Document third ST_Buffer signature (the one taking parameters as string).

git-svn-id: http://svn.osgeo.org/postgis/trunk@4205 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/reference.xml b/doc/reference.xml
index 2f54a2eef920aebbfb27690a949ca268e539080e..5a6862f52cd64c36571cc0fa9cdbc16c001e4354 100644 (file)
--- a/doc/reference.xml
+++ b/doc/reference.xml
@@ -11457,9 +11457,8 @@ SELECT ST_Buffer(ST_GeomFromText('POINT(50 50)'), 20) As smallc,
 
                                <refpurpose>Returns a geometry that represents all points whose distance
                        from this Geometry is less than or equal to distance. Calculations
-                       are in the Spatial Reference System of this Geometry. The optional
-                       third parameter sets the number of segments used to approximate a
-                       quarter circle (defaults to 8).</refpurpose>
+                       are in the Spatial Reference System of this Geometry.
+                       </refpurpose>
                        </refnamediv>
 
                        <refsynopsisdiv>
@@ -11477,6 +11476,13 @@ SELECT ST_Buffer(ST_GeomFromText('POINT(50 50)'), 20) As smallc,
                                        <paramdef><type>integer </type> <parameter>num_seg_quarter_circle</parameter></paramdef>
                                  </funcprototype>
 
+                                 <funcprototype>
+                                       <funcdef>geometry <function>ST_Buffer</function></funcdef>
+                                       <paramdef><type>geometry </type> <parameter>g1</parameter></paramdef>
+                                       <paramdef><type>float </type> <parameter>radius_of_buffer</parameter></paramdef>
+                                       <paramdef><type>string </type> <parameter>parameters</parameter></paramdef>
+                                 </funcprototype>
+
                                </funcsynopsis>
                        </refsynopsisdiv>
 
@@ -11485,11 +11491,27 @@ SELECT ST_Buffer(ST_GeomFromText('POINT(50 50)'), 20) As smallc,
 
                                <para>Returns a geometry that represents all points whose distance
                        from this Geometry is less than or equal to distance. Calculations
-                       are in the Spatial Reference System of this Geometry. The optional
-                       third parameter sets the number of segments used to approximate a
-                       quarter circle (defaults to 8).
+                       are in the Spatial Reference System of this Geometry.
                                </para>
-                               <para>Units are always measured in units of the spatial reference system.</para>
+                               <para>
+The optional third parameter can either specify number of segments used to approximate a quarter circle (integer case, defaults to 8) or a list of blank-separated key=value pairs (string case) to tweak operations as follows:
+<itemizedlist>
+<listitem>
+'quad_segs=#' : number of segments used to approximate a quarter circle (defaults to 8).
+</listitem>
+<listitem>
+'endcap=round|flat|square' : endcap style (defaults to "round", needs GEOS-3.2 or higher for a different value).
+</listitem>
+<listitem>
+'join=round|mitre|bevel' : join style (defaults to "round", needs GEOS-3.2 or higher for a different value).
+</listitem>
+<listitem>
+'mitre_limit=#.#' : mitre ratio limit (only affects mitred join style).
+</listitem>
+</itemizedlist>
+                               </para>
+
+                               <para>Units of radius are measured in units of the spatial reference system.</para>
                                <para>The inputs can be POINTS, MULTIPOINTS, LINESTRINGS, MULTILINESTRINGS, POLYGONS, MULTIPOLYGONS, and GeometryCollections.</para>
                                <note><para>This function ignores the third dimension (z) and will always give a 2-d buffer even when presented with a 3d-geometry.</para></note>