/**
Function initializing closestpoint calculations.
*/
LWGEOM *
lw_dist2d_distancepoint(LWGEOM *lw1, LWGEOM *lw2,int srid,int mode)
{
double x,y;
DISTPTS thedl;
double initdistance = MAXFLOAT;
LWGEOM *result;
thedl.mode = mode;
thedl.distance= initdistance;
thedl.tolerance = 0;
LWDEBUG(2, "lw_dist2d_distancepoint is called");
if (!lw_dist2d_comp( lw1,lw2,&thedl))
{
/*should never get here. all cases ought to be error handled earlier*/
lwerror("Some unspecified error.");
result = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
}
if (thedl.distance == initdistance)
{
LWDEBUG(3, "didn't find geometries to measure between, returning null");
result = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
}
else
{
x=thedl.p1.x;
y=thedl.p1.y;
result = (LWGEOM *)lwpoint_make2d(srid, x, y);
}
return result;
}
Datum point_from_geohash(PG_FUNCTION_ARGS)
{
GBOX *box = NULL;
LWPOINT *point = NULL;
GSERIALIZED *result = NULL;
text *geohash_input = NULL;
char *geohash = NULL;
double lon, lat;
int precision = -1;
if (PG_ARGISNULL(0))
{
PG_RETURN_NULL();
}
if (!PG_ARGISNULL(1))
{
precision = PG_GETARG_INT32(1);
}
geohash_input = PG_GETARG_TEXT_P(0);
geohash = text2cstring(geohash_input);
box = parse_geohash(geohash, precision);
lon = box->xmin + (box->xmax - box->xmin) / 2;
lat = box->ymin + (box->ymax - box->ymin) / 2;
point = lwpoint_make2d(SRID_UNKNOWN, lon, lat);
result = geometry_serialize((LWGEOM *) point);
lwfree(box);
PG_RETURN_POINTER(result);
}
/**
Function initializing shortestline and longestline calculations.
*/
LWGEOM *
lw_dist2d_distanceline(LWGEOM *lw1, LWGEOM *lw2,int srid,int mode)
{
double x1,x2,y1,y2;
double initdistance = ( mode == DIST_MIN ? MAXFLOAT : -1.0);
DISTPTS thedl;
LWPOINT *lwpoints[2];
LWGEOM *result;
thedl.mode = mode;
thedl.distance = initdistance;
thedl.tolerance = 0.0;
LWDEBUG(2, "lw_dist2d_distanceline is called");
if (!lw_dist2d_comp( lw1,lw2,&thedl))
{
/*should never get here. all cases ought to be error handled earlier*/
lwerror("Some unspecified error.");
result = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
}
/*if thedl.distance is unchanged there where only empty geometries input*/
if (thedl.distance == initdistance)
{
LWDEBUG(3, "didn't find geometries to measure between, returning null");
result = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
}
else
{
x1=thedl.p1.x;
y1=thedl.p1.y;
x2=thedl.p2.x;
y2=thedl.p2.y;
lwpoints[0] = lwpoint_make2d(srid, x1, y1);
lwpoints[1] = lwpoint_make2d(srid, x2, y2);
result = (LWGEOM *)lwline_from_lwpointarray(srid, 2, lwpoints);
}
return result;
}
Datum BOX2D_to_LWGEOM(PG_FUNCTION_ARGS)
{
GBOX *box = (GBOX *)PG_GETARG_POINTER(0);
POINTARRAY *pa = ptarray_construct_empty(0, 0, 5);
POINT4D pt;
GSERIALIZED *result;
/*
* Alter BOX2D cast so that a valid geometry is always
* returned depending upon the size of the BOX2D. The
* code makes the following assumptions:
* - If the BOX2D is a single point then return a
* POINT geometry
* - If the BOX2D represents either a horizontal or
* vertical line, return a LINESTRING geometry
* - Otherwise return a POLYGON
*/
if ( (box->xmin == box->xmax) && (box->ymin == box->ymax) )
{
/* Construct and serialize point */
LWPOINT *point = lwpoint_make2d(SRID_UNKNOWN, box->xmin, box->ymin);
result = geometry_serialize(lwpoint_as_lwgeom(point));
lwpoint_free(point);
}
else if ( (box->xmin == box->xmax) || (box->ymin == box->ymax) )
{
LWLINE *line;
/* Assign coordinates to point array */
pt.x = box->xmin;
pt.y = box->ymin;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmax;
pt.y = box->ymax;
ptarray_append_point(pa, &pt, LW_TRUE);
/* Construct and serialize linestring */
line = lwline_construct(SRID_UNKNOWN, NULL, pa);
result = geometry_serialize(lwline_as_lwgeom(line));
lwline_free(line);
}
else
{
LWPOLY *poly;
POINTARRAY **ppa = lwalloc(sizeof(POINTARRAY*));
/* Assign coordinates to point array */
pt.x = box->xmin;
pt.y = box->ymin;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmin;
pt.y = box->ymax;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmax;
pt.y = box->ymax;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmax;
pt.y = box->ymin;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmin;
pt.y = box->ymin;
ptarray_append_point(pa, &pt, LW_TRUE);
/* Construct polygon */
ppa[0] = pa;
poly = lwpoly_construct(SRID_UNKNOWN, NULL, 1, ppa);
result = geometry_serialize(lwpoly_as_lwgeom(poly));
lwpoly_free(poly);
}
PG_RETURN_POINTER(result);
}
