LibMeshb Save

libMeshb version 7.80

A library to handle the *.meshb file format.

Overview

The Gamma Mesh Format (GMF) and the associated library libMeshb provide programers of simulation and meshing software with an easy way to store their meshes and physical solutions.
The GMF features more than 200 kinds of data types, like vertex, polyhedron, normal vector or vector solution field.
The libMeshb provides a convenient way to move data between those files, via keyword tags, and the user's own structures.
Transparent handling of ASCII & binary files.
Transparent handling of little & big endian files.
Optional ultra fast asynchronous and low level transfers. Can call user's own pre and post processing routines in a separate thread while accessing a file.

Prerequisites for Linux or macOS

• Install CMake
• A valid C99 compiler
• Open a shell window

Prerequisites for Windows

• You first need to install CMake. Do not forget to choose "add cmake to the path for all users", from the install panel.
• Then you need a valid C compiler like the free Visual Studio Community 2019
• Open the x64 Native Tools Command Prompt for VS (or x86 if you need to build a 32-bit version)

Build commands for all platforms

• unarchive the ZIP file
• cd libMeshb-master
• mkdir build
• cd build
• cmake ..
• cmake --build . --target install

Usage

The libMeshb library is written in ANSI C.
It is made of a single C file and a header file to be compiled and linked alongside the calling program.
It may be used in C and C++ programs (a partial Fortran77 API is provided).
Tested on Linux, macOS, and Windows 7->10.

Reading a mesh file is fairly easy:

("triangles.meshb" should be in version 1 with single precision floating points numbers)

int64_t LibIdx;
int i, ver, dim, NmbVer, NmbTri, (*Nodes)[4], *Domains;
float (*Coords)[3];

// Open the mesh file for reading
LibIdx = GmfOpenMesh( "triangles.meshb", GmfRead, &ver, &dim );

// Get the number of vertices and triangles
NmbVer = GmfStatKwd( LibIdx, GmfVertices  );
NmbTri = GmfStatKwd( LibIdx, GmfTriangles );

// Allocate memory accordingly
Nodes   = malloc( NmbTri * 4 * sizeof(int)   );
Coords  = malloc( NmbVer * 3 * sizeof(float) );
Domains = malloc( NmbVer     * sizeof(int)   );

// Move the file pointer to the vertices keyword
GmfGotoKwd( LibIdx, GmfVertices );

// Read each line of vertex data into your own data structures
for(i=0;i<NmbVer;i++)
  GmfGetLin( LibIdx, GmfVertices, &Coords[i][0], &Coords[i][1], &Coords[i][2], &Domains[i] );

// Move the file pointer to the triangles keyword
GmfGotoKwd( LibIdx, GmfTriangles );

// Read each line of triangle data into your own data structures
for(i=0;i<NmbTri;i++)
  GmfGetLin( LibIdx, GmfTriangles, &Nodes[i][0], &Nodes[i][1], &Nodes[i][2], &Nodes[i][3] );

// Close the mesh file !
GmfCloseMesh( LibIdx );