_lwt_CheckEdgeCrossing()

static int _lwt_CheckEdgeCrossing ( LWT_TOPOLOGY *  topo, LWT_ELEMID  start_node, LWT_ELEMID  end_node, const LWLINE *  geom, LWT_ELEMID  myself  )

static

Definition at line 589 of file lwgeom_topo.c.

References _lwt_release_edges(), _lwt_release_nodes(), LWT_TOPOLOGY_T::be_iface, contains(), LWT_ISO_EDGE::edge_id, LWT_ISO_NODE::geom, LWT_ISO_EDGE::geom, LWDEBUGF, lwerror(), LWGEOM2GEOS(), lwgeom_geos_errmsg, lwgeom_geos_error(), lwgeom_get_bbox(), lwline_as_lwgeom(), lwnotice(), lwpoint_as_lwgeom(), lwt_be_getEdgeWithinBox2D(), lwt_be_getNodeWithinBox2D(), lwt_be_lastErrorMessage(), LWT_COL_EDGE_ALL, LWT_COL_NODE_ALL, LWTFMT_ELEMID, and LWT_ISO_NODE::node_id.

Referenced by _lwt_AddEdge(), lwt_AddIsoEdge(), and lwt_ChangeEdgeGeom().

{
  int i, num_nodes, num_edges;
  LWT_ISO_EDGE *edges;
  LWT_ISO_NODE *nodes;
  const GBOX *edgebox;
  GEOSGeometry *edgegg;
  const GEOSPreparedGeometry* prepared_edge;

  initGEOS(lwnotice, lwgeom_geos_error);

  edgegg = LWGEOM2GEOS( lwline_as_lwgeom(geom), 0);
  if ( ! edgegg ) {
    lwerror("Could not convert edge geometry to GEOS: %s", lwgeom_geos_errmsg);
    return -1;
  }
  prepared_edge = GEOSPrepare( edgegg );
  if ( ! prepared_edge ) {
    lwerror("Could not prepare edge geometry: %s", lwgeom_geos_errmsg);
    return -1;
  }
  edgebox = lwgeom_get_bbox( lwline_as_lwgeom(geom) );

  /* loop over each node within the edge's gbox */
  nodes = lwt_be_getNodeWithinBox2D( topo, edgebox, &num_nodes,
                                            LWT_COL_NODE_ALL, 0 );
  LWDEBUGF(1, "lwt_be_getNodeWithinBox2D returned %d nodes", num_nodes);
  if ( num_nodes == -1 ) {
    GEOSPreparedGeom_destroy(prepared_edge);
    GEOSGeom_destroy(edgegg);
    lwerror("Backend error: %s", lwt_be_lastErrorMessage(topo->be_iface));
    return -1;
  }
  for ( i=0; i<num_nodes; ++i )
  {
    LWT_ISO_NODE* node = &(nodes[i]);
    GEOSGeometry *nodegg;
    int contains;
    if ( node->node_id == start_node ) continue;
    if ( node->node_id == end_node ) continue;
    /* check if the edge contains this node (not on boundary) */
    nodegg = LWGEOM2GEOS( lwpoint_as_lwgeom(node->geom) , 0);
    /* ST_RelateMatch(rec.relate, 'T********') */
    contains = GEOSPreparedContains( prepared_edge, nodegg );
    GEOSGeom_destroy(nodegg);
    if (contains == 2)
    {
      GEOSPreparedGeom_destroy(prepared_edge);
      GEOSGeom_destroy(edgegg);
      _lwt_release_nodes(nodes, num_nodes);
      lwerror("GEOS exception on PreparedContains: %s", lwgeom_geos_errmsg);
      return -1;
    }
    if ( contains )
    {
      GEOSPreparedGeom_destroy(prepared_edge);
      GEOSGeom_destroy(edgegg);
      _lwt_release_nodes(nodes, num_nodes);
      lwerror("SQL/MM Spatial exception - geometry crosses a node");
      return -1;
    }
  }
  if ( nodes ) _lwt_release_nodes(nodes, num_nodes);
               /* may be NULL if num_nodes == 0 */

  /* loop over each edge within the edge's gbox */
  edges = lwt_be_getEdgeWithinBox2D( topo, edgebox, &num_edges, LWT_COL_EDGE_ALL, 0 );
  LWDEBUGF(1, "lwt_be_getEdgeWithinBox2D returned %d edges", num_edges);
  if ( num_edges == -1 ) {
    GEOSPreparedGeom_destroy(prepared_edge);
    GEOSGeom_destroy(edgegg);
    lwerror("Backend error: %s", lwt_be_lastErrorMessage(topo->be_iface));
    return -1;
  }
  for ( i=0; i<num_edges; ++i )
  {
    LWT_ISO_EDGE* edge = &(edges[i]);
    LWT_ELEMID edge_id = edge->edge_id;
    GEOSGeometry *eegg;
    char *relate;
    int match;

    if ( edge_id == myself ) continue;

    if ( ! edge->geom ) {
      _lwt_release_edges(edges, num_edges);
      lwerror("Edge %d has NULL geometry!", edge_id);
      return -1;
    }

    eegg = LWGEOM2GEOS( lwline_as_lwgeom(edge->geom), 0 );
    if ( ! eegg ) {
      GEOSPreparedGeom_destroy(prepared_edge);
      GEOSGeom_destroy(edgegg);
      _lwt_release_edges(edges, num_edges);
      lwerror("Could not convert edge geometry to GEOS: %s", lwgeom_geos_errmsg);
      return -1;
    }

    LWDEBUGF(2, "Edge %d converted to GEOS", edge_id);

    /* check if the edge crosses our edge (not boundary-boundary) */

    relate = GEOSRelateBoundaryNodeRule(eegg, edgegg, 2);
    if ( ! relate ) {
      GEOSGeom_destroy(eegg);
      GEOSPreparedGeom_destroy(prepared_edge);
      GEOSGeom_destroy(edgegg);
      _lwt_release_edges(edges, num_edges);
      lwerror("GEOSRelateBoundaryNodeRule error: %s", lwgeom_geos_errmsg);
      return -1;
    }

    LWDEBUGF(2, "Edge %d relate pattern is %s", edge_id, relate);

    match = GEOSRelatePatternMatch(relate, "F********");
    if ( match ) {
      /* error or no interior intersection */
      GEOSGeom_destroy(eegg);
      GEOSFree(relate);
      if ( match == 2 ) {
        _lwt_release_edges(edges, num_edges);
        GEOSPreparedGeom_destroy(prepared_edge);
        GEOSGeom_destroy(edgegg);
        lwerror("GEOSRelatePatternMatch error: %s", lwgeom_geos_errmsg);
        return -1;
      }
      else continue; /* no interior intersection */
    }

    match = GEOSRelatePatternMatch(relate, "1FFF*FFF2");
    if ( match ) {
      _lwt_release_edges(edges, num_edges);
      GEOSPreparedGeom_destroy(prepared_edge);
      GEOSGeom_destroy(edgegg);
      GEOSGeom_destroy(eegg);
      GEOSFree(relate);
      if ( match == 2 ) {
        lwerror("GEOSRelatePatternMatch error: %s", lwgeom_geos_errmsg);
      } else {
        lwerror("SQL/MM Spatial exception - coincident edge %" LWTFMT_ELEMID,
                edge_id);
      }
      return -1;
    }

    match = GEOSRelatePatternMatch(relate, "1********");
    if ( match ) {
      _lwt_release_edges(edges, num_edges);
      GEOSPreparedGeom_destroy(prepared_edge);
      GEOSGeom_destroy(edgegg);
      GEOSGeom_destroy(eegg);
      GEOSFree(relate);
      if ( match == 2 ) {
        lwerror("GEOSRelatePatternMatch error: %s", lwgeom_geos_errmsg);
      } else {
        lwerror("Spatial exception - geometry intersects edge %"
                LWTFMT_ELEMID, edge_id);
      }
      return -1;
    }

    match = GEOSRelatePatternMatch(relate, "T********");
    if ( match ) {
      _lwt_release_edges(edges, num_edges);
      GEOSPreparedGeom_destroy(prepared_edge);
      GEOSGeom_destroy(edgegg);
      GEOSGeom_destroy(eegg);
      GEOSFree(relate);
      if ( match == 2 ) {
        lwerror("GEOSRelatePatternMatch error: %s", lwgeom_geos_errmsg);
      } else {
        lwerror("SQL/MM Spatial exception - geometry crosses edge %"
                LWTFMT_ELEMID, edge_id);
      }
      return -1;
    }

    LWDEBUGF(2, "Edge %d analisys completed, it does no harm", edge_id);

    GEOSFree(relate);
    GEOSGeom_destroy(eegg);
  }
  if ( edges ) _lwt_release_edges(edges, num_edges);
              /* would be NULL if num_edges was 0 */

  GEOSPreparedGeom_destroy(prepared_edge);
  GEOSGeom_destroy(edgegg);

  return 0;
}

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