//  $Id$
//
//  SuperTuxKart - a fun racing game with go-kart
//  Copyright (C) 2004 Steve Baker <sjbaker1@airmail.net>
//
//  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.

#include "kart.hpp"
#include "constants.hpp"

inline float sgnsq ( float x ) { return ( x < 0 ) ? -(x * x) : (x * x) ; }


void TrafficDriver::update (float dt)
{
  /* Steering algorithm */

  /* If moving left-to-right and on the left - or right to left
     and on the right - do nothing. */

  sgVec2 track_velocity ;
  sgSubVec2 ( track_velocity, curr_track_coords, last_track_coords ) ;

  if ( ( track_velocity [ 0 ] < 0.0f && curr_track_coords [ 0 ] > 0.0f ) ||
       ( track_velocity [ 0 ] > 0.0f && curr_track_coords [ 0 ] < 0.0f ) )
    velocity.hpr[0] = sgnsq(curr_track_coords[0])*3.0f ;
  else
    velocity.hpr[0] = sgnsq(curr_track_coords[0])*12.0f ;

  velocity.xyz[1]  = TRAFFIC_VELOCITY ;
  velocity.xyz[2] -= GRAVITY * dt ;

  if ( wheelie_angle != 0.0f )
    wheelie_angle = 0.0f ;

  Kart::update (dt) ;
}

void TrafficDriver::doObjectInteractions () {}
void TrafficDriver::doLapCounting        () {}
void TrafficDriver::doZipperProcessing   () {}

