_lwt_FindAdjacentEdges()

static int _lwt_FindAdjacentEdges ( LWT_TOPOLOGY *  topo, LWT_ELEMID  node, edgeend *  data, edgeend *  other, int  myedge_id  )

static

Definition at line 1507 of file lwgeom_topo.c.

References _lwt_FirstDistinctVertex2D(), _lwt_release_edges(), azimuth_pt_pt(), LWT_TOPOLOGY_T::be_iface, edgeend_t::ccwFace, edgeend_t::cwFace, LWT_ISO_EDGE::edge_id, LWT_ISO_EDGE::end_node, LWT_ISO_EDGE::face_left, LWT_ISO_EDGE::face_right, LWT_ISO_EDGE::geom, getPoint2d_p(), LWDEBUGF, lwerror(), lwgeom_as_lwline(), lwgeom_free(), lwgeom_remove_repeated_points(), lwline_as_lwgeom(), lwt_be_getEdgeByNode(), lwt_be_lastErrorMessage(), LWT_COL_EDGE_ALL, LWTFMT_ELEMID, edgeend_t::myaz, edgeend_t::nextCCW, edgeend_t::nextCW, POINTARRAY::npoints, LWLINE::points, LWT_ISO_EDGE::start_node, POINT2D::x, and POINT2D::y.

Referenced by _lwt_AddEdge(), and lwt_ChangeEdgeGeom().

{
  LWT_ISO_EDGE *edges;
  int numedges = 1;
  int i;
  double minaz, maxaz;
  double az, azdif;

  data->nextCW = data->nextCCW = 0;
  data->cwFace = data->ccwFace = -1;

  if ( other ) {
    azdif = other->myaz - data->myaz;
    if ( azdif < 0 ) azdif += 2 * M_PI;
    minaz = maxaz = azdif;
    /* TODO: set nextCW/nextCCW/cwFace/ccwFace to other->something ? */
    LWDEBUGF(1, "Other edge end has cwFace=%d and ccwFace=%d",
                other->cwFace, other->ccwFace);
  } else {
    minaz = maxaz = -1;
  }

  LWDEBUGF(1, "Looking for edges incident to node %" LWTFMT_ELEMID
              " and adjacent to azimuth %g", node, data->myaz);

  /* Get incident edges */
  edges = lwt_be_getEdgeByNode( topo, &node, &numedges, LWT_COL_EDGE_ALL );
  if ( numedges == -1 ) {
    lwerror("Backend error: %s", lwt_be_lastErrorMessage(topo->be_iface));
    return 0;
  }

  LWDEBUGF(1, "getEdgeByNode returned %d edges, minaz=%g, maxaz=%g",
              numedges, minaz, maxaz);

  /* For each incident edge-end (1 or 2): */
  for ( i = 0; i < numedges; ++i )
  {
    LWT_ISO_EDGE *edge;
    LWGEOM *g;
    LWGEOM *cleangeom;
    POINT2D p1, p2;
    POINTARRAY *pa;

    edge = &(edges[i]);

    if ( edge->edge_id == myedge_id ) continue;

    g = lwline_as_lwgeom(edge->geom);
    /* NOTE: remove_repeated_points call could be replaced by
     * some other mean to pick two distinct points for endpoints */
    cleangeom = lwgeom_remove_repeated_points( g, 0 );
    pa = lwgeom_as_lwline(cleangeom)->points;

    if ( pa->npoints < 2 ) {{
      LWT_ELEMID id = edge->edge_id;
      _lwt_release_edges(edges, numedges);
      lwgeom_free(cleangeom);
      lwerror("corrupted topology: edge %" LWTFMT_ELEMID
              " does not have two distinct points", id);
      return -1;
    }}

    if ( edge->start_node == node ) {
      getPoint2d_p(pa, 0, &p1);
      if ( ! _lwt_FirstDistinctVertex2D(pa, &p1, 0, 1, &p2) )
      {
        lwerror("Edge %d has no distinct vertices: [%.15g %.15g,%.15g %.15g]: ",
                edge->edge_id, p1.x, p1.y, p2.x, p2.y);
        return -1;
      }
      LWDEBUGF(1, "edge %" LWTFMT_ELEMID
                  " starts on node %" LWTFMT_ELEMID
                  ", edgeend is %g,%g-%g,%g",
                  edge->edge_id, node, p1.x, p1.y, p2.x, p2.y);
      if ( ! azimuth_pt_pt(&p1, &p2, &az) ) {{
        LWT_ELEMID id = edge->edge_id;
        _lwt_release_edges(edges, numedges);
        lwgeom_free(cleangeom);
        lwerror("error computing azimuth of edge %d first edgeend [%.15g %.15g,%.15g %.15g]",
                id, p1.x, p1.y, p2.x, p2.y);
        return -1;
      }}
      azdif = az - data->myaz;
      LWDEBUGF(1, "azimuth of edge %" LWTFMT_ELEMID
                  ": %g (diff: %g)", edge->edge_id, az, azdif);

      if ( azdif < 0 ) azdif += 2 * M_PI;
      if ( minaz == -1 ) {
        minaz = maxaz = azdif;
        data->nextCW = data->nextCCW = edge->edge_id; /* outgoing */
        data->cwFace = edge->face_left;
        data->ccwFace = edge->face_right;
        LWDEBUGF(1, "new nextCW and nextCCW edge is %" LWTFMT_ELEMID
                    ", outgoing, "
                    "with face_left %" LWTFMT_ELEMID " and face_right %" LWTFMT_ELEMID
                    " (face_right is new ccwFace, face_left is new cwFace)",
                    edge->edge_id, edge->face_left,
                    edge->face_right);
      } else {
        if ( azdif < minaz ) {
          data->nextCW = edge->edge_id; /* outgoing */
          data->cwFace = edge->face_left;
          LWDEBUGF(1, "new nextCW edge is %" LWTFMT_ELEMID
                      ", outgoing, "
                      "with face_left %" LWTFMT_ELEMID " and face_right %" LWTFMT_ELEMID
                      " (previous had minaz=%g, face_left is new cwFace)",
                      edge->edge_id, edge->face_left,
                      edge->face_right, minaz);
          minaz = azdif;
        }
        else if ( azdif > maxaz ) {
          data->nextCCW = edge->edge_id; /* outgoing */
          data->ccwFace = edge->face_right;
          LWDEBUGF(1, "new nextCCW edge is %" LWTFMT_ELEMID
                      ", outgoing, "
                      "with face_left %" LWTFMT_ELEMID " and face_right %" LWTFMT_ELEMID
                      " (previous had maxaz=%g, face_right is new ccwFace)",
                      edge->edge_id, edge->face_left,
                      edge->face_right, maxaz);
          maxaz = azdif;
        }
      }
    }

    if ( edge->end_node == node ) {
      getPoint2d_p(pa, pa->npoints-1, &p1);
      if ( ! _lwt_FirstDistinctVertex2D(pa, &p1, pa->npoints-1, -1, &p2) )
      {
        lwerror("Edge %d has no distinct vertices: [%.15g %.15g,%.15g %.15g]: ",
                edge->edge_id, p1.x, p1.y, p2.x, p2.y);
        return -1;
      }
      LWDEBUGF(1, "edge %" LWTFMT_ELEMID " ends on node %" LWTFMT_ELEMID
                  ", edgeend is %g,%g-%g,%g",
                  edge->edge_id, node, p1.x, p1.y, p2.x, p2.y);
      if ( ! azimuth_pt_pt(&p1, &p2, &az) ) {{
        LWT_ELEMID id = edge->edge_id;
        _lwt_release_edges(edges, numedges);
        lwgeom_free(cleangeom);
        lwerror("error computing azimuth of edge %d last edgeend [%.15g %.15g,%.15g %.15g]",
                id, p1.x, p1.y, p2.x, p2.y);
        return -1;
      }}
      azdif = az - data->myaz;
      LWDEBUGF(1, "azimuth of edge %" LWTFMT_ELEMID
                  ": %g (diff: %g)", edge->edge_id, az, azdif);
      if ( azdif < 0 ) azdif += 2 * M_PI;
      if ( minaz == -1 ) {
        minaz = maxaz = azdif;
        data->nextCW = data->nextCCW = -edge->edge_id; /* incoming */
        data->cwFace = edge->face_right;
        data->ccwFace = edge->face_left;
        LWDEBUGF(1, "new nextCW and nextCCW edge is %" LWTFMT_ELEMID
                    ", incoming, "
                    "with face_left %" LWTFMT_ELEMID " and face_right %" LWTFMT_ELEMID
                    " (face_right is new cwFace, face_left is new ccwFace)",
                    edge->edge_id, edge->face_left,
                    edge->face_right);
      } else {
        if ( azdif < minaz ) {
          data->nextCW = -edge->edge_id; /* incoming */
          data->cwFace = edge->face_right;
          LWDEBUGF(1, "new nextCW edge is %" LWTFMT_ELEMID
                      ", incoming, "
                      "with face_left %" LWTFMT_ELEMID " and face_right %" LWTFMT_ELEMID
                      " (previous had minaz=%g, face_right is new cwFace)",
                      edge->edge_id, edge->face_left,
                      edge->face_right, minaz);
          minaz = azdif;
        }
        else if ( azdif > maxaz ) {
          data->nextCCW = -edge->edge_id; /* incoming */
          data->ccwFace = edge->face_left;
          LWDEBUGF(1, "new nextCCW edge is %" LWTFMT_ELEMID
                      ", outgoing, from start point, "
                      "with face_left %" LWTFMT_ELEMID " and face_right %" LWTFMT_ELEMID
                      " (previous had maxaz=%g, face_left is new ccwFace)",
                      edge->edge_id, edge->face_left,
                      edge->face_right, maxaz);
          maxaz = azdif;
        }
      }
    }

    lwgeom_free(cleangeom);
  }
  if ( numedges ) _lwt_release_edges(edges, numedges);

  LWDEBUGF(1, "edges adjacent to azimuth %g"
              " (incident to node %" LWTFMT_ELEMID ")"
              ": CW:%" LWTFMT_ELEMID "(%g) CCW:%" LWTFMT_ELEMID "(%g)",
              data->myaz, node, data->nextCW, minaz,
              data->nextCCW, maxaz);

  if ( myedge_id < 1 && numedges && data->cwFace != data->ccwFace )
  {
    if ( data->cwFace != -1 && data->ccwFace != -1 ) {
      lwerror("Corrupted topology: adjacent edges %" LWTFMT_ELEMID " and %" LWTFMT_ELEMID
              " bind different face (%" LWTFMT_ELEMID " and %" LWTFMT_ELEMID ")",
              data->nextCW, data->nextCCW,
              data->cwFace, data->ccwFace);
      return -1;
    }
  }

  /* Return number of incident edges found */
  return numedges;
}

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