| Bug #53744 | intersects returns false for a point on a vertex of polygon | ||
|---|---|---|---|
| Submitted: | 18 May 2010 10:24 | Modified: | 9 Jan 2014 12:57 |
| Reporter: | John Powell | Email Updates: | |
| Status: | Can't repeat | Impact on me: | |
| Category: | MySQL Server: GIS | Severity: | S3 (Non-critical) |
| Version: | 5.1 GIS | OS: | Any |
| Assigned to: | Assigned Account | CPU Architecture: | Any |
| Tags: | gis, intersection, spatial | ||
[18 May 2010 18:35]
MySQL Verification Team
Thank you for the bug report. Which source are you using?. I tried the regular mysql-5.1 and mysql-5.1-wl1326 with differents results than yours:
iguel@tikal:~/dbs/5.1GS/var$ cd
miguel@tikal:~$ dbs/5.1GS/bin/mysql -uroot
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.1.43 Source distribution
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> set @point=geomfromtext('POINT(0 0)');
Query OK, 0 rows affected (0.00 sec)
mysql> set @poly=geomfromtext('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))');
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> select intersects(@geom,@point);
+--------------------------+
| intersects(@geom,@point) |
+--------------------------+
| NULL |
+--------------------------+
1 row in set (0.00 sec)
mysql> set @point=geomfromtext('POINT(0 0)');
Query OK, 0 rows affected (0.00 sec)
mysql> set @poly=geomfromtext('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))');
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> select intersects(@geom,@point);
+--------------------------+
| intersects(@geom,@point) |
+--------------------------+
| NULL |
+--------------------------+
1 row in set (0.00 sec)
mysql> select mbrintersects(@geom,@point);
+-----------------------------+
| mbrintersects(@geom,@point) |
+-----------------------------+
| NULL |
+-----------------------------+
1 row in set (0.00 sec)
mysql> exit
Bye
Thanks in advance.
[18 May 2010 21:05]
John Powell
My apologies. @geom got substituted for @poly in the initial report.
set @point=geomfromtext('POINT(0 0)');
set @poly=geomfromtext('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))');
select intersects(@poly, @point);
+--------------------------+
| intersects(@geom,@point) |
+--------------------------+
| 0 |
+--------------------------+
[27 May 2010 1:57]
MySQL Verification Team
Thank you for the feedback. Verified as described:
mysql> set @point=geomfromtext('POINT(0 0)');
Query OK, 0 rows affected (0.00 sec)
mysql> set @poly=geomfromtext('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))');
Query OK, 0 rows affected (0.00 sec)
mysql> select intersects(@poly, @point);
+---------------------------+
| intersects(@poly, @point) |
+---------------------------+
| 0 |
+---------------------------+
1 row in set (0.00 sec)
mysql> exit
Bye
miguel@tikal:~$
[9 Jan 2014 12:57]
Erlend Dahl
This isn't repeatable on recent 5.1/5.5/5.6 or trunk.
Description: Intersects returns false when the enclosing polygon shares a point with the point being tested or when the point is on one of the polygon's line segments. mbrintersects returns true, correctly. How to repeat: set @point=geomfromtext('POINT(0 0)'); set @poly=geomfromtext('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))'); select intersects(@geom,@point); +--------------------------+ | intersects(@geom,@point) | +--------------------------+ | 0 | +--------------------------+ Or for a point on one of the polygon's line segments set @point=geomfromtext('POINT(0.5,0)'); select intersects(@geom,@point); +--------------------------+ | intersects(@geom,@point) | +--------------------------+ | 0 | +--------------------------+ However, mbrintersects returns correct value select mbrintersects(@geom,@point); +-----------------------------+ | mbrintersects(@geom,@point) | +-----------------------------+ | 1 | +-----------------------------+