---

flatten.C

Go to the documentation of this file.

//   version 1:  March 1994   Piet Hut

#include "dyn.h"

#ifndef TOOLBOX

//-----------------------------------------------------------------------------
//  unbundle_node  --  ...
//                 note:
//                      the positions and velocities of the daughters of the
//                      node-to-be-unbundled are increased by the values of the
//                      corresponding quantities of the node-to-be-unbundled;
//                      the other physical quantities of the daughters remain
//                      unchanged, while those of the node-to-be-unbundled are
//                      be discarded.
//                 note:
//                      the parent, daughter and grand daughters really should
//                      be synchronized in time; to be implemented.
//-----------------------------------------------------------------------------

local void  unbundle_node(dyn * ud)
    {
    dyn * parent;
    parent = ud->get_parent();

    if (parent == NULL)
        err_exit("unbundle() : no parent for this node");

    dyn * od;
    od = ud->get_oldest_daughter();

    if (od == NULL)
        return;                         // nothing left to unbundle

    vector pos = ud->get_pos();
    vector vel = ud->get_vel();

    for_all_daughters(dyn, ud, dd)
        {
        dd->inc_pos(pos);
        dd->inc_vel(vel);
        }

    // pointer adjustments:

    dyn * elder_sister;
    elder_sister = ud->get_elder_sister();

    if (elder_sister == NULL)
        parent->set_oldest_daughter(od);
    else
        {
        elder_sister->set_younger_sister(od);
        od->set_elder_sister(elder_sister);
        }

    dyn * d = od;
    dyn * pd;

    while (d)
        {
        d->set_parent(parent);
        pd = d;
        d = d->get_younger_sister();
        }
    
    dyn * younger_sister;
    younger_sister = ud->get_younger_sister();

    if (younger_sister)
        {
        younger_sister->set_elder_sister(pd);
        pd->set_younger_sister(younger_sister);
        }

    delete ud;
    }

/*-----------------------------------------------------------------------------
 *  flatten_node  --  
 *-----------------------------------------------------------------------------
 */
void  dyn::flatten_node()
    {
    for_all_daughters(dyn, this, d)
        {
        if (d->is_grandparent())
            d->flatten_node();

        unbundle_node(d);
        }
    }

/*===========================================================================*/

#else

//-----------------------------------------------------------------------------
//  main  --  driver to use  flatten_node() as a tool.
//-----------------------------------------------------------------------------

main(int argc, char ** argv)
{
    bool  c_flag = FALSE;
    char  *comment;

    check_help();

    extern char *poptarg;
    int c;
    char* param_string = "c:";

    while ((c = pgetopt(argc, argv, param_string)) != -1)
        switch(c) {

            case 'c': c_flag = TRUE;
                      comment = poptarg;
                      break;
            case '?': params_to_usage(cerr, argv[0], param_string);
                      get_help();
                      exit(1);
        }            

    dyn *b;

    while (b = get_dyn(cin)) {

        if (c_flag == TRUE)
            b->log_comment(comment);
        b->log_history(argc, argv);

        b->flatten_node();
        put_dyn(cout, *b);      
        delete b;
    }
}

#endif

// endof: flatten.C

---