src/Environment/environment_ctrl.cxx

   1 // environment_ctrl.cxx -- manager for natural environment information.
   2 //
   3 // Written by David Megginson, started February 2002.
   4 //
   5 // Copyright (C) 2002  David Megginson - david@megginson.com
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 //
  21 // $Id$
  22
  23 #include <simgear/debug/logstream.hxx>
  24
  25 #include <stdlib.h>
  26 #include <Main/fg_props.hxx>
  27
  28 #include "environment_ctrl.hxx"
  29
  30
  31 \f
  32 ////////////////////////////////////////////////////////////////////////
  33 // Implementation of FGEnvironmentCtrl abstract base class.
  34 ////////////////////////////////////////////////////////////////////////
  35
  36 FGEnvironmentCtrl::FGEnvironmentCtrl ()
  37   : _environment(0),
  38     _lon_deg(0),
  39     _lat_deg(0),
  40     _elev_ft(0)
  41 {
  42 }
  43
  44 FGEnvironmentCtrl::~FGEnvironmentCtrl ()
  45 {
  46 }
  47
  48 void
  49 FGEnvironmentCtrl::setEnvironment (FGEnvironment * environment)
  50 {
  51   _environment = environment;
  52 }
  53
  54 void
  55 FGEnvironmentCtrl::setLongitudeDeg (double lon_deg)
  56 {
  57   _lon_deg = lon_deg;
  58 }
  59
  60 void
  61 FGEnvironmentCtrl::setLatitudeDeg (double lat_deg)
  62 {
  63   _lat_deg = lat_deg;
  64 }
  65
  66 void
  67 FGEnvironmentCtrl::setElevationFt (double elev_ft)
  68 {
  69   _elev_ft = elev_ft;
  70 }
  71
  72 void
  73 FGEnvironmentCtrl::setPosition (double lon_deg, double lat_deg, double elev_ft)
  74 {
  75   _lon_deg = lon_deg;
  76   _lat_deg = lat_deg;
  77   _elev_ft = elev_ft;
  78 }
  79
  80
  81 \f
  82 ////////////////////////////////////////////////////////////////////////
  83 // Implementation of FGUserDefEnvironmentCtrl.
  84 ////////////////////////////////////////////////////////////////////////
  85
  86 FGUserDefEnvironmentCtrl::FGUserDefEnvironmentCtrl ()
  87   : _base_wind_speed_node(0),
  88     _gust_wind_speed_node(0),
  89     _current_wind_speed_kt(0),
  90     _delta_wind_speed_kt(0)
  91 {
  92 }
  93
  94 FGUserDefEnvironmentCtrl::~FGUserDefEnvironmentCtrl ()
  95 {
  96 }
  97
  98 void
  99 FGUserDefEnvironmentCtrl::init ()
 100 {
 101                                 // Fill in some defaults.
 102   if (!fgHasNode("/environment/params/base-wind-speed-kt"))
 103     fgSetDouble("/environment/params/base-wind-speed-kt",
 104                 fgGetDouble("/environment/wind-speed-kt"));
 105   if (!fgHasNode("/environment/params/gust-wind-speed-kt"))
 106     fgSetDouble("/environment/params/gust-wind-speed-kt",
 107                 fgGetDouble("/environment/params/base-wind-speed-kt"));
 108
 109   _base_wind_speed_node =
 110     fgGetNode("/environment/params/base-wind-speed-kt", true);
 111   _gust_wind_speed_node =
 112     fgGetNode("/environment/params/gust-wind-speed-kt", true);
 113
 114   _current_wind_speed_kt = _base_wind_speed_node->getDoubleValue();
 115   _delta_wind_speed_kt = 0.1;
 116 }
 117
 118 void
 119 FGUserDefEnvironmentCtrl::update (double dt)
 120 {
 121   double base_wind_speed = _base_wind_speed_node->getDoubleValue();
 122   double gust_wind_speed = _gust_wind_speed_node->getDoubleValue();
 123
 124   if (gust_wind_speed < base_wind_speed) {
 125       gust_wind_speed = base_wind_speed;
 126       _gust_wind_speed_node->setDoubleValue(gust_wind_speed);
 127   }
 128
 129   if (base_wind_speed == gust_wind_speed) {
 130     _current_wind_speed_kt = base_wind_speed;
 131   } else {
 132     int rn = rand() % 128;
 133     int sign = (_delta_wind_speed_kt < 0 ? -1 : 1);
 134     double gust = _current_wind_speed_kt - base_wind_speed;
 135     double incr = gust / 50;
 136
 137     if (rn == 0)
 138       _delta_wind_speed_kt = - _delta_wind_speed_kt;
 139     else if (rn < 4)
 140       _delta_wind_speed_kt -= incr * sign;
 141     else if (rn < 16)
 142       _delta_wind_speed_kt += incr * sign;
 143
 144     _current_wind_speed_kt += _delta_wind_speed_kt;
 145
 146     if (_current_wind_speed_kt < base_wind_speed) {
 147       _current_wind_speed_kt = base_wind_speed;
 148       _delta_wind_speed_kt = 0.01;
 149     } else if (_current_wind_speed_kt > gust_wind_speed) {
 150       _current_wind_speed_kt = gust_wind_speed;
 151       _delta_wind_speed_kt = -0.01;
 152     }
 153   }
 154
 155   if (_environment != 0)
 156     _environment->set_wind_speed_kt(_current_wind_speed_kt);
 157 }
 158
 159 // end of environment_ctrl.cxx