From 5be067fcc4bce218a842df02fa2f5bbd0f609d6e Mon Sep 17 00:00:00 2001
From: Darafei Praliaskouski <me@komzpa.net>
Date: Fri, 21 Sep 2018 13:20:50 +0000
Subject: [PATCH] ST_ChaikinSmoothing: also smooth start/end point of polygon
 by default

Closes #4156
Closes https://github.com/postgis/postgis/pull/305



git-svn-id: http://svn.osgeo.org/postgis/trunk@16828 b70326c6-7e19-0410-871a-916f4a2858ee
---
 doc/reference_processing.xml | 26 ++++++++++++--------------
 postgis/postgis.sql.in       |  2 +-
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/doc/reference_processing.xml b/doc/reference_processing.xml
index dd412603c..e48e7d8e9 100644
--- a/doc/reference_processing.xml
+++ b/doc/reference_processing.xml
@@ -3158,9 +3158,9 @@ LINESTRING(5 2,7 25,10 10)
 		<funcsynopsis>
 		  <funcprototype>
 			<funcdef>geometry <function>ST_ChaikinSmoothing</function></funcdef>
-			<paramdef><type>geometry</type> <parameter>geomA</parameter></paramdef>
-			<paramdef><type>integer</type> <parameter>nIterations</parameter></paramdef>
-			<paramdef><type>boolean</type> <parameter>preserveEndPoints</parameter></paramdef>
+			<paramdef><type>geometry</type> <parameter>geom</parameter></paramdef>
+			<paramdef><type>integer</type> <parameter>nIterations = 1</parameter></paramdef>
+			<paramdef><type>boolean</type> <parameter>preserveEndPoints = false</parameter></paramdef>
 		  </funcprototype>
 		</funcsynopsis>
 	  </refsynopsisdiv>
@@ -3173,13 +3173,12 @@ LINESTRING(5 2,7 25,10 10)
         The function puts new vertex points at 1/4 of the line before and after each point and removes the original point.
         To reduce the number of points use one of the simplification functions on the result.
         The new points gets interpolated values for all included dimensions, also z and m.</para>
-
+		<para>Second argument, number of iterations is limited to max 5 iterations</para>
+		<para>Note third argument is only valid for polygons, and will be ignored for linestrings</para>
+		<para>This function handles 3D and the third dimension will affect the result.</para>
 		<note><para>Note that returned geometry will get more points than the original.
                 To reduce the number of points again use one of the simplification functions on the result.
                 (see <xref linkend="ST_Simplify" /> and <xref linkend="ST_SimplifyVW" />)</para></note>
-		<note><para>Second argument, number of iterations is limited to max 5 iterations</para></note>
-		<note><para>Note third argument is only valid for polygons, and will be ignored for linestrings</para></note>
-		<note><para>This function handles 3D and the third dimension will affect the result.</para></note>
 		<para>Availability: 2.5.0</para>
 	  </refsection>
 
@@ -3187,14 +3186,13 @@ LINESTRING(5 2,7 25,10 10)
 			<title>Examples</title>
 			<para>A triangle is smoothed</para>
 				<programlisting>
-
 select ST_AsText(ST_ChaikinSmoothing(geom)) smoothed
-FROM (SELECT  'LINESTRING(0 0, 8 8, 0 16)'::geometry geom) As foo;
--result
- smoothed
-------------------------------
-LINESTRING(0 0,6 6,6 10,0 16)
-
+FROM (SELECT  'POLYGON((0 0, 8 8, 0 16, 0 0))'::geometry geom) As foo;
+┌───────────────────────────────────────────┐
+│                 smoothed                  │
+├───────────────────────────────────────────┤
+│ POLYGON((2 2,6 6,6 10,2 14,0 12,0 4,2 2)) │
+└───────────────────────────────────────────┘
 				</programlisting>
 		  </refsection>
 		  <refsection>
diff --git a/postgis/postgis.sql.in b/postgis/postgis.sql.in
index 12e0b774c..6afb0352a 100644
--- a/postgis/postgis.sql.in
+++ b/postgis/postgis.sql.in
@@ -3178,7 +3178,7 @@ CREATE OR REPLACE FUNCTION ST_FilterByM(geometry, double precision, double preci
 	COST 1; -- reset cost, see #3675
 
 -- Availability: 2.5.0
-CREATE OR REPLACE FUNCTION ST_ChaikinSmoothing(geometry, integer default 1, boolean default true)
+CREATE OR REPLACE FUNCTION ST_ChaikinSmoothing(geometry, integer default 1, boolean default false)
 	RETURNS geometry
 	AS 'MODULE_PATHNAME', 'LWGEOM_ChaikinSmoothing'
 	LANGUAGE 'c' IMMUTABLE STRICT _PARALLEL
-- 
2.40.0