meshGFaceTransfinite.cpp

// Gmsh - Copyright (C) 1997-2008 C. Geuzaine, J.-F. Remacle
//
// See the LICENSE.txt file for license information. Please report all
// bugs and problems to <gmsh@geuz.org>.

#include <map>
#include "meshGFace.h"
#include "GVertex.h"
#include "GEdge.h"
#include "GFace.h"
#include "MVertex.h"
#include "MElement.h"
#include "Context.h"
#include "GmshMessage.h"
#include "Numeric.h"

#define SQU(a)      ((a)*(a))

extern Context_T CTX;

/*
   s4 +-----c3-----+ s3
      |            |
      |            |
     c4            c2
      |            |
      |            |
   s1 +-----c1-----+ s2
*/

// f(u,v) = (1-u) c4(v) + u c2(v) + (1-v) c1(u) + v c3(u)
//          - [ (1-u)(1-v) s1 + u(1-v) s2 + uv s3 + (1-u)v s4 ]
#define TRAN_QUA(c1,c2,c3,c4,s1,s2,s3,s4,u,v) \
   (1.-u)*c4+u*c2+(1.-v)*c1+v*c3-((1.-u)*(1.-v)*s1+u*(1.-v)*s2+u*v*s3+(1.-u)*v*s4)

// s1=s4=c4
// f(u,v) = u c2 (v) + (1-v) c1(u) + v c3(u) - u(1-v) s2 - uv s3
#define TRAN_TRI(c1,c2,c3,s1,s2,s3,u,v) u*c2+(1.-v)*c1+v*c3-(u*(1.-v)*s2+u*v*s3)

int MeshTransfiniteSurface(GFace *gf)
{
  if(gf->meshAttributes.Method != MESH_TRANSFINITE) return 0;

  Msg::StatusBar(2, true, "Meshing surface %d (transfinite)", gf->tag());

  std::vector<MVertex*> corners;

  if(gf->meshAttributes.corners.size()){
    // corners have been specified explicitly
    for(unsigned int i = 0; i < gf->meshAttributes.corners.size(); i++)
      corners.push_back(gf->meshAttributes.corners[i]->mesh_vertices[0]);
  }
  else{
    // try to find the corners automatically
    GEdgeLoop el(gf->edges());
    for(GEdgeLoop::iter it = el.begin(); it != el.end(); it++)
      corners.push_back(it->getBeginVertex()->mesh_vertices[0]);
  }

  if(corners.size () != 3 && corners.size () != 4){
    Msg::Error("Surface %d is transfinite but has %d corners",
	       gf->tag(), corners.size());
    return 0;
  }

  std::vector<MVertex*> d_vertices;
  std::vector<int> indices;
  computeEdgeLoops(gf, d_vertices, indices);

  if(indices.size () != 2){