_lwt_AddLineEdge()

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

static

Definition at line 5426 of file lwgeom_topo.c.

References _lwt_GetEqualEdge(), _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_free(), lwt_AddEdgeModFace(), lwt_AddPoint(), 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().

{
  LWCOLLECTION *col;
  LWPOINT *start_point, *end_point;
  LWGEOM *tmp, *tmp2;
  LWT_ISO_NODE *node;
  LWT_ELEMID nid[2]; /* start_node, end_node */
  LWT_ELEMID id; /* edge id */
  POINT4D p4d;
  int nn, i;

  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, tol );
  lwpoint_free(start_point); /* too late if lwt_AddPoint calls lwerror */
  if ( nid[0] == -1 ) return -1; /* lwerror should have been called */

  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, tol );
  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
  */

  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 == -1 )
  {
    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 )
  {{

    col = lwcollection_extract(col, LINETYPE);

    /* Check if the so-snapped edge collapsed (see #1650) */
    if ( col->ngeoms == 0 )
    {
      lwcollection_free(col);
      lwgeom_free(tmp);
      LWDEBUG(1, "Made-valid snapped edge collapsed");
      return 0;
    }

    tmp2 = lwgeom_clone_deep( col->geoms[0] );
    lwgeom_free(tmp);
    tmp = tmp2;
    edge = lwgeom_as_lwline(tmp);
    lwcollection_free(col);
    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 );
  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); /* 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);
    lwgeom_free(tmp);
    tmp = tmp2;

    /* check if the so-decimated edge _now_ exists */
    id = _lwt_GetEqualEdge ( topo, edge );
    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_AddEdgeModFace( topo, nid[0], nid[1], edge, 0 );
  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 */

  return id;
}

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