_lwt_AddLineEdge()

static LWT_ELEMID _lwt_AddLineEdge ( LWT_TOPOLOGY *  topo, LWLINE *  edge, double  tol, int  handleFaceSplit, int *  forward  )

static

Definition at line 5394 of file lwgeom_topo.c.

{
  LWCOLLECTION *col;
  LWPOINT *start_point, *end_point;
  LWGEOM *tmp = 0, *tmp2;
  LWT_ISO_NODE *node;
  LWT_ELEMID nid[2]; /* start_node, end_node */
  LWT_ELEMID id; /* edge id */
  POINT4D p4d;
  uint64_t nn, i;
  int moved=0, mm;
 
  LWDEBUGG(1, lwline_as_lwgeom(edge), "_lwtAddLineEdge");
  LWDEBUGF(1, "_lwtAddLineEdge with tolerance %g", tol);
 
  start_point = lwline_get_lwpoint(edge, 0);
  if ( ! start_point )
  {
    lwnotice("Empty component of noded line");
    return 0; /* must be empty */
  }
  nid[0] = _lwt_AddPoint( topo, start_point,
                          _lwt_minTolerance(lwpoint_as_lwgeom(start_point)),
                          handleFaceSplit, &mm );
  lwpoint_free(start_point); /* too late if lwt_AddPoint calls lwerror */
  if ( nid[0] == -1 ) return -1; /* lwerror should have been called */
  moved += mm;
 
 
  end_point = lwline_get_lwpoint(edge, edge->points->npoints-1);
  if ( ! end_point )
  {
    lwerror("could not get last point of line "
            "after successfully getting first point !?");
    return -1;
  }
  nid[1] = _lwt_AddPoint( topo, end_point,
                          _lwt_minTolerance(lwpoint_as_lwgeom(end_point)),
                          handleFaceSplit, &mm );
  moved += mm;
  lwpoint_free(end_point); /* too late if lwt_AddPoint calls lwerror */
  if ( nid[1] == -1 ) return -1; /* lwerror should have been called */
 
  /*
    -- Added endpoints may have drifted due to tolerance, so
    -- we need to re-snap the edge to the new nodes before adding it
  */
  if ( moved )
  {
 
    nn = nid[0] == nid[1] ? 1 : 2;
    node = lwt_be_getNodeById( topo, nid, &nn,
                               LWT_COL_NODE_NODE_ID|LWT_COL_NODE_GEOM );
    if (nn == UINT64_MAX)
    {
      lwerror("Backend error: %s", lwt_be_lastErrorMessage(topo->be_iface));
      return -1;
    }
    start_point = NULL; end_point = NULL;
    for (i=0; i<nn; ++i)
    {
      if ( node[i].node_id == nid[0] ) start_point = node[i].geom;
      if ( node[i].node_id == nid[1] ) end_point = node[i].geom;
    }
    if ( ! start_point  || ! end_point )
    {
      if ( nn ) _lwt_release_nodes(node, nn);
      lwerror("Could not find just-added nodes % " LWTFMT_ELEMID
              " and %" LWTFMT_ELEMID, nid[0], nid[1]);
      return -1;
    }
 
    /* snap */
 
    getPoint4d_p( start_point->point, 0, &p4d );
    lwline_setPoint4d(edge, 0, &p4d);
 
    getPoint4d_p( end_point->point, 0, &p4d );
    lwline_setPoint4d(edge, edge->points->npoints-1, &p4d);
 
    if ( nn ) _lwt_release_nodes(node, nn);
 
    /* make valid, after snap (to handle collapses) */
    tmp = lwgeom_make_valid(lwline_as_lwgeom(edge));
 
    col = lwgeom_as_lwcollection(tmp);
    if ( col )
    {{
 
      LWCOLLECTION *colex = lwcollection_extract(col, LINETYPE);
 
      /* Check if the so-snapped edge collapsed (see #1650) */
      if ( colex->ngeoms == 0 )
      {
        lwcollection_free(colex);
        lwgeom_free(tmp);
        LWDEBUG(1, "Made-valid snapped edge collapsed");
        return 0;
      }
 
      tmp2 = lwgeom_clone_deep(colex->geoms[0]);
      lwgeom_free(tmp);
      tmp = tmp2;
      edge = lwgeom_as_lwline(tmp);
      lwcollection_free(colex);
      if ( ! edge )
      {
        /* should never happen */
        lwerror("lwcollection_extract(LINETYPE) returned a non-line?");
        return -1;
      }
    }}
    else
    {
      edge = lwgeom_as_lwline(tmp);
      if ( ! edge )
      {
        LWDEBUGF(1, "Made-valid snapped edge collapsed to %s",
                    lwtype_name(lwgeom_get_type(tmp)));
        lwgeom_free(tmp);
        return 0;
      }
    }
  }
 
  /* check if the so-snapped edge _now_ exists */
  id = _lwt_GetEqualEdge ( topo, edge, forward );
  LWDEBUGF(1, "_lwt_GetEqualEdge returned %" LWTFMT_ELEMID, id);
  if ( id == -1 )
  {
    if ( tmp ) lwgeom_free(tmp); /* probably too late, due to internal lwerror */
    return -1;
  }
  if ( id )
  {
    if ( tmp ) lwgeom_free(tmp); /* possibly takes "edge" down with it */
    return id;
  }
 
  /* No previously existing edge was found, we'll add one */
 
  /* Remove consecutive vertices below given tolerance
   * on edge addition */
  if ( tol )
  {{
    tmp2 = lwline_remove_repeated_points(edge, tol);
    LWDEBUGG(1, tmp2, "Repeated-point removed");
    edge = lwgeom_as_lwline(tmp2);
    if ( tmp ) lwgeom_free(tmp);
    tmp = tmp2;
 
    /* check if the so-decimated edge collapsed to single-point */
    if ( nid[0] == nid[1] && edge->points->npoints == 2 )
    {
      lwgeom_free(tmp);
      LWDEBUG(1, "Repeated-point removed edge collapsed");
      return 0;
    }
 
    /* check if the so-decimated edge _now_ exists */
    id = _lwt_GetEqualEdge ( topo, edge, forward );
    LWDEBUGF(1, "_lwt_GetEqualEdge returned %" LWTFMT_ELEMID, id);
    if ( id == -1 )
    {
      lwgeom_free(tmp); /* probably too late, due to internal lwerror */
      return -1;
    }
    if ( id )
    {
      lwgeom_free(tmp); /* takes "edge" down with it */
      return id;
    }
  }}
 
 
  /* TODO: skip checks ? */
  id = _lwt_AddEdge( topo, nid[0], nid[1], edge, 0, handleFaceSplit ?  1 : -1 );
  LWDEBUGF(1, "lwt_AddEdgeModFace returned %" LWTFMT_ELEMID, id);
  if ( id == -1 )
  {
    lwgeom_free(tmp); /* probably too late, due to internal lwerror */
    return -1;
  }
  lwgeom_free(tmp); /* possibly takes "edge" down with it */
 
  *forward = 1;
  return id;
}

References _lwt_AddEdge(), _lwt_AddPoint(), _lwt_GetEqualEdge(), _lwt_minTolerance(), _lwt_release_nodes(), LWT_TOPOLOGY_T::be_iface, LWT_ISO_NODE::geom, LWCOLLECTION::geoms, getPoint4d_p(), LINETYPE, lwcollection_extract(), lwcollection_free(), LWDEBUG, LWDEBUGF, LWDEBUGG, lwerror(), lwgeom_as_lwcollection(), lwgeom_as_lwline(), lwgeom_clone_deep(), lwgeom_free(), lwgeom_get_type(), lwgeom_make_valid(), lwline_as_lwgeom(), lwline_get_lwpoint(), lwline_remove_repeated_points(), lwline_setPoint4d(), lwnotice(), lwpoint_as_lwgeom(), lwpoint_free(), lwt_be_getNodeById(), lwt_be_lastErrorMessage(), LWT_COL_NODE_GEOM, LWT_COL_NODE_NODE_ID, LWTFMT_ELEMID, lwtype_name(), LWCOLLECTION::ngeoms, POINTARRAY::npoints, LWPOINT::point, and LWLINE::points.

Referenced by _lwt_AddLine().

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