212 lines
6.5 KiB
C++
212 lines
6.5 KiB
C++
// simulates ridge lift
|
|
//
|
|
// Written by Patrice Poly
|
|
// Copyright (C) 2009 Patrice Poly - p.polypa@gmail.com
|
|
//
|
|
//
|
|
// Entirely based on the paper :
|
|
// http://carrier.csi.cam.ac.uk/forsterlewis/soaring/sim/fsx/dev/sim_probe/sim_probe_paper.html
|
|
// by Ian Forster-Lewis, University of Cambridge, 26th December 2007
|
|
//
|
|
//
|
|
// 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
//
|
|
//
|
|
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
#include <Main/fg_props.hxx>
|
|
#include <Main/globals.hxx>
|
|
#include <Main/util.hxx>
|
|
#include <Scenery/scenery.hxx>
|
|
#include <string>
|
|
#include <cmath>
|
|
#include <simgear/sg_inlines.h>
|
|
|
|
using std::string;
|
|
|
|
#include "ridge_lift.hxx"
|
|
|
|
static const double BOUNDARY1_m = 40.0;
|
|
|
|
const double FGRidgeLift::dist_probe_m[] = { // in meters
|
|
0.0,
|
|
250.0,
|
|
750.0,
|
|
2000.0,
|
|
-100.0
|
|
};
|
|
|
|
//constructor
|
|
FGRidgeLift::FGRidgeLift () :
|
|
lift_factor(0.0)
|
|
{
|
|
strength = 0.0;
|
|
timer = 0.0;
|
|
for( int i = 0; i < 5; i++ )
|
|
probe_elev_m[i] = probe_lat_deg[i] = probe_lon_deg[i] = 0.0;
|
|
|
|
for( int i = 0; i < 4; i++ )
|
|
slope[i] = 0.0;
|
|
}
|
|
|
|
//destructor
|
|
FGRidgeLift::~FGRidgeLift()
|
|
{
|
|
|
|
}
|
|
|
|
void FGRidgeLift::init(void)
|
|
{
|
|
_enabled_node = fgGetNode( "/environment/ridge-lift/enabled", false );
|
|
|
|
_ridge_lift_fps_node = fgGetNode("/environment/ridge-lift-fps", true);
|
|
_surface_wind_from_deg_node =
|
|
fgGetNode("/environment/config/boundary/entry[0]/wind-from-heading-deg"
|
|
, true);
|
|
_surface_wind_speed_node =
|
|
fgGetNode("/environment/config/boundary/entry[0]/wind-speed-kt"
|
|
, true);
|
|
_user_longitude_node = fgGetNode("/position/longitude-deg", true);
|
|
_user_latitude_node = fgGetNode("/position/latitude-deg", true);
|
|
_user_altitude_agl_ft_node = fgGetNode("/position/altitude-agl-ft", true);
|
|
_ground_elev_node = fgGetNode("/position/ground-elev-ft", true );
|
|
}
|
|
|
|
void FGRidgeLift::bind() {
|
|
string prop;
|
|
|
|
_tiedProperties.setRoot( fgGetNode("/environment/ridge-lift",true));
|
|
for( int i = 0; i < 5; i++ ) {
|
|
_tiedProperties.Tie( "probe-elev-m", i, this, i, &FGRidgeLift::get_probe_elev_m );
|
|
_tiedProperties.Tie( "probe-lat-deg", i, this, i, &FGRidgeLift::get_probe_lat_deg );
|
|
_tiedProperties.Tie( "probe-lon-deg", i, this, i, &FGRidgeLift::get_probe_lon_deg );
|
|
}
|
|
|
|
for( int i = 0; i < 4; i++ ) {
|
|
_tiedProperties.Tie( "slope", i, this, i, &FGRidgeLift::get_slope );
|
|
}
|
|
}
|
|
|
|
void FGRidgeLift::unbind() {
|
|
_tiedProperties.Untie();
|
|
}
|
|
|
|
void FGRidgeLift::update(double dt) {
|
|
|
|
if( dt <= SGLimitsd::min() ) // paused, do nothing but keep current lift
|
|
return;
|
|
|
|
if( _enabled_node && false == _enabled_node->getBoolValue() ) {
|
|
// do nothing if lift has been zeroed
|
|
if( strength != 0.0 ) {
|
|
if( strength > 0.1 ) {
|
|
// slowly fade out strong lifts
|
|
strength = fgGetLowPass( strength, 0, dt );
|
|
} else {
|
|
strength = 0.0;
|
|
}
|
|
_ridge_lift_fps_node->setDoubleValue( strength );
|
|
}
|
|
return;
|
|
}
|
|
|
|
timer -= dt;
|
|
if (timer <= 0.0 ) {
|
|
|
|
// probe0 is current position
|
|
probe_lat_deg[0] = _user_latitude_node->getDoubleValue();
|
|
probe_lon_deg[0] = _user_longitude_node->getDoubleValue();
|
|
probe_elev_m[0] = _ground_elev_node->getDoubleValue() * SG_FEET_TO_METER;
|
|
|
|
// position is geodetic, need geocentric for advanceRadM
|
|
SGGeod myGeodPos = SGGeod::fromDegM( probe_lon_deg[0], probe_lat_deg[0], 20000.0 );
|
|
SGGeoc myGeocPos = SGGeoc::fromGeod( myGeodPos );
|
|
double ground_wind_from_rad = _surface_wind_from_deg_node->getDoubleValue() * SG_DEGREES_TO_RADIANS;
|
|
|
|
// compute the remaining probes
|
|
for (unsigned i = 1; i < sizeof(probe_elev_m)/sizeof(probe_elev_m[0]); i++) {
|
|
SGGeoc probe = myGeocPos.advanceRadM( ground_wind_from_rad, dist_probe_m[i] );
|
|
// convert to geodetic position for ground level computation
|
|
SGGeod probeGeod = SGGeod::fromGeoc( probe );
|
|
probe_lat_deg[i] = probeGeod.getLatitudeDeg();
|
|
probe_lon_deg[i] = probeGeod.getLongitudeDeg();
|
|
if (!globals->get_scenery()->get_elevation_m( probeGeod, probe_elev_m[i], NULL )) {
|
|
// no ground found? use elevation of previous probe :-(
|
|
probe_elev_m[i] = probe_elev_m[i-1];
|
|
}
|
|
}
|
|
|
|
// slopes
|
|
double adj_slope[sizeof(slope)];
|
|
slope[0] = (probe_elev_m[0] - probe_elev_m[1]) / dist_probe_m[1];
|
|
slope[1] = (probe_elev_m[1] - probe_elev_m[2]) / dist_probe_m[2];
|
|
slope[2] = (probe_elev_m[2] - probe_elev_m[3]) / dist_probe_m[3];
|
|
slope[3] = (probe_elev_m[4] - probe_elev_m[0]) / -dist_probe_m[4];
|
|
|
|
for (unsigned i = 0; i < sizeof(slope)/sizeof(slope[0]); i++)
|
|
adj_slope[i] = sin(atan(5.0 * pow ( (fabs(slope[i])),1.7) ) ) *SG_SIGN<double>(slope[i]);
|
|
|
|
//adjustment
|
|
adj_slope[0] *= 0.2;
|
|
adj_slope[1] *= 0.2;
|
|
if ( adj_slope [2] < 0.0 ) {
|
|
adj_slope[2] *= 0.5;
|
|
} else {
|
|
adj_slope[2] = 0.0 ;
|
|
}
|
|
|
|
if ( ( adj_slope [0] >= 0.0 ) && ( adj_slope [3] < 0.0 ) ) {
|
|
adj_slope[3] = 0.0;
|
|
} else {
|
|
adj_slope[3] *= 0.2;
|
|
}
|
|
lift_factor = adj_slope[0]+adj_slope[1]+adj_slope[2]+adj_slope[3];
|
|
|
|
// restart the timer
|
|
timer = 1.0;
|
|
}
|
|
|
|
//user altitude above ground
|
|
double user_altitude_agl_m = _user_altitude_agl_ft_node->getDoubleValue() * SG_FEET_TO_METER;
|
|
|
|
//boundaries
|
|
double boundary2_m = 130.0; // in the lift
|
|
if (lift_factor < 0.0) { // in the sink
|
|
double highest_probe_temp= std::max ( probe_elev_m[1], probe_elev_m[2] );
|
|
double highest_probe_downwind_m= std::max ( highest_probe_temp, probe_elev_m[3] );
|
|
boundary2_m = highest_probe_downwind_m - probe_elev_m[0];
|
|
}
|
|
|
|
double agl_factor;
|
|
if ( user_altitude_agl_m < BOUNDARY1_m ) {
|
|
agl_factor = 0.5+0.5*user_altitude_agl_m /BOUNDARY1_m ;
|
|
} else if ( user_altitude_agl_m < boundary2_m ) {
|
|
agl_factor = 1.0;
|
|
} else {
|
|
agl_factor = exp(-(2 + probe_elev_m[0] / 2000) *
|
|
(user_altitude_agl_m - boundary2_m) / std::max(probe_elev_m[0],200.0));
|
|
}
|
|
|
|
double ground_wind_speed_mps = _surface_wind_speed_node->getDoubleValue() * SG_NM_TO_METER / 3600;
|
|
double lift_mps = lift_factor* ground_wind_speed_mps * agl_factor;
|
|
|
|
//the updraft, finally, in ft per second
|
|
strength = fgGetLowPass( strength, lift_mps * SG_METER_TO_FEET, dt );
|
|
_ridge_lift_fps_node->setDoubleValue( strength );
|
|
}
|