From 2971da18bf0a2d17dc0b4f903689f4739147d65a Mon Sep 17 00:00:00 2001
From: Christophe Geuzaine <cgeuzaine@ulg.ac.be>
Date: Fri, 8 Oct 2004 02:41:56 +0000
Subject: [PATCH] A small utility that reads a Gmsh mesh file and makes the
numbering dense (without gaps in the node/element number sequences)
---
utils/misc/mshdensify.cpp | 267 ++++++++++++++++++++++++++++++++++++++
1 file changed, 267 insertions(+)
create mode 100644 utils/misc/mshdensify.cpp
diff --git a/utils/misc/mshdensify.cpp b/utils/misc/mshdensify.cpp
new file mode 100644
index 0000000000..b6c971c360
--- /dev/null
+++ b/utils/misc/mshdensify.cpp
@@ -0,0 +1,267 @@
+// $Id: mshdensify.cpp,v 1.1 2004-10-08 02:41:56 geuzaine Exp $
+//
+// Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+// USA.
+//
+// Please report all bugs and problems to <gmsh@geuz.org>.
+
+// A small utility that reads a Gmsh mesh file and makes the numbering
+// dense (without gaps in the node/element number sequences)
+
+#include <stdio.h>
+#include <strings.h>
+#include <vector>
+#include <map>
+
+using namespace std;
+
+int getNumNodes(int type)
+{
+ switch (type) {
+ case 15: return 1; // point
+ case 1 : return 2; // line 1
+ case 8 : return 2 + 1; // line 2
+ case 2 : return 3; // triangle 1
+ case 9 : return 3 + 3; // triangle 2
+ case 3 : return 4; // quadrangle 1
+ case 10: return 4 + 4 + 1; // quadrangle 2
+ case 4 : return 4; // tetrahedron 1
+ case 11: return 4 + 6; // tetrahedron 2
+ case 5 : return 8; // hexahedron 1
+ case 12: return 8 + 12 + 6 + 1; // hexahedron 2
+ case 6 : return 6; // prism 1
+ case 13: return 6 + 9 + 3; // prism 2
+ case 7 : return 5; // pyramid 1
+ case 14: return 5 + 8 + 1; // pyramid 2
+ default: return 0;
+ }
+}
+
+class node{
+ private:
+ int _num;
+ double _x, _y, _z;
+ public:
+ node(double x, double y, double z)
+ : _num(0), _x(x), _y(y), _z(z) {}
+ void setNum(int num){ _num = num; }
+ int getNum(){ return _num; }
+ void print(double version){
+ fprintf(stdout, "%d %.16g %.16g %.16g\n", _num, _x, _y, _z);
+ }
+};
+
+class element{
+ private:
+ int _num, _type, _physical, _elementary, _partition;
+ vector<node*> _nodes;
+ public:
+ element(int type, int physical, int elementary, int partition)
+ : _num(0), _type(type), _physical(physical), _elementary(elementary),
+ _partition(partition) {}
+ void setNum(int num){ _num = num; }
+ void addNode(node *n){ _nodes.push_back(n); }
+ void print(double version){
+ if(version == 2.0)
+ fprintf(stdout, "%d %d 3 %d %d %d", _num, _type, _physical,
+ _elementary, _partition);
+ else
+ fprintf(stdout, "%d %d %d %d %d", _num, _type, _physical,
+ _elementary, (int)_nodes.size());
+ for(unsigned int i = 0; i < _nodes.size(); i++)
+ fprintf(stdout, " %d", _nodes[i]->getNum());
+ fprintf(stdout, "\n");
+ }
+};
+
+double readMesh(char *fileName, map<int, node*> &nodes, vector<element*> &elements)
+{
+ FILE *fp = fopen(fileName, "r");
+
+ if(!fp){
+ fprintf(stderr, "Error: Unable to open file '%s'\n", fileName);
+ exit(1);
+ }
+
+ double version = 1.0;
+
+ while(1) {
+ char str[256];
+ do {
+ fgets(str, sizeof(str), fp);
+ if(feof(fp))
+ break;
+ } while(str[0] != '$');
+
+ if(feof(fp))
+ break;
+
+ if(!strncmp(&str[1], "MeshFormat", 10)) {
+ int format, size;
+ fscanf(fp, "%lf %d %d\n", &version, &format, &size);
+ if(version != 2.0){
+ fprintf(stderr, "Error: Wrong msh file version %g\n", version);
+ exit(1);
+ }
+ if(format){
+ fprintf(stderr, "Error: Unknown data format for mesh\n");
+ exit(1);
+ }
+ }
+ else if(!strncmp(&str[1], "NOD", 3) ||
+ !strncmp(&str[1], "NOE", 3) ||
+ !strncmp(&str[1], "Nodes", 5)) {
+ int numNodes;
+ fscanf(fp, "%d", &numNodes);
+ for(int i = 0; i < numNodes; i++) {
+ int num;
+ double x, y, z;
+ fscanf(fp, "%d %lf %lf %lf", &num, &x, &y, &z);
+ if(nodes.count(num)){
+ fprintf(stderr, "Error: node %d already exists\n", num);
+ exit(1);
+ }
+ else{
+ node *n = new node(x, y, z);
+ nodes[num] = n;
+ }
+ }
+ }
+ else if(!strncmp(&str[1], "ELM", 3) ||
+ !strncmp(&str[1], "Elements", 8)) {
+ int numElements;
+ fscanf(fp, "%d", &numElements);
+ for(int i = 0; i < numElements; i++) {
+ int num, type, physical, elementary, partition = 0, numNodes, numTags;
+ if(version <= 1.0){
+ fscanf(fp, "%d %d %d %d %d",
+ &num, &type, &physical, &elementary, &numNodes);
+ int numNodesCheck = getNumNodes(type);
+ if(!numNodesCheck){
+ fprintf(stderr, "Error: Unknown type %d for element %d\n", type, num);
+ exit(1);
+ }
+ if(numNodes != numNodesCheck){
+ fprintf(stderr, "Error: Wrong number of nodes for element %d\n", num);
+ exit(1);
+ }
+ }
+ else{
+ fscanf(fp, "%d %d %d", &num, &type, &numTags);
+ elementary = physical = partition = 1;
+ for(int j = 0; j < numTags; j++){
+ int tag;
+ fscanf(fp, "%d", &tag);
+ if(j == 0)
+ physical = tag;
+ else if(j == 1)
+ elementary = tag;
+ else if(j == 2)
+ partition = tag;
+ // ignore any other tags for now
+ }
+ numNodes = getNumNodes(type);
+ if(!numNodes){
+ fprintf(stderr, "Error: Unknown type %d for element %d\n", type, num);
+ exit(1);
+ }
+ }
+ element *e = new element(type, elementary, physical, partition);
+ for(int j = 0; j < numNodes; j++){
+ int numNode;
+ fscanf(fp, "%d", &numNode);
+ if(nodes.count(numNode)){
+ e->addNode(nodes[numNode]);
+ }
+ else{
+ fprintf(stderr, "Error: Unknown vertex %d in element %d\n", numNode, num);
+ exit(1);
+ }
+ }
+ elements.push_back(e);
+ }
+ }
+
+ do {
+ fgets(str, sizeof(str), fp);
+ if(feof(fp)){
+ fprintf(stderr, "Error: Prematured end of mesh file\n");
+ exit(1);
+ }
+ } while(str[0] != '$');
+
+ }
+
+ fclose(fp);
+
+ return version;
+}
+
+void printMesh(double version, map<int, node*> nodes, vector<element*> elements)
+{
+ map<int, node*>::const_iterator it = nodes.begin();
+ map<int, node*>::const_iterator ite = nodes.end();
+
+ if(version == 2.0){
+ fprintf(stdout, "$MeshFormat\n");
+ fprintf(stdout, "2.0 0 %d\n", sizeof(double));
+ fprintf(stdout, "$EndMeshFormat\n");
+ fprintf(stdout, "$Nodes\n");
+ }
+ else
+ fprintf(stdout, "$NOD\n");
+ fprintf(stdout, "%d\n", (int)nodes.size());
+
+ int index = 1;
+ for(;it!=ite;++it){
+ it->second->setNum(index++);
+ it->second->print(version);
+ }
+
+ if(version == 2.0){
+ fprintf(stdout, "$EndNodes\n");
+ fprintf(stdout, "$Elements\n");
+ }
+ else{
+ fprintf(stdout, "$ENDNOD\n");
+ fprintf(stdout, "$ELM\n");
+ }
+ fprintf(stdout, "%d\n", (int)elements.size());
+
+ for(unsigned int i = 0; i < elements.size(); i++){
+ elements[i]->setNum(i+1);
+ elements[i]->print(version);
+ }
+
+ if(version == 2.0)
+ fprintf(stdout, "$EndElements\n");
+ else
+ fprintf(stdout, "$ENDELM\n");
+}
+
+int main(int argc, char **argv)
+{
+ if(argc != 2){
+ fprintf(stderr, "Usage: %s file\n", argv[0]);
+ exit(1);
+ }
+
+ map<int, node*> nodes;
+ vector<element*> elements;
+ double version = readMesh(argv[1], nodes, elements);
+ printMesh(version, nodes, elements);
+}
--
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