Fix azimuth computation for 2.5D edge ends

The change disreguard vertical movemements of the edge and computes
azimuth of the first segment getting away from the node.

Includes automated testcase

See #3711

git-svn-id: http://svn.osgeo.org/postgis/trunk@15330 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/liblwgeom/lwgeom_topo.c b/liblwgeom/lwgeom_topo.c
index 9602238be9f5e2863600c00cf7801fa071c99218..17535cfacbc211b8b511d2731c71e05ebf6d5de6 100644 (file)
--- a/liblwgeom/lwgeom_topo.c
+++ b/liblwgeom/lwgeom_topo.c
@@ -1401,7 +1401,7 @@ typedef struct edgeend_t {
  * Get first distinct vertex from endpoint
  * @param pa the pointarray to seek points in
  * @param ref the point we want to search a distinct one
- * @param from vertex index to start from
+ * @param from vertex index to start from (will really start from "from"+dir)
  * @param dir  1 to go forward
  *            -1 to go backward
  * @return 0 if edge is collapsed (no distinct points)
@@ -1570,7 +1570,12 @@ _lwt_FindAdjacentEdges( LWT_TOPOLOGY* topo, LWT_ELEMID node, edgeend *data,
 
     if ( edge->start_node == node ) {
       getPoint2d_p(pa, 0, &p1);
-      getPoint2d_p(pa, 1, &p2);
+      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",
@@ -1627,7 +1632,12 @@ _lwt_FindAdjacentEdges( LWT_TOPOLOGY* topo, LWT_ELEMID node, edgeend *data,
 
     if ( edge->end_node == node ) {
       getPoint2d_p(pa, pa->npoints-1, &p1);
-      getPoint2d_p(pa, pa->npoints-2, &p2);
+      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);
@@ -2362,6 +2372,7 @@ _lwt_AddEdge( LWT_TOPOLOGY* topo,
   newedge.geom = geom;
   newedge.face_left = -1;
   newedge.face_right = -1;
+  /* TODO: should do the repeated points removal in 2D space */
   cleangeom = lwgeom_remove_repeated_points( lwline_as_lwgeom(geom), 0 );
 
   pa = lwgeom_as_lwline(cleangeom)->points;
@@ -2375,18 +2386,17 @@ _lwt_AddEdge( LWT_TOPOLOGY* topo,
   span.cwFace = span.ccwFace =
   epan.cwFace = epan.ccwFace = -1;
 
-  /* Compute azimut of first edge end on start node */
+  /* Compute azimuth of first edge end on start node */
   getPoint2d_p(pa, 0, &p1);
-  getPoint2d_p(pa, 1, &pn);
-  if ( p2d_same(&p1, &pn) ) {
+  if ( ! _lwt_FirstDistinctVertex2D(pa, &p1, 0, 1, &pn) )
+  {
     lwgeom_free(cleangeom);
-    /* Can still happen, for 2-point lines */
     lwerror("Invalid edge (no two distinct vertices exist)");
     return -1;
   }
   if ( ! azimuth_pt_pt(&p1, &pn, &span.myaz) ) {
     lwgeom_free(cleangeom);
-    lwerror("error computing azimuth of first edgeend [%g,%g-%g,%g]",
+    lwerror("error computing azimuth of first edgeend [%.15g %.15g,%.15g %.15g]",
             p1.x, p1.y, pn.x, pn.y);
     return -1;
   }
@@ -2394,10 +2404,16 @@ _lwt_AddEdge( LWT_TOPOLOGY* topo,
 
   /* Compute azimuth of last edge end on end node */
   getPoint2d_p(pa, pa->npoints-1, &p2);
-  getPoint2d_p(pa, pa->npoints-2, &pn);
+  if ( ! _lwt_FirstDistinctVertex2D(pa, &p2, pa->npoints-1, -1, &pn) )
+  {
+    lwgeom_free(cleangeom);
+    /* This should never happen as we checked the edge while computing first edgend */
+    lwerror("Invalid clean edge (no two distinct vertices exist) - should not happen");
+    return -1;
+  }
   lwgeom_free(cleangeom);
   if ( ! azimuth_pt_pt(&p2, &pn, &epan.myaz) ) {
-    lwerror("error computing azimuth of last edgeend [%g,%g-%g,%g]",
+    lwerror("error computing azimuth of last edgeend [%.15g %.15g,%.15g %.15g]",
             p2.x, p2.y, pn.x, pn.y);
     return -1;
   }

diff --git a/topology/test/regress/topogeo_addlinestring.sql b/topology/test/regress/topogeo_addlinestring.sql
index 283ef7048b08da4bb360dda76a5791d46da3f250..83397d0543d107afd00f928aad9c3d1efb5cb408 100644 (file)
--- a/topology/test/regress/topogeo_addlinestring.sql
+++ b/topology/test/regress/topogeo_addlinestring.sql
@@ -322,3 +322,13 @@ SELECT 't3412.L2', TopoGeo_AddLinestring('bug3412',
 '0102000000020000003AB42BBFEE4C22410010C5A997A6524167BB5DBDEE4C224117FE3DA85FA75241'
 ::geometry, 0);
 SELECT 't3412.end', DropTopology('bug3412');
+
+-- See http://trac.osgeo.org/postgis/ticket/3711
+SELECT 't3371.start', topology.CreateTopology('bug3711', 0, 0, true) > 1;
+SELECT 't3371.L1', topology.TopoGeo_AddLineString('bug3711',
+'LINESTRING (618369 4833784 0.88, 618370 4833784 1.93, 618370 4833780 1.90)'
+::geometry, 0);
+SELECT 't3371.L2', topology.TopoGeo_AddLineString( 'bug3711',
+'LINESTRING (618370 4833780 1.92, 618370 4833784 1.90, 618371 4833780 1.93)'
+::geometry, 0);
+SELECT 't3371.end', topology.DropTopology('bug3711');

diff --git a/topology/test/regress/topogeo_addlinestring_expected_newsnap b/topology/test/regress/topogeo_addlinestring_expected_newsnap
index 0c564763c3aae3a214479bfc4bdc182443eb2e27..475bb75982d06a5fe1abbecdc15c249644829e33 100644 (file)
--- a/topology/test/regress/topogeo_addlinestring_expected_newsnap
+++ b/topology/test/regress/topogeo_addlinestring_expected_newsnap
@@ -201,3 +201,8 @@ t3412.L2|3
 t3412.L2|5
 t3412.L2|4
 t3412.end|Topology 'bug3412' dropped
+t3371.start|t
+t3371.L1|1
+t3371.L2|3
+t3371.L2|2
+t3371.end|Topology 'bug3711' dropped

diff --git a/topology/test/regress/topogeo_addlinestring_expected_oldsnap b/topology/test/regress/topogeo_addlinestring_expected_oldsnap
index dec535d4b379e95bc8604b750549ea298144ccb4..f3e29c3c84848593e6273134651a551e951c23f2 100644 (file)
--- a/topology/test/regress/topogeo_addlinestring_expected_oldsnap
+++ b/topology/test/regress/topogeo_addlinestring_expected_oldsnap
@@ -198,3 +198,8 @@ t3412.L2|3
 t3412.L2|5
 t3412.L2|4
 t3412.end|Topology 'bug3412' dropped
+t3371.start|t
+t3371.L1|1
+t3371.L2|3
+t3371.L2|2
+t3371.end|Topology 'bug3711' dropped