long pointdist(Point *p1, Point *p2)
{
long result;
result = point_dt(p1, p2);
return(result);
}
Datum
pt_in_widget(PG_FUNCTION_ARGS)
{
Point *point = PG_GETARG_POINT_P(0);
WIDGET *widget = (WIDGET *) PG_GETARG_POINTER(1);
PG_RETURN_BOOL(point_dt(point, &widget->center) < widget->radius);
}
double path_ln(PATH *path)
{
double result;
int ct, i;
ct = path->npts - 1;
for (result = i = 0; i < ct; ++i)
result += point_dt(&path->p[i], &path->p[i+1]);
return(result);
}
double *path_length(PATH *path)
{
double *result;
int ct, i;
result = PALLOCTYPE(double);
ct = path->npts - 1;
for (i = 0; i < ct; ++i)
*result += point_dt(&path->p[i], &path->p[i+1]);
return(result);
}
Datum
regress_dist_ptpath(PG_FUNCTION_ARGS)
{
Point *pt = PG_GETARG_POINT_P(0);
PATH *path = PG_GETARG_PATH_P(1);
float8 result = 0.0; /* keep compiler quiet */
float8 tmp;
int i;
LSEG lseg;
switch (path->npts)
{
case 0:
PG_RETURN_NULL();
case 1:
result = point_dt(pt, &path->p[0]);
break;
default:
/*
* the distance from a point to a path is the smallest distance
* from the point to any of its constituent segments.
*/
Assert(path->npts > 1);
for (i = 0; i < path->npts - 1; ++i)
{
regress_lseg_construct(&lseg, &path->p[i], &path->p[i + 1]);
tmp = DatumGetFloat8(DirectFunctionCall2(dist_ps,
PointPGetDatum(pt),
LsegPGetDatum(&lseg)));
if (i == 0 || tmp < result)
result = tmp;
}
break;
}
PG_RETURN_FLOAT8(result);
}
