "shift: %.8g", shift);
LWDEBUGF(4, "before shift a1(%.8g %.8g) b1(%.8g %.8g)", a1.lat, a1.lon, b1.lat, b1.lon);
point_shift(&a1, shift);
point_shift(&b1, shift);
LWDEBUGF(4, "after shift a1(%.8g %.8g) b1(%.8g %.8g)", a1.lat, a1.lon, b1.lat, b1.lon);
}
delta_lon = fabs(b1.lon - a1.lon);
LWDEBUGF(4, "a1(%.18g %.18g) b1(%.18g %.18g)", a1.lat, a1.lon, b1.lat, b1.lon);
LWDEBUGF(4, "delta_lon %.18g", delta_lon);
LWDEBUGF(4, "delta_lon_tolerance %.18g", delta_lon_tolerance);
if ( delta_lon > 0.0 )
{
if ( delta_lon < delta_lon_tolerance )
{
strip_area = spheroid_striparea(&a1, &b1, latitude_min, spheroid);
LWDEBUGF(4, "strip_area %.12g", strip_area);
area += strip_area;
}
else
{
GEOGRAPHIC_POINT p, q;
double step = floor(delta_lon / delta_lon_tolerance);
double distance = spheroid_distance(&a1, &b1, spheroid);
double pDistance = 0.0;
int j = 0;
LWDEBUGF(4, "step %.18g", step);
LWDEBUGF(4, "distance %.18g", distance);
step = distance / step;
LWDEBUGF(4, "step %.18g", step);
p = a1;
while (pDistance < (distance - step * 1.01))
{
double azimuth = spheroid_direction(&p, &b1, spheroid);
j++;
LWDEBUGF(4, " iteration %d", j);
LWDEBUGF(4, " azimuth %.12g", azimuth);
pDistance = pDistance + step;
LWDEBUGF(4, " pDistance %.12g", pDistance);
spheroid_project(&p, spheroid, step, azimuth, &q);
strip_area = spheroid_striparea(&p, &q, latitude_min, spheroid);
LWDEBUGF(4, " strip_area %.12g", strip_area);
area += strip_area;
LWDEBUGF(4, " area %.12g", area);
p.lat = q.lat;
p.lon = q.lon;
}
strip_area = spheroid_striparea(&p, &b1, latitude_min, spheroid);
area += strip_area;
}
}
/* B gets incremented in the next loop, so we save the value here */
a = b;
}
return fabs(area);
}
