Computes an objective function and its gradient over a restricted Voronoi diagram. More...

#include <geogram/voronoi/integration_simplex.h>

Inheritance diagram for GEO::IntegrationSimplex:

Public Member Functions
	~IntegrationSimplex () override
	IntegrationSimplex destructor.

virtual double	eval (index_t center_vertex_index, const GEOGen::Vertex &v0, const GEOGen::Vertex &v1, const GEOGen::Vertex &v2, index_t t, index_t t_adj=index_t(-1), index_t v_adj=index_t(-1))=0
	Computes the contribution of a given integration simplex to the function and its gradient. An integration simplex is obtained as the intersection between a Voronoi cell and a triangle or tetrahedron of a background mesh. More...

void	set_points_and_gradient (coord_index_t dimension, index_t nb_points, const double points, double g, Process::SpinLockArray *spinlocks=nullptr)
	Sets the input points and the location where the computed gradient will be stored. More...

bool	volumetric () const
	Tests whether this IntegrationSimplex is volumetric. More...

bool	background_mesh_has_varying_attribute () const
	Specifies whether the background mesh has varying attributes used in the computation. More...

virtual void	reset_thread_local_storage ()
	Before starting computation, resets thread local storage variables. More...

Public Member Functions inherited from GEO::Counted
void	ref () const
	Increments the reference count. More...

void	unref () const
	Decrements the reference count. More...

bool	is_shared () const
	Check if the object is shared. More...

int	nb_refs () const
	Gets the number of references that point to this object. More...

Protected Member Functions
	IntegrationSimplex (const Mesh &mesh, bool volumetric, index_t nb_frames, index_t nb_comp_per_frame, const double *frames)
	Constructs a new IntegrationSimplex. More...

const double *	point (index_t i) const
	Gets a point by index. More...

const double *	frame (index_t i) const
	Gets a frame by index. More...

Protected Member Functions inherited from GEO::Counted
	Counted ()
	Creates a reference counted object. More...

virtual	~Counted ()
	Destroys a reference counted object. More...

Protected Attributes
const Mesh &	mesh_

bool	volumetric_

index_t	nb_points_

index_t	points_stride_

const double *	points_

double *	g_

index_t	nb_frames_

index_t	nb_comp_per_frame_

const double *	frames_

Process::SpinLockArray *	spinlocks_

bool	varying_background_

Additional Inherited Members
Static Public Member Functions inherited from GEO::Counted
static void	ref (const Counted *counted)
	Increments the reference count. More...

static void	unref (const Counted *counted)
	Decrements the reference count. More...

Detailed Description

Computes an objective function and its gradient over a restricted Voronoi diagram.

This function can be used by CentroidalVoronoiTesselation and its variants to optimize the placement of points by minimizing an objective function. Sub-classing this class makes it possible to define new objective functions.

Definition at line 72 of file integration_simplex.h.

Constructor & Destructor Documentation

◆ IntegrationSimplex()

GEO::IntegrationSimplex::IntegrationSimplex	(	const Mesh &	mesh,
		bool	volumetric,
		index_t	nb_frames,
		index_t	nb_comp_per_frame,
		const double *	frames
	)

protected

Constructs a new IntegrationSimplex.

Parameters

[in]	mesh	the mesh
[in]	volumetric	true if volumetric, false if surfacic
[in]	nb_frames	number of frames, typically number of elements of the background mesh
[in]	nb_comp_per_frame	number of components per frame, 3 for 3-axis anisotropy, 1 for vector anisotropy.
[in]	frames	a const pointer to the array of 3nb_framesnb_comp_per_frame of frame coordinates.

Member Function Documentation

◆ background_mesh_has_varying_attribute()

bool GEO::IntegrationSimplex::background_mesh_has_varying_attribute ( ) const

inline

Specifies whether the background mesh has varying attributes used in the computation.

The RestrictedVoronoiDiagram class computes the intersection between a Voronoi diagram and a background mesh. If the triangles or tetrahedra of this background mesh have a property that varies on each triangle / tetrahedron, then the intersection between the Voronoi cells and each individual triangle / tetrahedron is computed. Default mode is constant, subclasses may override.

Return values

true	if the background mesh has varying attributes
false	otherwise

Definition at line 173 of file integration_simplex.h.

◆ eval()

virtual double GEO::IntegrationSimplex::eval	(	index_t	center_vertex_index,
		const GEOGen::Vertex &	v0,
		const GEOGen::Vertex &	v1,
		const GEOGen::Vertex &	v2,
		index_t	t,
		index_t	t_adj = `index_t(-1)`,
		index_t	v_adj = `index_t(-1)`
	)

pure virtual

Computes the contribution of a given integration simplex to the function and its gradient. An integration simplex is obtained as the intersection between a Voronoi cell and a triangle or tetrahedron of a background mesh.

Parameters

[in]	center_vertex_index	index of the first vertex of the integration simplex, that corresponds to one of the vertices of the Delaunay triangulation
[in]	v0	second vertex of the integration simplex, in both geometric and symbolic forms
[in]	v1	third vertex of the integration simplex, in both geometric and symbolic forms
[in]	v2	fourth vertex of the integration simplex, in both geometric and symbolic forms
[in]	t	the triangle or tetrahedron of the background mesh
[in]	t_adj	the background mesh tetrahedron adjacent to this integration simplex accros (`v0`, `v1`, `v2`) or index_t(-1) if no such tetrahedron exists.
[in]	v_adj	if (`v0`, `v1`, `v2`) is supported by a bisector, the index of the other extremity of the bisector, else index_t(-1)

◆ frame()

const double* GEO::IntegrationSimplex::frame ( index_t i ) const

inlineprotected

Gets a frame by index.

Parameters

[in] i index of the frame

Returns: a const pointer to the nb_components_per_frame coordinates of the frame

Definition at line 224 of file integration_simplex.h.

◆ point()

const double* GEO::IntegrationSimplex::point ( index_t i ) const

inlineprotected

Gets a point by index.

Parameters

[in] i index of the point

Returns: a const pointer to the coordinates of the point

Definition at line 213 of file integration_simplex.h.

◆ reset_thread_local_storage()

virtual void GEO::IntegrationSimplex::reset_thread_local_storage ( )

virtual

Before starting computation, resets thread local storage variables.

RestrictedVoronoiDiagram can operate in multi-threading mode. Some derived classes may need to reset some thread local storage variables before starting each thread.

◆ set_points_and_gradient()

void GEO::IntegrationSimplex::set_points_and_gradient	(	coord_index_t	dimension,
		index_t	nb_points,
		const double *	points,
		double *	g,
		Process::SpinLockArray *	spinlocks = `nullptr`
	)

inline

Sets the input points and the location where the computed gradient will be stored.

This function needs to be called once per evaluation of the objective function, before evaluating the contribution of the simplices with eval().

Parameters

[in]	dimension	number of coordinates of the points, or number of doubles between two consecutive points
[in]	nb_points	number of points
[in]	points	a const pointer to the contiguous array of coordinates of the points
[out]	g	a pointer to the components of the gradient of the objective function
[in]	spinlocks	a pointer to the spinlocks array to be used in multithreading mode, or nullptr in single-threaded mode

Definition at line 130 of file integration_simplex.h.

◆ volumetric()

bool GEO::IntegrationSimplex::volumetric ( ) const

inline

Tests whether this IntegrationSimplex is volumetric.

A volumetric IntegrationSimplex is meant to be computed over the Voronoi cells restricted to the tetrahedra of the mesh. A surfacic one is meant to be computed over the Voronoi cells restricted to the facets of the mesh.

Return values

true	if this IntegrationSimplex is volumetric
false	otherwise (surfacic)

Definition at line 153 of file integration_simplex.h.

The documentation for this class was generated from the following file:

geogram/voronoi/integration_simplex.h

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ IntegrationSimplex()

Member Function Documentation

◆ background_mesh_has_varying_attribute()

◆ eval()

◆ frame()

◆ point()

◆ reset_thread_local_storage()

◆ set_points_and_gradient()

◆ volumetric()