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x_path.cpp

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// OMICRON ENGINE HEADER FILE
//
// --------------------------------------------------------------------------
// Copyright (C) 2001-2002 by Bjoern Paetzel <kolrabi@gmx.de>
//
// This file is part of the Omicron Engine.
//
// The Omicron Engine 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.
//
// The Omicron Engine  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 The Omicron Engine;  if not,  write to the  Free Software Foundation,
// Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
//
// --------------------------------------------------------------------------
// Last modified:       $Date: 2002/12/07 19:02:06 $
// By           :       $Author: kolrabi $
// $Id: x_path.cpp,v 1.1.1.1 2002/12/07 19:02:06 kolrabi Exp $ 

/*

  $Log: x_path.cpp,v $
  Revision 1.1.1.1  2002/12/07 19:02:06  kolrabi
  initial release


*/

#include            "omicron/internal.h"
#include            "omicron/path.h"

path_c::path_c() 
{ 
    nodes           = new list_c<node_s>;
    lengthfactor    = 1; 
} 
 
path_c::~path_c() 
{ 
    AssertThis;

    if (nodes) 
    { 
        node_s *n; 
 
        n = (node_s*)nodes->get_first(); 
        while(n) 
        { 
            SafeDelete(n); 
            n = (node_s*)nodes->get_next(); 
        } 
    } 
    SafeDelete(nodes); 
} 
 
void path_c::add_node(float t, vec3_t v) 
{ 
    AssertThis;

    node_s  *n = new node_s, *cn; 
 
    if (!n) 
        return;
 
    n->frac = t;
    n->pos  = v;
 
    cn = nodes->get_first(); 
 
    if (!cn) 
    { 
        nodes->append(n); 
        return; 
    } 
 
    while(cn && cn->frac<t) 
        cn = nodes->get_next(); 
     
    if (!cn) 
        cn = nodes->get_last(); 
 
    nodes->add_aftercurrent(n); 
} 

slong path_c::get_node_num(float t)
{ 
    AssertThisV;

    ulong i = 0; 
 
    node_s  *cn; 
 
    cn = nodes->get_first(); 
 
    while(cn) 
    { 
        if (cn->frac>t) 
            return i-1; 
 
        i++; 
        cn = nodes->get_next(); 
    } 
 
    return i-1; 
} 

path_c::node_s *path_c::get_node(slong num)
{ 
    AssertThisV;

    // note: only for non closed paths
    if (!closed)
    {
        if (num<0)
            num = 0;
        if (num>nodes->get_count())
            num = nodes->get_count();
    }
    else
    {
        while(num<0) 
            num += nodes->get_count();

        num %= nodes->get_count();
    }

    nodes->set_current_num(num); 
    return (node_s*)nodes->get_current(); 
} 
 
vec3_c path_c::get_pos(float tm) 
{ 
    AssertThisValue(vec3_c());

    tm *= lengthfactor; 
 
    node_s          *pn, *pn2; 
    float           tm1, tm2, frac; 
    vec3_c          pos0, pos1, pos2, pos3, tan1, tan2, vtmp; 
    ulong           num = get_node_num(tm); 
 
    pn      = get_node(num); 
    pn2     = get_node(num+1); 
 
    tm1     = pn->frac;
    tm2     = pn2->frac;

    while(tm2<tm1)
      tm2++;

    frac    = (tm-tm1)/(tm2-tm1); 
 
    pos0    = get_node(num-1)->pos;
    pos1    = pn->pos;
    pos2    = pn2->pos;
    pos3    = get_node(num+2)->pos;

    vtmp    = pos1 - pos0;
    tan1    = pos2 - pos1 + vtmp;

    vtmp    = pos2 - pos1;
    tan2    = pos3 - pos2 + vtmp;

    return vec3_c::hermite(pos1, tan1, pos2, tan2, frac);
}

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