[postgis-tickets] [PostGIS] #2093: Add extra policy argument to control ST_Simplify behavior

[PostGIS]

#2093: Add extra policy argument to control ST_Simplify behavior
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 Reporter:  robe         |       Owner:  strk         
     Type:  enhancement  |      Status:  new          
 Priority:  medium       |   Milestone:  PostGIS 2.2.0
Component:  postgis      |     Version:  trunk        
 Keywords:               |  
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Comment(by srstclair):

 Some quick tests indicate that the JTS Java library will not accept
 structurally invalid geometries (single vertex lines, 1-3 vertex polygons,
 unclosed polygons) but will accept topologically invalid geometries (two
 coindicent vertex lines, four coincident vertex polygons). So, at least
 considering GeoTools and all other applications using JTS, preserving
 structural integrity is important. Perhaps we just need a
 ST_SimplifyPreserveStructure which reduces lines to a minimum of two
 coincident verticies and polygons to a minimum of four coincident
 verticies with all holes removed?

 The suggestion of specifying the minimum number of (coincident) points for
 each type works too; it's definitely the most flexible, if a little
 cumbersome. To clarify, though, the minimum number of verticies would be
 specified for each type in the same call? Something like this?

 st_simplify(geometry geomA, float tolerance, int linestring_min_verticies,
 int polygon_shell_min_verticies, int polygon_hole_min_verticies)

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/2093#comment:20>
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