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p4est_connectivity.h File Reference

The coarse topological description of the forest. More...

#include <sc_io.h>
#include <p4est_base.h>

Go to the source code of this file.

Data Structures

struct  p4est_connectivity_t
 This structure holds the 2D inter-tree connectivity information. More...
 
struct  p4est_corner_transform_t
 
struct  p4est_corner_info_t
 

Macros

#define P4EST_DIM   2
 The spatial dimension.
 
#define P4EST_FACES   (2 * P4EST_DIM)
 The number of faces of a quadrant.
 
#define P4EST_CHILDREN   4
 The number of children of a quadrant. More...
 
#define P4EST_HALF   (P4EST_CHILDREN / 2)
 The number of children/corners touching one face.
 
#define P4EST_INSUL   9
 The size of insulation layer.
 
#define P4EST_FTRANSFORM   9
 
#define P4EST_STRING   "p4est"
 p4est identification string
 
#define P4EST_ONDISK_FORMAT   0x2000009
 

Enumerations

enum  p4est_connect_type_t { P4EST_CONNECT_FACE = 21, P4EST_CONNECT_CORNER = 22, P4EST_CONNECT_FULL = P4EST_CONNECT_CORNER }
 Characterize a type of adjacency. More...
 
enum  p4est_connectivity_encode_t { P4EST_CONN_ENCODE_NONE = SC_IO_ENCODE_NONE, P4EST_CONN_ENCODE_LAST }
 Typedef for serialization method. More...
 

Functions

int p4est_connect_type_int (p4est_connect_type_t btype)
 Convert the p4est_connect_type_t into a number. More...
 
const char * p4est_connect_type_string (p4est_connect_type_t btype)
 Convert the p4est_connect_type_t into a const string. More...
 
size_t p4est_connectivity_memory_used (p4est_connectivity_t *conn)
 Calculate memory usage of a connectivity structure. More...
 
int p4est_connectivity_face_neighbor_corner_orientation (int c, int f, int nf, int o)
 Transform a corner across one of the adjacent faces into a neighbor tree. More...
 
p4est_connectivity_tp4est_connectivity_new (p4est_topidx_t num_vertices, p4est_topidx_t num_trees, p4est_topidx_t num_corners, p4est_topidx_t num_ctt)
 Allocate a connectivity structure. More...
 
p4est_connectivity_tp4est_connectivity_new_copy (p4est_topidx_t num_vertices, p4est_topidx_t num_trees, p4est_topidx_t num_corners, const double *vertices, const p4est_topidx_t *ttv, const p4est_topidx_t *ttt, const int8_t *ttf, const p4est_topidx_t *ttc, const p4est_topidx_t *coff, const p4est_topidx_t *ctt, const int8_t *ctc)
 Allocate a connectivity structure and populate from constants. More...
 
void p4est_connectivity_destroy (p4est_connectivity_t *connectivity)
 Destroy a connectivity structure. More...
 
void p4est_connectivity_set_attr (p4est_connectivity_t *conn, size_t bytes_per_tree)
 Allocate or free the attribute fields in a connectivity. More...
 
int p4est_connectivity_is_valid (p4est_connectivity_t *connectivity)
 Examine a connectivity structure. More...
 
int p4est_connectivity_is_equal (p4est_connectivity_t *conn1, p4est_connectivity_t *conn2)
 Check two connectivity structures for equality. More...
 
int p4est_connectivity_sink (p4est_connectivity_t *conn, sc_io_sink_t *sink)
 Write connectivity to a sink object. More...
 
sc_array_tp4est_connectivity_deflate (p4est_connectivity_t *conn, p4est_connectivity_encode_t code)
 Allocate memory and store the connectivity information there. More...
 
int p4est_connectivity_save (const char *filename, p4est_connectivity_t *connectivity)
 Save a connectivity structure to disk. More...
 
p4est_connectivity_tp4est_connectivity_source (sc_io_source_t *source)
 Read connectivity from a source object. More...
 
p4est_connectivity_tp4est_connectivity_inflate (sc_array_t *buffer)
 Create new connectivity from a memory buffer. More...
 
p4est_connectivity_tp4est_connectivity_load (const char *filename, size_t *bytes)
 Load a connectivity structure from disk. More...
 
p4est_connectivity_tp4est_connectivity_new_unitsquare (void)
 Create a connectivity structure for the unit square.
 
p4est_connectivity_tp4est_connectivity_new_periodic (void)
 Create a connectivity structure for an all-periodic unit square.
 
p4est_connectivity_tp4est_connectivity_new_rotwrap (void)
 Create a connectivity structure for a periodic unit square. More...
 
p4est_connectivity_tp4est_connectivity_new_corner (void)
 Create a connectivity structure for a three-tree mesh around a corner.
 
p4est_connectivity_tp4est_connectivity_new_pillow (void)
 Create a connectivity structure for two trees on top of each other.
 
p4est_connectivity_tp4est_connectivity_new_moebius (void)
 Create a connectivity structure for a five-tree moebius band.
 
p4est_connectivity_tp4est_connectivity_new_star (void)
 Create a connectivity structure for a six-tree star.
 
p4est_connectivity_tp4est_connectivity_new_cubed (void)
 Create a connectivity structure for the six sides of a unit cube. More...
 
p4est_connectivity_tp4est_connectivity_new_disk (void)
 Create a connectivity structure for a five-tree flat spherical disk. More...
 
p4est_connectivity_tp4est_connectivity_new_brick (int mi, int ni, int periodic_a, int periodic_b)
 An m by n array with periodicity in x and y if periodic_a and periodic_b are true, respectively.
 
p4est_connectivity_tp4est_connectivity_new_byname (const char *name)
 Create connectivity structure from predefined catalogue. More...
 
void p4est_expand_face_transform (int iface, int nface, int ftransform[])
 Fill an array with the axis combination of a face neighbor transform. More...
 
p4est_topidx_t p4est_find_face_transform (p4est_connectivity_t *connectivity, p4est_topidx_t itree, int iface, int ftransform[])
 Fill an array with the axis combinations of a tree neighbor transform. More...
 
void p4est_find_corner_transform (p4est_connectivity_t *connectivity, p4est_topidx_t itree, int icorner, p4est_corner_info_t *ci)
 Fills an array with information about corner neighbors. More...
 
void p4est_connectivity_complete (p4est_connectivity_t *conn)
 Internally connect a connectivity based on tree_to_vertex information. More...
 
void p4est_connectivity_reduce (p4est_connectivity_t *conn)
 Removes corner information of a connectivity such that enough information is left to run p4est_connectivity_complete successfully. More...
 
void p4est_connectivity_permute (p4est_connectivity_t *conn, sc_array_t *perm, int is_current_to_new)
 p4est_connectivity_permute Given a permutation perm of the trees in a connectivity conn, permute the trees of conn in place and update conn to match. More...
 
void p4est_connectivity_join_faces (p4est_connectivity_t *conn, p4est_topidx_t tree_left, p4est_topidx_t tree_right, int face_left, int face_right, int orientation)
 p4est_connectivity_join_faces This function takes an existing valid connectivity conn and modifies it by joining two tree faces that are currently boundary faces. More...
 
int p4est_connectivity_is_equivalent (p4est_connectivity_t *conn1, p4est_connectivity_t *conn2)
 p4est_connectivity_is_equivalent This function compares two connectivities for equivalence: it returns true if they are the same connectivity, or if they have the same topology. More...
 
static p4est_corner_transform_tp4est_corner_array_index (sc_array_t *array, size_t it)
 Return a pointer to a p4est_corner_transform_t array element. More...
 
int p4est_connectivity_read_inp_stream (FILE *stream, p4est_topidx_t *num_vertices, p4est_topidx_t *num_trees, double *vertices, p4est_topidx_t *tree_to_vertex)
 Read an ABAQUS input file from a file stream. More...
 
p4est_connectivity_tp4est_connectivity_read_inp (const char *filename)
 Create a p4est connectivity from an ABAQUS input file. More...
 

Variables

const int p4est_face_corners [4][2]
 Store the corner numbers 0..4 for each tree face. More...
 
const int p4est_face_dual [4]
 Store the face numbers in the face neighbor's system. More...
 
const int p4est_corner_faces [4][2]
 Store the face numbers 0..3 for each tree corner. More...
 
const int p4est_corner_face_corners [4][4]
 Store the face corner numbers for the faces touching a tree corner. More...
 
const int p4est_child_corner_faces [4][4]
 Store the faces for each child and corner, can be -1. More...
 

Detailed Description

The coarse topological description of the forest.

Macro Definition Documentation

#define P4EST_CHILDREN   4

The number of children of a quadrant.

also the nmber of corners

Enumeration Type Documentation

Characterize a type of adjacency.

Several functions involve relationships between neighboring trees and/or quadrants, and their behavior depends on how one defines adjacency: 1) entities are adjacent if they share a face, or 2) entities are adjacent if they share a face or corner. p4est_connect_type_t is used to choose the desired behavior. This enum must fit into an int8_t.

Typedef for serialization method.

Enumerator
P4EST_CONN_ENCODE_LAST 

Invalid entry to close the list.

Function Documentation

int p4est_connect_type_int ( p4est_connect_type_t  btype)

Convert the p4est_connect_type_t into a number.

Parameters
[in]btypeThe balance type to convert.
Returns
Returns 1 or 2.
const char* p4est_connect_type_string ( p4est_connect_type_t  btype)

Convert the p4est_connect_type_t into a const string.

Parameters
[in]btypeThe balance type to convert.
Returns
Returns a pointer to a constant string.
void p4est_connectivity_complete ( p4est_connectivity_t conn)

Internally connect a connectivity based on tree_to_vertex information.

Periodicity that is not inherent in the list of vertices will be lost.

Parameters
[in,out]connThe connectivity needs to have proper vertices and tree_to_vertex fields. The tree_to_tree and tree_to_face fields must be allocated and satisfy p4est_connectivity_is_valid (conn) but will be overwritten. The corner fields will be freed and allocated anew.
sc_array_t* p4est_connectivity_deflate ( p4est_connectivity_t conn,
p4est_connectivity_encode_t  code 
)

Allocate memory and store the connectivity information there.

Parameters
[in]connThe connectivity structure to be exported to memory.
[in]codeEncoding and compression method for serialization.
Returns
Newly created array that contains the information.
void p4est_connectivity_destroy ( p4est_connectivity_t connectivity)

Destroy a connectivity structure.

Also destroy all attributes.

int p4est_connectivity_face_neighbor_corner_orientation ( int  c,
int  f,
int  nf,
int  o 
)

Transform a corner across one of the adjacent faces into a neighbor tree.

This version expects the neighbor face and orientation separately.

Parameters
[in]cA corner number in 0..3.
[in]fA face number that touches the corner c.
[in]nfA neighbor face that is on the other side of .
[in]oThe orientation between tree boundary faces f and .
p4est_connectivity_t* p4est_connectivity_inflate ( sc_array_t buffer)

Create new connectivity from a memory buffer.

Parameters
[in]bufferThe connectivity is created from this memory buffer.
Returns
The newly created connectivity, or NULL on error.
int p4est_connectivity_is_equal ( p4est_connectivity_t conn1,
p4est_connectivity_t conn2 
)

Check two connectivity structures for equality.

Returns
Returns true if structures are equal, false otherwise.
int p4est_connectivity_is_equivalent ( p4est_connectivity_t conn1,
p4est_connectivity_t conn2 
)

p4est_connectivity_is_equivalent This function compares two connectivities for equivalence: it returns true if they are the same connectivity, or if they have the same topology.

The definition of topological sameness is strict: there is no attempt made to determine whether permutation and/or rotation of the trees makes the connectivities equivalent.

Parameters
[in]conn1a valid connectivity
[out]conn2a valid connectivity
int p4est_connectivity_is_valid ( p4est_connectivity_t connectivity)

Examine a connectivity structure.

Returns
Returns true if structure is valid, false otherwise.
void p4est_connectivity_join_faces ( p4est_connectivity_t conn,
p4est_topidx_t  tree_left,
p4est_topidx_t  tree_right,
int  face_left,
int  face_right,
int  orientation 
)

p4est_connectivity_join_faces This function takes an existing valid connectivity conn and modifies it by joining two tree faces that are currently boundary faces.

Parameters
[in,out]connconnectivity that will be altered.
[in]tree_lefttree that will be on the left side of the joined faces.
[in]tree_righttree that will be on the right side of the joined faces.
[in]face_leftface of tree_left that will be joined.
[in]face_rightface of tree_right that will be joined.
[in]orientationthe orientation of face_left and face_right once joined (see the description of p4est_connectivity_t to understand orientation).
p4est_connectivity_t* p4est_connectivity_load ( const char *  filename,
size_t *  bytes 
)

Load a connectivity structure from disk.

Parameters
[in]filenameName of the file to read.
[in,out]bytesSize in bytes of connectivity on disk or NULL.
Returns
Returns valid connectivity, or NULL on file error.
size_t p4est_connectivity_memory_used ( p4est_connectivity_t conn)

Calculate memory usage of a connectivity structure.

Parameters
[in]connConnectivity structure.
Returns
Memory used in bytes.
p4est_connectivity_t* p4est_connectivity_new ( p4est_topidx_t  num_vertices,
p4est_topidx_t  num_trees,
p4est_topidx_t  num_corners,
p4est_topidx_t  num_ctt 
)

Allocate a connectivity structure.

The attribute fields are initialized to NULL.

Parameters
[in]num_verticesNumber of total vertices (i.e. geometric points).
[in]num_treesNumber of trees in the forest.
[in]num_cornersNumber of tree-connecting corners.
[in]num_cttNumber of total trees in corner_to_tree array.
Returns
A connectivity structure with allocated arrays.
p4est_connectivity_t* p4est_connectivity_new_byname ( const char *  name)

Create connectivity structure from predefined catalogue.

Parameters
[in]nameInvokes connectivity_new_* function. brick23 brick (2, 3, 0, 0) corner corner cubed cubed disk disk moebius moebius periodic periodic pillow pillow rotwrap rotwrap star star unit unitsquare
Returns
An initialized connectivity if name is defined, NULL else.
p4est_connectivity_t* p4est_connectivity_new_copy ( p4est_topidx_t  num_vertices,
p4est_topidx_t  num_trees,
p4est_topidx_t  num_corners,
const double *  vertices,
const p4est_topidx_t ttv,
const p4est_topidx_t ttt,
const int8_t *  ttf,
const p4est_topidx_t ttc,
const p4est_topidx_t coff,
const p4est_topidx_t ctt,
const int8_t *  ctc 
)

Allocate a connectivity structure and populate from constants.

The attribute fields are initialized to NULL.

Parameters
[in]num_verticesNumber of total vertices (i.e. geometric points).
[in]num_treesNumber of trees in the forest.
[in]num_cornersNumber of tree-connecting corners.
[in]coffCorner-to-tree offsets (num_corners + 1 values).
Returns
The connectivity is checked for validity.
p4est_connectivity_t* p4est_connectivity_new_cubed ( void  )

Create a connectivity structure for the six sides of a unit cube.

The ordering of the trees is as follows: 0 1 2 3 <– 3: axis-aligned top side 4 5. This choice has been made for maximum symmetry (see tree_to_* in .c file).

p4est_connectivity_t* p4est_connectivity_new_disk ( void  )

Create a connectivity structure for a five-tree flat spherical disk.

The ordering of the trees is as follows: 4 1 2 3 0.

p4est_connectivity_t* p4est_connectivity_new_rotwrap ( void  )

Create a connectivity structure for a periodic unit square.

The left and right faces are identified, and bottom and top opposite.

void p4est_connectivity_permute ( p4est_connectivity_t conn,
sc_array_t perm,
int  is_current_to_new 
)

p4est_connectivity_permute Given a permutation perm of the trees in a connectivity conn, permute the trees of conn in place and update conn to match.

Parameters
[in,out]connThe connectivity whose trees are permuted.
[in]permA permutation array, whose elements are size_t's.
[in]is_current_to_newif true, the jth entry of perm is the new index for the entry whose current index is j, otherwise the jth entry of perm is the current index of the tree whose index will be j after the permutation.
p4est_connectivity_t* p4est_connectivity_read_inp ( const char *  filename)

Create a p4est connectivity from an ABAQUS input file.

This utility function reads a basic ABAQUS file supporting element type with the prefix C2D4, CPS4, and S4 in 2D and of type C3D8 reading them as bilinear quadrilateral and trilinear hexahedral trees respectively.

A basic 2D mesh is given below. The *Node section gives the vertex number and x, y, and z components for each vertex. The *Element section gives the 4 vertices in 2D (8 vertices in 3D) of each element in counter clockwise order. So in 2D the nodes are given as:

4 3 +----------------—+

+----------------—+ 1 2

and in 3D they are given as:

8 7 +------------------—+ |\ |\ | \ | \ | \ | \ | \ | \ | 5+------------------—+6 | | | | +-—|-------------—+ | 4\ | 3 \ | \ | \ | \ | \ | | | +------------------—+ 1 2

*Heading
box.inp
*Node
1, -5, -5, 0
2, 5, -5, 0
3, 5, 5, 0
4, -5, 5, 0
5, 0, -5, 0
6, 5, 0, 0
7, 0, 5, 0
8, -5, 0, 0
9, 1, -1, 0
10, 0, 0, 0
11, -2, 1, 0
*Element, type=CPS4, ELSET=Surface1
1, 1, 10, 11, 8
2, 3, 10, 9, 6
3, 9, 10, 1, 5
4, 7, 4, 8, 11
5, 11, 10, 3, 7
6, 2, 6, 9, 5

This function reads a mesh from filename and returns an associated p4est connectivity.

Parameters
[in]filenamefile to read the connectivity from
Returns
an allocated connectivity associated with the mesh in filename or NULL if an error occurred.
int p4est_connectivity_read_inp_stream ( FILE *  stream,
p4est_topidx_t num_vertices,
p4est_topidx_t num_trees,
double *  vertices,
p4est_topidx_t tree_to_vertex 
)

Read an ABAQUS input file from a file stream.

This utility function reads a basic ABAQUS file supporting element type with the prefix C2D4, CPS4, and S4 in 2D and of type C3D8 reading them as bilinear quadrilateral and trilinear hexahedral trees respectively.

A basic 2D mesh is given below. The *Node section gives the vertex number and x, y, and z components for each vertex. The *Element section gives the 4 vertices in 2D (8 vertices in 3D) of each element in counter clockwise order. So in 2D the nodes are given as:

4 3 +----------------—+

+----------------—+ 1 2

and in 3D they are given as:

8 7 +------------------—+ |\ |\ | \ | \ | \ | \ | \ | \ | 5+------------------—+6 | | | | +-—|-------------—+ | 4\ | 3 \ | \ | \ | \ | \ | | | +------------------—+ 1 2

*Heading
box.inp
*Node
1, -5, -5, 0
2, 5, -5, 0
3, 5, 5, 0
4, -5, 5, 0
5, 0, -5, 0
6, 5, 0, 0
7, 0, 5, 0
8, -5, 0, 0
9, 1, -1, 0
10, 0, 0, 0
11, -2, 1, 0
*Element, type=CPS4, ELSET=Surface1
1, 1, 10, 11, 8
2, 3, 10, 9, 6
3, 9, 10, 1, 5
4, 7, 4, 8, 11
5, 11, 10, 3, 7
6, 2, 6, 9, 5

This code can be called two ways. The first, when vertex==NULL and tree_to_vertex==NULL, is used to count the number of tress and vertices in the connectivity to be generated by the .inp mesh in the stream. The second, when vertices!=NULL and tree_to_vertex!=NULL, fill vertices and tree_to_vertex. In this case num_vertices and num_trees need to be set to the maximum number of entries allocated in vertices and tree_to_vertex.

Parameters
[in,out]streamfile stream to read the connectivity from
[in,out]num_verticesthe number of vertices in the connectivity
[in,out]num_treesthe number of trees in the connectivity
[out]verticesthe list of vertices of the connectivity
[out]tree_to_vertexthe tree_to_vertex map of the connectivity
Returns
0 if successful and nonzero if not
void p4est_connectivity_reduce ( p4est_connectivity_t conn)

Removes corner information of a connectivity such that enough information is left to run p4est_connectivity_complete successfully.

The reduced connectivity still passes p4est_connectivity_is_valid.

Parameters
[in,out]connThe connectivity to be reduced.
int p4est_connectivity_save ( const char *  filename,
p4est_connectivity_t connectivity 
)

Save a connectivity structure to disk.

Parameters
[in]filenameName of the file to write.
[in]connectivityValid connectivity structure.
Returns
Returns 0 on success, nonzero on file error.
void p4est_connectivity_set_attr ( p4est_connectivity_t conn,
size_t  bytes_per_tree 
)

Allocate or free the attribute fields in a connectivity.

Parameters
[in,out]connThe conn->*_to_attr fields must either be NULL or previously be allocated by this function.
[in]bytes_per_treeIf 0, tree_to_attr is freed (being NULL is ok). If positive, requested space is allocated.
int p4est_connectivity_sink ( p4est_connectivity_t conn,
sc_io_sink_t *  sink 
)

Write connectivity to a sink object.

Parameters
[in]connThe connectivity to be written.
[in,out]sinkThe connectivity is written into this sink.
Returns
0 on success, nonzero on error.
p4est_connectivity_t* p4est_connectivity_source ( sc_io_source_t *  source)

Read connectivity from a source object.

Parameters
[in,out]sourceThe connectivity is read from this source.
Returns
The newly created connectivity, or NULL on error.
static p4est_corner_transform_t* p4est_corner_array_index ( sc_array_t array,
size_t  it 
)
inlinestatic

Return a pointer to a p4est_corner_transform_t array element.

void p4est_expand_face_transform ( int  iface,
int  nface,
int  ftransform[] 
)

Fill an array with the axis combination of a face neighbor transform.

Parameters
[in]ifaceThe number of the originating face.
[in]nfaceEncoded as nface = r * 4 + nf, where nf = 0..3 is the neigbbor's connecting face number and r = 0..1 is the relative orientation to the neighbor's face. This encoding matches p4est_connectivity_t.
[out]ftransformThis array holds 9 integers. [0,2] The coordinate axis sequence of the origin face, the first referring to the tangential and the second to the normal. A permutation of (0, 1). [3,5] The coordinate axis sequence of the target face. [6,8] Edge reversal flag for tangential axis (boolean); face code in [0, 3] for the normal coordinate q: 0: q' = -q 1: q' = q + 1 2: q' = q - 1 3: q' = 2 - q [1,4,7] 0 (unused for compatibility with 3D).
void p4est_find_corner_transform ( p4est_connectivity_t connectivity,
p4est_topidx_t  itree,
int  icorner,
p4est_corner_info_t ci 
)

Fills an array with information about corner neighbors.

Parameters
[in]itreeThe number of the originating tree.
[in]icornerThe number of the originating corner.
[in,out]ciA p4est_corner_info_t structure with initialized array.
p4est_topidx_t p4est_find_face_transform ( p4est_connectivity_t connectivity,
p4est_topidx_t  itree,
int  iface,
int  ftransform[] 
)

Fill an array with the axis combinations of a tree neighbor transform.

Parameters
[in]itreeThe number of the originating tree.
[in]ifaceThe number of the originating tree's face.
[out]ftransformThis array holds 9 integers. [0,2] The coordinate axis sequence of the origin face. [3,5] The coordinate axis sequence of the target face. [6,8] Edge reverse flag for axis t; face code for axis n. [1,4,7] 0 (unused for compatibility with 3D).
Returns
The face neighbor tree if it exists, -1 otherwise.

Variable Documentation

const int p4est_child_corner_faces[4][4]

Store the faces for each child and corner, can be -1.

const int p4est_corner_face_corners[4][4]

Store the face corner numbers for the faces touching a tree corner.

const int p4est_corner_faces[4][2]

Store the face numbers 0..3 for each tree corner.

const int p4est_face_corners[4][2]

Store the corner numbers 0..4 for each tree face.

const int p4est_face_dual[4]

Store the face numbers in the face neighbor's system.