warnings--

[flightgear.git] / src / AIModel / AIBallistic.cxx

diff --git a/src/AIModel/AIBallistic.cxx b/src/AIModel/AIBallistic.cxx
index 590177c310921136e0101ffe5ab83da794bc148c..c7a5ab72c2c78f94318df4e1fe7ba902e9d40c88 100644 (file)
--- a/src/AIModel/AIBallistic.cxx
+++ b/src/AIModel/AIBallistic.cxx
@@ -15,7 +15,7 @@
 //
 // 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 #ifdef HAVE_CONFIG_H
 #  include <config.h>
@@ -27,24 +27,40 @@
 #include "AIBallistic.hxx"
 
 
-FGAIBallistic::FGAIBallistic(FGAIManager* mgr) {
-    manager = mgr;
-    _type_str = "ballistic";
-    _otype = otBallistic;
+FGAIBallistic::FGAIBallistic() : FGAIBase(otBallistic) {
     drag_area = 0.007;
     life_timer = 0.0;
     gravity = 32;
 //  buoyancy = 64;
     no_roll = false;
+    aero_stabilised = false;
 }
 
 FGAIBallistic::~FGAIBallistic() {
 }
 
+void FGAIBallistic::readFromScenario(SGPropertyNode* scFileNode) {
+  if (!scFileNode)
+    return;
+
+  FGAIBase::readFromScenario(scFileNode);
+
+  setAzimuth(scFileNode->getDoubleValue("azimuth", 0.0));
+  setElevation(scFileNode->getDoubleValue("elevation", 0.0));
+  setDragArea(scFileNode->getDoubleValue("eda", 0.007));
+  setLife(scFileNode->getDoubleValue("life", 900.0));
+  setBuoyancy(scFileNode->getDoubleValue("buoyancy", 0));
+  setWind_from_east(scFileNode->getDoubleValue("wind_from_east", 0));
+  setWind_from_north(scFileNode->getDoubleValue("wind_from_north", 0));
+  setWind(scFileNode->getBoolValue("wind", false));
+  setRoll(scFileNode->getDoubleValue("roll", 0.0));
+  setCd(scFileNode->getDoubleValue("cd", 0.029));
+  setMass(scFileNode->getDoubleValue("mass", 0.007));
+  setStabilisation(scFileNode->getBoolValue("aero_stabilized", false));
+}
 
 bool FGAIBallistic::init() {
    FGAIBase::init();
-   aero_stabilized = true;
    hdg = azimuth;
    pitch = elevation;
    roll = rotation;
@@ -84,8 +100,8 @@ void FGAIBallistic::setRoll(double rl) {
    rotation = rl;
 }
 
-void FGAIBallistic::setStabilization(bool val) {
-   aero_stabilized = val;
+void FGAIBallistic::setStabilisation(bool val) {
+   aero_stabilised = val;
 }
 
 void FGAIBallistic::setDragArea(double a) {
@@ -116,37 +132,44 @@ void FGAIBallistic::setCd(double c) {
    Cd = c;
 }
 
-void FGAIBallistic::setWeight(double w) {
-   weight = w;
+void FGAIBallistic::setMass(double m) {
+   mass = m;
 }
 
 void FGAIBallistic::Run(double dt) {
 
    life_timer += dt;
+//    cout << "life timer 1" << life_timer <<  dt << endl;
    if (life_timer > life) setDie(true); 
 
    double speed_north_deg_sec;
    double speed_east_deg_sec;
    double wind_speed_from_north_deg_sec;
    double wind_speed_from_east_deg_sec;
-   double mass;
+   double Cdm;      // Cd adjusted by Mach Number
    
-   // the drag calculations below assume sea-level density,
-   // rho = 0.023780  slugs/ft3
-   // calculate mass
-   mass = weight * lbs_to_slugs;
+   // Adjust Cd by Mach number. The equations are based on curves
+   // for a conventional shell/bullet (no boat-tail). 
+   if ( Mach < 0.7 ) { Cdm = 0.0125 * Mach + Cd; }
+     else if ( 0.7 < Mach && Mach < 1.2 ) { 
+       Cdm = 0.3742 * pow ( Mach, 2) - 0.252 * Mach + 0.0021 + Cd; }
+     else { Cdm = 0.2965 * pow ( Mach, -1.1506 ) + Cd; }
+
+//   cout << " Mach , " << Mach << " , Cdm , " << Cdm << endl;
    
    // drag = Cd * 0.5 * rho * speed * speed * drag_area;
+   // rho is adjusted for altitude in void FGAIBase::update,
+   // using Standard Atmosphere (sealevel temperature 15C)
    // acceleration = drag/mass;
    // adjust speed by drag
-   speed -= (Cd * 0.5 * rho * speed * speed * drag_area/mass) * dt; 
+   speed -= (Cdm * 0.5 * rho * speed * speed * drag_area/mass) * dt; 
 
    // don't let speed become negative
    if ( speed < 0.0 ) speed = 0.0;
    
    // calculate vertical and horizontal speed components
    vs = sin( pitch * SG_DEGREES_TO_RADIANS ) * speed;
-   hs = cos( pitch * SG_DEGREES_TO_RADIANS ) * speed;
+   double hs = cos( pitch * SG_DEGREES_TO_RADIANS ) * speed;
 
    // convert horizontal speed (fps) to degrees per second
    speed_north_deg_sec = cos(hdg / SG_RADIANS_TO_DEGREES) * hs / ft_per_deg_lat;
@@ -163,29 +186,31 @@ void FGAIBallistic::Run(double dt) {
    wind_speed_from_east_deg_sec  = wind_from_east / ft_per_deg_lon;
    
    // set new position
-   pos.setlat( pos.lat() + (speed_north_deg_sec - wind_speed_from_north_deg_sec) * dt );
-   pos.setlon( pos.lon() + (speed_east_deg_sec - wind_speed_from_east_deg_sec) * dt ); 
+   pos.setLatitudeDeg( pos.getLatitudeDeg() + (speed_north_deg_sec - wind_speed_from_north_deg_sec) * dt );
+   pos.setLongitudeDeg( pos.getLongitudeDeg() + (speed_east_deg_sec - wind_speed_from_east_deg_sec) * dt ); 
 
    // adjust vertical speed for acceleration of gravity and buoyancy
    vs -= (gravity - buoyancy) * dt;
    
    // adjust altitude (feet)
-   altitude += vs * dt;
-   pos.setelev(altitude * SG_FEET_TO_METER); 
+   altitude_ft += vs * dt;
+   pos.setElevationFt(altitude_ft); 
 
    // recalculate pitch (velocity vector) if aerostabilized
-   if (aero_stabilized) pitch = atan2( vs, hs ) * SG_RADIANS_TO_DEGREES;
+   //   cout << "aero_stabilised " << aero_stabilised  << endl ;
+   if (aero_stabilised) pitch = atan2( vs, hs ) * SG_RADIANS_TO_DEGREES;
 
    // recalculate total speed
    speed = sqrt( vs * vs + hs * hs);
 
    // set destruction flag if altitude less than sea level -1000
-   if (altitude < -1000.0) setDie(true);
+   if (altitude_ft < -1000.0) setDie(true);
 
 }  // end Run
 
 double FGAIBallistic::_getTime() const {
-   return life_timer;
+//    cout << "life timer 2" << life_timer << endl;
+  return life_timer;
 }
 
 // end AIBallistic