_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 606 of file lwgeom_topo.c.

{
  uint64_t i, num_nodes, num_edges;
  LWT_ISO_EDGE *edges;
  LWT_ISO_NODE *nodes;
  const GBOX *edgebox;
  GEOSGeometry *edgegg;
 
  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;
  }
  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 %llu nodes", num_nodes);
  if (num_nodes == UINT64_MAX)
  {
    PGTOPO_BE_ERROR();
    return -1;
  }
  for ( i=0; i<num_nodes; ++i )
  {
    const POINT2D *pt;
    LWT_ISO_NODE* node = &(nodes[i]);
    if ( node->node_id == start_node ) continue;
    if ( node->node_id == end_node ) continue;
    /* check if the edge contains this node (not on boundary) */
    /* ST_RelateMatch(rec.relate, 'T********') */
    pt = getPoint2d_cp(node->geom->point, 0);
    int contains = ptarray_contains_point_partial(geom->points, pt, LW_FALSE, NULL) == LW_BOUNDARY;
    if ( contains )
    {
      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 %llu edges", num_edges);
  if (num_edges == UINT64_MAX)
  {
    GEOSGeom_destroy(edgegg);
    PGTOPO_BE_ERROR();
    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 %" LWTFMT_ELEMID " has NULL geometry!", edge_id);
      return -1;
    }
 
    eegg = LWGEOM2GEOS( lwline_as_lwgeom(edge->geom), 0 );
    if ( ! eegg ) {
      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 %" LWTFMT_ELEMID " converted to GEOS", edge_id);
 
    /* check if the edge has a non-boundary-boundary intersection with our edge */
 
    relate = GEOSRelateBoundaryNodeRule(eegg, edgegg, 2);
    GEOSGeom_destroy(eegg);
    if ( ! relate ) {
      GEOSGeom_destroy(edgegg);
      _lwt_release_edges(edges, num_edges);
      lwerror("GEOSRelateBoundaryNodeRule error: %s", lwgeom_geos_errmsg);
      return -1;
    }
 
    LWDEBUGF(2, "Edge %" LWTFMT_ELEMID " relate pattern is %s", edge_id, relate);
 
    match = GEOSRelatePatternMatch(relate, "FF*F*****");
    if ( match ) {
      /* error or no interior intersection */
      GEOSFree(relate);
      if ( match == 2 ) {
        _lwt_release_edges(edges, num_edges);
        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);
      GEOSGeom_destroy(edgegg);
      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);
      GEOSGeom_destroy(edgegg);
      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);
      GEOSGeom_destroy(edgegg);
      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;
    }
 
    match = GEOSRelatePatternMatch(relate, "*T*******");
    if ( match ) {
      _lwt_release_edges(edges, num_edges);
      GEOSGeom_destroy(edgegg);
      GEOSFree(relate);
      if ( match == 2 ) {
        lwerror("GEOSRelatePatternMatch error: %s", lwgeom_geos_errmsg);
      } else {
        lwerror("Spatial exception - geometry boundary touches interior of edge %"
                LWTFMT_ELEMID, edge_id);
      }
      return -1;
    }
 
    match = GEOSRelatePatternMatch(relate, "***T*****");
    if ( match ) {
      _lwt_release_edges(edges, num_edges);
      GEOSGeom_destroy(edgegg);
      GEOSFree(relate);
      if ( match == 2 ) {
        lwerror("GEOSRelatePatternMatch error: %s", lwgeom_geos_errmsg);
      } else {
        lwerror("Spatial exception - boundary of edge %" LWTFMT_ELEMID" touches interior of geometry", edge_id);
      }
      return -1;
    }
 
    LWDEBUGF(2, "Edge %" LWTFMT_ELEMID " analysis completed, it does no harm", edge_id);
 
    GEOSFree(relate);
  }
  LWDEBUGF(1, "No edge crossing detected among the %llu candidate edges", num_edges);
  if ( edges ) _lwt_release_edges(edges, num_edges);
              /* would be NULL if num_edges was 0 */
 
  GEOSGeom_destroy(edgegg);
 
  return 0;
}

References _lwt_release_edges(), _lwt_release_nodes(), contains(), LWT_ISO_EDGE::edge_id, LWT_ISO_NODE::geom, LWT_ISO_EDGE::geom, getPoint2d_cp(), LW_BOUNDARY, LW_FALSE, LWDEBUGF, lwerror(), LWGEOM2GEOS(), lwgeom_geos_errmsg, lwgeom_geos_error(), lwgeom_get_bbox(), lwline_as_lwgeom(), lwnotice(), lwt_be_getEdgeWithinBox2D(), lwt_be_getNodeWithinBox2D(), LWT_COL_EDGE_ALL, LWT_COL_NODE_ALL, LWTFMT_ELEMID, LWT_ISO_NODE::node_id, PGTOPO_BE_ERROR, LWPOINT::point, LWLINE::points, and ptarray_contains_point_partial().

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

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