PostGIS  3.0.6dev-r@@SVN_REVISION@@

◆ lwpoly_calculate_circ_tree()

static CIRC_NODE* lwpoly_calculate_circ_tree ( const LWPOLY lwpoly)
static

Definition at line 938 of file lwgeodetic_tree.c.

939 {
940  uint32_t i = 0, j = 0;
941  CIRC_NODE** nodes;
942  CIRC_NODE* node;
943 
944  /* One ring? Handle it like a line. */
945  if ( lwpoly->nrings == 1 )
946  {
947  node = circ_tree_new(lwpoly->rings[0]);
948  }
949  else
950  {
951  /* Calculate a tree for each non-trivial ring of the polygon */
952  nodes = lwalloc(lwpoly->nrings * sizeof(CIRC_NODE*));
953  for ( i = 0; i < lwpoly->nrings; i++ )
954  {
955  node = circ_tree_new(lwpoly->rings[i]);
956  if ( node )
957  nodes[j++] = node;
958  }
959  /* Put the trees into a spatially correlated order */
960  circ_nodes_sort(nodes, j);
961  /* Merge the trees pairwise up to a parent node and return */
962  node = circ_nodes_merge(nodes, j);
963  /* Don't need the working list any more */
964  lwfree(nodes);
965  }
966 
967  /* Metadata about polygons, we need this to apply P-i-P tests */
968  /* selectively when doing distance calculations */
969  node->geom_type = lwgeom_get_type((LWGEOM*)lwpoly);
970  lwpoly_pt_outside(lwpoly, &(node->pt_outside));
971 
972  return node;
973 }
void lwfree(void *mem)
Definition: lwutil.c:242
void * lwalloc(size_t size)
Definition: lwutil.c:227
int lwpoly_pt_outside(const LWPOLY *poly, POINT2D *pt_outside)
Definition: lwgeodetic.c:1527
CIRC_NODE * circ_tree_new(const POINTARRAY *pa)
Build a tree of nodes from a point array, one node per edge.
static CIRC_NODE * circ_nodes_merge(CIRC_NODE **nodes, int num_nodes)
static void circ_nodes_sort(CIRC_NODE **nodes, int num_nodes)
Given a list of nodes, sort them into a spatially consistent order, then pairwise merge them up into ...
static uint32_t lwgeom_get_type(const LWGEOM *geom)
Return LWTYPE number.
Definition: lwinline.h:135
POINTARRAY ** rings
Definition: liblwgeom.h:505
uint32_t nrings
Definition: liblwgeom.h:510
POINT2D pt_outside
uint32_t geom_type
Note that p1 and p2 are pointers into an independent POINTARRAY, do not free them.

References circ_nodes_merge(), circ_nodes_sort(), circ_tree_new(), circ_node::geom_type, lwalloc(), lwfree(), lwgeom_get_type(), lwpoly_pt_outside(), sort_node::node, LWPOLY::nrings, circ_node::pt_outside, and LWPOLY::rings.

Referenced by lwgeom_calculate_circ_tree().

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