//------------------------------------------------------------------------------
// burstFrame() -- generate a small burst of bullets (usually every 1/10 seconds)
//------------------------------------------------------------------------------
void Gun::burstFrame()
{
// Compute the number of rounds this burst
int ibullets = static_cast<int>(rcount + 0.5f);
// Do we have any bullets to fire ...
if (ibullets > 0){
// Decrease the number of rounds remaining
if ( !isUnlimited() ) {
if (ibullets > rounds) {
ibullets = rounds;
rcount = LCreal(ibullets);
}
rounds -= ibullets;
}
// Update the rounds fired count
rcount -= ibullets;
// Log this event
Player* ownship = static_cast<Player*>( findContainerByType(typeid(Player)) );
if (ownship != 0) {
BEGIN_RECORD_DATA_SAMPLE( getSimulation()->getDataRecorder(), REID_GUN_FIRED )
SAMPLE_1_OBJECT( ownship )
SAMPLE_1_VALUE( rcount )
END_RECORD_DATA_SAMPLE()
}
// TabLogger is deprecated
if (ownship != nullptr && getAnyEventLogger() != nullptr) {
TabLogger::TabLogEvent* evt = new TabLogger::LogGunActivity(1, ownship, ibullets); // type 1 == gun fired
getAnyEventLogger()->log(evt);
evt->unref();
}
// When we have a bullet model ... we're going to create a bullet (weapon)
// player to flyout the rounds.
Bullet* wpn = getBulletType();
Simulation* sim = static_cast<Simulation*>( findContainerByType(typeid(Simulation)) );
if (wpn != nullptr && ownship != nullptr && sim != nullptr) {
// Compute the bullet burst's initial position and velocity
osg::Vec3 ipos = computeInitBulletPosition();
osg::Vec3 ivel = computeInitBulletVelocity();
// Get the bullet player being used to fly-out the bullets
Bullet* flyout = static_cast<Bullet*>( wpn->getFlyoutWeapon() );
if (flyout == nullptr) {
// If we don't have the flyout bullet (i.e., weapon and player) ... create it
wpn->setLaunchVehicle(ownship);
flyout = static_cast<Bullet*>( wpn->release() );
}
// The flyout bullet (player) will handle this burst of bullets.
if (flyout != nullptr) {
flyout->burstOfBullets(&ipos, &ivel, ibullets, getRoundsPerMinute(), sim->getNewWeaponEventID() );
}
// Cleanup
if (flyout != nullptr) { flyout->unref(); flyout = nullptr; }
}
}
else rcount = 0;
//------------------------------------------------------------------------------
// weaponGuidance() -- default guidance; using Robot Aircraft (RAC) guidance
//------------------------------------------------------------------------------
void Missile::weaponGuidance(const LCreal dt)
{
// ---
// Control velocity: During burn time, accel to max velocity,
// after burn time, deaccelerate to min velocity.
// ---
if (isEngineBurnEnabled()) cmdVelocity = vpMax;
else cmdVelocity = vpMin;
// ---
// If the target's already dead,
// then don't go away mad, just go away.
// ---
const Player* tgt = getTargetPlayer();
const Track* trk = getTargetTrack();
if (trk != 0) tgt = trk->getTarget();
if (tgt != 0 && !tgt->isActive()) return;
osg::Vec3 los; // Target Line of Sight
osg::Vec3 vel; // Target velocity
// ---
// Basic guidance
// ---
{
// ---
// Get position and velocity vectors from the target/track
// ---
osg::Vec3 posx;
calculateVectors(tgt, trk, &los, &vel, &posx);
// compute range to target
LCreal trng0 = trng;
trng = los.length();
// compute range rate,
LCreal trdot0 = trdot;
if (dt > 0)
trdot = (trng - trng0)/dt;
else
trdot = 0;
// Target total velocit
LCreal totalVel = vel.length();
// compute target velocity parallel to LOS,
LCreal vtplos = (los * vel/trng);
// ---
// guidance - fly to intercept point
// ---
// if we have guidance ...
if ( isGuidanceEnabled() && trng > 0) {
// get missile velocity (must be faster than target),
LCreal v = vpMax;
if (v < totalVel) v = totalVel + 1;
// compute target velocity normal to LOS squared,
LCreal tgtVp = totalVel;
LCreal vtnlos2 = tgtVp*tgtVp - vtplos*vtplos;
// and compute missile velocity parallex to LOS.
LCreal vmplos = lcSqrt( v*v - vtnlos2 );
// Now, use both velocities parallel to LOS to compute
// closure rate.
LCreal vclos = vmplos - vtplos;
// Use closure rate and range to compute time to intercept.
LCreal dt1 = 0;
if (vclos > 0) dt1 = trng/vclos;
// Use time to intercept to extrapolate target position.
osg::Vec3 p1 = (los + (vel * dt1));
// Compute missile commanded heading and
cmdHeading = lcAtan2(p1.y(),p1.x());
// commanded pitch.
LCreal grng = lcSqrt(p1.x()*p1.x() + p1.y()*p1.y());
cmdPitch = -lcAtan2(p1.z(),grng);
}
}
// ---
// fuzing logic (let's see if we've scored a hit)
// (compute range at closest point and compare to max burst radius)
// (use target truth data)
// ---
{
// ---
// Get position and velocity vectors from the target (truth)
// (or default to the values from above)
// ---
if (tgt != 0) {
calculateVectors(tgt, 0, &los, &vel, 0);
}
// compute range to target
LCreal trng0 = trngT;
trngT = los.length();
// compute range rate,
LCreal trdot0 = trdotT;
if (dt > 0)
trdotT = (trngT - trng0)/dt;
else
trdotT = 0;
// when we've just passed the target ...
if (trdotT > 0 && trdot0 < 0 && !isDummy() && getTOF() > 2.0f) {
bool missed = true; // assume the worst
// compute relative velocity vector.
osg::Vec3 velRel = (vel - getVelocity());
// compute missile velocity squared,
LCreal vm2 = velRel.length2();
if (vm2 > 0) {
// relative range (dot) relative velocity
LCreal rdv = los * velRel;
// interpolate back to closest point
LCreal ndt = -rdv/vm2;
osg::Vec3 p0 = los + (velRel*ndt);
// range squared at closest point
LCreal r2 = p0.length2();
// compare to burst radius squared
if (r2 <= (getMaxBurstRng()*getMaxBurstRng()) ) {
// We've detonated
missed = false;
setMode(DETONATED);
setDetonationResults( DETONATE_ENTITY_IMPACT );
// compute location of the detonation relative to the target
osg::Vec3 p0n = -p0;
if (tgt != 0) p0n = tgt->getRotMat() * p0n;
setDetonationLocation(p0n);
// Did we hit anyone?
checkDetonationEffect();
// Log the event
LCreal detRange = getDetonationRange();
if (isMessageEnabled(MSG_INFO)) {
std::cout << "DETONATE_ENTITY_IMPACT rng = " << detRange << std::endl;
}
if (getAnyEventLogger() != 0) {
TabLogger::TabLogEvent* evt = new TabLogger::LogWeaponActivity(2, getLaunchVehicle(), this, getTargetPlayer(), DETONATE_ENTITY_IMPACT, detRange); // type 2 for "detonate"
getAnyEventLogger()->log(evt);
evt->unref();
}
}
}
// Did we miss the target?
if (missed) {
// We've detonated ...
setMode(DETONATED);
setDetonationResults( DETONATE_DETONATION );
// because we've just missed the target
setTargetPlayer(0,false);
setTargetTrack(0,false);
// Log the event
LCreal detRange = trngT;
if (isMessageEnabled(MSG_INFO)) {
std::cout << "DETONATE_OTHER rng = " << detRange << std::endl;
}
if (getAnyEventLogger() != 0) {
TabLogger::TabLogEvent* evt = new TabLogger::LogWeaponActivity(2, getLaunchVehicle(), this, getTargetPlayer(), DETONATE_DETONATION, getDetonationRange()); // type 2 for "detonate"
getAnyEventLogger()->log(evt);
evt->unref();
}
}
}
}
}
