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/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkFEMGenerateMesh.cxx,v $
Language: C++
Date: $Date: 2009-01-29 21:28:16 $
Version: $Revision: 1.9 $
Copyright (c) Insight Software Consortium. All rights reserved.
See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
#include "itkFEMGenerateMesh.h"
#include "itkFEMElement2DC0LinearQuadrilateral.h"
#include "itkFEMElement3DC0LinearHexahedron.h"
#include <math.h>
namespace itk {
namespace fem {
/**
* Generate a rectangular mesh of quadrilateral elements
*/
void Generate2DRectilinearMesh(itk::fem::Element::ConstPointer e0, Solver& S, vnl_vector<double>& orig, vnl_vector<double>& size, vnl_vector<double>& Nel)
{
// Check for correct number of dimensions
if(orig.size() != Element2DC0LinearQuadrilateral::NumberOfSpatialDimensions ||
size.size() != Element2DC0LinearQuadrilateral::NumberOfSpatialDimensions ||
Nel.size() != Element2DC0LinearQuadrilateral::NumberOfSpatialDimensions)
{
throw FEMException(__FILE__, __LINE__, "GenerateMesh<Element2DC0LinearQuadrilateral>::Rectangular");
}
// Clear existing elements, loads and nodes in Solver
S.load.clear();
S.el.clear();
S.node.clear();
// Number of nodes in each dimension
Nel[0]=vcl_floor(Nel[0]);
Nel[1]=vcl_floor(Nel[1]);
double Ni=static_cast<double>(Nel[0]);
double Nj=static_cast<double>(Nel[1]);
// Create nodes
Node::Pointer n;
int gn=0; // number of node
for(double j=0; j<=Nj; j++)
{
for(double i=0; i<=Ni; i++)
{
n=new Node(orig[0]+i*size[0]/Nel[0], orig[1]+j*size[1]/Nel[1]);
n->GN=gn;
gn++;
S.node.push_back(FEMP<Node>(n));
}
}
// Create elements
gn=0; // global number of the element
Element2DC0LinearQuadrilateral::Pointer e;
for(unsigned int j=0; j<Nj; j++)
{
for(unsigned int i=0; i<Ni; i++)
{
e=dynamic_cast<Element2DC0LinearQuadrilateral*>(e0->Clone());
e->SetNode(0,S.node.Find((unsigned int) (i+ (Ni+1)*j) ));
e->SetNode(1,S.node.Find((unsigned int) (i+1+(Ni+1)*j) ));
e->SetNode(2,S.node.Find((unsigned int) (i+1+(Ni+1)*(j+1)) ));
e->SetNode(3,S.node.Find((unsigned int) (i+ (Ni+1)*(j+1)) ));
e->GN=gn;
gn++;
S.el.push_back(FEMP<Element>(e));
}
}
}
/**
* Generate a rectangular mesh of hexahedron elements
*/
void Generate3DRectilinearMesh
(itk::fem::Element::ConstPointer e0, Solver& S, vnl_vector<double>& orig,
vnl_vector<double>& size, vnl_vector<double>& Nel)
{
// Check for correct number of dimensions
if(orig.size() != Element3DC0LinearHexahedron::NumberOfSpatialDimensions ||
size.size() != Element3DC0LinearHexahedron::NumberOfSpatialDimensions ||
Nel.size() != Element3DC0LinearHexahedron::NumberOfSpatialDimensions)
{
throw FEMException(__FILE__, __LINE__, "GenerateMesh<Element2DC0LinearQuadrilateral>::Rectangular");
}
// Number of nodes in each dimension
Nel[0]=vcl_floor(Nel[0]);
Nel[1]=vcl_floor(Nel[1]);
Nel[2]=vcl_floor(Nel[2]);
double Ni=static_cast<double>(Nel[0]);
double Nj=static_cast<double>(Nel[1]);
double Nk=static_cast<double>(Nel[2]);
// Create nodes
Node::Pointer n;
int gn=0; // number of node
for(double k=0; k<=Nk; k++)
{
for(double j=0; j<=Nj; j++)
{
for(double i=0; i<=Ni; i++)
{
double xx,yy,zz;
xx=orig[0]+i*size[0]/Nel[0];
yy=orig[1]+j*size[1]/Nel[1];
zz=orig[2]+k*size[2]/Nel[2];
//std::cout << " xx " << xx << " yy " << yy << " zz " << zz << std::endl;
n=new Node(xx,yy,zz);
n->GN=gn;
gn++;
S.node.push_back(FEMP<Node>(n));
}
}
}
// Create elements
gn=0; // global number of the element
itk::fem::Element3DC0LinearHexahedron::Pointer e;
for(unsigned int k=0; k<Nk; k++)
{
for(unsigned int j=0; j<Nj; j++)
{
for(unsigned int i=0; i<Ni; i++)
{
e=dynamic_cast<Element3DC0LinearHexahedron*>(e0->Clone());
e->SetNode(0,S.node.Find((unsigned int) (i+ (Ni+1)*(j +(Nj+1)*k) )));
e->SetNode(1,S.node.Find((unsigned int) (i+1+(Ni+1)*(j +(Nj+1)*k) )));
e->SetNode(2,S.node.Find((unsigned int) (i+1+(Ni+1)*(j+1+(Nj+1)*k) )));
e->SetNode(3,S.node.Find((unsigned int) (i+ (Ni+1)*(j+1+(Nj+1)*k) )));
e->SetNode(4,S.node.Find((unsigned int) (i+ (Ni+1)*(j +(Nj+1)*(k+1)) )));
e->SetNode(5,S.node.Find((unsigned int) (i+1+(Ni+1)*(j +(Nj+1)*(k+1)) )));
e->SetNode(6,S.node.Find((unsigned int) (i+1+(Ni+1)*(j+1+(Nj+1)*(k+1)) )));
e->SetNode(7,S.node.Find((unsigned int) (i+ (Ni+1)*(j+1+(Nj+1)*(k+1)) )));
e->GN=gn;
gn++;
S.el.push_back(FEMP<Element>(e));
}
}
}
}
}} // end namespace itk::fem
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