pggeodb.nancy.inra.fr/db_cefs - db_cefs on pggeodb.nancy.inra.fr

Function: intersects

Schema

topology

Owner

postgres

Descriptions

args: tg1, tg2 - Returns true if any pair of primitives from thetwo topogeometries intersect.

Options

Definition

CREATE OR REPLACE FUNCTION topology.intersects (
 tg1 topology.topogeometry,
 tg2 topology.topogeometry
)
RETURNS boolean AS
$span$
DECLARE
 tgbuf topology.TopoGeometry;
 rec RECORD;
 toponame varchar;
 query text;
BEGIN
 IF tg1.topology_id != tg2.topology_id THEN
   -- TODO: revert to ::geometry instead ?
   RAISE EXCEPTION 'Cannot compute intersection between TopoGeometries from different topologies';
 END IF;

 -- Order TopoGeometries so that tg1 has less-or-same
 -- dimensionality of tg1 (point,line,polygon,collection)
 IF tg1.type > tg2.type THEN
   tgbuf := tg2;
   tg2 := tg1;
   tg1 := tgbuf;
 END IF;

 --RAISE NOTICE 'tg1.id:% tg2.id:%', tg1.id, tg2.id;
 -- Geometry collection are not currently supported
 IF tg2.type = 4 THEN
   RAISE EXCEPTION 'GeometryCollection are not supported by intersects()';
 END IF;

       -- Get topology name
       SELECT name FROM topology.topology into toponame
               WHERE id = tg1.topology_id;

 -- Hierarchical TopoGeometries are not currently supported
 query = 'SELECT level FROM topology.layer'
   || ' WHERE '
   || ' topology_id = ' || tg1.topology_id
   || ' AND '
   || '( layer_id = ' || tg1.layer_id
   || ' OR layer_id = ' || tg2.layer_id
   || ' ) '
   || ' AND level > 0 ';

 --RAISE NOTICE '%', query;

 FOR rec IN EXECUTE query
 LOOP
   -- TODO: revert to ::geometry instead ?
   RAISE EXCEPTION 'Hierarchical TopoGeometries are not currently supported by intersects()';
 END LOOP;

 IF tg1.type = 1 THEN -- [multi]point


   IF tg2.type = 1 THEN -- point/point
 ---------------------------------------------------------
 --
 --  Two [multi]point features intersect if they share
 --  any Node
 --
 --
 --
     query =
       'SELECT a.topogeo_id FROM '
       || quote_ident(toponame) ||
       '.relation a, '
       || quote_ident(toponame) ||
       '.relation b '
       || 'WHERE a.layer_id = ' || tg1.layer_id
       || ' AND b.layer_id = ' || tg2.layer_id
       || ' AND a.topogeo_id = ' || tg1.id
       || ' AND b.topogeo_id = ' || tg2.id
       || ' AND a.element_id = b.element_id '
       || ' LIMIT 1';
     --RAISE NOTICE '%', query;
     FOR rec IN EXECUTE query
     LOOP
       RETURN TRUE; -- they share an element
     END LOOP;
     RETURN FALSE; -- no elements shared
 --
 ---------------------------------------------------------
     

   ELSIF tg2.type = 2 THEN -- point/line
 ---------------------------------------------------------
 --
 --  A [multi]point intersects a [multi]line if they share
 --  any Node.
 --
 --
 --
     query =
       'SELECT a.topogeo_id FROM '
       || quote_ident(toponame) ||
       '.relation a, '
       || quote_ident(toponame) ||
       '.relation b, '
       || quote_ident(toponame) ||
       '.edge_data e '
       || 'WHERE a.layer_id = ' || tg1.layer_id
       || ' AND b.layer_id = ' || tg2.layer_id
       || ' AND a.topogeo_id = ' || tg1.id
       || ' AND b.topogeo_id = ' || tg2.id
       || ' AND abs(b.element_id) = e.edge_id '
       || ' AND ( '
         || ' e.start_node = a.element_id '
         || ' OR '
         || ' e.end_node = a.element_id '
       || ' )'
       || ' LIMIT 1';
     --RAISE NOTICE '%', query;
     FOR rec IN EXECUTE query
     LOOP
       RETURN TRUE; -- they share an element
     END LOOP;
     RETURN FALSE; -- no elements shared
 --
 ---------------------------------------------------------

   ELSIF tg2.type = 3 THEN -- point/polygon
 ---------------------------------------------------------
 --
 --  A [multi]point intersects a [multi]polygon if any
 --  Node of the point is contained in any face of the
 --  polygon OR ( is end_node or start_node of any edge
 --  of any polygon face ).
 --
 --  We assume the Node-in-Face check is faster becasue
 --  there will be less Faces then Edges in any polygon.
 --
 --
 --
 --
     -- Check if any node is contained in a face
     query =
       'SELECT n.node_id as id FROM '
       || quote_ident(toponame) ||
       '.relation r1, '
       || quote_ident(toponame) ||
       '.relation r2, '
       || quote_ident(toponame) ||
       '.node n '
       || 'WHERE r1.layer_id = ' || tg1.layer_id
       || ' AND r2.layer_id = ' || tg2.layer_id
       || ' AND r1.topogeo_id = ' || tg1.id
       || ' AND r2.topogeo_id = ' || tg2.id
       || ' AND n.node_id = r1.element_id '
       || ' AND r2.element_id = n.containing_face '
       || ' LIMIT 1';
     --RAISE NOTICE '%', query;
     FOR rec IN EXECUTE query
     LOOP
       --RAISE NOTICE 'Node % in polygon face', rec.id;
       RETURN TRUE; -- one (or more) nodes are
                    -- contained in a polygon face
     END LOOP;

     -- Check if any node is start or end of any polygon
     -- face edge
     query =
       'SELECT n.node_id as nid, e.edge_id as eid '
       || ' FROM '
       || quote_ident(toponame) ||
       '.relation r1, '
       || quote_ident(toponame) ||
       '.relation r2, '
       || quote_ident(toponame) ||
       '.edge_data e, '
       || quote_ident(toponame) ||
       '.node n '
       || 'WHERE r1.layer_id = ' || tg1.layer_id
       || ' AND r2.layer_id = ' || tg2.layer_id
       || ' AND r1.topogeo_id = ' || tg1.id
       || ' AND r2.topogeo_id = ' || tg2.id
       || ' AND n.node_id = r1.element_id '
       || ' AND ( '
       || ' e.left_face = r2.element_id '
       || ' OR '
       || ' e.right_face = r2.element_id '
       || ' ) '
       || ' AND ( '
       || ' e.start_node = r1.element_id '
       || ' OR '
       || ' e.end_node = r1.element_id '
       || ' ) '
       || ' LIMIT 1';
     --RAISE NOTICE '%', query;
     FOR rec IN EXECUTE query
     LOOP
       --RAISE NOTICE 'Node % on edge % bound', rec.nid, rec.eid;
       RETURN TRUE; -- one node is start or end
                    -- of a face edge
     END LOOP;

     RETURN FALSE; -- no intersection
 --
 ---------------------------------------------------------

   ELSIF tg2.type = 4 THEN -- point/collection
     RAISE EXCEPTION 'Intersection point/collection not implemented yet';

   ELSE
     RAISE EXCEPTION 'Invalid TopoGeometry type %', tg2.type;
   END IF;

 ELSIF tg1.type = 2 THEN -- [multi]line
   IF tg2.type = 2 THEN -- line/line
 ---------------------------------------------------------
 --
 --  A [multi]line intersects a [multi]line if they share
 --  any Node.
 --
 --
 --
     query =
       'SELECT e1.start_node FROM '
       || quote_ident(toponame) ||
       '.relation r1, '
       || quote_ident(toponame) ||
       '.relation r2, '
       || quote_ident(toponame) ||
       '.edge_data e1, '
       || quote_ident(toponame) ||
       '.edge_data e2 '
       || 'WHERE r1.layer_id = ' || tg1.layer_id
       || ' AND r2.layer_id = ' || tg2.layer_id
       || ' AND r1.topogeo_id = ' || tg1.id
       || ' AND r2.topogeo_id = ' || tg2.id
       || ' AND abs(r1.element_id) = e1.edge_id '
       || ' AND abs(r2.element_id) = e2.edge_id '
       || ' AND ( '
       || ' e1.start_node = e2.start_node '
       || ' OR '
       || ' e1.start_node = e2.end_node '
       || ' OR '
       || ' e1.end_node = e2.start_node '
       || ' OR '
       || ' e1.end_node = e2.end_node '
       || ' )'
       || ' LIMIT 1';
     --RAISE NOTICE '%', query;
     FOR rec IN EXECUTE query
     LOOP
       RETURN TRUE; -- they share an element
     END LOOP;
     RETURN FALSE; -- no elements shared
 --
 ---------------------------------------------------------

   ELSIF tg2.type = 3 THEN -- line/polygon
 ---------------------------------------------------------
 --
 -- A [multi]line intersects a [multi]polygon if they share
 -- any Node (touch-only case), or if any line edge has any
 -- polygon face on the left or right (full-containment case
 -- + edge crossing case).
 --
 --
     -- E1 are line edges, E2 are polygon edges
     -- R1 are line relations.
     -- R2 are polygon relations.
     -- R2.element_id are FACE ids
     query =
       'SELECT e1.edge_id'
       || ' FROM '
       || quote_ident(toponame) ||
       '.relation r1, '
       || quote_ident(toponame) ||
       '.relation r2, '
       || quote_ident(toponame) ||
       '.edge_data e1, '
       || quote_ident(toponame) ||
       '.edge_data e2 '
       || 'WHERE r1.layer_id = ' || tg1.layer_id
       || ' AND r2.layer_id = ' || tg2.layer_id
       || ' AND r1.topogeo_id = ' || tg1.id
       || ' AND r2.topogeo_id = ' || tg2.id

       -- E1 are line edges
       || ' AND e1.edge_id = abs(r1.element_id) '

       -- E2 are face edges
       || ' AND ( e2.left_face = r2.element_id '
       || '   OR e2.right_face = r2.element_id ) '

       || ' AND ( '

       -- Check if E1 have left-or-right face
       -- being part of R2.element_id
       || ' e1.left_face = r2.element_id '
       || ' OR '
       || ' e1.right_face = r2.element_id '

       -- Check if E1 share start-or-end node
       -- with any E2.
       || ' OR '
       || ' e1.start_node = e2.start_node '
       || ' OR '
       || ' e1.start_node = e2.end_node '
       || ' OR '
       || ' e1.end_node = e2.start_node '
       || ' OR '
       || ' e1.end_node = e2.end_node '

       || ' ) '

       || ' LIMIT 1';
     --RAISE NOTICE '%', query;
     FOR rec IN EXECUTE query
     LOOP
       RETURN TRUE; -- either common node
                    -- or edge-in-face
     END LOOP;

     RETURN FALSE; -- no intersection
 --
 ---------------------------------------------------------

   ELSIF tg2.type = 4 THEN -- line/collection
     RAISE EXCEPTION 'Intersection line/collection not implemented yet';

   ELSE
     RAISE EXCEPTION 'Invalid TopoGeometry type %', tg2.type;
   END IF;


 ELSIF tg1.type = 3 THEN -- [multi]polygon

   IF tg2.type = 3 THEN -- polygon/polygon
 ---------------------------------------------------------
 --
 -- A [multi]polygon intersects a [multi]polygon if they share
 -- any Node (touch-only case), or if any face edge has any of the
 -- other polygon face on the left or right (full-containment case
 -- + edge crossing case).
 --
 --
     -- E1 are poly1 edges.
     -- E2 are poly2 edges
     -- R1 are poly1 relations.
     -- R2 are poly2 relations.
     -- R1.element_id are poly1 FACE ids
     -- R2.element_id are poly2 FACE ids
     query =
       'SELECT e1.edge_id'
       || ' FROM '
       || quote_ident(toponame) ||
       '.relation r1, '
       || quote_ident(toponame) ||
       '.relation r2, '
       || quote_ident(toponame) ||
       '.edge_data e1, '
       || quote_ident(toponame) ||
       '.edge_data e2 '
       || 'WHERE r1.layer_id = ' || tg1.layer_id
       || ' AND r2.layer_id = ' || tg2.layer_id
       || ' AND r1.topogeo_id = ' || tg1.id
       || ' AND r2.topogeo_id = ' || tg2.id

       -- E1 are poly1 edges
       || ' AND ( e1.left_face = r1.element_id '
       || '   OR e1.right_face = r1.element_id ) '

       -- E2 are poly2 edges
       || ' AND ( e2.left_face = r2.element_id '
       || '   OR e2.right_face = r2.element_id ) '

       || ' AND ( '

       -- Check if any edge from a polygon face
       -- has any of the other polygon face
       -- on the left or right
       || ' e1.left_face = r2.element_id '
       || ' OR '
       || ' e1.right_face = r2.element_id '
       || ' OR '
       || ' e2.left_face = r1.element_id '
       || ' OR '
       || ' e2.right_face = r1.element_id '

       -- Check if E1 share start-or-end node
       -- with any E2.
       || ' OR '
       || ' e1.start_node = e2.start_node '
       || ' OR '
       || ' e1.start_node = e2.end_node '
       || ' OR '
       || ' e1.end_node = e2.start_node '
       || ' OR '
       || ' e1.end_node = e2.end_node '

       || ' ) '

       || ' LIMIT 1';
     --RAISE NOTICE '%', query;
     FOR rec IN EXECUTE query
     LOOP
       RETURN TRUE; -- either common node
                    -- or edge-in-face
     END LOOP;

     RETURN FALSE; -- no intersection
 --
 ---------------------------------------------------------

   ELSIF tg2.type = 4 THEN -- polygon/collection
     RAISE EXCEPTION 'Intersection poly/collection not implemented yet';

   ELSE
     RAISE EXCEPTION 'Invalid TopoGeometry type %', tg2.type;
   END IF;

 ELSIF tg1.type = 4 THEN -- collection
   IF tg2.type = 4 THEN -- collection/collection
     RAISE EXCEPTION 'Intersection collection/collection not implemented yet';
   ELSE
     RAISE EXCEPTION 'Invalid TopoGeometry type %', tg2.type;
   END IF;

 ELSE
   RAISE EXCEPTION 'Invalid TopoGeometry type %', tg1.type;
 END IF;
END
$span$
LANGUAGE 'plpgsql'
STABLE
RETURNS NULL ON NULL INPUT
SECURITY INVOKER
COST 100;

COMMENT ON FUNCTION topology.intersects(tg1 topology.topogeometry, tg2 topology.topogeometry)
IS 'args: tg1, tg2 - Returns true if any pair of primitives from thetwo topogeometries intersect.';

This file was generated with SQL Manager for PostgreSQL (www.pgsqlmanager.com) at 13/03/2014 13:23