test-cube-with-hole.cc

Construct a topological cube with a through hole using Euler operators. Geometrically, the constructed cube collapses to a single point, because All vertices are assigned to the same coords(1,1,1); to form a real cube, assign different pnt apropriately at each operation.

Author:

Xianming Chen
Computer Science Department
University of Utah

Date:

16 Aug 2006
Copyright (c) 2006, University of Utah

/**
 *\file       test-cube-with-hole.cc
 *
 *\brief      Construct a topological cube with a through hole directly using Euler operators.  
 *
 *\example    test-cube-with-hole.cc
 *
 *            Construct a topological cube with a through hole using Euler operators.  
 *            Geometrically, the constructed cube collapses to a single point, because 
 *            All vertices are assigned to the same coords(1,1,1);                       
 *            to form a real cube, assign different pnt apropriately at each operation.
 *              
 *
 *\image        html construct-cube-with-hole.jpg
 *
 *\author       Xianming Chen\n
 *              Computer Science Department\n
 *              University of Utah
 *
 *\date          16 Aug 2006\n
 *              Copyright (c) 2006, University of Utah
 */


#include "print.h"
using namespace std;
using namespace euler;


int main()
{
  point_t p(1.,1.,1.);  // geometrically collapsed to one pnt.

  /* 
   * intialize to skeletal cube: 
   * topology = 1 0d-cell + 1 2d-cells
   */
  solid_t *s = solid_t :: mvfs(p);
  loop_t *l = s->f->l;   // singular loop: 0
  cout << s << endl;
  
  /* 
   * add 3 consecutive dangling edges to form an open square:
   * topology = 4 0d-cell + 3 1d-cells + 1 2d-cell          
   */
  l->mev( l->mev( l->mev( l->f->l->e, p ), p ), p );
  l->del_single_vertex_edge_pair();      // loop = 0 1 2 3 2 1
  cout << l << endl;   
  

  /*
   * close the open square by splitting the loop
   * topology = 2 2d-cells (faces) + 4 1d-cells (edges) + 4 0d-cells (vertices)
   */
  s->mef(l->e, l->e->nxt->nxt->nxt);    // new loop: 3 0 1 2  (top cube face), old loop l= 0 3 2 1
  cout << s << endl;                   
  cout << l << endl;                   

  
  /*
   * next, add a dangling edge to each vertex of the square
   */
  edge_t
    *e03 = l->e,
    *e10 = e03->pre,
    *e21 = e10->pre,
    *e32 = e21->pre;

  l->mev(e03, p);

  l->mev(e10, p);

  l->mev(e21, p);
  l->mev(e32, p);   // now: 0 3 7 3 2 6 2 1 5 1 0 4
  cout << s << endl;
  cout << l << endl;

  /*
   * close the 4 opening squares to form the cube
   */
  edge_t
    *e40 = l->e->pre,
    *e73 = l->e->nxt->nxt,
    *e62 = e73->nxt->nxt->nxt,
    *e51 = e62->nxt->nxt->nxt;
    
  s->mef(e40, e73);
  s->mef(e73, e62);
  s->mef(e62, e51);
  s->mef(e51, e51->nxt->nxt->nxt);

  cout << s << endl;
    
  
  /*
   * contruct the "inner cube"
   */

  /*
   * make inner top face  
   */
  face_t* top = s->f->nxt->nxt->nxt->nxt;  // 3 0 1 2
  face_t* btm = s->f->nxt->nxt->nxt->nxt->nxt;  // 5 4 7 6
  
  l = top->kemr( top->l->mev(top->l->e->nxt, p)->o ); // singular: 8
    
  l->mev( l->mev( l->mev(l->e,p), p ), p ); 
  l->del_single_vertex_edge_pair();        // 8 9 A B A 9 

  //now top face has 2 loops, with the inner one zero area.
  cout << s << endl;
  cout << l << endl;

  //cut top face into two
  face_t* inner_top = s->mef(l->e, l->e->nxt->nxt->nxt)->f;
  cout << s << endl;


  /*
   * make inner bottom face  
   */
  l = btm->kemr( btm->l->mev(btm->l->e->nxt, p)->o ); // singular: 12
  
  l->mev( l->mev( l->mev(l->e,p), p ), p ); 
  l->del_single_vertex_edge_pair();        // 8 9 A B A 9  (all +4)

  //now btm face has 2 loops, with the inner one zero area.
  cout << s << endl;
  cout << l << endl;     
  
  //cut btm face into two
  face_t* inner_btm = s->mef(l->e->nxt->nxt->nxt, l->e)->f;
  cout << s << endl;

  cout << "inner_top = " << inner_top << endl;
  cout << "inner_btm = " << inner_btm << endl;
  

  s->kfmrh(inner_top, inner_btm);

  face_t* hole = inner_top;
  //now the vertical hole is annulus (or cynliner)
  cout << s << endl;
  cout << "...hole = \n" << hole << endl;

  edge_t
    *e89 = hole->l->e->nxt,     *eDC = hole->l->nxt->e->pre,
    *e9A = e89->nxt,            *eED = eDC->pre,                
    *eAB = e9A->nxt,            *eFE = eED->pre,                
    *eB8 = eAB->nxt,            *eCF = eFE->pre;                

//   cout << e89 << endl;
//   cout << e9A << endl;
//   cout << eAB << endl;
//   cout << eB8 << endl;

//   cout << eDC << endl;
//   cout << eED << endl;
//   cout << eFE << endl;
//   cout << eCF << endl;

  hole->mekr(e89, eCF);
  cout << s << endl;

  cout << "hole = \n" << hole << endl;
  //  exit(0);
  
  cout << "e9A=" << e9A << endl;
  cout << "eDC=" << eDC << endl;
  s->mef(e9A, eDC);
  cout << "hole = \n" << hole << endl;


  s->mef(eAB, eED);

  cout << eFE << endl << endl;
  cout << eB8 << endl;
  cout << eB8->nxt << endl;
  cout << eB8->nxt->nxt << endl;
  cout << eB8->nxt->nxt->nxt << endl;
  cout << eB8->nxt->nxt->nxt->nxt << endl;
  //  exit(0);
  
  s->mef(eB8, eFE);
  
  cout << s << endl;
  
    
  return 0;
}

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