From 4949cad47cd619bed81bc2aec4ab1f925dbc8863 Mon Sep 17 00:00:00 2001 From: Sean Gillies Date: Fri, 3 Jan 2014 14:56:42 -0700 Subject: [PATCH] Change LinearRing to linear ring. I feel like this makes it less of a concrete thing. --- middle.mkd | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/middle.mkd b/middle.mkd index 96bd39b..70bf982 100644 --- a/middle.mkd +++ b/middle.mkd @@ -215,22 +215,26 @@ of LineString coordinate arrays. ### Polygon To specify a constraint specific to polygons, it is useful to introduce -the concept of a linear ring (LinearRing): +the concept of a linear ring: -* A LinearRing is a closed LineString with 4 or more positions. +* A linear ring is a closed LineString with 4 or more positions. * The first and last positions are equivalent (they represent equivalent points). -Though a LinearRing is not explicitly represented as a GeoJSON geometry +* A linear ring is the boundary of a polygonal region or the boundary of a hole. + +Though a linear ring is not explicitly represented as a GeoJSON geometry type, it leads to a canonical formulation of the Polygon geometry type definition as follows: * For type "Polygon", the "coordinates" member MUST be an array of - LinearRing coordinate arrays. + linear ring coordinate arrays. * For Polygons with more than one of these rings, the first MUST be the - exterior ring and any others MUST be interior rings or holes. + exterior ring and any others MUST be interior rings. The exterior ring bounds + the polygonal region and the interiors rings (if present) bound holes within + the polygonal region. ### MultiPolygon