仅提取个人认为较为重要的内容
#ifndef NGLIB
#define NGLIB
/*!
\file nglib.h
\brief Library interface to the netgen meshing kernel
\author Joachim Schoeberl
\date 7. May 2000
This header file provides access to the core functionality of the Netgen
Mesher via a library interface, without an interactive User Interface.
The intention of providing these set of functions is to allow system
developers to integrate Netgen into top-level code, to act as the low
level mesh generation / optimisation kernel.
*/
// ** Constants used within Netgen *********************
/// Maximum allowed number of nodes per volume element
#define NG_VOLUME_ELEMENT_MAXPOINTS 10
/// Maximum allowed number of nodes per surface element
#define NG_SURFACE_ELEMENT_MAXPOINTS 8
// *** Data-types for accessing Netgen functionality ***
/// Data type for NETGEN mesh
typedef
void
* Ng_Mesh;
/// Data type for NETGEN CSG geometry
typedef
void
* Ng_CSG_Geometry;
/// Data type for NETGEN 2D geometry
typedef
void
* Ng_Geometry_2D;
/// Data type for NETGEN STL geometry
typedef
void
* Ng_STL_Geometry;
OCCT必备类型,用于存储OCC模型相关
#ifdef OCCGEOMETRY
/// Data type for NETGEN OpenCascade geometry
typedef
void
* Ng_OCC_Geometry;
typedef
void
* Ng_OCC_TopTools_IndexedMapOfShape;
#endif
// *** Special Enum types used within Netgen ***********
/// Currently implemented surface element types
enum
Ng_Surface_Element_Type
{ NG_TRIG = 1, NG_QUAD = 2, NG_TRIG6 = 3, NG_QUAD6 = 4, NG_QUAD8 = 5 };
/// Currently implemented volume element types
enum
Ng_Volume_Element_Type
{ NG_TET = 1, NG_PYRAMID = 2, NG_PRISM = 3, NG_TET10 = 4 };
/// Values returned by Netgen functions
enum
Ng_Result
{
NG_ERROR = -1,
NG_OK = 0,
NG_SURFACE_INPUT_ERROR = 1,
NG_VOLUME_FAILURE = 2,
NG_STL_INPUT_ERROR = 3,
NG_SURFACE_FAILURE = 4,
NG_FILE_NOT_FOUND = 5
};
最为关键的类, 配离散需要的大多数参数
// *** Classes required for use within Netgen **********
/// Netgen Meshing Parameters class
class
Ng_Meshing_Parameters
{
public
:
int
uselocalh;
//!< Switch to enable / disable usage of local mesh size modifiers
double
maxh;
//!< Maximum global mesh size allowed
double
minh;
//!< Minimum global mesh size allowed
double
fineness;
//!< Mesh density: 0...1 (0 => coarse; 1 => fine)
double
grading;
//!< Mesh grading: 0...1 (0 => uniform mesh; 1 => aggressive local grading)
double
elementsperedge;
//!< Number of elements to generate per edge of the geometry
double
elementspercurve;
//!< Elements to generate per curvature radius
int
closeedgeenable;
//!< Enable / Disable mesh refinement at close edges
double
closeedgefact;
//!< Factor to use for refinement at close edges (larger => finer)
int
second_order;
//!< Generate second-order surface and volume elements
int
quad_dominated;
//!< Creates a Quad-dominated mesh
char
* meshsize_filename;
//!< Optional external mesh size file
int
optsurfmeshenable;
//!< Enable / Disable automatic surface mesh optimization
int
optvolmeshenable;
//!< Enable / Disable automatic volume mesh optimization
int
optsteps_3d;
//!< Number of optimize steps to use for 3-D mesh optimization
int
optsteps_2d;
//!< Number of optimize steps to use for 2-D mesh optimization
// Philippose - 13/09/2010
// Added a couple more parameters into the meshing parameters list
// from Netgen into Nglib
int
invert_tets;
//!< Invert all the volume elements
int
invert_trigs;
//!< Invert all the surface triangle elements
int
check_overlap;
//!< Check for overlapping surfaces during Surface meshing
int
check_overlapping_boundary;
//!< Check for overlapping surface elements before volume meshing
/*!全部参数的默认值
Default constructor for the Mesh Parameters class
Note: This constructor initialises the variables in the
class with the following default values
- #uselocalh: 1
- #maxh: 1000.0
- #fineness: 0.5
- #grading: 0.3
- #elementsperedge: 2.0
- #elementspercurve: 2.0
- #closeedgeenable: 0
- #closeedgefact: 2.0
- #secondorder: 0
- #meshsize_filename: null
- #quad_dominated: 0
- #optsurfmeshenable: 1
- #optvolmeshenable: 1
- #optsteps_2d: 3
- #optsteps_3d: 3
- #invert_tets: 0
- #invert_trigs:0
- #check_overlap: 1
- #check_overlapping_boundary: 1
*/
DLL_HEADER Ng_Meshing_Parameters();
/*!
Reset the meshing parameters to their defaults
This member function resets all the meshing parameters
of the object to the default values
*/
DLL_HEADER
void
Reset_Parameters();
/*!
Transfer local meshing parameters to internal meshing parameters
This member function transfers all the meshing parameters
defined in the local meshing parameters structure of nglib into
the internal meshing parameters structure used by the Netgen core
*/
DLL_HEADER
void
Transfer_Parameters();
};
// *** Functions Exported by this Library *************
// ------------------------------------------------------------------
// Netgen library initialisation / destruction functions
/*! \brief Initialise the Netgen library and prepare for use
This function needs to be called by the third-party
program before beginning to use the other Netgen
specific functions.
在自己的开发程序中,这个是第一个必须调用的函数
*/
DLL_HEADER
void
Ng_Init ();
/*! \brief Exit the Netgen meshing kernel in a clean manner
Use this function to exit the meshing sub-system in
a clean and orderly manner.
在自己的开发程序中,在最后一个一定要调用这个程序
*/
DLL_HEADER
void
Ng_Exit ();
/*! \brief Create a new (and empty) Netgen Mesh Structure
This function creates a new Netgen Mesh, initialises
it, and returns a pointer to the created mesh structure.
Use the returned pointer for subsequent operations
which involve mesh operations.
\return Ng_Mesh Pointer to a Netgen Mesh type #Ng_Mesh
创建一个Netgen对象,并初始化,返回该对象的指针.
*/
DLL_HEADER Ng_Mesh * Ng_NewMesh ();
/*! \brief Delete an existing Netgen Mesh Structure
Use this function to delete an existing Netgen mesh
structure and release the used memory.
\param mesh Pointer to an existing Netgen Mesh structure
of type #Ng_Mesh
删除一个已存在的Netgen对象
*/
DLL_HEADER
void
Ng_DeleteMesh (Ng_Mesh * mesh);
/*! \brief Save a Netgen Mesh to disk
This function allows a generated mesh structure to be saved
to disk.
A Mesh saved using this function, will be written to disk
in the Netgen VOL file format.
\param mesh Pointer to an existing Netgen Mesh structure
of type #Ng_Mesh
\param filename Pointer to a character array containing the
name of the file to which the mesh should
be saved
将已经mesh后的结果保存到电脑磁盘上,保存格式为vol (vol为Netgen自有格式)
*/
DLL_HEADER
void
Ng_SaveMesh(Ng_Mesh * mesh,
const
char
* filename);
/*! \brief Load a Netgen VOL Mesh from disk into memory
A Netgen mesh saved in the internal VOL format can be loaded
into a Netgen Mesh structure using this function.
\param filename Pointer to a character array containing the
name of the file to load
\return Ng_Mesh Pointer to a Netgen Mesh type #Ng_Mesh containing
the mesh loaded from disk
从电脑磁盘中加载一个vol格式的文件,返回一个指向Ng_Mesh类型的指针
*/
DLL_HEADER Ng_Mesh * Ng_LoadMesh(
const
char
* filename);
/*! \brief Merge a Netgen VOL Mesh from disk into an existing mesh in memory
A Netgen mesh saved in the internal VOL format can be merged
into an existing Netgen Mesh structure using this function.
\param mesh Name of the Mesh structure already existent in memory
\param filename Pointer to a character array containing the
name of the file to load
\return Ng_Result Status of the merge operation
*/
DLL_HEADER Ng_Result Ng_MergeMesh(Ng_Mesh * mesh,
const
char
* filename);
/*! \brief Merge one Netgen Mesh into another Netgen Mesh in the case
when both are already in memory
(NOTE: FUNCTION STILL WORK IN PROGRESS!!!)
This function can be used to merge two Netgen meshes already present
in memory.
\param mesh1 Parent Mesh structure into which the second mesh
will be merged
\param mesh2 Child mesh structure which will get merged into
the parent mesh
\return Ng_Result Status of the merge operation
用于合并两个已经存在于内存中的mesh文件.这里mesh2会被合并到mesh1中
*/
DLL_HEADER Ng_Result Ng_MergeMesh(Ng_Mesh * mesh1, Ng_Mesh * mesh2);
// ------------------------------------------------------------------
// ------------------------------------------------------------------
// Basic Meshing functions for manually adding points, surface elements
// and volume elements to a Netgen Mesh structure
/*! \brief Add a point to a given Netgen Mesh Structure
This function allows points to be directly added to a Netgen
mesh structure by providing the co-ordinates.
Each call to the function allows only one point to be added.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\param x Pointer to an array of type double containing the co-ordinates
of the point to be added in the form: \n
- x[0] = X co-ordinate
- x[1] = Y co-ordinate
- x[2] = Z co-ordinate
将一个点添加到mesh结构体中
*/
DLL_HEADER
void
Ng_AddPoint (Ng_Mesh * mesh,
double
* x);
/*! \brief Add a surface element to a given Netgen Mesh Structure
This function allows the top-level code to directly add individual
Surface Elements to a Netgen Mesh Structure by providing the type of
element to be added and the indices of the points which constitute the
element.
<i>Note:</i>
- The points referred to by the surface elements must have been
added prior to calling this function.
- Currently only triangular elements are supported, and the Surface Element
Type argument is not used.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\param et Surface Element type provided via the enumerated type
#Ng_Surface_Element_Type
\param pi Pointer to an array of integers containing the indices of the
points which constitute the surface element being added
将一个面添加到mesh结构体中.pi为指向一组点的下标.这些点是组成该面元素是已经被添加了的 ?
*/
DLL_HEADER
void
Ng_AddSurfaceElement (Ng_Mesh * mesh, Ng_Surface_Element_Type et,
int
* pi);
/*! \brief Add a volume element to a given Netgen Mesh Structure
This function allows the top-level code to directly add individual
Volume Elements to a Netgen Mesh Structure by providing the type of
element to be added and the indices of the points which constitute the
element.
<i>Note:</i>
- The points referred to by the volume elements must have been
added prior to calling this function.
- Currently only tetrahedral elements are supported, and the Volume Element
Type argument is not used.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\param et Volume Element type provided via the enumerated type
#Ng_Volume_Element_Type
\param pi Pointer to an array of integers containing the indices of the
points which constitute the volume element being added
添加volume元素
*/
DLL_HEADER
void
Ng_AddVolumeElement (Ng_Mesh * mesh, Ng_Volume_Element_Type et,
int
* pi);
// ------------------------------------------------------------------
// ------------------------------------------------------------------
// Local Mesh Size restriction / limiting utilities
/*! \brief Apply a global restriction on mesh element size
This utility allows the user to apply a global mesh element
size limitation.
During mesh creation, in the absence of an explicit local
size restriction around the neighbourhood of a point within
the meshing domain, this global size restriction will be
utilised.
<b>Note</b>: This function only limits the <b>Maximum</b>
size of an element within the mesh.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\param h Variable of type <i>double</i>, specifying the maximum
allowable mesh size
*/
DLL_HEADER
void
Ng_RestrictMeshSizeGlobal (Ng_Mesh * mesh,
double
h);
/*! \brief Locally restrict the mesh element size at the given point
Unlike the function #Ng_RestrictMeshSizeGlobal, this function
allows the user to locally restrict the maximum allowable mesh
size at a given point.
The point is specified via its three cartesian co-ordinates.
<b>Note</b>: This function only limits the <b>Maximum</b> size
of the elements around the specified point.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\param p Pointer to an Array of type <i>double</i>, containing
the three co-ordinates of the point in the form: \n
- p[0] = X co-ordinate
- p[1] = Y co-ordinate
- p[2] = Z co-ordinate
\param h Variable of type <i>double</i>, specifying the maximum
allowable mesh size at that point
*/
DLL_HEADER
void
Ng_RestrictMeshSizePoint (Ng_Mesh * mesh,
double
* p,
double
h);
/*! \brief Locally restrict the mesh element size within a specified box
Similar to the function #Ng_RestrictMeshSizePoint, this function
allows the size of elements within a mesh to be locally limited.
However, rather than limit the mesh size at a single point, this
utility restricts the local mesh size within a 3D Box region, specified
via the co-ordinates of the two diagonally opposite points of a cuboid.
<b>Note</b>: This function only limits the <b>Maximum</b> size
of the elements within the specified region.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\param pmin Pointer to an Array of type <i>double</i>, containing
the three co-ordinates of the first point of the cuboid: \n
- pmin[0] = X co-ordinate
- pmin[1] = Y co-ordinate
- pmin[2] = Z co-ordinate
\param pmax Pointer to an Array of type <i>double</i>, containing
the three co-ordinates of the opposite point of the
cuboid: \n
- pmax[0] = X co-ordinate
- pmax[1] = Y co-ordinate
- pmax[2] = Z co-ordinate
\param h Variable of type <i>double</i>, specifying the maximum
allowable mesh size at that point
*/
DLL_HEADER
void
Ng_RestrictMeshSizeBox (Ng_Mesh * mesh,
double
* pmin,
double
* pmax,
double
h);
// ------------------------------------------------------------------
// ------------------------------------------------------------------
// 3D Mesh Generation functions
/*! \brief Create a 3D Volume Mesh given a Surface Mesh
After creating a surface mesh, this function can be utilised
to automatically generate the corresponding 3D Volume Mesh.
Mesh generation parameters (such as grading, maximum element size,
etc.) are specified via the meshing parameters class which also
needs to be passed to this function.
<b>Note</b>: Currently, Netgen generates pure tetrahedral volume
meshes.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\param mp Pointer to a copy of the Meshing Parameters class
(#Ng_Meshing_Parameters), filled up with the
required values
\return Ng_Result Status of the Mesh Generation routine. More
details regarding the return value can be
found in the description of #Ng_Result
*/
DLL_HEADER Ng_Result Ng_GenerateVolumeMesh (Ng_Mesh * mesh, Ng_Meshing_Parameters * mp);
// ------------------------------------------------------------------
// ------------------------------------------------------------------
// Basic Mesh information functions
/*! \brief Returns the Number of Points present in the specified Mesh
Given an already existent Netgen Mesh Structure, this function
returns the number of points currently present within the Mesh.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\return
Integer Data-type with the number of points in the Mesh
返回mesh中点的数量
*/
DLL_HEADER
int
Ng_GetNP (Ng_Mesh * mesh);
/*! \brief Returns the Number of Surface Elements present in the specified Mesh
Given an already existent Netgen Mesh Structure, this function
returns the number of surface elements currently present within
the Mesh.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\return
Integer Data-type with the number of surface elements in the Mesh
返回mesh中面的数量
*/
DLL_HEADER
int
Ng_GetNSE (Ng_Mesh * mesh);
/*! \brief Returns the Number of Volume Elements present in the specified Mesh
Given an already existent Netgen Mesh Structure, this function
returns the number of volume elements currently present within
the Mesh.
\param mesh Pointer to an existing Netgen Mesh structure of
type #Ng_Mesh
\return
Integer Data-type with the number of volume elements in the Mesh
返回mesh中volume的数量
*/
DLL_HEADER
int
Ng_GetNE (Ng_Mesh * mesh);
// ------------------------------------------------------------------
// ------------------------------------------------------------------
// Mesh Topology functions
// Use these functions to extract points, surface / volume elements,
// perform topological searches, etc..etc...
// Return the Point Coordinates of a specified Point
// The x, y and z co-ordinates are returned in the array pointer as
// x[0] = x ; x[1] = y ; x[2] = z
//根据下标得到点三维坐标
DLL_HEADER
void
Ng_GetPoint (Ng_Mesh * mesh,
int
num,
double
* x);
// return surface and volume element in pi
DLL_HEADER Ng_Surface_Element_Type
Ng_GetSurfaceElement (Ng_Mesh * mesh,
int
num,
int
* pi);
DLL_HEADER Ng_Volume_Element_Type
Ng_GetVolumeElement (Ng_Mesh * mesh,
int
num,
int
* pi);
// ------------------------------------------------------------------
// **********************************************************
// ** STL Meshing **
// **********************************************************
// loads geometry from STL file
DLL_HEADER Ng_STL_Geometry * Ng_STL_LoadGeometry (
const
char
* filename,
int
binary = 0);
// generate new STL Geometry
DLL_HEADER Ng_STL_Geometry * Ng_STL_NewGeometry ();
// fills STL Geometry
// positive orientation
// normal vector may be null-pointer
DLL_HEADER
void
Ng_STL_AddTriangle (Ng_STL_Geometry * geom,
double
* p1,
double
* p2,
double
* p3,
double
* nv = NULL);
// add (optional) edges :
DLL_HEADER
void
Ng_STL_AddEdge (Ng_STL_Geometry * geom,
double
* p1,
double
* p2);
// after adding triangles (and edges) initialize
DLL_HEADER Ng_Result Ng_STL_InitSTLGeometry (Ng_STL_Geometry * geom);
// automatically generates edges:
DLL_HEADER Ng_Result Ng_STL_MakeEdges (Ng_STL_Geometry * geom,
Ng_Mesh* mesh,
Ng_Meshing_Parameters * mp);
// generates mesh, empty mesh must be already created.
DLL_HEADER Ng_Result Ng_STL_GenerateSurfaceMesh (Ng_STL_Geometry * geom,
Ng_Mesh * mesh,
Ng_Meshing_Parameters * mp);
#ifdef ACIS
// **********************************************************
// ** ACIS Meshing **
// **********************************************************
/// Data type for NETGEN STL geomty
typedef
void
* Ng_ACIS_Geometry;
// loads geometry from STL file
DLL_HEADER Ng_ACIS_Geometry * Ng_ACIS_LoadGeometry (
const
char
* filename);
// generates mesh, empty mesh must be already created.
DLL_HEADER Ng_Result Ng_ACIS_GenerateSurfaceMesh (Ng_ACIS_Geometry * geom,
Ng_Mesh * mesh,
Ng_Meshing_Parameters * mp);
#endif
#ifdef OCCGEOMETRY
// ***************************************************************************
// ** OpenCascade Geometry / Meshing Utilities 使用OCC相关离散函数
**
// ***************************************************************************
// Create new OCC Geometry Object
//创建一个OCC对象
DLL_HEADER Ng_OCC_Geometry * Ng_OCC_NewGeometry ();
// Delete an OCC Geometry Object
//删除OCC对象
DLL_HEADER Ng_Result Ng_OCC_DeleteGeometry (Ng_OCC_Geometry * geom);
// Loads geometry from STEP file
//加载STEP文件
DLL_HEADER Ng_OCC_Geometry * Ng_OCC_Load_STEP (
const
char
* filename);
// Loads geometry from IGES file
//加载IGES文件
DLL_HEADER Ng_OCC_Geometry * Ng_OCC_Load_IGES (
const
char
* filename);
// Loads geometry from BREP file
//加载BREP文件
DLL_HEADER Ng_OCC_Geometry * Ng_OCC_Load_BREP (
const
char
* filename);
// Set the local mesh size based on geometry / topology
设置局部离散尺寸
DLL_HEADER Ng_Result Ng_OCC_SetLocalMeshSize (Ng_OCC_Geometry * geom,
Ng_Mesh * mesh,
Ng_Meshing_Parameters * mp);
// Mesh the edges and add Face descriptors to prepare for surface meshing
DLL_HEADER Ng_Result Ng_OCC_GenerateEdgeMesh (Ng_OCC_Geometry * geom,
Ng_Mesh * mesh,
Ng_Meshing_Parameters * mp);
// Mesh the surfaces of an OCC geometry
DLL_HEADER Ng_Result Ng_OCC_GenerateSurfaceMesh (Ng_OCC_Geometry * geom,
Ng_Mesh * mesh,
Ng_Meshing_Parameters * mp);
// Get the face map of an already loaded OCC geometry
DLL_HEADER Ng_Result Ng_OCC_GetFMap(Ng_OCC_Geometry * geom,
Ng_OCC_TopTools_IndexedMapOfShape * FMap);
#endif // OCCGEOMETRY
// **********************************************************
// ** Mesh refinement algorithms **
// **********************************************************
// uniform mesh refinement
DLL_HEADER
void
Ng_Uniform_Refinement (Ng_Mesh * mesh);
// uniform mesh refinement with geometry adaption:
DLL_HEADER
void
Ng_2D_Uniform_Refinement (Ng_Geometry_2D * geom,
Ng_Mesh * mesh);
DLL_HEADER
void
Ng_STL_Uniform_Refinement (Ng_STL_Geometry * geom,
Ng_Mesh * mesh);
DLL_HEADER
void
Ng_CSG_Uniform_Refinement (Ng_CSG_Geometry * geom,
Ng_Mesh * mesh);
#ifdef OCCGEOMETRY
DLL_HEADER
void
Ng_OCC_Uniform_Refinement (Ng_OCC_Geometry * geom,
Ng_Mesh * mesh);
#endif
// **********************************************************
// ** Second Order mesh algorithms **
// **********************************************************
// convert mesh to second order
DLL_HEADER
void
Ng_Generate_SecondOrder (Ng_Mesh * mesh);
// convert mesh to second order with geometry adaption:
DLL_HEADER
void
Ng_2D_Generate_SecondOrder (Ng_Geometry_2D * geom,
Ng_Mesh * mesh);
DLL_HEADER
void
Ng_STL_Generate_SecondOrder (Ng_STL_Geometry * geom,
Ng_Mesh * mesh);
DLL_HEADER
void
Ng_CSG_Generate_SecondOrder (Ng_CSG_Geometry * geom,
Ng_Mesh * mesh);
#ifdef OCCGEOMETRY
DLL_HEADER
void
Ng_OCC_Generate_SecondOrder (Ng_OCC_Geometry * geom,
Ng_Mesh * mesh);
#endif
#endif // NGLIB
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