4.3.0.2 Definition/initialisation of MMG_Mesh structure:

to define the MMG_Mesh structure, you need to allocate and initialize all the elements described on the previous paragraph. The next steps explains how to do that and dive the C-code corresponding:

1. Define a pointer on a MMG_Mesh structure:
   

   MMG_pMesh mymmgmesh
   

2. Allocate this pointer:
   

   mymmgmesh = (MMG_pMesh)calloc(1,sizeof(MMG_Mesh));
   

3. Give the nodes, triangles and tetrahedra numbers of your mesh:
   

   mymmgmesh->np = nbpoint;
   mymmgmesh->nt = nbtri;
   mymmgmesh->ne = nbtetra;
   

4. Give the nodes, triangles, tetrahedra maximum numbers:
   

   mymmgmesh->npmax = nbpointmax;
   mymmgmesh->ntmax = nbtrimax;
   mymmgmesh->nemax = nbtetramax;
   

5. Allocate the structure Point, Tetra, Tria, Disp et adja
   

   mymmgmesh->point = (MMG_pPoint)calloc(mymmgmesh->npmax+1,sizeof(MMG_Point));
   mymmgmesh->tetra = (MMG_pTetra)calloc(mymmgmesh->nemax+1,sizeof(MMG_Tetra));
   mymmgmesh->tria = (MMG_pTria) calloc(mymmgmesh->ntmax+1,sizeof(MMG_Tria));
   mymmgmesh->adja = (int*)calloc(4*mymmgmesh->nemax+5,sizeof(int));
   mymmgmesh->disp = (MMG_pDispl)calloc(mymmgmesh->npmax+1,sizeof(MMG_Displ));
   mymmgmesh->disp->mv = (double*)calloc(3*(mymmgmesh->npmax+1),sizeof(double));
   mymmgmesh->disp->alpha = (short*)calloc(mymmgmesh->npmax+1,sizeof(short));
   

6. Initialize the Point structure, that means for all the nodes, give the coordinates and the reference:
   

   MMG_pMesh mymmgmesh;

   MMG_pPoint ppt;

   for (k=1; k<=mymmgmesh->np; k++) {

   ppt = &mymmgmesh->point[k];

   ppt->c[0] = coorx;

   ppt->c[1] = coory;

   ppt->c[2] = coorz;

   ppt->ref = logic;

   }

   NB :The node are numbered from $1$ to mymmgmesh->np in a contiguous way.
   

7. Initialize the Tetra structure, that means for all tetrahedra, give the number nodes of the four vertex and the reference:
   

   MMG_pMesh mymmgmesh;

   MMG_pTetra ptetra;

   for (k=1; k<=mymmgmesh->ne; k++) {

   ptetra = &mymmgmesh->tetra[k];

   ptetra->v[0] = num1;

   ptetra->v[1] = num2;

   ptetra->v[2] = num3;

   ptetra->v[3] = num4;

   ptetra->ref = logic;

   }

   NB :The tetrahedra are numbered from $1$ to mymmgmesh->ne in a contiguous way.
   

8. (optional) Initialize the Tria structure, that means for all surface triangles, dive the node number of the three vertex and the reference.
   

   MMG_pMesh mymmgmesh;

   MMG_pTria ptriangle;

   for (k=1; k<=mymmgmesh->nt; k++) {

   ptriangle = &mymmgmesh->tria[k];

   ptriangle->v[0] = num1;

   ptriangle->v[1] = num2;

   ptriangle->v[2] = num3;

   ptriangle->ref = logic;

   }

   NB :The node are numbered from $1$ to mymmgmesh->nt in a contiguous way
   

9. (optional) If you treat bodies movements, initialize the Disp structure:
   

   MMG_pMesh mymmgmesh;

   MMG_pDispl pd;

   for (k=1; k<mymmgmesh->np; k++) {

   pd = &mesh->mymmgdisp[k];

   pd->mv[0] = depx;

   pd->mv[1] = depy;

   pd->mv[2] = depz;

   }

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