Forest topology in a conventional mesh format. More...

#include <p8est_ghost.h>

Include dependency graph for p8est_mesh.h:

This graph shows which files directly or indirectly include this file:

Data Structures
struct	p8est_mesh_params_t
	This structure contains the different parameters of mesh creation. More...

struct	p8est_mesh_t
	This structure contains complete mesh information on a 2:1 balanced forest. More...

struct	p8est_mesh_face_neighbor_t
	This structure can be used as the status of a face neighbor iterator. More...

Functions
size_t	p8est_mesh_memory_used (p8est_mesh_t *mesh)
	Calculate the memory usage of the mesh structure. More...

void	p8est_mesh_params_init (p8est_mesh_params_t *params)
	Initialize a default p8est_mesh_params_t structure. More...

p8est_mesh_t *	p8est_mesh_new (p8est_t p8est, p8est_ghost_t ghost, p8est_connect_type_t btype)
	Create a p8est_mesh structure. More...

p8est_mesh_t *	p8est_mesh_new_params (p8est_t p8est, p8est_ghost_t ghost, p8est_mesh_params_t *params)
	Create a new mesh. More...

void	p8est_mesh_destroy (p8est_mesh_t *mesh)
	Destroy a p8est_mesh structure. More...

p8est_quadrant_t *	p8est_mesh_get_quadrant (p8est_t p4est, p8est_mesh_t mesh, p4est_locidx_t qid)
	Access a process-local quadrant inside a forest. More...

p4est_locidx_t	p8est_mesh_get_neighbors (p8est_t p4est, p8est_ghost_t ghost, p8est_mesh_t mesh, p4est_locidx_t curr_quad_id, p4est_locidx_t direction, sc_array_t neighboring_quads, sc_array_t neighboring_encs, sc_array_t neighboring_qids)
	Lookup neighboring quads of quadrant in a specific direction. More...

p8est_quadrant_t *	p8est_mesh_quadrant_cumulative (p8est_t p8est, p8est_mesh_t mesh, p4est_locidx_t cumulative_id, p4est_topidx_t which_tree, p4est_locidx_t quadrant_id)
	Find a quadrant based on its cumulative number in the local forest. More...

void	p8est_mesh_face_neighbor_init2 (p8est_mesh_face_neighbor_t mfn, p8est_t p8est, p8est_ghost_t ghost, p8est_mesh_t mesh, p4est_topidx_t which_tree, p4est_locidx_t quadrant_id)
	Initialize a mesh neighbor iterator by quadrant index. More...

void	p8est_mesh_face_neighbor_init (p8est_mesh_face_neighbor_t mfn, p8est_t p8est, p8est_ghost_t ghost, p8est_mesh_t mesh, p4est_topidx_t which_tree, p8est_quadrant_t *quadrant)
	Initialize a mesh neighbor iterator by quadrant pointer. More...

p8est_quadrant_t *	p8est_mesh_face_neighbor_next (p8est_mesh_face_neighbor_t mfn, p4est_topidx_t ntree, p4est_locidx_t nquad, int nface, int *nrank)
	Move the iterator forward to loop around neighbors of the quadrant. More...

void *	p8est_mesh_face_neighbor_data (p8est_mesh_face_neighbor_t mfn, void ghost_data)
	Get the user data for the current face neighbor. More...

Detailed Description

Forest topology in a conventional mesh format.

A typical workflow starts with p8est_mesh_params_init to initialize a p8est_mesh_params_t, followed by eventual user-dependent changes to the parameters.

Next a p8est_mesh_t is created with p8est_mesh_new_params.

Now, the user can create a p8est_mesh_face_neighbor_t with p8est_mesh_face_neighbor_init and loop over a quadrants face neighbors by repeated calls to p8est_mesh_face_neighbor_next.

Once done, the mesh has to be destroyed with p8est_mesh_destroy.

Function Documentation

◆ p8est_mesh_destroy()

void p8est_mesh_destroy ( p8est_mesh_t * mesh )

Destroy a p8est_mesh structure.

Parameters

[in] mesh Mesh structure previously created by p8est_mesh_new.

◆ p8est_mesh_face_neighbor_data()

void * p8est_mesh_face_neighbor_data	(	p8est_mesh_face_neighbor_t *	mfn,
		void *	ghost_data
	)

Get the user data for the current face neighbor.

Parameters

[in]	mfn	Internal status of the iterator.
[in]	ghost_data	Data for the ghost quadrants that has been synchronized with p4est_ghost_exchange_data.

Returns: A pointer to the user data for the current neighbor.

◆ p8est_mesh_face_neighbor_init()

void p8est_mesh_face_neighbor_init	(	p8est_mesh_face_neighbor_t *	mfn,
		p8est_t *	p8est,
		p8est_ghost_t *	ghost,
		p8est_mesh_t *	mesh,
		p4est_topidx_t	which_tree,
		p8est_quadrant_t *	quadrant
	)

Initialize a mesh neighbor iterator by quadrant pointer.

Parameters

[out]	mfn	A p8est_mesh_face_neighbor_t to be initialized.
[in]	p8est	Forest to be worked with.
[in]	ghost	Ghost layer of the forest.
[in]	mesh	A mesh derived from the forest.
[in]	which_tree	Tree of quadrant whose neighbors are looped over.
[in]	quadrant	Pointer to quadrant contained in which_tree.

◆ p8est_mesh_face_neighbor_init2()

void p8est_mesh_face_neighbor_init2	(	p8est_mesh_face_neighbor_t *	mfn,
		p8est_t *	p8est,
		p8est_ghost_t *	ghost,
		p8est_mesh_t *	mesh,
		p4est_topidx_t	which_tree,
		p4est_locidx_t	quadrant_id
	)

Initialize a mesh neighbor iterator by quadrant index.

Parameters

[out]	mfn	A p8est_mesh_face_neighbor_t to be initialized.
[in]	p8est	Forest to be worked with.
[in]	ghost	Ghost layer of the forest.
[in]	mesh	A mesh derived from the forest.
[in]	which_tree	Tree of quadrant whose neighbors are looped over.
[in]	quadrant_id	Index relative to which_tree of quadrant.

◆ p8est_mesh_face_neighbor_next()

p8est_quadrant_t * p8est_mesh_face_neighbor_next	(	p8est_mesh_face_neighbor_t *	mfn,
		p4est_topidx_t *	ntree,
		p4est_locidx_t *	nquad,
		int *	nface,
		int *	nrank
	)

Move the iterator forward to loop around neighbors of the quadrant.

Parameters

[in,out]	mfn	Internal status of the iterator.
[out]	ntree	If not NULL, the tree number of the neighbor.
[out]	nquad	If not NULL, the quadrant number within tree. For ghosts instead the number in ghost layer.
[out]	nface	If not NULL, neighbor's face encoding as in quad_to_face array of p8est_mesh_t.
[out]	nrank	If not NULL, the owner process of the neighbor.

Returns: Either a real quadrant or one from the ghost layer. Returns NULL when the iterator is done.

◆ p8est_mesh_get_neighbors()

p4est_locidx_t p8est_mesh_get_neighbors	(	p8est_t *	p4est,
		p8est_ghost_t *	ghost,
		p8est_mesh_t *	mesh,
		p4est_locidx_t	curr_quad_id,
		p4est_locidx_t	direction,
		sc_array_t *	neighboring_quads,
		sc_array_t *	neighboring_encs,
		sc_array_t *	neighboring_qids
	)

Lookup neighboring quads of quadrant in a specific direction.

Parameters

[in]	p4est	Forest to be worked with.
[in]	ghost	Ghost quadrants.
[in]	mesh	Mesh structure.
[in]	curr_quad_id	Process-local ID of current quad.
[in]	direction	Direction in which to look for adjacent quadrants is encoded as follows: 0 .. 5 neighbor(-s) across f_i, 6 .. 17 neighbor(-s) across e_{i-6} 18 .. 25 neighbor(-s) across c_{i-18}
[out]	neighboring_quads	Array containing neighboring quad(-s) Needs to be empty, contains p4est_quadrant_t. May be NULL, then neighboring_qids* must not be NULL.
[out]	neighboring_encs	Array containing encodings for neighboring quads as described below Needs to be empty, contains int. CAUTION: Note, that the encodings differ from the encodings saved in the mesh. Positive values are for local quadrants, negative values indicate ghost quadrants. Faces: 1 .. 24 => same size neighbor (r * 6 + nf) + 1; nf = 0 .. 5 face index; r = 0 .. 3 relative orientation 25 .. 120 => double size neighbor 25 + h * 24 + r * 6 + nf; h = 0 .. 3 number of the subface; r, nf as above 121 .. 144 => half size neighbors 121 + r * 6 + nf; r, nf as above Edges: 1 .. 24 => same size neighbor r * 12 + ne + 1; ne = 0 .. 11 edge index; r = 0 .. 1 relative orientation 25 .. 72 => double size neighbor 25 + h * 24 + r * 12 + ne; h = 0 .. 1 number of the subedge; r, ne as above 73 .. 96 => half size neighbors 73 + r * 12 + ne; r, ne as above Corners: 1 .. 8 => nc + 1; nc = 0 .. 7 corner index
[out]	neighboring_qids	Array containing quadrant ids for neighboring quadrants. May be NULL, then no neighboring qids are collected. If non-NULL the array needs to be empty and will contain int.

◆ p8est_mesh_get_quadrant()

p8est_quadrant_t * p8est_mesh_get_quadrant	(	p8est_t *	p4est,
		p8est_mesh_t *	mesh,
		p4est_locidx_t	qid
	)

Access a process-local quadrant inside a forest.

Needs a mesh with populated quad_to_tree array. This is a special case of p8est_mesh_quadrant_cumulative.

Parameters

[in]	p4est	The forest.
[in]	mesh	The mesh.
[in]	qid	Process-local id of the quadrant (cumulative over trees).

Returns: A pointer to the requested quadrant.

◆ p8est_mesh_memory_used()

size_t p8est_mesh_memory_used ( p8est_mesh_t * mesh )

Calculate the memory usage of the mesh structure.

Parameters

[in] mesh Mesh structure.

Returns: Memory used in bytes.

◆ p8est_mesh_new()

p8est_mesh_t * p8est_mesh_new	(	p8est_t *	p8est,
		p8est_ghost_t *	ghost,
		p8est_connect_type_t	btype
	)

Create a p8est_mesh structure.

This function does not populate the quad_to_tree and quad_level fields and ignores corner neighbors across edge-hanging corners. To populate them, use p8est_mesh_new_params.

Parameters

[in]	p8est	A forest that is fully 2:1 balanced.
[in]	ghost	The ghost layer created from the provided p4est.
[in]	btype	Determines the highest codimension of neighbors.

Returns: A fully allocated mesh structure.

◆ p8est_mesh_new_params()

p8est_mesh_t * p8est_mesh_new_params	(	p8est_t *	p8est,
		p8est_ghost_t *	ghost,
		p8est_mesh_params_t *	params
	)

Create a new mesh.

Parameters

[in]	p8est	A forest that is fully 2:1 balanced.
[in]	ghost	The ghost layer created from the provided p4est.
[in]	params	The mesh creation parameters. If NULL, the function defaults to the parameters of p8est_mesh_params_init.

Returns: A fully allocated mesh structure.

◆ p8est_mesh_params_init()

void p8est_mesh_params_init ( p8est_mesh_params_t * params )

Initialize a default p8est_mesh_params_t structure.

The parameters are set to create the most basic mesh structure, without tree index and level lists and considering only face connections.

◆ p8est_mesh_quadrant_cumulative()

p8est_quadrant_t * p8est_mesh_quadrant_cumulative	(	p8est_t *	p8est,
		p8est_mesh_t *	mesh,
		p4est_locidx_t	cumulative_id,
		p4est_topidx_t *	which_tree,
		p4est_locidx_t *	quadrant_id
	)

Find a quadrant based on its cumulative number in the local forest.

If the quad_to_tree field of the mesh structure exists, this is O(1). Otherwise, we perform a binary search over the processor-local trees.

Parameters

[in]	p8est	Forest to be worked with.
[in]	mesh	A mesh derived from the forest.
[in]	cumulative_id	Cumulative index over all trees of quadrant. Must refer to a local (non-ghost) quadrant.
[in,out]	which_tree	If not NULL, the input value can be -1 or an initial guess for the quadrant's tree and output is the tree of returned quadrant.
[out]	quadrant_id	If not NULL, the number of quadrant in tree.

Returns: The identified quadrant.

Data Structures

Functions

Detailed Description

Function Documentation

◆ p8est_mesh_destroy()

◆ p8est_mesh_face_neighbor_data()

◆ p8est_mesh_face_neighbor_init()

◆ p8est_mesh_face_neighbor_init2()

◆ p8est_mesh_face_neighbor_next()

◆ p8est_mesh_get_neighbors()

◆ p8est_mesh_get_quadrant()

◆ p8est_mesh_memory_used()

◆ p8est_mesh_new()

◆ p8est_mesh_new_params()

◆ p8est_mesh_params_init()

◆ p8est_mesh_quadrant_cumulative()