[postgis-tickets] [PostGIS] #3689: Your "Right Hand Rule" is wrong

PostGIS trac at osgeo.org
Thu Jan 19 16:47:16 PST 2017


#3689: Your "Right Hand Rule" is wrong
-----------------------+---------------------------
  Reporter:  jyutzler  |      Owner:  strk
      Type:  defect    |     Status:  new
  Priority:  medium    |  Milestone:  PostGIS 2.3.2
 Component:  postgis   |    Version:  2.3.x
Resolution:            |   Keywords:
-----------------------+---------------------------

Comment (by pramsey):

 We can't just kill the function sig, even if we don't agree w/ it. I'm on
 side w/ dbaston that the correct replacements drop reference to "rules"
 and talk about CW/CCW orientation instead.

 Incidentally, the RHR thing came from BC, where the standard for map data
 building "right hand rule" was as strk describes it above: a person
 walking the line would have their right hand within the bounded area.
 However, since computer graphics and mathematics all use it in the reverse
 sense (let your right thumb be orthogonal to the plane, and the direct of
 your fingers is the vertex you should use to bound the area) and there a
 lot more of those folks out there, we should start to deprecate the old
 sig.

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/3689#comment:5>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.


More information about the postgis-tickets mailing list