void AI::Attack(Ship &ship, Command &command, const Ship &target)
{
Point d = target.Position() - ship.Position();
// First, figure out what your shortest-range weapon is.
double shortestRange = 4000.;
for(const Armament::Weapon &weapon : ship.Weapons())
{
const Outfit *outfit = weapon.GetOutfit();
if(outfit && !weapon.IsAntiMissile())
shortestRange = min(outfit->Range(), shortestRange);
}
// Deploy any fighters you are carrying.
if(!ship.IsYours())
command |= Command::DEPLOY;
// If this ship only has long-range weapons, it should keep its distance
// instead of trying to close with the target ship.
if(shortestRange > 1000. && d.Length() < .5 * shortestRange)
{
command.SetTurn(TurnToward(ship, -d));
if(ship.Facing().Unit().Dot(d) <= 0.)
command |= Command::FORWARD;
return;
}
// First of all, aim in the direction that will hit this target.
command.SetTurn(TurnToward(ship, TargetAim(ship)));
// Calculate this ship's "turning radius; that is, the smallest circle it
// can make while at full speed.
double stepsInFullTurn = 360. / ship.TurnRate();
double circumference = stepsInFullTurn * ship.Velocity().Length();
double diameter = max(200., circumference / PI);
// This isn't perfect, but it works well enough.
if((ship.Facing().Unit().Dot(d) >= 0. && d.Length() > diameter)
|| (ship.Velocity().Dot(d) < 0. && ship.Facing().Unit().Dot(d.Unit()) >= .9))
command |= Command::FORWARD;
}
void Engine::CalculateStep()
{
FrameTimer loadTimer;
// Clear the list of objects to draw.
draw[calcTickTock].Clear(step);
radar[calcTickTock].Clear();
if(!player.GetSystem())
return;
// Now, all the ships must decide what they are doing next.
ai.Step(ships, player);
const Ship *flagship = player.Flagship();
bool wasHyperspacing = (flagship && flagship->IsEnteringHyperspace());
// Now, move all the ships. We must finish moving all of them before any of
// them fire, or their turrets will be targeting where a given ship was
// instead of where it is now. This is also where ships get deleted, and
// where they may create explosions if they are dying.
for(auto it = ships.begin(); it != ships.end(); )
{
int hyperspaceType = (*it)->HyperspaceType();
bool wasHere = (flagship && (*it)->GetSystem() == flagship->GetSystem());
bool wasHyperspacing = (*it)->IsHyperspacing();
// Give the ship the list of effects so that it can draw explosions,
// ion sparks, jump drive flashes, etc.
if(!(*it)->Move(effects, flotsam))
{
// If Move() returns false, it means the ship should be removed from
// play. That may be because it was destroyed, because it is an
// ordinary ship that has been out of system for long enough to be
// "forgotten," or because it is a fighter that just docked with its
// mothership. Report it destroyed if that's really what happened:
if((*it)->IsDestroyed())
eventQueue.emplace_back(nullptr, *it, ShipEvent::DESTROY);
it = ships.erase(it);
}
else
{
if(&**it != flagship)
{
// Did this ship just begin hyperspacing?
if(wasHere && !wasHyperspacing && (*it)->IsHyperspacing())
Audio::Play(
Audio::Get(hyperspaceType >= 200 ? "jump out" : "hyperdrive out"),
(*it)->Position());
// Did this ship just jump into the player's system?
if(!wasHere && flagship && (*it)->GetSystem() == flagship->GetSystem())
Audio::Play(
Audio::Get(hyperspaceType >= 200 ? "jump in" : "hyperdrive in"),
(*it)->Position());
}
// Boarding:
bool autoPlunder = !(*it)->GetGovernment()->IsPlayer();
shared_ptr<Ship> victim = (*it)->Board(autoPlunder);
if(victim)
eventQueue.emplace_back(*it, victim,
(*it)->GetGovernment()->IsEnemy(victim->GetGovernment()) ?
ShipEvent::BOARD : ShipEvent::ASSIST);
++it;
}
}
if(!wasHyperspacing && flagship && flagship->IsEnteringHyperspace())
Audio::Play(Audio::Get(flagship->HyperspaceType() >= 200 ? "jump drive" : "hyperdrive"));
if(flagship && player.GetSystem() != flagship->GetSystem())
{
// Wormhole travel:
if(!wasHyperspacing)
for(const auto &it : player.GetSystem()->Objects())
if(it.GetPlanet() && it.GetPlanet()->IsWormhole() &&
it.GetPlanet()->WormholeDestination(player.GetSystem()) == flagship->GetSystem())
player.Visit(it.GetPlanet());
doFlash = Preferences::Has("Show hyperspace flash");
player.SetSystem(flagship->GetSystem());
EnterSystem();
}
// Draw the planets.
Point newCenter = center;
Point newCenterVelocity;
if(flagship)
{
newCenter = flagship->Position();
newCenterVelocity = flagship->Velocity();
}
else
doClick = false;
draw[calcTickTock].SetCenter(newCenter, newCenterVelocity);
radar[calcTickTock].SetCenter(newCenter);
for(const StellarObject &object : player.GetSystem()->Objects())
if(object.HasSprite())
{
// Don't apply motion blur to very large planets and stars.
if(object.Width() >= 280.)
draw[calcTickTock].AddUnblurred(object);
else
draw[calcTickTock].Add(object);
double r = max(2., object.Radius() * .03 + .5);
radar[calcTickTock].Add(RadarType(object), object.Position(), r, r - 1.);
if(object.GetPlanet())
object.GetPlanet()->DeployDefense(ships);
Point position = object.Position() - newCenter;
if(doClick && object.GetPlanet() && (clickPoint - position).Length() < object.Radius())
{
if(&object == player.Flagship()->GetTargetPlanet())
{
if(!object.GetPlanet()->CanLand())
Messages::Add("The authorities on " + object.GetPlanet()->Name() +
" refuse to let you land.");
else
{
clickCommands |= Command::LAND;
Messages::Add("Landing on " + object.GetPlanet()->Name() + ".");
}
}
else
player.Flagship()->SetTargetPlanet(&object);
}
}
// Add all neighboring systems to the radar.
const System *targetSystem = flagship ? flagship->GetTargetSystem() : nullptr;
const vector<const System *> &links = (flagship && flagship->Attributes().Get("jump drive")) ?
player.GetSystem()->Neighbors() : player.GetSystem()->Links();
for(const System *system : links)
radar[calcTickTock].AddPointer(
(system == targetSystem) ? Radar::SPECIAL : Radar::INACTIVE,
system->Position() - player.GetSystem()->Position());
// Now that the planets have been drawn, we can draw the asteroids on top
// of them. This could be done later, as long as it is done before the
// collision detection.
asteroids.Step();
asteroids.Draw(draw[calcTickTock], newCenter);
// Move existing projectiles. Do this before ships fire, which will create
// new projectiles, since those should just stay where they are created for
// this turn. This is also where projectiles get deleted, which may also
// result in a "die" effect or a sub-munition being created. We could not
// move the projectiles before this because some of them are homing and need
// to know the current positions of the ships.
list<Projectile> newProjectiles;
for(auto it = projectiles.begin(); it != projectiles.end(); )
{
if(!it->Move(effects))
{
it->MakeSubmunitions(newProjectiles);
it = projectiles.erase(it);
}
else
++it;
}
projectiles.splice(projectiles.end(), newProjectiles);
// Move the flotsam, which should be drawn underneath the ships.
for(auto it = flotsam.begin(); it != flotsam.end(); )
{
if(!it->Move(effects))
{
it = flotsam.erase(it);
continue;
}
Ship *collector = nullptr;
for(const shared_ptr<Ship> &ship : ships)
{
if(ship->GetSystem() != player.GetSystem() || ship->CannotAct())
continue;
if(ship.get() == it->Source() || ship->Cargo().Free() < it->UnitSize())
continue;
const Mask &mask = ship->GetMask(step);
if(mask.Contains(it->Position() - ship->Position(), ship->Facing()))
{
collector = ship.get();
break;
}
}
if(collector)
{
string name;
if(collector->IsYours())
{
if(collector->GetParent())
name = "Your ship \"" + collector->Name() + "\" picked up ";
else
name = "You picked up ";
}
string commodity;
int amount = 0;
if(it->OutfitType())
{
amount = collector->Cargo().Add(it->OutfitType(), it->Count());
if(!name.empty())
{
if(it->OutfitType()->Get("installable") < 0.)
commodity = it->OutfitType()->Name();
else
Messages::Add(name + Format::Number(amount) + " " + it->OutfitType()->Name()
+ (amount == 1 ? "." : "s."));
}
}
else
{
amount = collector->Cargo().Add(it->CommodityType(), it->Count());
if(!name.empty())
commodity = it->CommodityType();
}
if(!commodity.empty())
Messages::Add(name + (amount == 1 ? "a ton" : Format::Number(amount) + " tons")
+ " of " + Format::LowerCase(commodity) + ".");
it = flotsam.erase(it);
continue;
}
// Draw this flotsam.
draw[calcTickTock].Add(*it);
++it;
}
// Keep track of the relative strength of each government in this system. Do
// not add more ships to make a winning team even stronger. This is mostly
// to avoid having the player get mobbed by pirates, say, if they hang out
// in one system for too long.
map<const Government *, int64_t> strength;
// Now, ships fire new projectiles, which includes launching fighters. If an
// anti-missile system is ready to fire, it does not actually fire unless a
// missile is detected in range during collision detection, below.
vector<Ship *> hasAntiMissile;
double clickRange = 50.;
const Ship *previousTarget = nullptr;
const Ship *clickTarget = nullptr;
if(player.Flagship() && player.Flagship()->GetTargetShip())
previousTarget = &*player.Flagship()->GetTargetShip();
bool showFlagship = false;
bool hasHostiles = false;
for(shared_ptr<Ship> &ship : ships)
if(ship->GetSystem() == player.GetSystem())
{
strength[ship->GetGovernment()] += ship->Cost();
// Note: if a ship "fires" a fighter, that fighter was already in
// existence and under the control of the same AI as the ship, but
// its system was null to mark that it was not active.
ship->Launch(ships);
if(ship->Fire(projectiles, effects))
hasAntiMissile.push_back(ship.get());
int scan = ship->Scan();
if(scan)
{
shared_ptr<Ship> target = ship->GetTargetShip();
if(target && target->IsTargetable())
eventQueue.emplace_back(ship, target, scan);
}
// This is a good opportunity to draw all the ships in system.
if(!ship->HasSprite())
continue;
// Draw the flagship separately, on top of everything else.
if(ship.get() != flagship)
{
AddSprites(*ship);
if(ship->IsThrusting())
{
for(const auto &it : ship->Attributes().FlareSounds())
if(it.second > 0)
Audio::Play(it.first, ship->Position());
}
}
else
showFlagship = true;
// Do not show cloaked ships on the radar, except the player's ships.
bool isPlayer = ship->GetGovernment()->IsPlayer();
if(ship->Cloaking() == 1. && !isPlayer)
continue;
if(doClick && &*ship != player.Flagship() && ship->IsTargetable())
{
Point position = ship->Position() - newCenter;
const Mask &mask = ship->GetMask(step);
double range = mask.Range(clickPoint - position, ship->Facing());
if(range <= clickRange)
{
clickRange = range;
clickTarget = ship.get();
player.Flagship()->SetTargetShip(ship);
// If we've found an enemy within the click zone, favor
// targeting it rather than any other ship. Otherwise, keep
// checking for hits because another ship might be an enemy.
if(!range && ship->GetGovernment()->IsEnemy())
doClick = false;
}
}
double size = sqrt(ship->Width() + ship->Height()) * .14 + .5;
bool isYourTarget = (flagship && ship == flagship->GetTargetShip());
int type = RadarType(*ship);
hasHostiles |= (type == Radar::HOSTILE);
radar[calcTickTock].Add(isYourTarget ? Radar::SPECIAL : type, ship->Position(), size);
}
if(flagship && showFlagship)
{
AddSprites(*flagship);
if(flagship->IsThrusting())
{
for(const auto &it : flagship->Attributes().FlareSounds())
if(it.second > 0)
Audio::Play(it.first);
}
}
if(clickTarget && clickTarget == previousTarget)
clickCommands |= Command::BOARD;
if(alarmTime)
--alarmTime;
else if(hasHostiles && !hadHostiles)
{
if(Preferences::Has("Warning siren"))
Audio::Play(Audio::Get("alarm"));
alarmTime = 180;
hadHostiles = true;
}
else if(!hasHostiles)
hadHostiles = false;
// Collision detection:
if(grudgeTime)
--grudgeTime;
for(Projectile &projectile : projectiles)
{
// The asteroids can collide with projectiles, the same as any other
// object. If the asteroid turns out to be closer than the ship, it
// shields the ship (unless the projectile has a blast radius).
Point hitVelocity;
double closestHit = 0.;
shared_ptr<Ship> hit;
const Government *gov = projectile.GetGovernment();
// If this "projectile" is a ship explosion, it always explodes.
if(gov)
{
closestHit = asteroids.Collide(projectile, step, &hitVelocity);
// Projectiles can only collide with ships that are in the current
// system and are not landing, and that are hostile to this projectile.
for(shared_ptr<Ship> &ship : ships)
if(ship->GetSystem() == player.GetSystem() && !ship->IsLanding() && ship->Cloaking() < 1.)
{
if(ship.get() != projectile.Target() && !gov->IsEnemy(ship->GetGovernment()))
continue;
// This returns a value of 0 if the projectile has a trigger
// radius and the ship is within it.
double range = projectile.CheckCollision(*ship, step);
if(range < closestHit)
{
closestHit = range;
hit = ship;
hitVelocity = ship->Velocity();
}
}
}
if(closestHit < 1.)
{
// Create the explosion the given distance along the projectile's
// motion path for this step.
projectile.Explode(effects, closestHit, hitVelocity);
// If this projectile has a blast radius, find all ships within its
// radius. Otherwise, only one is damaged.
if(projectile.HasBlastRadius())
{
// Even friendly ships can be hit by the blast.
for(shared_ptr<Ship> &ship : ships)
if(ship->GetSystem() == player.GetSystem() && ship->Zoom() == 1.)
if(projectile.InBlastRadius(*ship, step, closestHit))
{
int eventType = ship->TakeDamage(projectile, ship != hit);
if(eventType)
eventQueue.emplace_back(
projectile.GetGovernment(), ship, eventType);
}
}
else if(hit)
{
int eventType = hit->TakeDamage(projectile);
if(eventType)
eventQueue.emplace_back(
projectile.GetGovernment(), hit, eventType);
}
if(hit)
DoGrudge(hit, projectile.GetGovernment());
}
else if(projectile.MissileStrength())
{
bool isEnemy = projectile.GetGovernment() && projectile.GetGovernment()->IsEnemy();
radar[calcTickTock].Add(
isEnemy ? Radar::SPECIAL : Radar::INACTIVE, projectile.Position(), 1.);
// If the projectile did not hit anything, give the anti-missile
// systems a chance to shoot it down.
for(Ship *ship : hasAntiMissile)
if(ship == projectile.Target()
|| gov->IsEnemy(ship->GetGovernment())
|| ship->GetGovernment()->IsEnemy(gov))
if(ship->FireAntiMissile(projectile, effects))
{
projectile.Kill();
break;
}
}
else if(projectile.HasBlastRadius())
radar[calcTickTock].Add(Radar::SPECIAL, projectile.Position(), 1.8);
// Now, we can draw the projectile. The motion blur should be reduced
// depending on how much motion blur is in the sprite itself:
double innateVelocity = 2. * projectile.GetWeapon().Velocity();
Point relativeVelocity = projectile.Velocity() - projectile.Unit() * innateVelocity;
draw[calcTickTock].AddProjectile(projectile, relativeVelocity, closestHit);
}
// Finally, draw all the effects, and then move them (because their motion
// is not dependent on anything else, and this way we do all the work on
// them in a single place.
for(auto it = effects.begin(); it != effects.end(); )
{
draw[calcTickTock].AddUnblurred(*it);
if(!it->Move())
it = effects.erase(it);
else
++it;
}
// Add incoming ships.
for(const System::FleetProbability &fleet : player.GetSystem()->Fleets())
if(!Random::Int(fleet.Period()))
{
const Government *gov = fleet.Get()->GetGovernment();
if(!gov)
continue;
int64_t enemyStrength = 0;
for(const auto &it : strength)
if(gov->IsEnemy(it.first))
enemyStrength += it.second;
if(enemyStrength && strength[gov] > 2 * enemyStrength)
continue;
fleet.Get()->Enter(*player.GetSystem(), ships);
}
if(!Random::Int(36000) && !player.GetSystem()->Links().empty())
{
// Loop through all persons once to see if there are any who can enter
// this system.
int sum = 0;
for(const auto &it : GameData::Persons())
sum += it.second.Frequency(player.GetSystem());
if(sum)
{
// Adjustment factor: special persons will appear once every ten
// minutes, but much less frequently if the game only specifies a
// few of them. This way, they will become more common as I add
// more, without needing to change the 10-minute constant above.
sum = Random::Int(sum + 1000);
for(const auto &it : GameData::Persons())
{
const Person &person = it.second;
sum -= person.Frequency(player.GetSystem());
if(sum < 0)
{
shared_ptr<Ship> ship = person.GetShip();
ship->Recharge();
ship->SetName(it.first);
ship->SetGovernment(person.GetGovernment());
ship->SetPersonality(person.GetPersonality());
ship->SetHail(person.GetHail());
Fleet::Enter(*player.GetSystem(), *ship);
ships.push_front(ship);
break;
}
}
}
}
// Occasionally have some ship hail you.
if(!Random::Int(600) && !ships.empty())
{
shared_ptr<Ship> source;
unsigned i = Random::Int(ships.size());
for(const shared_ptr<Ship> &it : ships)
if(!i--)
{
source = it;
break;
}
if(source->GetGovernment() && !source->GetGovernment()->IsPlayer()
&& !source->IsDisabled() && source->Crew())
{
string message = source->GetHail();
if(!message.empty() && source->GetSystem() == player.GetSystem())
Messages::Add(source->GetGovernment()->GetName() + " ship \""
+ source->Name() + "\": " + message);
}
}
// A mouse click should only be active for a single step.
doClick = false;
// Keep track of how much of the CPU time we are using.
loadSum += loadTimer.Time();
if(++loadCount == 60)
{
load = loadSum;
loadSum = 0.;
loadCount = 0;
}
}
// Pick a new target for the given ship.
shared_ptr<Ship> AI::FindTarget(const Ship &ship, const list<shared_ptr<Ship>> &ships) const
{
// If this ship has no government, it has no enemies.
shared_ptr<Ship> target;
const Government *gov = ship.GetGovernment();
if(!gov)
return target;
bool isPlayerEscort = ship.IsYours();
if(isPlayerEscort)
{
shared_ptr<Ship> locked = sharedTarget.lock();
if(locked && locked->GetSystem() == ship.GetSystem() && !locked->IsDisabled())
return locked;
}
// If this ship is not armed, do not make it fight.
double minRange = numeric_limits<double>::infinity();
double maxRange = 0.;
for(const Armament::Weapon &weapon : ship.Weapons())
if(weapon.GetOutfit() && !weapon.IsAntiMissile())
{
minRange = min(minRange, weapon.GetOutfit()->Range());
maxRange = max(maxRange, weapon.GetOutfit()->Range());
}
if(!maxRange)
return target;
shared_ptr<Ship> oldTarget = ship.GetTargetShip();
if(oldTarget && !oldTarget->IsTargetable())
oldTarget.reset();
shared_ptr<Ship> parentTarget;
if(ship.GetParent())
parentTarget = ship.GetParent()->GetTargetShip();
if(parentTarget && !parentTarget->IsTargetable())
parentTarget.reset();
// Find the closest enemy ship (if there is one). If this ship is "heroic,"
// it will attack any ship in system. Otherwise, if all its weapons have a
// range higher than 2000, it will engage ships up to 50% beyond its range.
// If a ship has short range weapons and is not heroic, it will engage any
// ship that is within 3000 of it.
const Personality &person = ship.GetPersonality();
double closest = person.IsHeroic() ? numeric_limits<double>::infinity() :
(minRange > 1000.) ? maxRange * 1.5 : 4000.;
const System *system = ship.GetSystem();
bool isDisabled = false;
for(const auto &it : ships)
if(it->GetSystem() == system && it->IsTargetable() && gov->IsEnemy(it->GetGovernment()))
{
if(person.IsNemesis() && !it->GetGovernment()->IsPlayer())
continue;
double range = it->Position().Distance(ship.Position());
// Preferentially focus on your previous target or your parent ship's
// target if they are nearby.
if(it == oldTarget || it == parentTarget)
range -= 500.;
// If your personality it to disable ships rather than destroy them,
// never target disabled ships.
if(it->IsDisabled() && !person.Plunders()
&& (person.Disables() || (!person.IsNemesis() && it != oldTarget)))
continue;
if(!person.Plunders())
range += 5000. * it->IsDisabled();
else
{
bool hasBoarded = Has(ship, it, ShipEvent::BOARD);
// Don't plunder unless there are no "live" enemies nearby.
range += 2000. * (2 * it->IsDisabled() - !hasBoarded);
}
// Focus on nearly dead ships.
range += 500. * (it->Shields() + it->Hull());
if(range < closest)
{
closest = range;
target = it;
isDisabled = it->IsDisabled();
}
}
bool cargoScan = ship.Attributes().Get("cargo scan");
bool outfitScan = ship.Attributes().Get("outfit scan");
if(!target && (cargoScan || outfitScan) && !isPlayerEscort)
{
closest = numeric_limits<double>::infinity();
for(const auto &it : ships)
if(it->GetSystem() == system && it->GetGovernment() != gov && it->IsTargetable())
{
if((cargoScan && !Has(ship, it, ShipEvent::SCAN_CARGO))
|| (outfitScan && !Has(ship, it, ShipEvent::SCAN_OUTFITS)))
{
double range = it->Position().Distance(ship.Position());
if(range < closest)
{
closest = range;
target = it;
}
}
}
}
// Run away if your target is not disabled and you are badly damaged.
if(!isDisabled && (ship.GetPersonality().IsFleeing() ||
(ship.Shields() + ship.Hull() < 1. && !ship.GetPersonality().IsHeroic())))
target.reset();
return target;
}
void AI::MoveIndependent(Ship &ship, Command &command) const
{
if(ship.Position().Length() >= 10000.)
{
MoveTo(ship, command, Point(), 40., .8);
return;
}
shared_ptr<const Ship> target = ship.GetTargetShip();
if(target && (ship.GetGovernment()->IsEnemy(target->GetGovernment())
|| (ship.IsYours() && target == sharedTarget.lock())))
{
bool shouldBoard = ship.Cargo().Free() && ship.GetPersonality().Plunders();
bool hasBoarded = Has(ship, target, ShipEvent::BOARD);
if(shouldBoard && target->IsDisabled() && !hasBoarded)
{
if(ship.IsBoarding())
return;
MoveTo(ship, command, target->Position(), 40., .8);
command |= Command::BOARD;
}
else
Attack(ship, command, *target);
return;
}
else if(target)
{
bool cargoScan = ship.Attributes().Get("cargo scan");
bool outfitScan = ship.Attributes().Get("outfit scan");
if((!cargoScan || Has(ship, target, ShipEvent::SCAN_CARGO))
&& (!outfitScan || Has(ship, target, ShipEvent::SCAN_OUTFITS)))
target.reset();
else
{
CircleAround(ship, command, *target);
if(!ship.GetGovernment()->IsPlayer())
command |= Command::SCAN;
}
return;
}
// If this ship is moving independently because it has a target, not because
// it has no parent, don't let it make travel plans.
if(ship.GetParent() && !ship.GetPersonality().IsStaying())
return;
if(!ship.GetTargetSystem() && !ship.GetTargetPlanet() && !ship.GetPersonality().IsStaying())
{
int jumps = ship.JumpsRemaining();
// Each destination system has an average priority of 10.
// If you only have one jump left, landing should be high priority.
int planetWeight = jumps ? (1 + 40 / jumps) : 1;
vector<int> systemWeights;
int totalWeight = 0;
const vector<const System *> &links = ship.Attributes().Get("jump drive")
? ship.GetSystem()->Neighbors() : ship.GetSystem()->Links();
if(jumps)
{
for(const System *link : links)
{
// Prefer systems in the direction we're facing.
Point direction = link->Position() - ship.GetSystem()->Position();
int weight = static_cast<int>(
11. + 10. * ship.Facing().Unit().Dot(direction.Unit()));
systemWeights.push_back(weight);
totalWeight += weight;
}
}
int systemTotalWeight = totalWeight;
// Anywhere you can land that has a port has the same weight. Ships will
// not land anywhere without a port.
vector<const StellarObject *> planets;
for(const StellarObject &object : ship.GetSystem()->Objects())
if(object.GetPlanet() && object.GetPlanet()->HasSpaceport()
&& object.GetPlanet()->CanLand(ship))
{
planets.push_back(&object);
totalWeight += planetWeight;
}
if(!totalWeight)
return;
int choice = Random::Int(totalWeight);
if(choice < systemTotalWeight)
{
for(unsigned i = 0; i < systemWeights.size(); ++i)
{
choice -= systemWeights[i];
if(choice < 0)
{
ship.SetTargetSystem(links[i]);
break;
}
}
}
else
{
choice = (choice - systemTotalWeight) / planetWeight;
ship.SetTargetPlanet(planets[choice]);
}
}
if(ship.GetTargetSystem())
{
PrepareForHyperspace(ship, command);
bool mustWait = false;
for(const weak_ptr<const Ship> &escort : ship.GetEscorts())
{
shared_ptr<const Ship> locked = escort.lock();
mustWait = locked && locked->CanBeCarried();
}
if(!mustWait)
command |= Command::JUMP;
}
else if(ship.GetTargetPlanet())
{
MoveToPlanet(ship, command);
if(!ship.GetPersonality().IsStaying())
command |= Command::LAND;
else if(ship.Position().Distance(ship.GetTargetPlanet()->Position()) < 100.)
ship.SetTargetPlanet(nullptr);
}
else if(ship.GetPersonality().IsStaying() && ship.GetSystem()->Objects().size())
{
unsigned i = Random::Int(ship.GetSystem()->Objects().size());
ship.SetTargetPlanet(&ship.GetSystem()->Objects()[i]);
}
}
// Fire whichever of the given ship's weapons can hit a hostile target.
Command AI::AutoFire(const Ship &ship, const list<shared_ptr<Ship>> &ships, bool secondary) const
{
Command command;
int index = -1;
// Special case: your target is not your enemy. Do not fire, because you do
// not want to risk damaging that target. The only time a ship other than
// the player will target a friendly ship is if the player has asked a ship
// for assistance.
shared_ptr<Ship> currentTarget = ship.GetTargetShip();
const Government *gov = ship.GetGovernment();
bool isSharingTarget = ship.IsYours() && currentTarget == sharedTarget.lock();
bool currentIsEnemy = currentTarget
&& currentTarget->GetGovernment()->IsEnemy(gov)
&& currentTarget->GetSystem() == ship.GetSystem();
if(currentTarget && !(currentIsEnemy || isSharingTarget))
currentTarget.reset();
// Only fire on disabled targets if you don't want to plunder them.
bool spareDisabled = (ship.GetPersonality().Disables() || ship.GetPersonality().Plunders());
// Find the longest range of any of your non-homing weapons.
double maxRange = 0.;
for(const Armament::Weapon &weapon : ship.Weapons())
if(weapon.IsReady() && !weapon.IsHoming() && (secondary || !weapon.GetOutfit()->Icon()))
maxRange = max(maxRange, weapon.GetOutfit()->Range());
// Extend the weapon range slightly to account for velocity differences.
maxRange *= 1.5;
// Find all enemy ships within range of at least one weapon.
vector<shared_ptr<const Ship>> enemies;
if(currentTarget)
enemies.push_back(currentTarget);
for(auto target : ships)
if(target->IsTargetable() && gov->IsEnemy(target->GetGovernment())
&& target->Velocity().Length() < 20.
&& target->GetSystem() == ship.GetSystem()
&& target->Position().Distance(ship.Position()) < maxRange
&& target != currentTarget)
enemies.push_back(target);
for(const Armament::Weapon &weapon : ship.Weapons())
{
++index;
// Skip weapons that are not ready to fire. Also skip homing weapons if
// no target is selected, and secondary weapons if only firing primaries.
if(!weapon.IsReady() || (!currentTarget && weapon.IsHoming()))
continue;
if(!secondary && weapon.GetOutfit()->Icon())
continue;
// Special case: if the weapon uses fuel, be careful not to spend so much
// fuel that you cannot leave the system if necessary.
if(weapon.GetOutfit()->FiringFuel())
{
double fuel = ship.Fuel() * ship.Attributes().Get("fuel capacity");
fuel -= weapon.GetOutfit()->FiringFuel();
// If the ship is not ever leaving this system, it does not need to
// reserve any fuel.
bool isStaying = ship.GetPersonality().IsStaying();
if(!secondary || fuel < (isStaying ? 0. : ship.JumpFuel()))
continue;
}
// Figure out where this weapon will fire from, but add some randomness
// depending on how accurate this ship's pilot is.
Point start = ship.Position() + ship.Facing().Rotate(weapon.GetPoint());
start += ship.GetPersonality().Confusion();
const Outfit *outfit = weapon.GetOutfit();
double vp = outfit->Velocity();
double lifetime = outfit->TotalLifetime();
if(currentTarget && (weapon.IsHoming() || weapon.IsTurret()))
{
bool hasBoarded = Has(ship, currentTarget, ShipEvent::BOARD);
if(currentTarget->IsDisabled() && spareDisabled && !hasBoarded)
continue;
Point p = currentTarget->Position() - start;
Point v = currentTarget->Velocity() - ship.Velocity();
// By the time this action is performed, the ships will have moved
// forward one time step.
p += v;
if(p.Length() < outfit->BlastRadius())
continue;
double steps = Armament::RendevousTime(p, v, vp);
if(steps == steps && steps <= lifetime)
{
command.SetFire(index);
continue;
}
}
// Don't fire homing weapons with no target.
if(weapon.IsHoming())
continue;
for(const shared_ptr<const Ship> &target : enemies)
{
if(!target->IsTargetable()
|| target->Velocity().Length() > 20.
|| target->GetSystem() != ship.GetSystem())
continue;
// Don't shoot ships we want to plunder.
bool hasBoarded = Has(ship, target, ShipEvent::BOARD);
if(target->IsDisabled() && spareDisabled && !hasBoarded)
continue;
Point p = target->Position() - start;
Point v = target->Velocity() - ship.Velocity();
// By the time this action is performed, the ships will have moved
// forward one time step.
p += v;
// Get the vector the weapon will travel along.
v = (ship.Facing() + weapon.GetAngle()).Unit() * vp - v;
// Extrapolate over the lifetime of the projectile.
v *= lifetime;
const Mask &mask = target->GetSprite().GetMask(step);
if(mask.Collide(-p, v, target->Facing()) < 1.)
{
command.SetFire(index);
break;
}
}
}
return command;
}
