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flightgear/src/AIModel/AIAircraft.cxx
durk fdc1a2ba54 Bugfixes: 1) Fix the if (next) setLeadDistance bug 
(reported by Csaba Halaszi /helijah)
          2) Decrease AI aircraft Heading error tolerance to 1% of its
             original value. This is necessary to mitigate spinning and
             makes for actual "on-runway" landings.
2007-07-10 07:01:54 +00:00

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// FGAIAircraft - FGAIBase-derived class creates an AI airplane
//
// Written by David Culp, started October 2003.
//
// Copyright (C) 2003 David P. Culp - davidculp2@comcast.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <simgear/math/point3d.hxx>
#include <simgear/route/waypoint.hxx>
#include <Main/fg_props.hxx>
#include <Main/globals.hxx>
#include <Main/viewer.hxx>
#include <Scenery/scenery.hxx>
#include <Scenery/tilemgr.hxx>
#include <string>
#include <math.h>
#include <time.h>
#ifdef _MSC_VER
# include <float.h>
# define finite _finite
#elif defined(__sun) || defined(sgi)
# include <ieeefp.h>
#endif
SG_USING_STD(string);
#include "AIAircraft.hxx"
#include "performancedata.hxx"
#include "performancedb.hxx"
//#include <Airports/trafficcontroller.hxx>
static string tempReg;
class AI_OutOfSight{};
class FP_Inactive{};
FGAIAircraft::FGAIAircraft(FGAISchedule *ref) : FGAIBase(otAircraft) {
trafficRef = ref;
if (trafficRef) {
groundOffset = trafficRef->getGroundOffset();
setCallSign(trafficRef->getCallSign());
}
else
groundOffset = 0;
fp = 0;
controller = 0;
prevController = 0;
dt_count = 0;
dt_elev_count = 0;
use_perf_vs = true;
no_roll = false;
tgt_speed = 0;
speed = 0;
groundTargetSpeed = 0;
// set heading and altitude locks
hdg_lock = false;
alt_lock = false;
roll = 0;
headingChangeRate = 0.0;
holdPos = false;
_performance = 0; //TODO initialize to JET_TRANSPORT from PerformanceDB
}
FGAIAircraft::~FGAIAircraft() {
//delete fp;
if (controller)
controller->signOff(getID());
}
void FGAIAircraft::readFromScenario(SGPropertyNode* scFileNode) {
if (!scFileNode)
return;
FGAIBase::readFromScenario(scFileNode);
setPerformance(scFileNode->getStringValue("class", "jet_transport"));
setFlightPlan(scFileNode->getStringValue("flightplan"),
scFileNode->getBoolValue("repeat", false));
setCallSign(scFileNode->getStringValue("callsign"));
}
void FGAIAircraft::bind() {
FGAIBase::bind();
props->tie("controls/gear/gear-down",
SGRawValueMethods<FGAIAircraft,bool>(*this,
&FGAIAircraft::_getGearDown));
props->tie("callsign",
SGRawValueMethods<FGAIAircraft,const char *>(*this,
&FGAIAircraft::_getCallSign));
//props->setStringValue("callsign", callsign.c_str());
}
void FGAIAircraft::unbind() {
FGAIBase::unbind();
props->untie("controls/gear/gear-down");
props->untie("callsign");
}
void FGAIAircraft::update(double dt) {
FGAIBase::update(dt);
Run(dt);
Transform();
}
void FGAIAircraft::setPerformance(const std::string& acclass) {
static PerformanceDB perfdb; //TODO make it a global service
setPerformance(perfdb.getDataFor(acclass));
}
void FGAIAircraft::setPerformance(PerformanceData *ps) {
_performance = ps;
}
void FGAIAircraft::Run(double dt) {
FGAIAircraft::dt = dt;
try {
updatePrimaryTargetValues(); // target hdg, alt, speed
}
catch (AI_OutOfSight) {
return;
}
catch (FP_Inactive) {
return;
}
handleATCRequests(); // ATC also has a word to say
updateSecondaryTargetValues(); // target roll, vertical speed, pitch
updateActualState();
UpdateRadar(manager);
}
void FGAIAircraft::AccelTo(double speed) {
tgt_speed = speed;
}
void FGAIAircraft::PitchTo(double angle) {
tgt_pitch = angle;
alt_lock = false;
}
void FGAIAircraft::RollTo(double angle) {
tgt_roll = angle;
hdg_lock = false;
}
void FGAIAircraft::YawTo(double angle) {
tgt_yaw = angle;
}
void FGAIAircraft::ClimbTo(double alt_ft ) {
tgt_altitude_ft = alt_ft;
alt_lock = true;
}
void FGAIAircraft::TurnTo(double heading) {
tgt_heading = heading;
hdg_lock = true;
}
double FGAIAircraft::sign(double x) {
if (x == 0.0)
return x;
else
return x/fabs(x);
}
void FGAIAircraft::setFlightPlan(const std::string& flightplan, bool repeat) {
if (!flightplan.empty()) {
FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
fp->setRepeat(repeat);
SetFlightPlan(fp);
}
}
void FGAIAircraft::SetFlightPlan(FGAIFlightPlan *f) {
delete fp;
fp = f;
}
void FGAIAircraft::ProcessFlightPlan( double dt, time_t now ) {
// the one behind you
FGAIFlightPlan::waypoint* prev = 0;
// the one ahead
FGAIFlightPlan::waypoint* curr = 0;
// the next plus 1
FGAIFlightPlan::waypoint* next = 0;
prev = fp->getPreviousWaypoint();
curr = fp->getCurrentWaypoint();
next = fp->getNextWaypoint();
dt_count += dt;
///////////////////////////////////////////////////////////////////////////
// Initialize the flightplan
//////////////////////////////////////////////////////////////////////////
if (!prev) {
handleFirstWaypoint();
return;
} // end of initialization
if (! fpExecutable(now))
return;
dt_count = 0;
if (! leadPointReached(curr)) {
controlHeading(curr);
controlSpeed(curr, next);
} else {
if (curr->finished) //end of the flight plan
{
if (fp->getRepeat())
fp->restart();
else
setDie(true);
return;
}
if (next) {
//TODO more intelligent method in AIFlightPlan, no need to send data it already has :-)
tgt_heading = fp->getBearing(curr, next);
spinCounter = 0;
}
//TODO let the fp handle this (loading of next leg)
fp->IncrementWaypoint((bool) trafficRef);
if (!(fp->getNextWaypoint()) && trafficRef)
loadNextLeg();
prev = fp->getPreviousWaypoint();
curr = fp->getCurrentWaypoint();
next = fp->getNextWaypoint();
// Now that we have incremented the waypoints, excute some traffic manager specific code
if (trafficRef) {
//TODO isn't this best executed right at the beginning?
if (! aiTrafficVisible()) {
setDie(true);
return;
}
if (! handleAirportEndPoints(prev, now)) {
setDie(true);
return;
}
announcePositionToController();
}
if (next) {
fp->setLeadDistance(speed, tgt_heading, curr, next);
}
if (!(prev->on_ground)) // only update the tgt altitude from flightplan if not on the ground
{
tgt_altitude_ft = prev->altitude;
if (curr->crossat > -1000.0) {
use_perf_vs = false;
tgt_vs = (curr->crossat - altitude_ft) / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
/ 6076.0 / speed*60.0);
tgt_altitude_ft = curr->crossat;
} else {
use_perf_vs = true;
}
}
tgt_speed = prev->speed;
hdg_lock = alt_lock = true;
no_roll = prev->on_ground;
}
}
void FGAIAircraft::initializeFlightPlan() {
}
bool FGAIAircraft::_getGearDown() const {
return _performance->gearExtensible(this);
}
const char * FGAIAircraft::_getCallSign() const {
return callsign.c_str();
}
void FGAIAircraft::loadNextLeg() {
int leg;
if ((leg = fp->getLeg()) == 10) {
trafficRef->next();
setCallSign(trafficRef->getCallSign());
//props->setStringValue("callsign", callsign.c_str());
leg = 1;
fp->setLeg(leg);
}
FGAirport *dep = trafficRef->getDepartureAirport();
FGAirport *arr = trafficRef->getArrivalAirport();
if (!(dep && arr)) {
setDie(true);
} else {
double cruiseAlt = trafficRef->getCruiseAlt() * 100;
fp->create (dep,
arr,
leg,
cruiseAlt, //(trafficRef->getCruiseAlt() * 100), // convert from FL to feet
trafficRef->getSpeed(),
_getLatitude(),
_getLongitude(),
false,
trafficRef->getRadius(),
trafficRef->getFlightType(),
acType,
company);
}
}
// Note: This code is copied from David Luff's AILocalTraffic
// Warning - ground elev determination is CPU intensive
// Either this function or the logic of how often it is called
// will almost certainly change.
void FGAIAircraft::getGroundElev(double dt) {
dt_elev_count += dt;
// Update minimally every three secs, but add some randomness
// to prevent all IA objects doing this in synchrony
if (dt_elev_count < (3.0) + (rand() % 10))
return;
dt_elev_count = 0;
// Only do the proper hitlist stuff if we are within visible range of the viewer.
if (!invisible) {
double visibility_meters = fgGetDouble("/environment/visibility-m");
FGViewer* vw = globals->get_current_view();
double course, distance;
SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
SGWayPoint view (vw->getLongitude_deg(), vw->getLatitude_deg(), 0);
view.CourseAndDistance(current, &course, &distance);
if (distance > visibility_meters) {
//aip.getSGLocation()->set_cur_elev_m(aptElev);
return;
}
// FIXME: make sure the pos.lat/pos.lon values are in degrees ...
double range = 500.0;
if (!globals->get_tile_mgr()->scenery_available(pos.getLatitudeDeg(), pos.getLongitudeDeg(), range)) {
// Try to shedule tiles for that position.
globals->get_tile_mgr()->update( aip.getSGLocation(), range );
}
// FIXME: make sure the pos.lat/pos.lon values are in degrees ...
double alt;
if (globals->get_scenery()->get_elevation_m(pos.getLatitudeDeg(), pos.getLongitudeDeg(), 20000.0, alt, 0))
tgt_altitude_ft = alt * SG_METER_TO_FEET;
}
}
void FGAIAircraft::setCallSign(const string& s) {
callsign = s;
}
void FGAIAircraft::doGroundAltitude() {
if (fabs(altitude_ft - (tgt_altitude_ft+groundOffset)) > 1000.0)
altitude_ft = (tgt_altitude_ft + groundOffset);
else
altitude_ft += 0.1 * ((tgt_altitude_ft+groundOffset) - altitude_ft);
}
void FGAIAircraft::announcePositionToController() {
if (trafficRef) {
int leg = fp->getLeg();
// Note that leg was been incremented after creating the current leg, so we should use
// leg numbers here that are one higher than the number that is used to create the leg
//
switch (leg) {
case 3: // Taxiing to runway
if (trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork()->exists())
controller = trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork();
break;
case 4: //Take off tower controller
if (trafficRef->getDepartureAirport()->getDynamics()) {
controller = trafficRef->getDepartureAirport()->getDynamics()->getTowerController();
//if (trafficRef->getDepartureAirport()->getId() == "EHAM") {
//cerr << trafficRef->getCallSign() << " at runway " << fp->getRunway() << "Ready for departure "
// << trafficRef->getFlightType() << " to " << trafficRef->getArrivalAirport()->getId() << endl;
// if (controller == 0) {
//cerr << "Error in assigning controller at " << trafficRef->getDepartureAirport()->getId() << endl;
//}
} else {
cerr << "Error: Could not find Dynamics at airport : " << trafficRef->getDepartureAirport()->getId() << endl;
}
break;
case 9: // Taxiing for parking
if (trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork()->exists())
controller = trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork();
break;
default:
controller = 0;
break;
}
if ((controller != prevController) && (prevController != 0)) {
prevController->signOff(getID());
string callsign = trafficRef->getCallSign();
if ( trafficRef->getHeavy())
callsign += "Heavy";
switch (leg) {
case 3:
//cerr << callsign << " ready to taxi to runway " << fp->getRunway() << endl;
break;
case 4:
//cerr << callsign << " at runway " << fp->getRunway() << "Ready for take-off. "
// << trafficRef->getFlightRules() << " to " << trafficRef->getArrivalAirport()->getId()
// << "(" << trafficRef->getArrivalAirport()->getName() << ")."<< endl;
break;
}
}
prevController = controller;
if (controller) {
controller->announcePosition(getID(), fp, fp->getCurrentWaypoint()->routeIndex,
_getLatitude(), _getLongitude(), hdg, speed, altitude_ft,
trafficRef->getRadius(), leg, trafficRef->getCallSign());
}
}
}
void FGAIAircraft::processATC(FGATCInstruction instruction) {
if (instruction.getCheckForCircularWait()) {
// This is not exactly an elegant solution,
// but at least it gives me a chance to check
// if circular waits are resolved.
// For now, just take the offending aircraft
// out of the scene
setDie(true);
// a more proper way should be - of course - to
// let an offending aircraft take an evasive action
// for instance taxi back a little bit.
}
//cerr << "Processing ATC instruction (not Implimented yet)" << endl;
if (instruction.getHoldPattern ()) {}
// Hold Position
if (instruction.getHoldPosition ()) {
if (!holdPos) {
holdPos = true;
}
AccelTo(0.0);
} else {
if (holdPos) {
//if (trafficRef)
// cerr << trafficRef->getCallSign() << " Resuming Taxi " << endl;
holdPos = false;
}
// Change speed Instruction. This can only be excecuted when there is no
// Hold position instruction.
if (instruction.getChangeSpeed ()) {
// if (trafficRef)
//cerr << trafficRef->getCallSign() << " Changing Speed " << endl;
AccelTo(instruction.getSpeed());
} else {
if (fp) AccelTo(fp->getPreviousWaypoint()->speed);
}
}
if (instruction.getChangeHeading ()) {
hdg_lock = false;
TurnTo(instruction.getHeading());
} else {
if (fp) {
hdg_lock = true;
}
}
if (instruction.getChangeAltitude()) {}
}
void FGAIAircraft::handleFirstWaypoint() {
bool eraseWaypoints; //TODO YAGNI
if (trafficRef) {
eraseWaypoints = true;
} else {
eraseWaypoints = false;
}
FGAIFlightPlan::waypoint* prev = 0; // the one behind you
FGAIFlightPlan::waypoint* curr = 0; // the one ahead
FGAIFlightPlan::waypoint* next = 0;// the next plus 1
spinCounter = 0;
tempReg = "";
//TODO fp should handle this
fp->IncrementWaypoint(eraseWaypoints);
if (!(fp->getNextWaypoint()) && trafficRef)
loadNextLeg();
prev = fp->getPreviousWaypoint(); //first waypoint
curr = fp->getCurrentWaypoint(); //second waypoint
next = fp->getNextWaypoint(); //third waypoint (might not exist!)
setLatitude(prev->latitude);
setLongitude(prev->longitude);
setSpeed(prev->speed);
setAltitude(prev->altitude);
if (prev->speed > 0.0)
setHeading(fp->getBearing(prev->latitude, prev->longitude, curr));
else
setHeading(fp->getBearing(curr->latitude, curr->longitude, prev));
// If next doesn't exist, as in incrementally created flightplans for
// AI/Trafficmanager created plans,
// Make sure lead distance is initialized otherwise
if (next)
fp->setLeadDistance(speed, hdg, curr, next);
if (curr->crossat > -1000.0) //use a calculated descent/climb rate
{
use_perf_vs = false;
tgt_vs = (curr->crossat - prev->altitude)
/ (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
/ 6076.0 / prev->speed*60.0);
tgt_altitude_ft = curr->crossat;
} else {
use_perf_vs = true;
tgt_altitude_ft = prev->altitude;
}
alt_lock = hdg_lock = true;
no_roll = prev->on_ground;
if (no_roll) {
Transform(); // make sure aip is initialized.
getGroundElev(60.1); // make sure it's executed first time around, so force a large dt value
doGroundAltitude();
}
// Make sure to announce the aircraft's position
announcePositionToController();
prevSpeed = 0;
}
/**
* Check Execution time (currently once every 100 ms)
* Add a bit of randomization to prevent the execution of all flight plans
* in synchrony, which can add significant periodic framerate flutter.
*
* @param now
* @return
*/
bool FGAIAircraft::fpExecutable(time_t now) {
double rand_exec_time = (rand() % 100) / 100;
return (dt_count > (0.1+rand_exec_time)) && (fp->isActive(now));
}
/**
* Check to see if we've reached the lead point for our next turn
*
* @param curr
* @return
*/
bool FGAIAircraft::leadPointReached(FGAIFlightPlan::waypoint* curr) {
double dist_to_go = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
//cerr << "2" << endl;
double lead_dist = fp->getLeadDistance();
//cerr << " Distance : " << dist_to_go << ": Lead distance " << lead_dist << endl;
// experimental: Use fabs, because speed can be negative (I hope) during push_back.
if (lead_dist < fabs(2*speed)) {
//don't skip over the waypoint
lead_dist = fabs(2*speed);
//cerr << "Extending lead distance to " << lead_dist << endl;
}
//prev_dist_to_go = dist_to_go;
return dist_to_go < lead_dist;
}
bool FGAIAircraft::aiTrafficVisible() {
double userLatitude = fgGetDouble("/position/latitude-deg");
double userLongitude = fgGetDouble("/position/longitude-deg");
double course, distance;
SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
SGWayPoint user (userLongitude, userLatitude, 0);
user.CourseAndDistance(current, &course, &distance);
return ((distance * SG_METER_TO_NM) <= TRAFFICTOAIDIST);
}
/**
* Handle release of parking gate, once were taxiing. Also ensure service time at the gate
* in the case of an arrival.
*
* @param prev
* @return
*/
//TODO the trafficRef is the right place for the method
bool FGAIAircraft::handleAirportEndPoints(FGAIFlightPlan::waypoint* prev, time_t now) {
// prepare routing from one airport to another
FGAirport * dep = trafficRef->getDepartureAirport();
FGAirport * arr = trafficRef->getArrivalAirport();
if (!( dep && arr))
return false;
// This waypoint marks the fact that the aircraft has passed the initial taxi
// departure waypoint, so it can release the parking.
if (prev->name == "park2") {
dep->getDynamics()->releaseParking(fp->getGate());
}
// This is the last taxi waypoint, and marks the the end of the flight plan
// so, the schedule should update and wait for the next departure time.
if (prev->name == "END") {
time_t nextDeparture = trafficRef->getDepartureTime();
// make sure to wait at least 20 minutes at parking to prevent "nervous" taxi behavior
if (nextDeparture < (now+1200)) {
nextDeparture = now + 1200;
}
fp->setTime(nextDeparture); // should be "next departure"
}
return true;
}
/**
* Check difference between target bearing and current heading and correct if necessary.
*
* @param curr
*/
void FGAIAircraft::controlHeading(FGAIFlightPlan::waypoint* curr) {
double calc_bearing = fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
//cerr << "Bearing = " << calc_bearing << endl;
if (speed < 0) {
calc_bearing +=180;
if (calc_bearing > 360)
calc_bearing -= 360;
}
if (finite(calc_bearing)) {
double hdg_error = calc_bearing - tgt_heading;
if (fabs(hdg_error) > 0.01) {
TurnTo( calc_bearing );
}
} else {
cerr << "calc_bearing is not a finite number : "
<< "Speed " << speed
<< "pos : " << pos.getLatitudeDeg() << ", " << pos.getLongitudeDeg()
<< "waypoint " << curr->latitude << ", " << curr->longitude << endl;
cerr << "waypoint name " << curr->name;
exit(1); // FIXME
}
}
/**
* Update the lead distance calculation if speed has changed sufficiently
* to prevent spinning (hopefully);
*
* @param curr
* @param next
*/
void FGAIAircraft::controlSpeed(FGAIFlightPlan::waypoint* curr, FGAIFlightPlan::waypoint* next) {
double speed_diff = speed - prevSpeed;
if (fabs(speed_diff) > 10) {
prevSpeed = speed;
if (next) {
fp->setLeadDistance(speed, tgt_heading, curr, next);
}
}
}
/**
* Update target values (heading, alt, speed) depending on flight plan or control properties
*/
void FGAIAircraft::updatePrimaryTargetValues() {
if (fp) // AI object has a flightplan
{
//TODO make this a function of AIBase
time_t now = time(NULL) + fgGetLong("/sim/time/warp");
//cerr << "UpateTArgetValues() " << endl;
ProcessFlightPlan(dt, now);
if (! fp->isActive(now)) {
// Do execute Ground elev for inactive aircraft, so they
// Are repositioned to the correct ground altitude when the user flies within visibility range.
// In addition, check whether we are out of user range, so this aircraft
// can be deleted.
if (onGround()) {
Transform(); // make sure aip is initialized.
if (trafficRef) {
//cerr << trafficRef->getRegistration() << " Setting altitude to " << altitude_ft;
if (! aiTrafficVisible()) {
setDie(true);
throw AI_OutOfSight();
}
getGroundElev(dt);
doGroundAltitude();
// Transform();
pos.setElevationFt(altitude_ft);
}
}
throw FP_Inactive();
}
}
else {
// no flight plan, update target heading, speed, and altitude
// from control properties. These default to the initial
// settings in the config file, but can be changed "on the
// fly".
string lat_mode = props->getStringValue("controls/flight/lateral-mode");
if ( lat_mode == "roll" ) {
double angle
= props->getDoubleValue("controls/flight/target-roll" );
RollTo( angle );
} else {
double angle
= props->getDoubleValue("controls/flight/target-hdg" );
TurnTo( angle );
}
string lon_mode
= props->getStringValue("controls/flight/longitude-mode");
if ( lon_mode == "alt" ) {
double alt = props->getDoubleValue("controls/flight/target-alt" );
ClimbTo( alt );
} else {
double angle
= props->getDoubleValue("controls/flight/target-pitch" );
PitchTo( angle );
}
AccelTo( props->getDoubleValue("controls/flight/target-spd" ) );
}
}
void FGAIAircraft::updatePosition() {
// convert speed to degrees per second
double speed_north_deg_sec = cos( hdg * SGD_DEGREES_TO_RADIANS )
* speed * 1.686 / ft_per_deg_lat;
double speed_east_deg_sec = sin( hdg * SGD_DEGREES_TO_RADIANS )
* speed * 1.686 / ft_per_deg_lon;
// set new position
pos.setLatitudeDeg( pos.getLatitudeDeg() + speed_north_deg_sec * dt);
pos.setLongitudeDeg( pos.getLongitudeDeg() + speed_east_deg_sec * dt);
}
void FGAIAircraft::updateHeading() {
// adjust heading based on current bank angle
if (roll == 0.0)
roll = 0.01;
if (roll != 0.0) {
// double turnConstant;
//if (no_roll)
// turnConstant = 0.0088362;
//else
// turnConstant = 0.088362;
// If on ground, calculate heading change directly
if (onGround()) {
double headingDiff = fabs(hdg-tgt_heading);
if (headingDiff > 180)
headingDiff = fabs(headingDiff - 360);
groundTargetSpeed = tgt_speed - (tgt_speed * (headingDiff/45));
if (sign(groundTargetSpeed) != sign(tgt_speed))
groundTargetSpeed = 0.21 * sign(tgt_speed); // to prevent speed getting stuck in 'negative' mode
if (headingDiff > 30.0) {
// invert if pushed backward
headingChangeRate += dt * sign(roll);
if (headingChangeRate > 30)
headingChangeRate = 30;
else if (headingChangeRate < -30)
headingChangeRate = -30;
} else {
if (fabs(headingChangeRate) > headingDiff)
headingChangeRate = headingDiff*sign(roll);
else
headingChangeRate += dt * sign(roll);
}
hdg += headingChangeRate * dt;
} else {
if (fabs(speed) > 1.0) {
turn_radius_ft = 0.088362 * speed * speed
/ tan( fabs(roll) / SG_RADIANS_TO_DEGREES );
} else {
// Check if turn_radius_ft == 0; this might lead to a division by 0.
turn_radius_ft = 1.0;
}
double turn_circum_ft = SGD_2PI * turn_radius_ft;
double dist_covered_ft = speed * 1.686 * dt;
double alpha = dist_covered_ft / turn_circum_ft * 360.0;
hdg += alpha * sign(roll);
}
while ( hdg > 360.0 ) {
hdg -= 360.0;
spinCounter++;
}
while ( hdg < 0.0) {
hdg += 360.0;
spinCounter--;
}
}
}
void FGAIAircraft::updateBankAngleTarget() {
// adjust target bank angle if heading lock engaged
if (hdg_lock) {
double bank_sense = 0.0;
double diff = fabs(hdg - tgt_heading);
if (diff > 180)
diff = fabs(diff - 360);
double sum = hdg + diff;
if (sum > 360.0)
sum -= 360.0;
if (fabs(sum - tgt_heading) < 1.0) {
bank_sense = 1.0; // right turn
} else {
bank_sense = -1.0; // left turn
}
if (diff < _performance->maximumBankAngle()) {
tgt_roll = diff * bank_sense;
} else {
tgt_roll = _performance->maximumBankAngle() * bank_sense;
}
if ((fabs((double) spinCounter) > 1) && (diff > _performance->maximumBankAngle())) {
tgt_speed *= 0.999; // Ugly hack: If aircraft get stuck, they will continually spin around.
// The only way to resolve this is to make them slow down.
}
}
}
void FGAIAircraft::updateVerticalSpeedTarget() {
// adjust target Altitude, based on ground elevation when on ground
if (onGround()) {
getGroundElev(dt);
doGroundAltitude();
} else if (alt_lock) {
// find target vertical speed
if (use_perf_vs) {
if (altitude_ft < tgt_altitude_ft) {
tgt_vs = tgt_altitude_ft - altitude_ft;
if (tgt_vs > _performance->climbRate())
tgt_vs = _performance->climbRate();
} else {
tgt_vs = tgt_altitude_ft - altitude_ft;
if (tgt_vs < (-_performance->descentRate()))
tgt_vs = -_performance->descentRate();
}
} else {
double max_vs = 4*(tgt_altitude_ft - altitude_ft);
double min_vs = 100;
if (tgt_altitude_ft < altitude_ft)
min_vs = -100.0;
if ((fabs(tgt_altitude_ft - altitude_ft) < 1500.0)
&& (fabs(max_vs) < fabs(tgt_vs)))
tgt_vs = max_vs;
if (fabs(tgt_vs) < fabs(min_vs))
tgt_vs = min_vs;
}
} //else
// tgt_vs = 0.0;
}
void FGAIAircraft::updatePitchAngleTarget() {
// if on ground and above vRotate -> initial rotation
if (onGround() && (speed > _performance->vRotate()))
tgt_pitch = 8.0; // some rough B737 value
//TODO pitch angle on approach and landing
// match pitch angle to vertical speed
else if (tgt_vs > 0) {
tgt_pitch = tgt_vs * 0.005;
} else {
tgt_pitch = tgt_vs * 0.002;
}
}
void FGAIAircraft::handleATCRequests() {
//TODO implement NullController for having no ATC to save the conditionals
if (controller) {
controller->update(getID(),
pos.getLatitudeDeg(),
pos.getLongitudeDeg(),
hdg,
speed,
altitude_ft, dt);
processATC(controller->getInstruction(getID()));
}
}
void FGAIAircraft::updateActualState() {
//update current state
//TODO have a single tgt_speed and check speed limit on ground on setting tgt_speed
updatePosition();
if (onGround())
speed = _performance->actualSpeed(this, groundTargetSpeed, dt);
else
speed = _performance->actualSpeed(this, tgt_speed, dt);
updateHeading();
roll = _performance->actualBankAngle(this, tgt_roll, dt);
// adjust altitude (meters) based on current vertical speed (fpm)
altitude_ft += vs / 60.0 * dt;
pos.setElevationFt(altitude_ft);
vs = _performance->actualVerticalSpeed(this, tgt_vs, dt);
pitch = _performance->actualPitch(this, tgt_pitch, dt);
}
void FGAIAircraft::updateSecondaryTargetValues() {
// derived target state values
updateBankAngleTarget();
updateVerticalSpeedTarget();
updatePitchAngleTarget();
//TODO calculate wind correction angle (tgt_yaw)
}
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