KT-Robots Programming Reference

May 10, 2021

Pre-Build Lambda-Robots

The lambda-robots/src/main/kotlin/io.onema.ktrobots.lambda/functions/ folder contains additional robots that are deployed, these have different behaviors. Next, we need a few robots to battle it out.

TargetRobot: This is a stationary robot for other robots to practice on.
YosemiteSam: This robot runs around shooting in random directions as fast as it can.
HotShot: This robot uses its radar to find other robots and fire at them. When hit, this robot moves around the board.
RoboDog: This robot moves around shooting straight in front of it, when it finds a target it changes direction and chasses it, this robot will do collision damage.

LambdaRobots SDK

Derive your Lambda-Robot from the LambdaRobotFunction provided by the SDK.

Abstract Methods

The base class requires two methods to be implemented:

Method	Description
`fun getBuild(state: LambdaRobotState): Pair<LambdaRobotBuild, LambdaRobotState>`	This method returns the robot build information, including its name, armor, engine, missile, and radar types, and the robot state object. Note that a build cannot exceed 8 points by default, or the robot will be disqualified at the beginning of the match.
`fun getAction(state: LambdaRobotState): Pair<LambdaRobotAction, LambdaRobotState>`	This method returns the actions taken by the robot during the turn and the updated robot state

Properties

The most commonly needed properties are readily available as properties from the base class. Additional information about the game or the robot is available via the Game and Robot properties, respectively.

Property	Type	Description
`gameInfo`	`GameInfo`	Game information data structure. See below.
`robot`	`LambdaRobot`	Robot information data structure. See below.

`Robot` Properties

Property	Type	Description
`arn`	`string`	Robot invokation identifier, either the AWS Lambda ARN or class namespace + class name.
`id`	`string`	Globally unique robot ID.
`index`	`int`	Index position of robot. Starts at `0`.
`name`	`string`	Robot display name.
`status`	`LambdaRobotStatus`	Robot status. Either `alive` or `dead`.
`x`	`double`	Robot horizontal position.
`y`	`double`	Robot vertical position.
`heading`	`double`	Robot heading. Between `0` and `360`. (degrees)
`maxDamage`	`double`	Maximum damage before the robot is destroyed.
`maxSpeed`	`double`	Engine Maximum speed - armor speed modifier for robot. (m/s)
`isAlive()`	`boolean`	True if the status == LambdaRobotStatus.alive else false
`canFire()`	`boolean`	True if the reloadCoolDown == 0 else false
`addDamageDealt()`	`LambdaRobot`	Increments the count to the totalDamageDealt
`addHit()`	`LambdaRobot`	Increments the count to the totalMissileHitCount
`maxTurnSpeed`	`double`	Maximum speed at which the robot can change heading without a sudden stop. (m/s)
`speed`	`double`	Robot speed. Between `0` and `engine.maxSpeed`. (m/s)
`reloadCoolDown`	`double`	Number of seconds before the robot can fire another missile. (s)
`targetHeading`	`double`	Desired heading for robot. The heading will be adjusted accordingly every turn. (degrees)
`targetSpeed`	`double`	Desired speed for robot. The current speed will be adjusted accordingly every turn. (m/s)
`timeOfDeathGameTurn`	`int`	Game turn during which the robot died. `-1` if robot is alive.
`totalCollisions`	`int`	Number of collisions with walls or other robots during match.
`totalDamageDealt`	`double`	Damage dealt by missiles during match.
`totalKills`	`int`	Number of confirmed kills during match.
`totalMissileFiredCount`	`int`	Number of missiles fired by robot during match.
`totalMissileHitCount`	`int`	Number of missiles that hit a target during match.
`totalTravelDistance`	`double`	Total distance traveled by robot during the match. (m)
`damage`	`double`	Accumulated robot damage. Between `0` and `MaxDamage`.
`armor.deceleration`	`double`	Deceleration when speeding up. (m/s^2)
`armor.collisionDamage`	`double`	Amount of damage the robot receives from a collision.
`armor.directHitDamage`	`double`	Amount of damage the robot receives from a direct hit.
`armor.farHitDamage`	`double`	Amount of damage the robot receives from a far hit.
`armor.nearHitDamage`	`double`	Amount of damage the robot receives from a near hit.
`engine.acceleration`	`double`	Acceleration when speeding up. (m/s^2)
`engine.maxSpeed`	`double`	Maximum speed for robot. (m/s)
`missile.directHitDamageBonus`	`double`	Bonus damage on target for a direct hit.
`missile.farHitDamageBonus`	`double`	Bonus damage on target for a far hit.
`missile.nearHitDamageBonus`	`double`	Bonus damage on target for a near hit.
`missile.range`	`double`	Maximum range for missile. (m)
`missile.reloadCooldown`	`double`	Number of seconds between each missile launch. (s)
`missile.velocity`	`double`	Travel velocity for missile. (m/s)
`radar.maxResolution`	`double`	Maximum degrees the radar can scan beyond the selected heading. (degrees)
`radar.range`	`double`	Maximum range at which the radar can detect an opponent. (m)

`GameInfo` Properties

Property	Type	Description
`boardWidth`	`double`	Width of the game board.
`boardHeight`	`double`	Height of the game board.
`secondsPerTurn`	`double`	Number of seconds elapsed per game turn.
`directHitRange`	`double`	Distance for missile impact to count as direct hit.
`nearHitRange`	`double`	Distance for missile impact to count as near hit.
`farHitRange`	`double`	Distance for missile impact to count as far hit.
`collisionRange`	`double`	Distance between robots to count as a collision.
`gameTurn`	`int`	Current game turn. Starts at `1`.
`maxGameTurns`	`int`	Maximum number of turns before the game ends in a draw.
`maxBuildPoints`	`int`	Maximum number of build points a robot can use.
`apiUrl`	`string`	URL for game server API.

`LambdaRobotAction` Properties

Property	Type	Description
`speed`	`double`	Update the robot speed up to `engine.maxSpeed`.
`heading`	`double`	Update the robot heading.
`fireMissileHeading`	`double`	Heading of a new fired missile.
`fireMissileDistance`	`double`	Distance a fired missile can travel up to `missile.range`.
`fired`	`boolean`	Whether a missile was fired or not.
`arrivedAtDestination`	`boolean`	Whether or not the robot arrived at it’s destination.

Primary Methods

The following methods represent the core capabilities of the robot. They are used to move, fire missiles, and scan their surroundings.

Method	ReturnType	Description
`scan(heading: Double, resolution: Double)`	`ScanEnemiesResponse`	Scan the game board in a given deading and resolution. The resolution specifies in the scan arc centered on `heading` with +/- `resolution` tolerance. The max resolution is limited to `Robot.RadarMaxResolution`.
`angleToXY(x: Double, y: Double)`	`Double`	Determine the angel in degrees relative to the current robot position. Returns a value between -180 and 180 degrees.
`distanceToXY(x: Double, y: Double)`	`Double`	Determine the distance to X, Y relative to the current robot position.
`normalizeAngle(angle: Double)`	`Double`	Normalize angle to be between -180 and 180.
`getNewHeading(minDistanceToEdge: Int = 100)`	`Int`	Check if the robot needs to turn based on a minimum distance to the edge and return a new heading if it does.

Support extension functions

The following methods are available to make some operations easier:

LambdaRobotAction Extension Functions	ReturnType	Description
`LambdaRobotAction.fireMissile(heading: Double, distance: Double)`	`LambdaRobotAction`	Fire a missile in a given direction with impact at a given distance. A missile can only be fired if `Robot.ReloadCoolDown` is `0`.
`LambdaRobotAction.fireMissileToXY(x: Double, y: Double)`	`LambdaRobotAction`	Convenience function to fire a missile at a specific set of coordinages.
`LambdaRobotAction.moveToXY(x: Double, y: Double)`	`LambdaRobotAction`	Convenience method to move the robot to a specific location.

LambdaRobotState Extension Functions	ReturnType	Description
`LambdaRobotState.initialize()`	`LambdaRobotState`	Convenience function to set the state to initialized.

Robot Build

By default, 8 build points are available to allocate in any fashion. The robot is disqualified if its build exceeds the maximum number of build points.

Radar

radar

Radar Type	Radar Range	Radar Resolution	Points
ultraShortRange	200 meters	45 degrees	0
shortRange	400 meters	20 degrees	1
midRange	600 meters	10 degrees	2
longRange	800 meters	8 degrees	3
ultraLongRange	1,000 meters	5 degrees	4

Engine

engine

Engine Type	Max. Speed	Acceleration	Points
economy	60 m/s	7 m/s^2	0
compact	80 m/s	8 m/s^2	1
standard	100 m/s	10 m/s^2	2
large	120 m/s	12 m/s^2	3
extraLarge	140 m/s	13 m/s^2	4

Armor

armor

Armor Type	Direct Hit	Near Hit	Far Hit	Collision	Max. Speed	Deceleration	Points
ultraLight	50	25	12	10	+35 m/s	30 m/s^2	0
light	16	8	4	3	+25 m/s	25 m/s^2	1
medium	8	4	2	2	-	20 m/s^2	2
heavy	4	2	1	1	-25 m/s	15 m/s^2	3
ultraHeavy	2	1	0	1	-45 m/s	10 m/s^2	4

Missile

missile

When shooting a missile a heading and a range must be set. Depending on the missile, the range cannot exceed the Max. Range. Each missile causes damage only when it reaches its set range, none otherwise. When a missile explodes it can cause up to three types of damage:

Shooting	Direct hit damage	Near hit damage	Far hit damage

Missile Type	Max. Range	Velocity	Direct Hit Bonus	Near Hit Bonus	Far Hit Bonus	Cooldown	Points
dart	1,200 meters	250 m/s	0	0	0	0.0 sec	0
arrow	900 meters	200 m/s	2	1	0.5	0.5 sec	1
javelin	700 meters	150 m/s	6	3	1	1.0 sec	2
cannon	500 meters	100 m/s	10	8	6	1.5 sec	3
BFG	350 meters	75 m/s	40	20	10	2.0 sec	4
sniperRifle	1200 meters	1750 m/s	30	15	0	4.0 sec	5