/*-------------------------------------------------------------------------

 *

 * spgproc.c

 *    Common supporting procedures for SP-GiST opclasses.

 *

 *

 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group

 * Portions Copyright (c) 1994, Regents of the University of California

 *

 * IDENTIFICATION

 *      src/backend/access/spgist/spgproc.c

 *

 *-------------------------------------------------------------------------

 */

#include "postgres.h"

#include <math.h>

#include "access/spgist_private.h"

#include "utils/float.h"

#include "utils/fmgrprotos.h"

#include "utils/geo_decls.h"

#define point_point_distance(p1,p2) \

  DatumGetFloat8(DirectFunctionCall2(point_distance, \

                     PointPGetDatum(p1), PointPGetDatum(p2)))

/* Point-box distance in the assumption that box is aligned by axis */

static double

point_box_distance(Point *point, BOX *box)

{

  double    dx,

        dy;

  if (isnan(point->x) || isnan(box->low.x) ||

    isnan(point->y) || isnan(box->low.y))

    return get_float8_nan();

  if (point->x < box->low.x)

    dx = box->low.x - point->x;

  else if (point->x > box->high.x)

    dx = point->x - box->high.x;

  else

    dx = 0.0;

  if (point->y < box->low.y)

    dy = box->low.y - point->y;

  else if (point->y > box->high.y)

    dy = point->y - box->high.y;

  else

    dy = 0.0;

  return HYPOT(dx, dy);

}

/*

 * Returns distances from given key to array of ordering scan keys.  Leaf key

 * is expected to be point, non-leaf key is expected to be box.  Scan key

 * arguments are expected to be points.

 */

double *

spg_key_orderbys_distances(Datum key, bool isLeaf,

               ScanKey orderbys, int norderbys)

{

  int     sk_num;

  double     *distances = (double *) palloc(norderbys * sizeof(double)),

         *distance = distances;

  for (sk_num = 0; sk_num < norderbys; ++sk_num, ++orderbys, ++distance)

  {

    Point    *point = DatumGetPointP(orderbys->sk_argument);

    *distance = isLeaf ? point_point_distance(point, DatumGetPointP(key))

      : point_box_distance(point, DatumGetBoxP(key));

  }

  return distances;

}

BOX *

box_copy(BOX *orig)

{

  BOX      *result = palloc(sizeof(BOX));

  *result = *orig;

  return result;

}