OXP howto AI

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Contents

Methods for AI

Exerpt from the [OoliteAIreference.html]:

AI Script Format

The AI system consists of a stack of state machines (only the top one of which is active), which respond to game events sent to them as messages. They respond by calling a series of methods which affect the behaviour of the entity and possibly trigger changes to the AI by changing the state or (more drastically) the state machine.

Each state machine (or AI script) is described in a property list in either ASCII or XML format, which can be edited with a text editor or with Property List Editor. The structure is of a dictionary containing each of the machine's possible states referenced by an identifying state name. Each state comprises a dictionary of responses to messages the AI might receive, referenced by the message itself. Each response is an array of methods that will be called when the AI receives that message.

The AI function calls within a message handler are separated from each other by a comma. If a function takes a parameter the value is separated from the function name by a colon and a space, and both the function name and value are enclosed in double quotes.

In ASCII format a simple (two-state) machine looks like this: 

{
     "STATE_1" = {
         "ENTER" = ();
         "MESSAGE_A" = ("method1: value", method2, method3);
         "MESSAGE_B" = (method4, "setStateTo: STATE_2");
         EXIT = ();
         UPDATE = ();
     };
     "STATE_2" = {
         "ENTER" = ();
         "MESSAGE_A" = ("method1: another_value", method5);
         "MESSAGE_B" = (method6, method7, "setStateTo: STATE_1");
         EXIT = ();
         UPDATE = ();
     };
}

The same script in XML.

AI

* exitAI;

Exits current AI.

* messageMother:(NSString *)msgString;

Sends a AImessage to the mothership/leader of a group.

Example: 

INCOMING_MISSILE = ("messageMother: INCOMING_MISSILE");

The mothership will then behave as if it was targetted by the missile.

pauseAI:(NSString *)intervalString;

Sets AI think-time in seconds.

setAITo:(NSString *)aiString;

Pauses current AI and switches to anotherAI.plist, this becomes the top AI on the 'AI-stack'. When anotherAI.plist exits (exitAI), the previousAI becomes topAI again and AI-state is messaged RESTARTED.

setStateTo: SOMESTATE

Changes the AI state to SOMESTATE.

switchAITo:(NSString *)aiString;

Switches entity AI to another *AI.plist, the previous AI will be exited.

AI choices

fightOrFleeHostiles;

Has entity consider whether to fight, deploy missiles or flee. Returns "FIGHTING", "DEPLOYING_ESCORTS" or "FLEEING".

fightOrFleeMissile;

Deals with missiles, launches ECM if available, flees if not, marks as offender if police.


Perform Action

acceptDistressMessageFrom:(ShipEntity *)other;

Has police either respond to a distress call, or possibly decide it is too busy or too scared.

becomeEnergyBlast

Used in the Qbomb.

becomeExplosion

The entity model is replaced by an explosion.

becomeLargeExplosion

Used at player entity death, not for use in other instances.

dealEnergyDamageWithinDesiredRange

Needs desiredRange to be set first, then deals weaponEnergy(Shipdata.plist) damage within this sphere.

deployEscorts

Deploys an escort.

ejectCargo;

Ejects cargo.

enterTargetWormhole;

Will locate nearest wormhole, and enter it.

escortCheckMother;

Returns "ESCORTING" or "NOT_ESCORTING".

fireECM

Used by stations and hermits.

groupAttackTarget;

All ships in group will have their targets set to this entity's target and performAttack.

landOnPlanet;

Selects the nearest planet it can find, lands (10km from planet) and 'removes' the entity.

Launch..Someship

Launches a ship fron a dockable entity, various types of this method exist.

  • LaunchDefenceShip
  • LaunchMiner
  • LaunchPolice
  • LaunchScavenger

Probably will work for other roles too?

markTargetForFines;

Deals out a fine to target. Example: 

"markTargetForFines 100"

Will fine the target 10Cr. N.b. for commercial transactions "awardMoney -$" is a more suitable method.

markTargetForOffence:(NSString*) valueString;

Has police mark up the criminal record (Legal status) of target entity.

messageMother:(NSString *)msgString;

Sends a AImessage to the mothership/leader of a group. Example: 

INCOMING_MISSILE = ("messageMother: INCOMING_MISSILE");

The mothership will then behave as if it was targetted by the missile.

performAttack;

Attacks target.

performCollect;

Performs 'collection' of target.

performDocking;

NOT YET IMPLEMENTED.

performEscort;

Performs escorting.

performFaceDestination;

Has entity face destination.

performFlee;

Sets the caller (AI) to flee from it's primary target at maximum speed. If the caller has a cloacking device, it will be activated.

performFlyToRangeFromDestination;

NOT YET IMPLEMENTED. Sets the AI's current state to CONDITION_FLY_RANGE_FROM_DESTINATION. While in this state the entity will attempt to fly to its current destination, stopping at the desired range from it.

performHold;

Performs idleness while tracking a potential target, speed is set to zero. frustrationlevel is reset.

performHyperSpaceExit;

Gets a list of destinations within range, checks if clear of nearby masses, and select one at random. May return "WITCHSPACE UNAVAILABLE" or "WITCHSPACE BLOCKED".

performIdle;

Performs idleness. Ship corrects its roll and pitch to 'horizontal' flight, speed is unaffected. frustrationlevel is reset to zero.

performIntercept;

Performs target interception.

performMining;

Performs mining. (Finds, intercepts and shoots asteroids with mining laser, if fitted.)

performTumble;

Performs random pitch and roll, 'evasive maneuvers'.

setSpeedTo:(NSString *)speedString;

Sets desired speed to an absolute value, entity cannot go faster than maxspeed value determined in the shipdata.plist. If speed is above maxspeed, entity will use fuelinjectors if available.

setSpeedFactorTo:(NSString *)speedString;

Sets the desired speed to a percentage of maxspeed (0->1=0%->100%). If speedfactor is set above 100%, entity will use fuelinjectors if available.

suggestEscort;

Has an escort seek employment and either gets accepted or rejected by the "mother".

switchLightsOff

If an entity has lights (or flashers), this command will turn them off. Default state is on. (See shipdata.plist)

switchLightsOn

Will turn flashers back on.

wormholeEntireGroup;

Wormholes ships in this group.

wormholeEscorts;

Wormholes official escorts.

wormholeGroup;

Wormholes ships in group of which this is a leader.


Navigation

getWitchspaceEntryCoordinates;

Calculates coordinates from the nearest station it can find, or just fly 10s forward.

recallDockingInstructions;

...

requestDockingCoordinates;

Requests coordinates from the nearest station it can find (which may be a rock hermit).

setCoordinates:(NSString *)system_x_y_z;

Sets PWM destination coords.

setCourseToPlanet;

Selects the nearest planet it can find, reaching desired range 50 km from the planet.

setCourseToWitchpoint;

Sets destination coords to Witchpoint area.

setDesiredRangeTo:(NSString *)rangeString;

Some methods (such as scanForNearestMerchantmen, checkCourseToDestination, checkDistanceTravelled, etc) require a "desired range" parameter to be set before they can be used.

This method is used to set the desired range. There is only one value for desired range within an instance of the AI. The value of desired range is modified internally by AI methods such as fightOrFleeMissile, setCourseToWitchpoint, and setPlanetPatrolCoordinates.

setDestinationFromCoordinates;

Enables the plotting of manual waypoints.

setDestinationToCurrentLocation;

This method sets the destination of the current entity to its current location plus a random offset of up to 0.5 metres in the X, Y, and Z coordinates. This can be used to make a ship idle in a small area of space without being completely still.

setDestinationToDockingAbort;

DockingAbort coordinates...Xm in front of a dockingslit?

setDestinationToStationBeacon;

Gets station beacon position.

setDestinationToTarget;

Sets destination to target coords.

setDestinationToWitchpoint;

Sets destination coords to WitchspaceExitPosition.

setDestinationWithinTarget;

Handy for ramming and racing.

setPlanetPatrolCoordinates;

Check we've arrived near the last given coordinates.

setSunSkimEndCoordinates;

...

setSunSkimExitCoordinates;

...

setSunSkimStartCoordinates;

...


Communication

broadcastDistressMessage;

Locates all the stations, bounty hunters and police ships in range and tells them that you are under attack.

commsMessage:(NSString *)valueString;

Broadcasts a general message to player. Example: 

"sendCommsMessage: [thargoid_curses]"

initialiseTurret;

Prepares the turret.

patrolReportIn;

...

sendTargetCommsMessage:(NSString*) message;

Sends any message to the established (found) target.

Example: 

"sendTargetCommsMessage: Listen to me!!"


Locating stuff

All these methods require a range to be set by setDesiredRange or by <scanner_range> in shipdata.plist, all will return the message TARGET_FOUND or NOTHING_FOUND. The calling entity remembers the found target, but it does not become the current (universal) target. It can be made the current target by responding to the TARGET_FOUND message with a call to setTargetToFoundTarget.

find..

findNearestPlanet;

(PlanetEntity *) Will scan for planetentity.

scanFor..

scanForFormationLeader;

Locates the nearest suitable formation leader in range.

scanForHostiles;

Locates all the ships in range targetting the receiver and chooses the nearest.

scanForLoot;

Locates the nearest debris in range.

scanForNearestMerchantmen;

Locates the nearest merchantman in range

scanForNearestShipWithRole:(NSString*) scanRole;

Locates all the ships in range and chooses the nearest.

scanForNonThargoid;

Locates all the non thargoid ships in range and chooses the nearest.

scanForOffenders;

Locates all the ships in range and compares their legal status or bounty, and chooses the worst offender.

scanForRandomLoot;

Locates the all debris in range and chooses a piece at random from the first sixteen found.

scanForRandomMerchantmen;

Locates one of the merchantman in range.

scanForRocks;

Locates the all boulders and asteroids in range and selects one of up to 16. Returns "TARGET_FOUND" or"NOTHING_FOUND".

scanForThargoid;

Locates all the thargoid warships in range and chooses the nearest.

CheckFor..

"Check for.." methods are a bit more variable in their output messages.

checkCourseToDestination;

Will return "COURSE_OK" or in case of obstacles on the direct route, "WAYPOINT_SET".

checkDistanceTravelled;

May return "GONE_BEYOND_RANGE" or DESIRED_RANGE_ACHIEVED.

checkGroupOddsVersusTarget;

Will return "ODDS_GOOD" or "ODDS_BAD".

checkForFullHold;

If entity's cargo capacity is reached, will return "HOLD_FULL".

checkForMotherStation;

Will return "STATION_FOUND" or "NOTHING_FOUND".

checkForNormalSpace;

Will return "NORMAL_SPACE" or "INTERSTELLAR_SPACE".

checkTargetLegalStatus;

Returns "TARGET_CLEAN, "TARGET_MINOR_OFFENDER", "TARGET_OFFENDER", "TARGET_FUGITIVE" or "NO_TARGET".


Targetting

requestNewTarget;

Locates all the ships in range targetting the mother ship, and chooses the nearest/biggest.

setTargetToFoundTarget;

Affirms a TARGET_FOUND by a scanFor- or find-Something-method as the universal target.

setTargetToPrimaryAggressor;

Changes to a different enemy target if attacked, unless already very busy attacking another.


Miscellaneous

addFuel:(NSString*) fuel_number;

Changes fuel level (only of player entity?) by fuel_numer LY's, max to 7.0 min to 0.0.

rollD:(NSString*) die_number;

Uses "dice" for random situation use.

scriptActionOnTarget:(NSString*) action;

Will cause immediate reaction to any changes this makes.

setTakeOffFromPlanet;

Selects the nearest planet it can find and adds entity 10 km from planet, unless there is no planet to be found.











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