PostGIS  2.2.8dev-r@@SVN_REVISION@@

◆ circ_tree_distance_tree_internal()

static double circ_tree_distance_tree_internal ( const CIRC_NODE n1,
const CIRC_NODE n2,
double  threshold,
double *  min_dist,
double *  max_dist,
GEOGRAPHIC_POINT closest1,
GEOGRAPHIC_POINT closest2 
)
static

Definition at line 578 of file lwgeodetic_tree.c.

References circ_node_is_leaf(), circ_node_max_distance(), circ_node_min_distance(), circ_tree_contains_point(), circ_tree_get_point(), edge_distance_to_edge(), edge_distance_to_point(), edge_intersection(), edge_intersects(), circ_node::edge_num, GEOGRAPHIC_EDGE::end, FP_MIN, geog2cart(), geographic_point_init(), circ_node::geom_type, LWDEBUG, LWDEBUGF, lwtype_is_collection(), circ_node::nodes, circ_node::num_nodes, circ_node::p1, circ_node::p2, POLYGONTYPE, circ_node::pt_outside, sphere_distance(), GEOGRAPHIC_EDGE::start, POINT2D::x, and POINT2D::y.

Referenced by circ_tree_distance_tree().

579 {
580  double max;
581  double d, d_min;
582  int i;
583 
584  LWDEBUGF(4, "entered, min_dist=%.8g max_dist=%.8g, type1=%d, type2=%d", *min_dist, *max_dist, n1->geom_type, n2->geom_type);
585 /*
586  circ_tree_print(n1, 0);
587  circ_tree_print(n2, 0);
588 */
589 
590  /* Short circuit if we've already hit the minimum */
591  if( *min_dist < threshold || *min_dist == 0.0 )
592  return *min_dist;
593 
594  /* If your minimum is greater than anyone's maximum, you can't hold the winner */
595  if( circ_node_min_distance(n1, n2) > *max_dist )
596  {
597  LWDEBUGF(4, "pruning pair %p, %p", n1, n2);
598  return FLT_MAX;
599  }
600 
601  /* If your maximum is a new low, we'll use that as our new global tolerance */
602  max = circ_node_max_distance(n1, n2);
603  LWDEBUGF(5, "max %.8g", max);
604  if( max < *max_dist )
605  *max_dist = max;
606 
607  /* Polygon on one side, primitive type on the other. Check for point-in-polygon */
608  /* short circuit. */
609  if ( n1->geom_type == POLYGONTYPE && n2->geom_type && ! lwtype_is_collection(n2->geom_type) )
610  {
611  POINT2D pt;
612  circ_tree_get_point(n2, &pt);
613  LWDEBUGF(4, "n1 is polygon, testing if contains (%.5g,%.5g)", pt.x, pt.y);
614  if ( circ_tree_contains_point(n1, &pt, &(n1->pt_outside), NULL) )
615  {
616  LWDEBUG(4, "it does");
617  *min_dist = 0.0;
618  geographic_point_init(pt.x, pt.y, closest1);
619  geographic_point_init(pt.x, pt.y, closest2);
620  return *min_dist;
621  }
622  }
623  /* Polygon on one side, primitive type on the other. Check for point-in-polygon */
624  /* short circuit. */
625  if ( n2->geom_type == POLYGONTYPE && n1->geom_type && ! lwtype_is_collection(n1->geom_type) )
626  {
627  POINT2D pt;
628  circ_tree_get_point(n1, &pt);
629  LWDEBUGF(4, "n2 is polygon, testing if contains (%.5g,%.5g)", pt.x, pt.y);
630  if ( circ_tree_contains_point(n2, &pt, &(n2->pt_outside), NULL) )
631  {
632  LWDEBUG(4, "it does");
633  geographic_point_init(pt.x, pt.y, closest1);
634  geographic_point_init(pt.x, pt.y, closest2);
635  *min_dist = 0.0;
636  return *min_dist;
637  }
638  }
639 
640  /* Both leaf nodes, do a real distance calculation */
641  if( circ_node_is_leaf(n1) && circ_node_is_leaf(n2) )
642  {
643  double d;
644  GEOGRAPHIC_POINT close1, close2;
645  LWDEBUGF(4, "testing leaf pair [%d], [%d]", n1->edge_num, n2->edge_num);
646  /* One of the nodes is a point */
647  if ( n1->p1 == n1->p2 || n2->p1 == n2->p2 )
648  {
649  GEOGRAPHIC_EDGE e;
650  GEOGRAPHIC_POINT gp1, gp2;
651 
652  /* Both nodes are points! */
653  if ( n1->p1 == n1->p2 && n2->p1 == n2->p2 )
654  {
655  geographic_point_init(n1->p1->x, n1->p1->y, &gp1);
656  geographic_point_init(n2->p1->x, n2->p1->y, &gp2);
657  close1 = gp1; close2 = gp2;
658  d = sphere_distance(&gp1, &gp2);
659  }
660  /* Node 1 is a point */
661  else if ( n1->p1 == n1->p2 )
662  {
663  geographic_point_init(n1->p1->x, n1->p1->y, &gp1);
664  geographic_point_init(n2->p1->x, n2->p1->y, &(e.start));
665  geographic_point_init(n2->p2->x, n2->p2->y, &(e.end));
666  close1 = gp1;
667  d = edge_distance_to_point(&e, &gp1, &close2);
668  }
669  /* Node 2 is a point */
670  else
671  {
672  geographic_point_init(n2->p1->x, n2->p1->y, &gp1);
673  geographic_point_init(n1->p1->x, n1->p1->y, &(e.start));
674  geographic_point_init(n1->p2->x, n1->p2->y, &(e.end));
675  close1 = gp1;
676  d = edge_distance_to_point(&e, &gp1, &close2);
677  }
678  LWDEBUGF(4, " got distance %g", d);
679  }
680  /* Both nodes are edges */
681  else
682  {
683  GEOGRAPHIC_EDGE e1, e2;
685  POINT3D A1, A2, B1, B2;
686  geographic_point_init(n1->p1->x, n1->p1->y, &(e1.start));
687  geographic_point_init(n1->p2->x, n1->p2->y, &(e1.end));
688  geographic_point_init(n2->p1->x, n2->p1->y, &(e2.start));
689  geographic_point_init(n2->p2->x, n2->p2->y, &(e2.end));
690  geog2cart(&(e1.start), &A1);
691  geog2cart(&(e1.end), &A2);
692  geog2cart(&(e2.start), &B1);
693  geog2cart(&(e2.end), &B2);
694  if ( edge_intersects(&A1, &A2, &B1, &B2) )
695  {
696  d = 0.0;
697  edge_intersection(&e1, &e2, &g);
698  close1 = close2 = g;
699  }
700  else
701  {
702  d = edge_distance_to_edge(&e1, &e2, &close1, &close2);
703  }
704  LWDEBUGF(4, "edge_distance_to_edge returned %g", d);
705  }
706  if ( d < *min_dist )
707  {
708  *min_dist = d;
709  *closest1 = close1;
710  *closest2 = close2;
711  }
712  return d;
713  }
714  else
715  {
716  d_min = FLT_MAX;
717  /* Drive the recursion into the COLLECTION types first so we end up with */
718  /* pairings of primitive geometries that can be forced into the point-in-polygon */
719  /* tests above. */
720  if ( n1->geom_type && lwtype_is_collection(n1->geom_type) )
721  {
722  for ( i = 0; i < n1->num_nodes; i++ )
723  {
724  d = circ_tree_distance_tree_internal(n1->nodes[i], n2, threshold, min_dist, max_dist, closest1, closest2);
725  d_min = FP_MIN(d_min, d);
726  }
727  }
728  else if ( n2->geom_type && lwtype_is_collection(n2->geom_type) )
729  {
730  for ( i = 0; i < n2->num_nodes; i++ )
731  {
732  d = circ_tree_distance_tree_internal(n1, n2->nodes[i], threshold, min_dist, max_dist, closest1, closest2);
733  d_min = FP_MIN(d_min, d);
734  }
735  }
736  else if ( ! circ_node_is_leaf(n1) )
737  {
738  for ( i = 0; i < n1->num_nodes; i++ )
739  {
740  d = circ_tree_distance_tree_internal(n1->nodes[i], n2, threshold, min_dist, max_dist, closest1, closest2);
741  d_min = FP_MIN(d_min, d);
742  }
743  }
744  else if ( ! circ_node_is_leaf(n2) )
745  {
746  for ( i = 0; i < n2->num_nodes; i++ )
747  {
748  d = circ_tree_distance_tree_internal(n1, n2->nodes[i], threshold, min_dist, max_dist, closest1, closest2);
749  d_min = FP_MIN(d_min, d);
750  }
751  }
752  else
753  {
754  /* Never get here */
755  }
756 
757  return d_min;
758  }
759 }
double sphere_distance(const GEOGRAPHIC_POINT *s, const GEOGRAPHIC_POINT *e)
Given two points on a unit sphere, calculate their distance apart in radians.
Definition: lwgeodetic.c:898
double edge_distance_to_edge(const GEOGRAPHIC_EDGE *e1, const GEOGRAPHIC_EDGE *e2, GEOGRAPHIC_POINT *closest1, GEOGRAPHIC_POINT *closest2)
Calculate the distance between two edges.
Definition: lwgeodetic.c:1217
Two-point great circle segment from a to b.
Definition: lwgeodetic.h:41
int circ_tree_get_point(const CIRC_NODE *node, POINT2D *pt)
Returns a POINT2D that is a vertex of the input shape.
POINT2D * p2
#define POLYGONTYPE
Definition: liblwgeom.h:72
POINT2D * p1
#define LWDEBUG(level, msg)
Definition: lwgeom_log.h:50
static double circ_tree_distance_tree_internal(const CIRC_NODE *n1, const CIRC_NODE *n2, double threshold, double *min_dist, double *max_dist, GEOGRAPHIC_POINT *closest1, GEOGRAPHIC_POINT *closest2)
#define FP_MIN(A, B)
Point in spherical coordinates on the world.
Definition: lwgeodetic.h:32
double x
Definition: liblwgeom.h:312
static int circ_node_is_leaf(const CIRC_NODE *node)
Internal nodes have their point references set to NULL.
static double circ_node_max_distance(const CIRC_NODE *n1, const CIRC_NODE *n2)
GEOGRAPHIC_POINT start
Definition: lwgeodetic.h:43
double edge_distance_to_point(const GEOGRAPHIC_EDGE *e, const GEOGRAPHIC_POINT *gp, GEOGRAPHIC_POINT *closest)
Definition: lwgeodetic.c:1166
int circ_tree_contains_point(const CIRC_NODE *node, const POINT2D *pt, const POINT2D *pt_outside, int *on_boundary)
Walk the tree and count intersections between the stab line and the edges.
int lwtype_is_collection(uint8_t type)
Determine whether a type number is a collection or not.
Definition: lwgeom.c:999
GEOGRAPHIC_POINT end
Definition: lwgeodetic.h:44
double y
Definition: liblwgeom.h:312
void geog2cart(const GEOGRAPHIC_POINT *g, POINT3D *p)
Convert spherical coordinates to cartesion coordinates on unit sphere.
Definition: lwgeodetic.c:354
int edge_intersects(const POINT3D *A1, const POINT3D *A2, const POINT3D *B1, const POINT3D *B2)
Returns non-zero if edges A and B interact.
Definition: lwgeodetic.c:3099
static double circ_node_min_distance(const CIRC_NODE *n1, const CIRC_NODE *n2)
void geographic_point_init(double lon, double lat, GEOGRAPHIC_POINT *g)
Initialize a geographic point.
Definition: lwgeodetic.c:156
POINT2D pt_outside
#define LWDEBUGF(level, msg,...)
Definition: lwgeom_log.h:55
int edge_intersection(const GEOGRAPHIC_EDGE *e1, const GEOGRAPHIC_EDGE *e2, GEOGRAPHIC_POINT *g)
Returns true if an intersection can be calculated, and places it in *g.
Definition: lwgeodetic.c:1075
struct circ_node ** nodes
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