Oolite Javascript Reference: PriorityAI Documentation

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This page describes the priority-based Javascript AI system, which allows more flexible behaviour than the old plist-based AIs to be written in fewer lines of code. New programmers may find the priority AI tutorial to be more useful as an introduction.

Priority-based Javascript AI is available from Oolite 1.79 onwards.

Contents

Constructor and general functions

Constructor

new PriorityAIController(ship : Ship) : PriorityAIController

Creates a priority AI and attaches it to the specified ship. Using this from anywhere other than that ship's AI script is not recommended.

var ai = new worldScripts["oolite-libPriorityAI"].PriorityAIController(this.ship);

Properties

ship

ship : Ship (read-only)

The ship to which the priority AI is attached.

General Methods

Additional methods are described in later sections, sorted by purpose.

applyHandlers

function applyHandlers(handlers : Object)

Deletes any existing event handlers applied to the ship's AI Script by a previous invocation of applyHandlers, and copies the handlers in the argument object to the AI Script. All handlers applied this way run with 'this' equal to the PriorityAIController, not to the AI Script.

clearHandlers

function clearHandlers(handlers : Object)

Deletes any existing event handlers applied to the ship's AI Script by a previous invocation of applyHandlers.

communicate

function communicate(key : String, params : Object, priority : Number)

If the communication "key" has previously been defined for this ship's communications role and personality, retrieves it, calls expandDescription on it, using the parameters in the object (which can either be a dictionary, or a Ship). This message may then broadcast on the public channel, depending on the priority. If the object is a Ship, it will be converted to a dictionary for expandDescription with the following parameters:

  • oolite_entityClass = ship.shipClassName
  • oolite_entityName = ship.shipUniqueName

Other parameters may be added later to this expansion.

The priority can be a number from 1 to 4

  1. Always send this message
  2. Send this message if no messages sent in the last 10 seconds
  3. Send this message if no messages sent or received in the last 10 seconds
  4. Send this message if no messages sent or received in the last 60 seconds

This is used to prevent an overwhelming number of comms messages being sent. While priority 1 is necessary for messages which must be heard by the player, care must be taken to ensure by other means that they cannot be sent repeatedly.

communicationsPersonality

function communicationsPersonality() : String

The current communications personality

communicationsRole

function communicationsRole() : String

The current communications role

getParameter

function getParameter(key : String) : Value

If a parameter with that key has previously been set, return its value. Otherwise return null. Note that the return value can be of any type, so you must be careful when setting and retrieving parameters to avoid type errors.

getWaypointGenerator

function getWaypointGenerator() : Function

If a waypoint generation function has previously been set, return it.

noteCommsHeard

function noteCommsHeard()

This function is used to reset the timers for priority 3 and 4 communications. The standard event handlers will call this for you, but you may need to call it manually otherwise.

reconsiderIn

function reconsiderIn(delay : Number)

Force a reconsideration of the AI's priority list ahead of schedule, if no request for sooner reconsideration has already been received. delay must be at least 0.1 seconds.

reconsiderNow

function reconsiderNow()

Force a reconsideration of the AI's priority list ahead of schedule.

setCommunicationsRole

function setCommunicationsRole(role : String)

Sets the ship's communications role to the given value. This is then used to vary the communications messages as defined by _setCommunication.

If personalities have previously been defined for this role, and the ship's current personality is either "generic" or not one defined for this role, then it will also select a new communications personality at this point, based on ship.entityPersonality. If the "oolite_personalityMatchesLeader" parameter has been set, then this is a 0..1 chance that the ship will instead take the personality of its group leader (if this ship is the group leader, this instead is the chance it will copy its personality to group members)

setCommunicationsPersonality

function setCommunicationsPersonality(role : String)

Sets the ship's communications personality to the given value. This is then used to vary the communications messages as defined by _setCommunication.

setParameter

function setParameter(key : String, value : Value)

Set the named parameter to the given value. Values may be of any type. To remove a parameter, use a value of null. See the Parameters section below for parameter keys used by the core AIs and the standard priority AI library.

setPriorities

function setPriorities(priorities : Array [, delay: Number])

Set the priority list for the AI, and evaluate it. The format of the priority list is described in the next section.

An optional delay parameter can be set, which will cause evaluation to start only after this many seconds. If it is unset, the AI will start after a random period between 0 and 1 seconds.

setWaypointGenerator

function setWaypointGenerator(generator : Function)

Sets the AI's Waypoint Generators waypoint generator function.

Parameters

The following parameters are used by the standard library and accessed using getParameter and setParameter, but you can also define your own for custom AIs. More detailed documentation will be provided soon.

As with all custom items, prefixing new parameter names with a key unique to your OXP is strongly advised.

Flag Parameters

Flag parameters are intended to be set in the AI initialisation routine to vary the behaviour of the AI.

oolite_flag_allowPlanetaryLanding
oolite_flag_autoSpreadMissiles
oolite_flag_behaviourLogging
oolite_flag_continueUnlikelyPursuits
oolite_flag_escortsCoverRetreat
oolite_flag_fightsNearHostileStations
oolite_flag_fleesPreemptively
oolite_flag_likesInterstellarSpace
oolite_flag_listenForDistressCall
oolite_flag_markOffenders
oolite_flag_neverFleeToWitchspace
oolite_flag_noDockingUntilDestination
oolite_flag_noSpecialThargoidReaction
oolite_flag_patrolStation
oolite_flag_scanIgnoresUnpowered
oolite_flag_selfDestructAbandonedShip
oolite_flag_sendsDistressCalls
oolite_flag_surrendersEarly
oolite_flag_surrendersLate
oolite_flag_watchForCargo
oolite_flag_witchspacePursuit

Other parameters

These parameters are used for storage of long-term state that may need to be kept between runs of the priority tree. In general, Configuration and Response functions set them, and Condition, Behaviour and Response functions read them, but this is only a guideline. Implementors of custom functions may need to get or set these parameters for proper interaction with built-in functions used by the same AI.

oolite_cargoDropped
oolite_cascadeDetected
oolite_distressAggressor
oolite_distressSender
oolite_distressTimestamp
oolite_dockingStation
oolite_escortRole
oolite_friendlyRoles
oolite_groupPower
oolite_interceptCoordinates
oolite_interceptTarget
oolite_lastAssist
oolite_lastFleeing
oolite_lastPirateVictim
oolite_leaderRole
oolite_personalityMatchesLeader
oolite_pirateLurk
oolite_playerFriendlyFireAlready
oolite_rememberedTarget
oolite_scanResults
oolite_scanResultSpecific
oolite_selectedPlanet
oolite_selectedStation
oolite_stationPatrolRole
oolite_waypoint
oolite_waypointRange
oolite_waypoints
oolite_witchspaceDestination
oolite_witchspaceEntry
oolite_witchspaceWormhole

Writing a priority list

The priority list is the core of the priority AI. The list will be reevaluated periodically - either timed, or when events occur - and on each reevaluation it will be searched from top to bottom. When a valid priority is found, searching will stop, and that priority will be executed.

If the parameter "oolite_flag_behaviourLogging" is set with setParameter then verbose information will be written to the log file regarding the processing of the priority list. It is generally advisable to use the debug console to do this for one ship at a time, rather than setting it generally!

Basic structure

The priority list is an array of objects. Each object contains a set of keys and values. The keys are considered in the following order and are all optional.

  • preconfiguration: function run unconditionally if this element of the list is reached.
  • condition: function run unconditionally if this element of the list is reached. If it returns false, the remainder of the object is ignored, and consideration moves to the next list element.
  • notcondition: function run unconditionally if this element of the list is reached. If it returns true, the remainder of the object is ignored, and consideration moves to the next list element.

If neither condition nor notcondition are set, this is treated as if a condition was set and was true.

  • configuration: function run if conditions allow
  • behaviour: function run if conditions allow. If this exists, no further elements of the priority list will be considered.
  • reconsider: A number. If a behaviour is executed, the priority list will next be reconsidered in this many seconds. If this value is absent the priority list will only be considered if an event causes it.
  • truebranch: a priority list array. If there was no behaviour, but the conditions allow one to be run, the truebranch will be evaluated as a priority list. If the truebranch causes a behaviour to be executed, consideration will end here. If the truebranch reaches its end without executing a behaviour, consideration will continue with the next element of the main priority list.
  • falsebranch: a priority list array. This will be executed if the the conditions caused the previous four elements to be skipped.

If evaluation reaches the end of the main priority list without finding a behaviour to execute, an error will be noted in the log. In general the last element of the main priority list should always be unconditional (or have a truebranch and a falsebranch, both of which have an unconditional last element).

Example of simple behaviour: (from thargoid AI)

 {
   preconfiguration: ai.configurationCheckScanner,
   condition: ai.conditionScannerContainsNonThargoid,
   configuration: ai.configurationAcquireScannedTarget,
   behaviour: ai.behaviourDestroyCurrentTarget,
   reconsider: 1
 },

Example of branch usage: (from police AI)

 {
   /* The group leader leads the patrol */
   condition: ai.conditionIsGroupLeader,
   truebranch: [
     /* Nothing interesting here. Patrol for a bit */
     {
       condition: ai.conditionHasWaypoint,
       configuration: ai.configurationSetDestinationToWaypoint,
       behaviour: ai.behaviourApproachDestination,
       reconsider: 30
     },
     /* No patrol route set up. Make one */
     {
       configuration: ai.configurationSetWaypoint,
       behaviour: ai.behaviourApproachDestination,
       reconsider: 30
     }
   ],
   /* Other ships in the group will set themselves up
   * as escorts if possible, or looser followers if
   * not */
   falsebranch: [
     {
       preconfiguration: ai.configurationEscortGroupLeader,
       condition: ai.conditionIsEscorting,
       behaviour: ai.behaviourEscortMothership,
       reconsider: 30
     },
     /* if we can't set up as an escort */
     {
       behaviour: ai.behaviourFollowGroupLeader,
       reconsider: 15
     }
   ]
 }

The AI Library provides a selection of standard condition, configuration and behaviour functions for us in AIs, but you can also write your own.

 /* Ship is unstable and may explode under stress */
 {
   condition: function()
   {
     return Math.random() < 0.01; // 1% chance per evaluation
   }				
   behaviour: function()
   {
     this.ship.explode();
   }
 }

Evaluation context

All condition, configuration and behaviour functions are evaluated in the context of the AI object. The 'this' variable when one of these functions is run therefore points to the priority AI, not to the AI Script.

Note that this.ship is defined and will be equivalent to the this.ship seen by the AI Script. However, if you wish to access properties of the AI Script you must use this.ship.AIScript.property. Properties and methods of the priority AI may be accessed directly, e.g. this.allied(this.ship,this.ship.target).


Behaviour functions

Behaviour functions determine what the ship will do next. They generally begin a particular behaviour, and set up event handlers (generally aided by the response templates) to allow interruption or modification of that behaviour should anything interesting happen.

Behaviour functions take no arguments and return nothing.

General behaviours

Behaviours intended for ships in general. These mostly use responsesAddStandard, and occasionally add others.

behaviourApproachDestination

function behaviourApproachDestination()

Travels from the current position to within desiredRange of destination, avoiding obstacles on the way.

If a waypoint is set in the parameters "oolite_waypoint" and "oolite_waypointRange", it will clear these parameters if when it reaches its destination it is sufficiently close to the waypoint. If the parameter "oolite_flag_patrolStation" is set, and its group leader is a station, it will report in to the station upon reaching the waypoint.

Temporary waypoints needed to avoid obstacles will be stored in the "oolite_waypoints" parameter.

behaviourAssassinateCurrentTarget

function behaviourAssassinateCurrentTarget()

This behaviour attacks the current target, only stopping when interrupted or when the target is destroyed. It will potentially send both "oolite_beginningAssassination" and "oolite_beginningFight" communications messages (though if the former is defined, the latter will not be sent due to the communications priority system). This is otherwise identical in behaviour to behaviourCommenceAttackOnCurrentTarget

behaviourAvoidCascadeExplosion

function behaviourAvoidCascadeExplosion()

Fly, using injectors if available, to a safe distance from any nearby quirium cascades (or active mines)

behaviourBecomeInactiveThargon

function behaviourBecomeInactiveThargon()

This behaviour is intended to deactivate thargons and should generally only be used for that purpose. It changes the scan class to CLASS_CARGO, clears the ship's targeting information, brings it to a stop, removes it from its ship groups, and removes it from nearby NPCs targeting systems (it can be retargeted). Unlike the equivalent plist AI command, it does not remove it as a player target.

behaviourCollectSalvage

function behaviourCollectSalvage()

This behaviour attempts to scoop the current target. If it is successful, the "oolite_cargoDropped" parameter recording the number of seen cargo pods will be cleared.

behaviourCommenceAttackOnCurrentTarget

function behaviourCommenceAttackOnCurrentTarget()

This behaviour attacks the current target, only stopping when interrupted or when the target is destroyed. Unlike the behaviourDestroyCurrentTarget behaviour, it may first send the "oolite_beginningFight" communications message, so should only be used when starting a fight with a new target/group - not when in the middle of a fight.

behaviourDestroyCurrentTarget

function behaviourDestroyCurrentTarget()

This behaviour attacks the current target, only stopping when interrupted or when the target is destroyed.

behaviourDockWithStation

function behaviourDockWithStation()

This behaviour docks with the station specified in the parameter "oolite_dockingStation". If the target refuses docking or the ship is too big to dock, the parameter will be cleared.

behaviourEnterWitchspace

function behaviourEnterWitchspace()

This behaviour attempts to enter witchspace. It can do this in several ways:

  • If the parameter "oolite_witchspaceWormhole" is set to an active wormhole, it will try to fly to and use that wormhole.
  • If the parameter "oolite_witchspaceDestination" is set, then it will try to jump to that destination using its own drive. It will wait for its escorts to be launched, and will start spinning up this drive. Calling this behaviour again after 15 seconds will cause it to jump out.
  • Otherwise, it will wait for a wormhole to be suggested by another member of its group, or for the player to create one.

behaviourEscortMothership

function behaviourEscortMothership()

This behaviour performs non-combat escorting of the ship's group leader, in the formation requested by the lead ship.

behaviourFineCurrentTarget

function behaviourFineCurrentTarget()

If the ship has scan class "CLASS_POLICE" and a current target, mark that target for fines when it next docks.

behaviourFleeCombat

function behaviourFleeCombat()

The ship will flee from hostility, in the following order:

  • Cascade explosions (coordinates from the parameter "oolite_cascadeDetected")
  • Its current target, if it can see it
  • Its defense targets, if it can see them


behaviourFollowCurrentTarget

function behaviourFollowCurrentTarget()

The ship will follow the current target, including through a witchspace jump if necessary, and will additionally remember the target.

behaviourFollowGroupLeader

function behaviourFollowGroupLeader()

The ship will follow the group leader if there is one, attempting to remain within a few kilometres of it.

behaviourGuardTarget

function behaviourGuardTarget()

The ship will fly to within a few kilometres of its current target. Similar to behaviourFollowCurrentTarget but will not follow the target into witchspace and will not remember that it was doing so if distracted.

behaviourJoinTargetGroup

function behaviourJoinTargetGroup()

The ship will add itself to its target's ship group. You should previously have used appropriate condition tests to check that this is appropriate behaviour.

behaviourLandOnPlanet

function behaviourLandOnPlanet()

Lands on the nearest planet. Unlike most behaviours, this one does not include the standard responses, so you should generally wait until the ship is only a few hundred metres above the surface before using it.

behaviourLeaveVicinityOfDestination

function behaviourLeaveVicinityOfDestination()

Moves outside scanner range of the current destination coordinates.

behaviourLeaveVicinityOfTarget

function behaviourLeaveVicinityOfTarget()

Moves outside scanner range of the current target. Unlike fleeing, this does not use fuel injectors if they are fitted, and does not cause the ship to appear hostile to its target.

behaviourMineTarget

function behaviourMineTarget()

Attacks the current target with a mining laser to break it into splinters. If the current target is not a rock, this behaviour will be cancelled and the target will be lost.

behaviourOfferToEscort

function behaviourOfferToEscort()

Offers to escort the ship identified by the parameter "oolite_scanResultSpecific". Unless this parameter has been set by the scanner condition conditionScannerContainsShipNeedingEscort this is extremely likely to fail.

To be accepted as an escort, the ship must have a primary role in the oolite-escorts role category.

behaviourPayOffPirates

function behaviourPayOffPirates()

If a pirate demand to dump cargo exists, dump that many cargo canisters (or all of them, if fewer), and then switch to behaviourFleeCombat

behaviourReconsider

function behaviourReconsider()

Does nothing except schedule a re-evaluation of the priority list.

behaviourRejoinMothership

function behaviourRejoinMothership()

This behaviour flies to rejoin the mothership, and then escorts it as in behaviourEscortMothership.

behaviourRepelCurrentTarget

function behaviourRepelCurrentTarget()

This behaviour attacks the current target, but will break off the attack (and ask its escorts to do the same) if the target starts fleeing.

behaviourRespondToDistressCall

function behaviourRespondToDistressCall()

If the ship has a valid distress call represented by the parameters "oolite_distressAggressor" and "oolite_distressSender" it will attack the aggressor if it can see it. Otherwise it will fly (with injectors if available) to near the sender, attempting to locate the aggressor.

If the aggressor has a lower bounty than the sender, then the ship will assume that the distress call is "unjust", and attack the sender instead.

behaviourRobTarget

function behaviourRobTarget()

If an existing group demand for cargo is in effect, attack the current target in the hope that it meets it. Demands are stored with the group leader if possible.

If there is no existing demand for cargo, create one based on the cargo capacity of the target ship, the current system government, the cargo capacity of the group, and other factors.

behaviourSunskim

function behaviourSunskim()

Fly along until fuel tanks are full. In general, this behaviour should not be started until sunskimming height is reached (test with conditionReadyToSunskim), and configurationSetDestinationToSunskimEnd should be used to set a safe sunskimming direction.

behaviourTumble

function behaviourTumble()

Start tumbling. Unlike most behaviours, this one does not include the standard responses, so you will need to manually request a reconsideration of priorities if one is needed.

behaviourWaitHere

This method was added in Oolite test release 1.81.

function behaviourWaitHere()

Stop at (or close to) the current location, and wait for something to happen.

Missile behaviours

Missile behaviours use responsesAddMissile. More discussion of setting missile parameters, ECM response, and detonation can be found there.

behaviourMissileInterceptCoordinates

function behaviourMissileInterceptCoordinates()

Close to the desired missile range (default 25m, or specified by the oolite_missile_proximity key in script info), detonating when reached. The coordinates to close in on are specified in the "oolite_interceptCoordinates". This is used to track missile targets which cloak.

behaviourMissileInterceptTarget

function behaviourMissileInterceptTarget()

Close to the desired missile range (default 25m, or specified by the oolite_missile_proximity key in script info), detonating when reached.

behaviourMissileSelfDestruct

function behaviourMissileSelfDestruct()

Destroys the missile without detonating the payload.


Station behaviours

Station behaviours use responsesAddStation to set up their general handlers, as most standard behaviours are unnecessary or unhelpful for a stationary station.

behaviourStationLaunchDefenseShips

function behaviourStationLaunchDefenseShips()

If the station has a target and the target is aggressive, launches a defense ship if any remain, increases the alert condition to Red, and requests a group attack on the target. Otherwise does nothing.

behaviourStationLaunchMiner

function behaviourStationLaunchMiner()

If the station does not currently have a miner in its ship group, launches one. Also reduces the alert condition by one step.

behaviourStationLaunchPatrol

function behaviourStationLaunchPatrol()

If the station does not currently have a ship in its ship group with the primary role equal to the parameter "oolite_stationPatrolRole", launches one. Also reduces the alert condition by one step.

behaviourStationLaunchSalvager

function behaviourStationLaunchMiner()

Launches a salvager. Also reduces the alert condition by one step.

behaviourStationManageTraffic

function behaviourStationManageTraffic()

The station idles. If the system repopulator has requested launches that this station can fulfil, it may launch a ship.

behaviourStationRespondToDistressCall

function behaviourStationRespondToDistressCall()

Locates the aggressor and sender in the same way as [[#behaviourRespondToDistressCall|behaviourRespondToDistressCall]. If the aggressor is not visible, does nothing, otherwise sets the aggressor as a target, increases alert condition to Red, and launches a defense ship to attack the aggressor.

Condition functions

Condition functions are used to determine whether to execute a priority AI behaviour. They take no arguments and return a Boolean.

Combat conditions

Conditions related to the ship's performance in combat.

conditionCascadeDetected

function conditionCascadeDetected() : Boolean

Returns true if a cascade explosion has been detected recently (as given by the parameter "oolite_cascadeDetected" containing the explosion coordinates).

conditionCombatOdds*

function conditionCombatOddsTerrible() : Boolean
function conditionCombatOddsBad() : Boolean
function conditionCombatOddsGood() : Boolean
function conditionCombatOddsExcellent() : Boolean

These functions return true if the perceived odds of this ship's group winning a fight against the target ship's group can reasonably be described with the appropriate description. "Good" and "Excellent" require the odds to be better than a particular threshold (so Excellent odds are always also Good), while "Bad" and "Terrible" require the odds to be worse than that threshold.

conditionGroupAttritionReached

function conditionGroupAttritionReached() : Boolean

This condition is true if the ship is in a group and that group has lost more than a quarter of its initial ships.

conditionGroupSuppliesLow

function conditionGroupSuppliesLow() : Boolean

This condition is true if the ship's group is running out of consumables such as missiles or fuel, or has several damaged ships.

conditionInCombat

function conditionInCombat() : Boolean

The ship is currently attacking other ships, or a ship in its group or one of its escorts is.

conditionInCombatWithHostiles

function conditionInCombat() : Boolean

The ship is currently attacking other ships, or a ship in its group or one of its escorts is. Additionally, at least one of the targets of those ships is itself attacking (though not necessarily attacking anything from this ship's group)

conditionLosingCombat

function conditionLosingCombat() : Boolean

The ship is in combat, but is losing. The exact definition of "losing" may vary, and is intended to account for the overall tactical situation.

conditionMothershipInCombat

function conditionMothershipInCombat() : Boolean

This ship's group leader is attacking and/or being attacked. Other ships in the group are not considered. This ship must be able to see its leader's target.

conditionMothershipIsAttacking

function conditionMothershipIsAttacking() : Boolean

This ship's group leader is attacking a target. This ship must be able to see its leader's target.

conditionMothershipIsAttackingHostileTarget

function conditionMothershipIsAttacking() : Boolean

This ship's group leader is attacking a target which is itself attacking something. This ship must be able to see its leader's target.

conditionMothershipUnderAttack

function conditionMothershipUnderAttack() : Boolean

This ship's group leader is currently being targeted. This ship must be able to see the attacker.

conditionSuppliesLow

function conditionSuppliesLow() : Boolean

This condition is true if this ship is personally running out of consumables such as missiles or fuel, or is damaged. This is effectively a wrapper around ship.damageAssessment().

Navigation conditions

Conditions related to the ship's surroundings and navigation through the system.

conditionCanWitchspaceOnRoute

function conditionCanWitchspaceOnRoute() : Boolean

The ship has a witchspace drive, a witchspace route, and the next system on its route is within range with the current fuel supply.

conditionCanWitchspaceOut

function conditionCanWitchspaceOut() : Boolean

The ship has a witchspace drive, and at least one other system is within range with the current fuel supply.

conditionFriendlyStationExists

function conditionFriendlyStationExists() : Boolean

There is at least one friendly station in the system.

conditionFriendlyStationNearby

function conditionFriendlyStationNearby() : Boolean

There is at least one friendly station within scanner range

conditionGroupIsSeparated

function conditionGroupIsSeparated() : Boolean

The ship is in a group and has a group leader, and is out of scanner range of that leader (or out of 2x scanner range if the leader is a station)

conditionHasSelectedPlanet

function conditionHasSelectedPlanet() : Boolean

The ship has a valid planet in the "oolite_selectedPlanet" parameter.

conditionHasSelectedStation

function conditionHasSelectedStation() : Boolean

The ship has a valid station in the "oolite_selectedStation" parameter.

conditionHomeStationExists

function conditionHomeStationExists() : Boolean

The ship's home station still exists

conditionHomeStationNearby

function conditionHomeStationNearby() : Boolean

The ship's home station is within scanner range.

conditionHostileStationNearby

function conditionHostileStationNearby() : Boolean

There is at least one hostile station within scanner range

conditionInInterstellarSpace

function conditionInInterstellarSpace() : Boolean

The ship is currently in interstellar space.

conditionMainPlanetNearby

function conditionMainPlanetNearby() : Boolean

The ship is within 3 radii of the surface of the main planet

conditionNearDestination

function conditionNearDestination() : Boolean

The ship is closer than the desired range to its destination

conditionPlayerNearby

function conditionPlayerNearby() : Boolean

The player's ship is within scanner range.

conditionReadyToSunskim

function conditionReadyToSunskim() : Boolean

The ship is close enough to the sun to scoop fuel.

conditionSelectedStationNearby

function conditionSelectedStationNearby() : Boolean

The ship has a selected station in the "oolite_selectedStation" parameter, and it is within scanner range.

conditionSelectedStationNearMainPlanet

function conditionSelectedStationNearMainPlanet() : Boolean

The ship has a selected station in the "oolite_selectedStation" parameter, and it is within 3 radii of the surface of the main planet.

conditionStationNearby

function conditionStationNearby() : Boolean

There is a station within scanner range.

conditionSunskimPossible

function conditionSunskimPossible() : Boolean

There is a sun, it's not going nova, it hasn't gone nova, the ship has a non-full fuel tank and fuel scoops, and the ship has sufficient heat insulation to skim safely.

conditionWormholeNearby

function conditionWormholeNearby() : Boolean

There is an entry wormhole within scanner range.

Piracy-related conditions

Conditions involved in piratical activities.

conditionCargoDemandsMet

function conditionCargoDemandsMet() : Boolean

Since this ship (or an ally) made a cargo demand, this ship has seen enough cargo dropped to meet that demand.

conditionGroupHasEnoughLoot

function conditionGroupHasEnoughLoot() : Boolean

The group this ship belongs to has obtained enough cargo to call it a day. Currently this happens when cargo space usage is above 50%, but more sophisticated checks are planned involving damage or lost ships, expenditure of consumables, and so on.

conditionPiratesCanBePaidOff

function conditionPiratesCanBePaidOff() : Boolean

Pirates have demanded that this ship dump cargo, and it currently has enough cargo on board to meet that demand.

Scanning conditions

These conditions check the ship's latest scan (configurationCheckScanner) for ships meeting particular requirements. If a ship is found, it will be placed in the "oolite_scanResultSpecific" parameter, in addition to the condition returning true.

conditionScannerContainsAssassinationTarget

function conditionScannerContainsAssassinationTarget() : Boolean

The scan contains an assassination target (i.e. an escape capsule)

conditionScannerContainsCleanShip

function conditionScannerContainsCleanShip() : Boolean

The scan contains a clean ship

conditionScannerContainsCourier

function conditionScannerContainsCourier() : Boolean

The scan contains a courier ship

conditionScannerContainsEscapePods

function conditionScannerContainsEscapePods() : Boolean

The scan contains an escape pod travelling slower than this ship's maximum speed, and this ship is able to scoop cargo.

conditionScannerContainsFineableOffender

function conditionScannerContainsFineableOffender() : Boolean

The scan contains a piloted ship with an offender legal status at or below the system threshold (varies with government) that has not already been marked for fines.

conditionScannerContainsFugitive

function conditionScannerContainsFugitive() : Boolean

The scan contains a fugitive ship

conditionScannerContainsHuntableOffender

function conditionScannerContainsHuntableOffender() : Boolean

The scan contains a piloted ship with an offender legal status not too small to bother with (varies with government).

conditionScannerContainsSeriousOffender

function conditionScannerContainsSeriousOffender() : Boolean

The scan contains a piloted ship with an offender legal status at or above the system threshold for fines (varies with government).

conditionScannerContainsHunters

function conditionScannerContainsHunters() : Boolean

The scan contains a ship with role "hunter", or a police ship, or the main station.

conditionScannerContainsLoneVictim

function conditionScannerContainsLoneVictim() : Boolean

The scan contains a single pirate victim and no other unallied ships.

conditionScannerContainsMiningOpportunity

function conditionScannerContainsMiningOpportunity() : Boolean

The scan contains a boulder (preferentially) or an asteroid, and the ship has a mining laser, a fuel scoop, and a non-full hold.

conditionScannerContainsNonThargoid

function conditionScannerContainsNonThargoid() : Boolean

The scan contains a ship which is not a Thargoid ship. Rocks and cargo will only be returned if there is nothing more interesting about.

conditionScannerContainsPirateLeader

function conditionScannerContainsPirateLeader() : Boolean

The scan contains a pirate leader (usually a heavily-armed freighter)

conditionScannerContainsPirateVictims

function conditionScannerContainsPirateVictims() : Boolean

The scan contains a pirate victim (as defined by role-categories.plist) which is carrying at least some cargo and has not recently been robbed.

conditionScannerContainsReadyThargoidMothership

function conditionScannerContainsReadyThargoidMothership() : Boolean

The scan contains a thargoid mothership which has the capability to control at least one more thargon.

conditionScannerContainsRocks

function conditionScannerContainsRocks() : Boolean

The scan contains boulders (preferentially) or asteroids.

conditionScannerContainsSalvage

function conditionScannerContainsSalvage() : Boolean

The scan contains cargo which could in theory be scooped.

conditionScannerContainsSalvageForGroup

function conditionScannerContainsSalvageForGroup() : Boolean

The scan contains cargo which could in theory be scooped, and it is travelling slowly enough that at least one of the ships in the group with fuel scoops and cargo space can collect it..

conditionScannerContainsSalvageForMe

function conditionScannerContainsSalvageForMe() : Boolean

The scan contains cargo which can be scooped by this ship (travelling slowly enough, and this ship has scoops and space)

conditionScannerContainsShipNeedingEscort

function conditionScannerContainsShipNeedingEscort() : Boolean

The scan contains a ship which has fewer escorts than its maximum. If the ship is clean, this will only detect other clean ships. If the ship is not clean, this will only detect other non-clean ships.

conditionScannerContainsSuspiciousShip

function conditionScannerContainsSuspiciousShip() : Boolean

The scan contains a ship with a criminal reputation (whether or not it currently carries a bounty)

conditionScannerContainsThargoidMothership

function conditionScannerContainsThargoidMothership() : Boolean

The scan contains a thargoid mothership which has the capability to control thargons. The number of thargons currently being controlled is irrelevant to this scan.

conditionScannerContainsUnspreadMissile

function conditionScannerContainsUnspreadMissile() : Boolean

The scan contains a missile which has the same target and owner as this ship, but is closer to the target and within 500 metres of this ship. This is mainly used for "smart" missiles to ensure that impact times for a salvo are spread out.

State querying conditions

Conditions related to the state of the ship

conditionAllEscortsInFlight

function conditionAllEscortsInFlight() : Boolean

If the ship has living escorts, then this function returns true only if they are all in normal flight (and not docked, launching, or in a wormhole). If the ship has no escorts then this function also returns true.

conditionCanScoopCargo

function conditionCanScoopCargo() : Boolean

The ship has a working fuel scoop and at least 1 TC of free space in its hold.

conditionCargoIsProfitableHere

function conditionCargoIsProfitableHere() : Boolean

The current contents of the ship's hold can be sold at an above average price at the main station (this is currently determined very approximately - solely asking "is the current system on the right side of the Ind/Agri divide" - rather than checking station prices.

conditionCoinFlip

function conditionCoinFlip() : Boolean

Returns true half the time.

conditionGroupLeaderIsStation

function conditionGroupLeaderIsStation() : Boolean

The ship has a group leader and the group leader is a station.

conditionHasInterceptCoordinates

function conditionHasInterceptCoordinates() : Boolean

The ship has intercept coordinates set in the parameter "oolite_interceptCoordinates". These are used by missiles to home in on a last-known location if the target cloaks.

conditionHasMothership

function conditionHasMothership() : Boolean

The ship has a group leader which is not itself.

conditionHasNonThargoidTarget

function conditionHasNonThargoidTarget() : Boolean

The ship's target is not null, and is not a thargoid ship (by scan class).

conditionHasReceivedDistressCall

function conditionHasReceivedDistressCall() : Boolean

The ship has recently received a distress call. Distress calls expire after 30 seconds, or if the sender is no longer visible, or if the aggressor is dead.

conditionHasRememberedTarget

function conditionHasRememberedTarget() : Boolean

The ship has a remembered target. This is set by behaviourFollowCurrentTarget to allow persistent tracking of a ship.

conditionHasTarget

function conditionHasTarget() : Boolean

The ship's target is not null.

conditionHasWaypoint

function conditionHasWaypoint() : Boolean

The ship has a waypoint set by its waypoint generator.

conditionIsActiveThargon

function conditionIsActiveThargon() : Boolean

The ship is a thargon ("EQ_THARGON") and is active.

conditionIsEscorting

function conditionIsEscorting() : Boolean

The ship is currently escorting another ship. Stricter than conditionHasMothership: this also requires this ship to be in the group leader's escort group.

conditionIsGroupLeader

function conditionIsGroupLeader() : Boolean

The ship is in a group and is the leader of the group

conditionMissileNeedsLaunchEvasion

function conditionMissileNeedsLaunchEvasion() : Boolean

This function checks if the oolite_flag_launchAdjustMissile parameter is set to a non-null value, and returns true if so.

Missile AI scripts may find the following code useful to set this flag to avoid collisions with the launching ship.

this.shipSpawned = function()
{
  /* Launch correction when fired at target in aft arc */
  var s = this.ship; 
  if(s.target && s.target.position.subtract(s.position).direction().dot(s.vectorForward) < -0.8)
  {
    this.oolite_priorityai.setParameter("oolite_flag_launchAdjustMissile",true);
  }
}

See also configurationMissileAdjustLaunch

conditionMissileOutOfFuel

function conditionMissileOutOfFuel() : Boolean

The ship has travelled beyond the maximum missile range. The default is 30km, but this may be overridden by the oolite_missile_range parameter in the ship's script info.

conditionPatrolIsOver

function conditionPatrolIsOver() : Boolean

The ship's patrol is over (either due to distance travelled or a need to re-arm and repair). Note that the distance threshold is relatively low, so for ships on long patrol routes between system bodies this function should only be called when reaching appropriate waypoints.

From Oolite 1.81, the distance threshold can be changed from the default 200km by setting the oolite_patrolLength parameter.

conditionWitchspaceEntryRequested

function conditionWitchspaceEntryRequested() : Boolean

The ship has been requested to enter a wormhole set in the "oolite_witchspaceWormhole" parameter.

Configuration functions

Configuration functions are usually used to set up parameters needed for a behaviour, though some may be used at the preconfiguration stage to set up parameters for a condition test. They take no arguments and do not return anything.

Destination configurations

These configurations set a destination, a desired range and a desired speed suitable for use with behaviourApproachDestination. Unless otherwise stated, cruiseSpeed will be used as the desired speed.

If they are unable to set a destination, they may set the destination to the ship's current position, or may do nothing. Generally a condition should be used to check that the configuration is sensible.

configurationMissileAdjustLaunch

function configurationMissileAdjustLaunch()

This function causes the missile to dive sharply. The intended use is in conjunction with conditionMissileNeedsLaunchEvasion to avoid collisions with the launching ship.

configurationMissileAdjustSpread

function configurationMissileAdjustSpread()

This function sets an intermediate destination for "smart" missiles which are adjusting their flight path to spread out a salvo's impacts on target.

configurationSetDestinationToHomeStation

function configurationSetDestinationToHomeStation()

Locates the home station, sets the destination to its position and the desired range to 15km.

configurationSetDestinationToGroupLeader

function configurationSetDestinationToGroupLeader()

Locates the group leader, sets the destination to its position and the desired range to 15km. Maximum flight speed is used.

configurationSetDestinationToMainPlanet

function configurationSetDestinationToMainPlanet()

Sets the destination to the main planet's position, and the desired range to 3 radii (i.e. 2 radii from the surface).

configurationSetDestinationToMainStation

function configurationSetDestinationToMainStation()

Sets the destination to the main station's position, and the desired range to 15km

configurationSetDestinationToNearestHostileStation

function configurationSetDestinationToNearestHostileStation()

Locates the nearest friendly station, sets the destination to its position and the desired range to 15km.

configurationSetDestinationToNearestFriendlyStation

function configurationSetDestinationToNearestFriendlyStation()

Locates the nearest friendly station, sets the destination to its position and the desired range to 15km.

configurationSetDestinationToNearestStation

function configurationSetDestinationToNearestStation()

Locates the nearest station, sets the destination to its position and the desired range to 15km.

configurationSetDestinationToNearestWormhole

function configurationSetDestinationToNearestWormhole()

Locates the nearest entry wormhole, sets the destination to its position and the desired range to zero.

configurationSetDestinationToPirateLurk

function configurationSetDestinationToPirateLurk()

If the parameter "oolite_pirateLurk" is set, then set the destination to that. If currently on a lane, set the destination to the current position. Otherwise, pick a random point on one of the lanes (strongly preferring witchpoint-planet). Once a destination is selected, store it to the parameter "oolite_pirateLurk".

The desired range is 1km.


configurationSetDestinationToScannedTarget

function configurationSetDestinationToScannedTarget()

Sets the destination to the position of the ship in the parameter "oolite_scanResultSpecific", and the desired range to 400m. This can be used to follow a ship without targeting it.

configurationSetDestinationToSelectedPlanet

function configurationSetDestinationToSelectedPlanet()

Sets the destination to the position of the planet in the parameter "oolite_selectedPlanet", and the desired range to 100m from the surface.

configurationSetDestinationToSelectedStation

function configurationSetDestinationToSelectedStation()

Sets the destination to the position of the station in the parameter "oolite_selectedStation", and the desired range to 15km.

configurationSetDestinationToSunskimEnd

function configurationSetDestinationToSunskimEnd()

Sets the destination to a course parallel to the sun's surface, at a range which should allow the fuel tanks to be completely refilled. The desired range is 0, and the desired speed is maximum speed.

Note: if this function is used above sunskimming height, it will still move parallel to the sun's surface, but this will not be much use.

configurationSetDestinationToSunskimStart

function configurationSetDestinationToSunskimStart()

Sets the destination to the sun's position, and the desired range to sunskimming height.

configurationSetDestinationToWaypoint

function configurationSetDestinationToWaypoint()

If the parameters "oolite_waypoint" and "oolite_waypointRange" are set, use those as the destination and desired range.

configurationSetDestinationToWitchpoint

function configurationSetDestinationToWitchpoint()

Sets the destination to the witchpoint and the range to 10km

configurationSetWaypoint

function configurationSetWaypoint()

If a waypoint generator function has been registered, runs that function to set the "oolite_waypoint" and "oolite_waypointRange" parameters, then sets the destination from those parameters.

Docking configurations

Each of these configurations sets the "oolite_dockingStation" parameter used by behaviourDockWithStation

configurationSetNearbyFriendlyStationForDocking

function configurationSetNearbyFriendlyStationForDocking()

Sets the "oolite_dockingStation" parameter to a friendly station in scanner range, if possible.

configurationSetHomeStationForDocking

function configurationSetHomeStationForDocking()

Sets the "oolite_dockingStation" parameter to the ship's home station.

configurationSetSelectedStationForDocking

function configurationSetHomeStationForDocking()

Sets the "oolite_dockingStation" parameter to the station in the parameter "oolite_selectedStation".

Miscellaneous configurations

configurationAppointGroupLeader

function configurationAppointGroupLeader()

If the ship is in a group but the group has no leader, set one of the ships in the group to be the leader. Witchspace-capable ships will be preferred over those which are not.

If the parameter "oolite_leaderRole" is set, the primary role of the new leader will be changed to that role.

configurationEscortGroupLeader

function configurationEscortGroupLeader()

If the ship is in a group and the group has a leader which is not this ship and the ship is not already escorting the group leader, and the parameter "oolite_escortRole" is set, then attempt to escort the group leader. The ship's primary role will be set to "oolite_escortRole" if the escort attempt is successful, and this role must therefore be a valid escort role.

configurationForgetCargoDemand

function configurationForgetCargoDemand()

If the ship has a cargo demand active (the demand must be stored on this ship, not just on a group member), discard it, and reset the "oolite_cargoDropped" parameter of this ship and all group members to zero.

configurationLeaveEscortGroup

function configurationLeaveEscortGroup()

If the ship is currently escorting another ship, leave the escort group.

configurationLightsOff

function configurationLightsOff()

Set the ship's flashers to the 'off' state.

configurationLightsOn

function configurationLightsOn()

Set the ship's flashers to the 'on' state.

configurationSetRemoteControl

function configurationSetRemoteControl()

If the ship has a group leader, set its own accuracy to that ship's accuracy. This is used by thargons when the mothership controlling them is changed.

Navigation configurations

configurationSelectPlanet

function configurationSelectPlanet()

This function places a randomly selected planet or moon in the parameter "oolite_selectedPlanet"

configurationSelectRandomTradeStation

function configurationSelectRandomTradeStation()

This function places a suitable station in the parameter "oolite_selectedStation". If the ship is clean, then 90% of the time this will be the main station. If the ship is an offender, but has a bounty not greater than the fine threshold, then 50% of the time this will be the main station.

If the main station was not selected at the previous step, a random friendly station will be selected (which may be the main station anyway)

configurationSelectShuttleDestination

function configurationSelectShuttleDestination()

This function selects a random planet or station. The entity selected must be at least 10km from the ship. If any such entities are within 5 times the radius of the main planet from the ship, more distant entities will be ignored.

If the selected entity was a planet, it will be stored in "oolite_selectedPlanet". Otherwise, it will be stored in "oolite_selectedStation".

configurationSelectWitchspaceDestination

function configurationSelectWitchspaceDestination()

If the ship has no witchspace drive, unset the "oolite_witchspaceDestination" parameter. If that parameter is already set, and is not the current system, and the ship has enough fuel to reach that system, do nothing. Otherwise, select a random system in range and place its ID in the "oolite_witchspaceDestination" parameter.

configurationSelectWitchspaceDestinationInbound

function configurationSelectWitchspaceDestination()

If the ship has no witchspace drive, unset the "oolite_witchspaceDestination" parameter. If the ship's home system and destination system are unequal, select the next system on the route to the home system. Otherwise, select a random system in range and place its ID in the "oolite_witchspaceDestination" parameter.

configurationSelectWitchspaceDestinationOutbound

function configurationSelectWitchspaceDestination()

If the ship has no witchspace drive, unset the "oolite_witchspaceDestination" parameter. If the ship's home system and destination system are unequal, select the next system on the route to the destination system. Otherwise, select a random system in range and place its ID in the "oolite_witchspaceDestination" parameter.

Station configurations

configurationStationReduceAlertLevel

function configurationStationReduceAlertLevel()

Reduce the alert level of the station by one stage if it is not already Green.

configurationStationValidateTarget

function configurationStationValidateTarget()

Check that the station's current target is within scanner range, and discard it if not. This is necessary for stations as unlike ships their low-level behaviour does not generally do this automatically.

Target acquisition configurations

configurationAcquireCombatTarget

function configurationAcquireCombatTarget()

If the ship's target is valid, not cargo and not an ally, keep the current target. Otherwise, promote one defense target to a target. If the ship has no defense targets, check to see if any ships in the group or escort group have a combat target (but do not check their defense targets).

configurationAcquireDefensiveEscortTarget

function configurationAcquireDefensiveEscortTarget()

Search the current group leader's target and defense targets for a visible ship attacking the group leader, and target it if one is found. Otherwise, retain current target.

configurationAcquireHostileCombatTarget

function configurationAcquireHostileCombatTarget()

As configurationAcquireCombatTarget but only targets which are hostile (i.e. would be valid for behaviourRepelTarget) will be selected.

configurationAcquireOffensiveEscortTarget

function configurationAcquireOffensiveEscortTarget()

If this ship's group leader is attacking a target, and this ship can see that target, acquire that target. Otherwise retain current target.

configurationAcquirePlayerAsTarget

function configurationAcquirePlayerAsTarget()

Set this ship's target to the player.

configurationAcquireScannedTarget

function configurationAcquireScannedTarget()

Set this ship's target to the entity in the parameter "oolite_scanResultSpecific". This parameter is set by the checkScannerWithPredicate function, which is usually called from a conditionScannerContains... condition.

configurationCheckScanner

function configurationCheckScanner()

Scans the ship's scanner range, placing a list of detected targets into the "oolite_scanResults" parameter. This is generally called in a preconfiguration before the first use of a conditionScannerContains... condition in the priority list.

If the scanner is particularly full, the list will not contain all visible objects. The current scan limit is 16.

Response definition functions and components

Response definition functions

Response definition functions are used to set up event handlers in the AI script. They take an object as an argument, and add event handlers to that object. They do not return anything as such, but modify their argument.

They are generally used in behaviour functions to set up common responses.

var handlers = {}; // new handler object
this.responsesAddStandard(handlers); // add standard response set
// add a handler for this behaviour
handlers.shipEnteredStationAegis = function(station)
{
  this.ship.beaconCode = null; // stop transmitting
}
this.applyHandlers(handlers);

responsesAddDocking

function responsesAddDocking(handlers : Object)

Provides some additional event handlers for use when docking with a station.

responsesAddEscort

function responsesAddEscort(handlers : Object)

Provides some additional event handlers for use when escorting a ship, and changes the response to in-group help requests.

responsesAddMissile

function responsesAddMissile(handlers : Object)

A standard set of event handlers for missiles, which should be used instead of responsesAddStandard.

A number of script info keys are used to modify the responses.

  • oolite_missile_blastPower, oolite_missile_blastRadius, oolite_missile_blastShaping: If oolite_missile_detonation is not set, the default detonation function calls this.ship.dealEnergyDamage with the defined power, radius, and shaping. If these parameters are not set the defaults are power 170, radius 32.5, and shaping 0.25.
  • oolite_missile_detonation: names a function in the AI script. This function will be called when the missile reaches the desired range from its target or destination. If this function is not set, the oolite_missile_blast* keys are used to set up an explosion.
  • oolite_missile_ecmResponse: names a function in the AI script. This function will be called if the missile detects an ECM pulse. If no function is set, the missile will self destruct.

responsesAddScooping

function responsesAddScooping(handlers : Object)

Provides some additional event handlers for use when scooping fuel.

responsesAddStandard

function responsesAddStandard(handlers : Object)

Sets up standard event handlers to detect and respond to attacks, and to manage other common events. Certain parameter flags are used:

  • oolite_flag_allowPlanetaryLanding: if true, the ship will land on a planet if it receives the approachingPlanetSurface event. Otherwise, it will immediately reconsider its behaviour.
  • oolite_flag_listenForDistressCall: if true, the ship will set the "oolite_distressAggressor", "oolite_distressSender" and "oolite_distressTimestamp" parameters if it receives a distress call.
  • oolite_flag_markOffenders: if true, the ship will apply a small bounty increase to ships it sees committing crimes.
  • oolite_flag_sendsDistressCalls: if true, the ship will send distress calls when attacked.
  • oolite_flag_watchForCargo: if true, the ship will increment the "oolite_cargoDropped" parameter if cargo is dumped nearby.

If multiple standard responses are being applied, this one should be the first one applied.

responsesAddStation

function responsesAddStation(handlers : Object)

A standard set of event handlers for stations, which should be used instead of responsesAddStandard. The "oolite_flag_listenForDistressCall" and "oolite_flag_markOffenders" parameters have the same use as in responsesAddStandard.

Response definition components

The components are standard event handlers used by the standard response functions. The following response components are available. Each is named "responseComponent_responseGroup_handlerName". You can use them in your own handler definition functions for efficiency.

var handlers = {};
handlers.approachingPlanetSurface = this.responseComponent_standard_approachingPlanetSurface;
// .. etc ..
this.applyHandlers(handlers);

Standard components

Standard event handlers for normal ships.

responseComponent_standard_approachingPlanetSurface
responseComponent_standard_cargoDumpedNearby
responseComponent_standard_cascadeWeaponDetected
responseComponent_standard_commsMessageReceived
responseComponent_standard_distressMessageReceived
responseComponent_standard_escortAccepted
responseComponent_standard_helpRequestReceived
responseComponent_standard_offenceCommittedNearby
responseComponent_standard_playerWillEnterWitchspace
responseComponent_standard_shipAcceptedEscort
responseComponent_standard_shipAchievedDesiredRange
responseComponent_standard_shipAttackedOther
responseComponent_standard_shipAttackedWithMissile
responseComponent_standard_shipAttackerDistracted
responseComponent_standard_shipBeingAttacked
responseComponent_standard_shipBeingAttackedUnsuccessfully
responseComponent_standard_shipFiredMissile
responseComponent_standard_shipKilledOther
responseComponent_standard_shipLaunchedEscapePod
responseComponent_standard_shipLaunchedFromStation
responseComponent_standard_shipScoopedOther
responseComponent_standard_shipTargetLost
responseComponent_standard_shipWillEnterWormhole
responseComponent_standard_shipWitchspaceBlocked
responseComponent_standard_wormholeSuggested

Missile components

Standard event handlers for missiles.

responseComponent_missile_commsMessageReceived
responseComponent_missile_shipHitByECM
responseComponent_missile_shipTargetCloaked
responseComponent_missile_shipTargetLost
responseComponent_missile_shipAchievedDesiredRange


Station components

Standard event handlers for stations.

responseComponent_station_commsMessageReceived
responseComponent_station_cascadeWeaponDetected
responseComponent_station_shipAttackedWithMissile
responseComponent_station_shipBeingAttacked
responseComponent_station_shipAttackedOther
responseComponent_station_shipFiredMissile
responseComponent_station_shipKilledOther
responseComponent_station_shipTargetLost
responseComponent_station_helpRequestReceived
responseComponent_station_distressMessageReceived
responseComponent_station_offenceCommittedNearby

Docking components

Alternative event handlers for docking ships.

responseComponent_docking_shipAchievedDesiredRange
responseComponent_docking_stationWithdrewDockingClearance
responseComponent_docking_shipAIFrustrated

Escort components

Alternative event handlers for escorts.

responseComponent_escort_escortDock
responseComponent_escort_helpRequestReceived

Expect-witchspace components

Alternative event handlers for ships expecting that their target might enter witchspace to escape

responseComponent_expectWitchspace_shipTargetLost

Scooping components

Alternative event handlers for ships scooping fuel.

responseComponent_scooping_shipAchievedDesiredRange
responseComponent_scooping_shipScoopedFuel

Track-player components

Alternative event handlers for ships following the player.

responseComponent_trackPlayer_playerWillEnterWitchspace

Template functions

These functions return standard blocks of priorities for insertion into a priority list. Each of them returns an array, so can be used as a branch in its own right, or concatenated on to an existing array. Remember that unlike a standard priority entry, you need the result of these functions, not a reference to the function.

{
  condition: ai.conditionInCombat,
  falsebranch: ai.templateReturnToBase()
}

or

priorities.concat(ai.templateReturnToBase());

templateLeadHuntingMission

function templateLeadHuntingMission() : Array

Return the priorities for leading a patrol between waypoints. Setting the waypoint generator and handling fighting and scanning along the course of the patrol should be handled by higher priorities.

templateLeadPirateMission

function templateLeadPirateMission() : Array

Return the priorities for selecting targets to rob if any are about, or moving to a suitable lurk position otherwise.

templateReturnToBase

function templateReturnToBase() : Array

Return the priorities for travelling to and docking with a suitable station.

templateReturnToBaseOrPlanet

function templateReturnToBaseOrPlanet() : Array

Return the priorities for travelling to and docking with a suitable station, or landing on a planet if no suitable stations are found.

templateWitchspaceJumpAnywhere

function templateWitchspaceJumpAnywhere() : Array

Returns priorities for getting the ship out of the current system somehow - either by jumping out, or by finding a wormhole to hitchhike.

templateWitchspaceJumpInbound

function templateWitchspaceJumpInbound() : Array

Returns priorities for jumping closer to the home system, sunskimming if fuel is short. You should previously have checked that the ship is not in the home system.

templateWitchspaceJumpOutbound

function templateWitchspaceJumpOutbound() : Array

Returns priorities for jumping closer to the destination system, sunskimming if fuel is short. You should previously have checked that the ship is not in the destination system.

Utility functions

These functions are provided to make standardised checks easier to write and to wrap certain ship methods to make them easier to work with in the AI controller.

allied

function allied(ship1, ship2) : Boolean

Returns true if the two ships are considered allied, false otherwise. Ships are considered allied if they are in the same group, or if they are escorts of ships in the same group.

broadcastDistressMessage

function broadcastDistressMessage()

Broadcasts a distress message, but with a delay to ensure that ship.broadcastDistressMessage() is not called too often.


checkScannerWithPredicate

function checkScannerWithPredicate(function) : Boolean

Called after configurationCheckScanner to locate a ship on the scanner matching a particular predicate. The predicate function must take a Ship, and return a Boolean.

If the predicate function matches a ship, the first such match will be stored in the parameter "oolite_scanResultSpecific", and the method will return true. Otherwise the method returns false.

cruiseSpeed

function cruiseSpeed() : Number

Returns a suitable speed for the ship to travel at if it is interested in preserving group or escort coherence. Generally this will be 80% of its maximum speed, but it will be slower if other group members or escorts are slower.

distance

function distance(position : vectorExpression)

Returns the distance to the given coordinates. This is more efficient than calling this.ship.position.distanceTo(position).

entityCommsParams

function entityCommsParams(entity : Entity) : Object

Returns an object of communications parameters relating to the given entity. Used internally by communicate() but may be of use elsewhere.

fineThreshold

function fineThreshold() : Number

The maximum bounty at which an offender should be fined rather than attacked by police ships. (Ships caught redhanded may be attacked regardless of bounty) Varies from system to system.

friendlyStation

function friendlyStation(station) : Boolean

Returns true if the station is friendly to the current ship, false otherwise. The main station is unfriendly to Fugitive ships and Offenders above the current fineThreshold. Other stations are only considered unfriendly to their current combat target.

homeStation

function homeStation() : Boolean

Returns the home station of this ship. If the ship has an owner, and the owner is a station, then that is the home station. Otherwise, the first station in the ship's group is returned.

If no home station can be found, returns null.

ignorePlayerFriendlyFire

function ignorePlayerFriendlyFire() : Boolean

Returns true if this ship should ignore friendly fire from the player as they would for a known ally. Note that this function's results will change if called repeatedly, so you should only call it once per instance of friendly fire, and never call it speculatively.

isAggressive

function isAggressive() : Boolean

Returns true if the ship is an active danger to its current target (approximately: it is in a combat behaviour other than fleeing)

isEscaping

function isEscaping() : Boolean

Returns true if the ship is successfully running away from this ship (i.e. it is not attacking, it is travelling faster than this ship can, and it is already outside effective weapons range.

isFighting

function isAggressive() : Boolean

Returns true if the ship is in combat (including fleeing). Similar to ship.hasHostileTarget but works for stations as well.

noteDistraction

function noteDistraction(whom : Entity)

If this ship is switching combat targets because another ship distracted it, then call this function just before switching. whom is the entity that this ship will soon switch to attacking. This calls the shipAttackerDistracted event handler on the current target.

oddsAssessment

function oddsAssessment() : Number

Carry out an odds assessment of this ship's group versus the target ship's group. This will return a positive number of the ratio between the two values, with a number greater than 1 implying that this ship's group is stronger, and a number less than 1 implying the target's group is stronger. The odds assessment of the target group will omit certain information unless the target is currently in combat. Ships outside of scanner range, whether friendly or hostile, will also be ignored in the assessment.

playerRoleAssessment

function playerRoleAssessment() : String

Determines a single perceived role for the player based on player.roleWeights. In general, the perception will be the same for all ships in a group. This can then be used with Ship.roleIsInCategory to determine the appropriate response.

respondToThargoids

function respondToThargoids(whom : Ship, passon : Boolean) : Boolean

This function causes the ship (and if the passon parameter is set, its group members) to respond to the appearance of the Thargoid ship whom. It will return true if this ship responds, or false if not.

You must ensure that ships responding to a Thargoid as a result of a notification by a group member do not themselves set passon as this may cause an infinite loop.

setWitchspaceRouteTo

function setWitchspaceRouteTo(dest : Number)

This function sets the oolite_witchspaceDestination parameter according to the needs of reaching the system with the system ID equal to dest. As this function involves route planning, which is relatively slow, it should be called only rarely. This can then be used to determine whether to refuel or attempt to jump.

shipHasRiskyContracts

function shipHasRiskyContracts(ship : Ship) : Boolean

Sometimes returns true (non-deterministically) if the target ship is carrying contracts that someone might want assassinated or destroyed. The chance of returning true increases with the number of risky contracts carried. Currently this will always return false for a non-player ship: you can check these with the oolite-courier role category instead.

shipInRoleCategory

function shipInRoleCategory(ship : Ship, category : String) : Boolean

This is a wrapper around Ship.roleIsInCategory which accounts for the player's effective role not being the same as player.ship.primaryRole. You should generally call this instead of calling Ship.roleIsInCategory directly.

stationAllegiance

function stationAllegiance(station : Station) : String

Returns station.allegiance for the given station, but if this is null (as it will be for pre-1.79 stations), first sets it using a heuristic calculation.

threatAssessment

function threatAssessment(ship : Ship, full : Boolean) : Number

This is a wrapper around _threatAssessment which is itself a wrapper around ship.threatAssessment(). The combination of the two ensures that the assessment is correct for the relative combat states of this ship and the ship being assessed, as well as including effects of the player's reputation.

Waypoint Generators

Waypoint generators are used to set patrol or other multipoint routes. When called, they should consider the ship's current position (and possibly other things), and then set the parameters "oolite_waypoint" and "oolite_waypointRange". These functions have no arguments and no return value.

In general, you should only call a waypoint generator if a waypoint is not already set.

waypointsSpacelanePatrol

function waypointsSpacelanePatrol()

If the ship is near the main planet, sun, or witchpoint, pick one of the other two points (biased towards the witchpoint-planet route) and set that as the waypoint. Otherwise, if the ship is on a lane already, pick one end of the lane at random. Otherwise, pick the planet.

Set a waypoint within 7500m of the witchpoint, 2 radii of the centre of the planet, or 2.5 radii of the centre of the sun.

waypointsStationPatrol

function waypointsStationPatrol()

If the ship has a station as its group leader, define waypoints from that station. Otherwise define them from the main station. If there is no main station either, set the witchpoint as the waypoint.

If there is a station, pick four points describing a square of diagonal length 50km centred on the station and lying in the station's xy plane. If the ship is not within 500 metres of any of these points, select one of the points as the waypoint. Otherwise, select the next point around the list as the waypoint.

waypointsWitchpointPatrol

function waypointsWitchpointPatrol()

Pick four points describing a square of diagonal length 30km centred on the witchpoint and lying approximately in the system's xy plane. If the ship is not within 500 metres of any of these points, select one of the points as the waypoint. Otherwise, select the next point around the list as the waypoint.

Global Configuration

All PriorityAIControllers share a single communications message library. This library may be edited using functions in the priority AI worldscript

Usage

When a key is asked for, the communications library will be checked in the following order:

  1. for a key with the specified role and personality
  2. if the role does not start with "_", a key with the specified personality and the role "generic"
  3. if the personality does not start with "_", a key with the specified role and the personality "generic"
  4. if neither role nor personality start with "_", a key with "generic" role and personality.

In general, setting keys for the generic role (and especially with a generic personality as well) should be used with caution.

The key's value is then expanded using expandDescription (possibly with added parameters), so entries in descriptions.plist may be used to add variety to the communications. Alternatively, a static text string also works as the value.

Standard Communications Keys

The following communications keys are currently defined in standard Oolite, but you can define more. Those with a parameter of Ship can have a Ship object passed to them, which will be replaced with definitions for the parameters "oolite_entityClass", "oolite_entityCrew" and "oolite_entityName".

oolite_agreeingToDumpCargo
Parameter: "oolite_demandSize" (size of demand in TC)
Priority: 1

Used when a ship dumps cargo to satisfy a pirate demand

oolite_attackLowEnergy
Parameter: Ship,
Priority: 2

Used when requesting help as under attack and close to death

oolite_beginningAssassination
Parameter: Ship, plus "oolite_entityContracts" parameter
Priority: 3

Used when commencing a fight with the Ship defined in the parameter, like oolite_beginningFight, but specifically for an assassination target. The extra communications parameter contains the name of a passenger (or parcel owner) relevant to this ship (for the player, this may intentionally be someone for whom delivery has been completed - either it's a revenge hit, or they're just working from outdated intelligence)

oolite_beginningAttack
Parameter: Ship
Priority: 3

Used when commencing an attack on the Ship defined in the parameter.

oolite_beginningAttackInanimate
Parameter: Ship
Priority: 3

Used when commencing an attack on the Ship (expected to be an uncrewed object like an asteroid, cargo pod, etc.) defined in the parameter.

oolite_beginningAttackThargoid
Parameter: Ship
Priority: 3

Used when commencing an attack on the Ship (expected to be a Thargoid ship) defined in the parameter.

oolite_beginningFight
Parameter: Ship
Priority: 3

Used when commencing a fight with the Ship defined in the parameter. (Beginning Attack means attacking a target previously not under attack but which there may have been a reason to fight from previous combats; Beginning Fight is stronger - this ship is initiating hostilities)

oolite_continueFleeing
Parameter: Ship
Priority: 4

Used when the ship has been unable to reach safety from its attacker.

oolite_continuingAttack
Parameter: Ship
Priority: 4

Used when continuing an attack on the Ship defined in the parameter (the low priority means this is relatively rarely used, of course)

oolite_continuingAttackInanimate
Parameter: Ship
Priority: 4

Used when continuing an attack on the Ship (if likely to be uncrewed) defined in the parameter (the low priority means this is relatively rarely used, of course)

oolite_continuingAttackThargoid
Parameter: Ship
Priority: 4

Used when continuing an attack on the Ship (if Thargoid) defined in the parameter (the low priority means this is relatively rarely used, of course)

oolite_distressResponseAggressor
Parameter: Ship
Priority: 2

Used to threaten the ship a distress call has been sent about.

oolite_distressResponseSender
Parameter: Ship
Priority: 2 or 3

Used to reassure a ship sending a distress call that help is on the way. oolite_distressResponseAggressor is preferred - this will only be used if the ship sending the message is near the sender but not the aggressor.

oolite_dockingWait
Parameter: none
Priority: 4

Used when a ship is waiting in a docking queue.

oolite_eject
Parameter: none
Priority: 1

Used when a ship launches an escape pod (the communication comes from the ship, not the pod, as the pod is being launched)

oolite_engageWitchspaceDrive
Parameter: none
Priority: 4

Used when a lone ship is beginning its witchspace entry sequence, and is expected to enter witchspace in around 15 seconds.

oolite_engageWitchspaceDriveFlee
Parameter: none
Priority: 2

Used when a ship is preparing to escape from a fight by making a witchspace jump

oolite_engageWitchspaceDriveGroup
Parameter: none
Priority: 4

Used when a grouped ship is beginning its witchspace entry sequence, and is expected to enter witchspace in around 15 seconds.

oolite_escortAccepted
Parameter: Ship
Priority: 2

Used when a ship accepts a new escort. The new escort will be passed as the parameter.

oolite_escortFormation
Parameter: Ship
Priority: 4

Used when a ship is entering or maintaining escort formation. The mothership will be passed as the parameter.

oolite_escortMotherAccepted
Parameter: Ship
Priority: 2

Used when a ship is accepted as a new escort. The ship being escorted will be passed as the parameter.

oolite_firedMissile
Parameter: Ship
Priority: 4

Used when firing a missile. The target of the missile will be passed as the parameter.

oolite_friendlyFire
Parameter: Ship
Priority: 2, 3 or 4 depending on circumstances

Used when a ship is hit by weapons fire from another ship it considers "on its side" either because of common group or because of similar roles.

oolite_groupIsOutnumbered
Parameter: none
Priority: 2 if group leader, 4 otherwise

Used when a ship realises it is in a fight with a group which seriously outclasses it, and therefore should flee.

oolite_hitTarget
Parameter: Ship
Priority: 4

Used when the ship hits its target. The target is passed as the parameter.

oolite_incomingMissile
Parameter: Ship
Priority: 3

Used when the ship has had a missile launched at it and is unable to use ECM. The missile is passed as the parameter.

oolite_killedAlly
Parameter: Ship
Priority: 3

Used when the ship destroys an allied ship. The target is passed as the parameter.

oolite_killedTarget
Parameter: Ship
Priority: 2 (3 for stations)

Used when the ship destroys its current target. The target is passed as the parameter.

oolite_killedNonTarget
Parameter: Ship
Priority: 3

Used when the ship destroys something other than its current target. The target is passed as the parameter.

oolite_killedUncrewedTarget
Parameter: Ship
Priority: 3 (4 for stations)

Used when the ship destroys an uncrewed object which is its current target. The target is passed as the parameter.

oolite_killedUncrewedNonTarget
Parameter: Ship
Priority: 3 (4 for stations)

Used when the ship destroys an uncrewed object other than its current target. The target is passed as the parameter.

oolite_landingOnPlanet
Parameter: none
Priority: 4

Used when beginning final landing approach to a planet.

oolite_launchDefenseShips, oolite_launchMiner, oolite_launchPatrol, oolite_launchSalvager
Parameter: Ship
Priority: 3

Used when a station launches a ship of a particular type. The parameter is the station's current target.

oolite_leaveVicinity
Parameter: Ship
Priority: 3

Used when a ship is executing behaviourLeaveVicinityOfDestination. The parameter is the current target.

oolite_makeDistressCall
Parameter: Ship
Priority: 2

Used as the message when a distress call is sent. The parameter is the ship's primary aggressor.

oolite_makePirateDemand
Parameter: Ship and "oolite_demandSize"
Priority: 1

Used when making a piracy demand on a ship. The Ship parameters are from the ship being robbed.

oolite_markForFines
Parameter: Ship
Priority: 1

Used when a police ship is marking another ship for fines on docking. The parameter is the ship being marked.

oolite_mining
Parameter: none
Priority: 4

Used when carrying out mining activity

oolite_newAssailiant
Parameter: Ship
Priority: 3

Used when the ship is attacked by someone not previously considered hostile. The attacker is the parameter.

oolite_offenceDetected
Parameter: Ship
Priority: 3 if this increases the aggressor's bounty, 4 otherwise

Used when a police ship detects illegal hostilities. The parameter is the aggressor.

oolite_patrolReportIn
Parameter: Ship
Priority: 4

Used when a station patrol ship reaches a waypoint. The parameter is its parent station.

oolite_quiriumCascade
Parameter: none
Priority: 3

Used when a quirium cascade or an imminent cascade is detected.

oolite_scoopedCargo
Parameter: "oolite_goodsDescription" is a description of the cargo commodity
Priority: 4

Used when this ship scoops cargo.

oolite_selectedStation
Parameter: Ship
Priority: 4

Used when a ship selects a station to navigate to (e.g. traders, shuttles). The parameter is the selected station.

oolite_selectedWitchspaceDestination
Parameter: "oolite_witchspaceDestination" is the name of the destination system
Priority: 4

Used when a ship selects its witchspace destination.

oolite_startFleeing
Parameter: Ship
Priority: 3

Used when a ship begins fleeing combat, with the parameter being the ship's current target.

oolite_startHelping
Parameter: Ship
Priority: 4

Used when a ship responds to a request for help from another grouped ship by changing its target. The parameter is the new target.

oolite_surrender
Parameter: none
Priority: 3

Messages sent by fleeing ships still being fired upon, in attempt to beg for mercy. oolite_agreeingToDumpCargo is used instead in the one case in the core game where an attacker might accept a surrender (as opposed to breaking off an attack on a fleeing ship to attack a non-fleeing one)

oolite_thanksForHelp
Parameter: Ship
Priority: 1 if thanking the player, 3 otherwise

This message is sent if an attack on this ship's aggressor causes it to break off its own attack. The parameter is the ship helping out.

oolite_thargoidAttack
Parameter: Ship
Priority: 2

This message is sent if the ship is attacked by a Thargoid ship while not previously fighting Thargoids. The parameter is the Thargoid ship. This is generally accompanied by a quick cessation of hostilities between Cooperative vessels for a short-term truce against the invaders.

oolite_waypointReached
Parameter: none
Priority: 3

This message is sent when a ship reaches a waypoint set with the waypoint generator function.

oolite_witchspaceBlocked
Parameter: Ship
Priority: 3

This message is sent when a large nearby mass (usually a station or asteroid) prevents witchspace entry. The parameter is the blocking mass.

Standard Communications Roles

The following communications roles are used by the standard Oolite AIs. Some of the roles have fallback roles used by the standard AIs, noted below. If the fallback role does not exist, or is not specified, it will fall back to using "generic" as usual.

Note that OXP AIs might not specify the same fallback roles. OXP AIs wishing to can use code like

if (worldScripts["oolite-libPriorityAI"]._getCommunicationPersonalities("hermit").length > 0)
{
	ai.setCommunicationsRole("hermit");
}
else
{
	ai.setCommunicationsRole("station");
}
  • assassin - assassins
  • defenseShip - defense ships
  • escapepod - escape pods
  • escort - escorts
  • hermit - rock hermits. If no personalities are defined for this role, "station" will be used instead.
  • hunter - bounty hunters
  • pirate - pirates
  • pirate-aegis-raider - pirates showing off by attacking the main station. If no personalities are defined for this role, "pirate" will be used instead.
  • pirate-freighter - pirate freighters leading a pack. If no personalities are defined for this role, "pirate" will be used instead.
  • pirate-interceptor - pirates assigned to distract police and hunters. If no personalities are defined for this role, "pirate" will be used instead.
  • police - police ships
  • scavenger - scavengers and miners.
  • shuttle - orbital shuttles (usually unarmed)
  • station - stations.
  • trader - traders
  • trader-courier - couriers. If no personalities are defined for this role, "trader" will be used instead.
  • trader-opportunist - opportunistic traders. If no personalities are defined for this role, "trader" will be used instead.
  • trader-smuggler - smugglers. If no personalities are defined for this role, "trader" will be used instead.

Thargoids are set slightly differently: all the core game ones get the "_thargoid" role, with the warships getting the "thargoid" personality, and the drones getting the "tharglet" personality, even if those personalities are not otherwise defined. Note that the underscore in the role prevents fallback to "generic" messages here.

Methods

_getCommunication

function _getCommunication(role : String, personality : String, key : String) : StringOrFunction

This function returns either a string suitable for passing to expandDescription containing the communications for the specified key, or a function called with key and parameters returning a communications string, if a ship of the specified role and personality is speaking.

_getCommunicationPersonalities

function _getCommunicationPersonalities(role : String) : Array

Returns the personalities which have at least one communication key defined for the given role.

_setCommunication

function _setCommunication(role : String, personality : String, key : String, value : StringOrFunction)

This function sets the communications values returned by getCommunication. The value may either be:

  • a String, which will be passed to expandDescription
  • a Function, which will be called with two parameters: the key, and the parameters object.

For example

worldScripts["oolite-libPriorityAI"]._setCommunication("myoxp_role","generic",
    "oolite_continuingAttack","[myoxp_role_continuesAttack]");
worldScripts["oolite-libPriorityAI"]._setCommunication("myoxp_role","generic",
    "oolite_continuingAttack",function(k,p) { return "Targeting the "+p.oolite_entityName+". Cover me."; });

_setCommunications

function _setCommunications(comms : Object)

This function can be used to set multiple communications keys at once. The format of the object is

comms[role][personality][key] = value;
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