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hlinnakahlinnaka
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Add point <-> polygon distance operator.
Alexander Korotkov, reviewed by Emre Hasegeli.
1 parent ee3bec5 commit 4520ba6

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6 files changed

+82
-16
lines changed

6 files changed

+82
-16
lines changed

‎src/backend/utils/adt/geo_ops.c

Lines changed: 60 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -73,6 +73,7 @@ static double dist_ps_internal(Point *pt, LSEG *lseg);
7373
static Point *line_interpt_internal(LINE *l1, LINE *l2);
7474
static bool lseg_inside_poly(Point *a, Point *b, POLYGON *poly, int start);
7575
static Point *lseg_interpt_internal(LSEG *l1, LSEG *l2);
76+
static double dist_ppoly_internal(Point *pt, POLYGON *poly);
7677

7778

7879
/*
@@ -2415,6 +2416,9 @@ lseg_interpt(PG_FUNCTION_ARGS)
24152416
* Minimum distance from one object to another.
24162417
*-------------------------------------------------------------------*/
24172418

2419+
/*
2420+
* Distance from a point to a line
2421+
*/
24182422
Datum
24192423
dist_pl(PG_FUNCTION_ARGS)
24202424
{
@@ -2431,6 +2435,9 @@ dist_pl_internal(Point *pt, LINE *line)
24312435
HYPOT(line->A, line->B));
24322436
}
24332437

2438+
/*
2439+
* Distance from a point to a lseg
2440+
*/
24342441
Datum
24352442
dist_ps(PG_FUNCTION_ARGS)
24362443
{
@@ -2494,7 +2501,7 @@ dist_ps_internal(Point *pt, LSEG *lseg)
24942501
}
24952502

24962503
/*
2497-
** Distance from a point to a path
2504+
* Distance from a point to a path
24982505
*/
24992506
Datum
25002507
dist_ppath(PG_FUNCTION_ARGS)
@@ -2550,6 +2557,9 @@ dist_ppath(PG_FUNCTION_ARGS)
25502557
PG_RETURN_FLOAT8(result);
25512558
}
25522559

2560+
/*
2561+
* Distance from a point to a box
2562+
*/
25532563
Datum
25542564
dist_pb(PG_FUNCTION_ARGS)
25552565
{
@@ -2566,7 +2576,9 @@ dist_pb(PG_FUNCTION_ARGS)
25662576
PG_RETURN_FLOAT8(result);
25672577
}
25682578

2569-
2579+
/*
2580+
* Distance from a lseg to a line
2581+
*/
25702582
Datum
25712583
dist_sl(PG_FUNCTION_ARGS)
25722584
{
@@ -2589,7 +2601,9 @@ dist_sl(PG_FUNCTION_ARGS)
25892601
PG_RETURN_FLOAT8(result);
25902602
}
25912603

2592-
2604+
/*
2605+
* Distance from a lseg to a box
2606+
*/
25932607
Datum
25942608
dist_sb(PG_FUNCTION_ARGS)
25952609
{
@@ -2608,7 +2622,9 @@ dist_sb(PG_FUNCTION_ARGS)
26082622
PG_RETURN_DATUM(result);
26092623
}
26102624

2611-
2625+
/*
2626+
* Distance from a line to a box
2627+
*/
26122628
Datum
26132629
dist_lb(PG_FUNCTION_ARGS)
26142630
{
@@ -2625,21 +2641,53 @@ dist_lb(PG_FUNCTION_ARGS)
26252641
PG_RETURN_NULL();
26262642
}
26272643

2628-
2644+
/*
2645+
* Distance from a circle to a polygon
2646+
*/
26292647
Datum
26302648
dist_cpoly(PG_FUNCTION_ARGS)
26312649
{
26322650
CIRCLE *circle = PG_GETARG_CIRCLE_P(0);
26332651
POLYGON *poly = PG_GETARG_POLYGON_P(1);
26342652
float8 result;
2653+
2654+
/* calculate distance to center, and subtract radius */
2655+
result = dist_ppoly_internal(&circle->center, poly);
2656+
2657+
result -= circle->radius;
2658+
if (result < 0)
2659+
result = 0;
2660+
2661+
PG_RETURN_FLOAT8(result);
2662+
}
2663+
2664+
/*
2665+
* Distance from a point to a polygon
2666+
*/
2667+
Datum
2668+
dist_ppoly(PG_FUNCTION_ARGS)
2669+
{
2670+
Point *point = PG_GETARG_POINT_P(0);
2671+
POLYGON *poly = PG_GETARG_POLYGON_P(1);
2672+
float8 result;
2673+
2674+
result = dist_ppoly_internal(point, poly);
2675+
2676+
PG_RETURN_FLOAT8(result);
2677+
}
2678+
2679+
static double
2680+
dist_ppoly_internal(Point *pt, POLYGON *poly)
2681+
{
2682+
float8 result;
26352683
float8 d;
26362684
int i;
26372685
LSEG seg;
26382686

2639-
if (point_inside(&(circle->center), poly->npts, poly->p) != 0)
2687+
if (point_inside(pt, poly->npts, poly->p) != 0)
26402688
{
26412689
#ifdef GEODEBUG
2642-
printf("dist_cpoly- center inside of polygon\n");
2690+
printf("dist_ppoly_internal- point inside of polygon\n");
26432691
#endif
26442692
PG_RETURN_FLOAT8(0.0);
26452693
}
@@ -2649,9 +2697,9 @@ dist_cpoly(PG_FUNCTION_ARGS)
26492697
seg.p[0].y = poly->p[0].y;
26502698
seg.p[1].x = poly->p[poly->npts - 1].x;
26512699
seg.p[1].y = poly->p[poly->npts - 1].y;
2652-
result = dist_ps_internal(&circle->center, &seg);
2700+
result = dist_ps_internal(pt, &seg);
26532701
#ifdef GEODEBUG
2654-
printf("dist_cpoly- segment 0/n distance is %f\n", result);
2702+
printf("dist_ppoly_internal- segment 0/n distance is %f\n", result);
26552703
#endif
26562704

26572705
/* check distances for other segments */
@@ -2661,19 +2709,15 @@ dist_cpoly(PG_FUNCTION_ARGS)
26612709
seg.p[0].y = poly->p[i].y;
26622710
seg.p[1].x = poly->p[i + 1].x;
26632711
seg.p[1].y = poly->p[i + 1].y;
2664-
d = dist_ps_internal(&circle->center, &seg);
2712+
d = dist_ps_internal(pt, &seg);
26652713
#ifdef GEODEBUG
2666-
printf("dist_cpoly- segment %d distance is %f\n", (i + 1), d);
2714+
printf("dist_ppoly_internal- segment %d distance is %f\n", (i + 1), d);
26672715
#endif
26682716
if (d < result)
26692717
result = d;
26702718
}
26712719

2672-
result -= circle->radius;
2673-
if (result < 0)
2674-
result = 0;
2675-
2676-
PG_RETURN_FLOAT8(result);
2720+
return result;
26772721
}
26782722

26792723

‎src/include/catalog/pg_operator.h

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1016,6 +1016,8 @@ DATA(insert OID = 1521 ( "#" PGNSP PGUID l f f 0 604 23 0 0 poly_npo
10161016
DESCR("number of points");
10171017
DATA(insert OID = 1522 ( "<->" PGNSP PGUID b f f 600 718 701 0 0 dist_pc - - ));
10181018
DESCR("distance between");
1019+
DATA(insert OID = 3276 ( "<->" PGNSP PGUID b f f 600 604 701 0 0 dist_ppoly - - ));
1020+
DESCR("distance between");
10191021
DATA(insert OID = 1523 ( "<->" PGNSP PGUID b f f 718 604 701 0 0 dist_cpoly - - ));
10201022
DESCR("distance between");
10211023

‎src/include/catalog/pg_proc.h

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -844,6 +844,7 @@ DATA(insert OID = 726 ( dist_lb PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 70
844844
DATA(insert OID = 727 ( dist_sl PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 701 "601 628" _null_ _null_ _null_ _null_ dist_sl _null_ _null_ _null_ ));
845845
DATA(insert OID = 728 ( dist_cpoly PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 701 "718 604" _null_ _null_ _null_ _null_ dist_cpoly _null_ _null_ _null_ ));
846846
DATA(insert OID = 729 ( poly_distance PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 701 "604 604" _null_ _null_ _null_ _null_ poly_distance _null_ _null_ _null_ ));
847+
DATA(insert OID = 3275 ( dist_ppoly PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 701 "600 604" _null_ _null_ _null_ _null_ dist_ppoly _null_ _null_ _null_ ));
847848

848849
DATA(insert OID = 740 ( text_lt PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "25 25" _null_ _null_ _null_ _null_ text_lt _null_ _null_ _null_ ));
849850
DATA(insert OID = 741 ( text_le PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "25 25" _null_ _null_ _null_ _null_ text_le _null_ _null_ _null_ ));

‎src/include/utils/geo_decls.h

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -395,6 +395,7 @@ extern Datum circle_radius(PG_FUNCTION_ARGS);
395395
extern Datum circle_distance(PG_FUNCTION_ARGS);
396396
extern Datum dist_pc(PG_FUNCTION_ARGS);
397397
extern Datum dist_cpoly(PG_FUNCTION_ARGS);
398+
extern Datum dist_ppoly(PG_FUNCTION_ARGS);
398399
extern Datum circle_center(PG_FUNCTION_ARGS);
399400
extern Datum cr_circle(PG_FUNCTION_ARGS);
400401
extern Datum box_circle(PG_FUNCTION_ARGS);

‎src/test/regress/expected/polygon.out

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -279,3 +279,14 @@ SELECT '((200,800),(800,800),(800,200),(200,200))' && '(1000,1000,0,0)'::polygo
279279
t
280280
(1 row)
281281

282+
-- distance from a point
283+
SELECT '(0,0)'::point <-> '((0,0),(1,2),(2,1))'::polygon as on_corner,
284+
'(1,1)'::point <-> '((0,0),(2,2),(1,3))'::polygon as on_segment,
285+
'(2,2)'::point <-> '((0,0),(1,4),(3,1))'::polygon as inside,
286+
'(3,3)'::point <-> '((0,2),(2,0),(2,2))'::polygon as near_corner,
287+
'(4,4)'::point <-> '((0,0),(0,3),(4,0))'::polygon as near_segment;
288+
on_corner | on_segment | inside | near_corner | near_segment
289+
-----------+------------+--------+-----------------+--------------
290+
0 | 0 | 0 | 1.4142135623731 | 3.2
291+
(1 row)
292+

‎src/test/regress/sql/polygon.sql

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -172,3 +172,10 @@ SELECT '((0,4),(6,4),(1,2),(6,0),(0,0))'::polygon && '((2,1),(2,3),(3,3),(3,1))'
172172
-- +-------+
173173
SELECT '((1,4),(1,1),(4,1),(4,2),(2,2),(2,4),(1,4))'::polygon && '((3,3),(4,3),(4,4),(3,4),(3,3))'::polygon AS "false";
174174
SELECT '((200,800),(800,800),(800,200),(200,200))' && '(1000,1000,0,0)'::polygon AS "true";
175+
176+
-- distance from a point
177+
SELECT '(0,0)'::point <-> '((0,0),(1,2),(2,1))'::polygon as on_corner,
178+
'(1,1)'::point <-> '((0,0),(2,2),(1,3))'::polygon as on_segment,
179+
'(2,2)'::point <-> '((0,0),(1,4),(3,1))'::polygon as inside,
180+
'(3,3)'::point <-> '((0,2),(2,0),(2,2))'::polygon as near_corner,
181+
'(4,4)'::point <-> '((0,0),(0,3),(4,0))'::polygon as near_segment;

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