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Brian McKenna's Bot from Scalatron hack night at ScalaSyd May 9, 2012
// Brian McKenna's Bot - based on Scalatron Reference Bot - from Scalatron hack night at ScalaSyd May 9, 2012
import util.Random
object ControlFunction
{
def forMaster(bot: Bot) {
val (directionValue, nearestEnemyMaster, nearestEnemySlave, nearestGoodBeast, nearestGoodPlant) = analyzeViewAsMaster(bot.view)
val dontFireMissileUntil = bot.inputAsIntOrElse("dontFireMissileUntil", -1)
val lastDirection = bot.inputAsIntOrElse("lastDirection", 0)
val botCount = bot.inputAsIntOrElse("botCount", 0)
// determine movement direction
directionValue(lastDirection) += 10 // try to break ties by favoring the last direction
val bestDirection45 = directionValue.zipWithIndex.maxBy(_._1)._2
val direction = XY.fromDirection45(bestDirection45)
bot.move(direction)
bot.set("lastDirection" -> bestDirection45)
bot.view.offsetToNearest('s').orElse(bot.view.offsetToNearest('P')).orElse(bot.view.offsetToNearest('B')) match {
case None =>
case Some(relPos) =>
val unitDelta = relPos.signum
val remainder = relPos - unitDelta // we place slave nearer target, so subtract that from overall delta
bot.spawn(unitDelta, "target" -> remainder)
}
}
def forSlave(bot: MiniBot) {
if(bot.time >= (5000 - bot.offsetToMaster.length) - 5) {
bot.move(bot.offsetToMaster)
return
}
bot.view.offsetToNearest('m') match {
case Some(delta: XY) =>
if(delta.length <= 2) {
// yes -- blow it up!
bot.explode(4)
return
}
case None =>
}
if(bot.energy > 1000) {
bot.move(bot.offsetToMaster)
return
} else if(bot.energy > 100) {
bot.view.offsetToNearest('M') match {
case Some(delta: XY) =>
bot.move(delta.signum)
bot.set("rx" -> delta.x, "ry" -> delta.y)
return
case None =>
}
}
bot.view.offsetToNearest('s').orElse(bot.view.offsetToNearest('P')).orElse(bot.view.offsetToNearest('B')) match {
case Some(delta: XY) =>
// another slave is visible at the given relative position (i.e. position delta)
// move closer!
bot.move(delta.signum)
bot.set("rx" -> delta.x, "ry" -> delta.y)
case None =>
bot.view.offsetToNearest('W') match {
case Some(delta: XY) =>
bot.move(delta.negate)
case None =>
// no target visible -- follow our targeting strategy
val target = bot.inputAsXYOrElse("target", XY.Zero)
// did we arrive at the target?
if(target.isNonZero) {
// no -- keep going
val unitDelta = target.signum // e.g. CellPos(-8,6) => CellPos(-1,1)
bot.move(unitDelta)
// compute the remaining delta and encode it into a new 'target' property
val remainder = target - unitDelta // e.g. = CellPos(-7,5)
bot.set("target" -> remainder)
} else {
bot.move(XY(Random.nextInt, Random.nextInt))
}
}
}
}
/** Analyze the view, building a map of attractiveness for the 45-degree directions and
* recording other relevant data, such as the nearest elements of various kinds.
*/
def analyzeViewAsMaster(view: View) = {
val directionValue = Array.ofDim[Double](8)
var nearestEnemyMaster: Option[XY] = None
var nearestEnemySlave: Option[XY] = None
var nearestGoodBeast: Option[XY] = None
var nearestGoodPlant: Option[XY] = None
val cells = view.cells
val cellCount = cells.length
for(i <- 0 until cellCount) {
val cellRelPos = view.relPosFromIndex(i)
if(cellRelPos.isNonZero) {
val stepDistance = cellRelPos.stepCount
val value: Double = cells(i) match {
case 'm' => // another master: not dangerous, but an obstacle
nearestEnemyMaster = Some(cellRelPos)
if(stepDistance < 2) -1000 else 0
case 's' => // another slave: potentially dangerous?
nearestEnemySlave = Some(cellRelPos)
-100 / stepDistance
case 'S' => // out own slave
100
case 'B' => // good beast: valuable, but runs away
nearestGoodBeast = Some(cellRelPos)
if(stepDistance == 1) 600
else if(stepDistance == 2) 300
else (150 - stepDistance * 15).max(10)
case 'P' => // good plant: less valuable, but does not run
nearestGoodPlant = Some(cellRelPos)
if(stepDistance == 1) 500
else if(stepDistance == 2) 300
else (150 - stepDistance * 10).max(10)
case 'b' => // bad beast: dangerous, but only if very close
if(stepDistance < 4) -400 / stepDistance else -50 / stepDistance
case 'p' => // bad plant: bad, but only if I step on it
if(stepDistance < 2) -1000 else 0
case 'W' => // wall: harmless, just don't walk into it
if(stepDistance < 2) -1000 else 0
case _ => 0.0
}
val direction45 = cellRelPos.toDirection45
directionValue(direction45) += value
}
}
(directionValue, nearestEnemyMaster, nearestEnemySlave, nearestGoodBeast, nearestGoodPlant)
}
}
// -------------------------------------------------------------------------------------------------
// Framework
// -------------------------------------------------------------------------------------------------
class ControlFunctionFactory {
def create = (input: String) => {
val (opcode, params) = CommandParser(input)
opcode match {
case "React" =>
val bot = new BotImpl(params)
if( bot.generation == 0 ) {
ControlFunction.forMaster(bot)
} else {
ControlFunction.forSlave(bot)
}
bot.toString
case _ => "" // OK
}
}
}
// -------------------------------------------------------------------------------------------------
trait Bot {
// inputs
def inputOrElse(key: String, fallback: String): String
def inputAsIntOrElse(key: String, fallback: Int): Int
def inputAsXYOrElse(keyPrefix: String, fallback: XY): XY
def view: View
def energy: Int
def time: Int
def generation: Int
// outputs
def move(delta: XY) : Bot
def say(text: String) : Bot
def status(text: String) : Bot
def spawn(offset: XY, params: (String,Any)*) : Bot
def set(params: (String,Any)*) : Bot
def log(text: String) : Bot
}
trait MiniBot extends Bot {
// inputs
def offsetToMaster: XY
// outputs
def explode(blastRadius: Int) : Bot
}
case class BotImpl(inputParams: Map[String, String]) extends MiniBot {
// input
def inputOrElse(key: String, fallback: String) = inputParams.getOrElse(key, fallback)
def inputAsIntOrElse(key: String, fallback: Int) = inputParams.get(key).map(_.toInt).getOrElse(fallback)
def inputAsXYOrElse(key: String, fallback: XY) = inputParams.get(key).map(s => XY(s)).getOrElse(fallback)
val view = View(inputParams("view"))
val energy = inputParams("energy").toInt
val time = inputParams("time").toInt
val generation = inputParams("generation").toInt
def offsetToMaster = inputAsXYOrElse("master", XY.Zero)
// output
private var stateParams = Map.empty[String,Any] // holds "Set()" commands
private var commands = "" // holds all other commands
private var debugOutput = "" // holds all "Log()" output
/** Appends a new command to the command string; returns 'this' for fluent API. */
private def append(s: String) : Bot = { commands += (if(commands.isEmpty) s else "|" + s); this }
/** Renders commands and stateParams into a control function return string. */
override def toString = {
var result = commands
if(!stateParams.isEmpty) {
if(!result.isEmpty) result += "|"
result += stateParams.map(e => e._1 + "=" + e._2).mkString("Set(",",",")")
}
if(!debugOutput.isEmpty) {
if(!result.isEmpty) result += "|"
result += "Log(text=" + debugOutput + ")"
}
result
}
def log(text: String) = { debugOutput += text + "\n"; this }
def move(direction: XY) = append("Move(direction=" + direction + ")")
def say(text: String) = append("Say(text=" + text + ")")
def status(text: String) = append("Status(text=" + text + ")")
def explode(blastRadius: Int) = append("Explode(size=" + blastRadius + ")")
def spawn(offset: XY, params: (String,Any)*) =
append("Spawn(direction=" + offset +
(if(params.isEmpty) "" else "," + params.map(e => e._1 + "=" + e._2).mkString(",")) +
")")
def set(params: (String,Any)*) = { stateParams ++= params; this }
def set(keyPrefix: String, xy: XY) = { stateParams ++= List(keyPrefix+"x" -> xy.x, keyPrefix+"y" -> xy.y); this }
}
// -------------------------------------------------------------------------------------------------
/** Utility methods for parsing strings containing a single command of the format
* "Command(key=value,key=value,...)"
*/
object CommandParser {
/** "Command(..)" => ("Command", Map( ("key" -> "value"), ("key" -> "value"), ..}) */
def apply(command: String): (String, Map[String, String]) = {
/** "key=value" => ("key","value") */
def splitParameterIntoKeyValue(param: String): (String, String) = {
val segments = param.split('=')
(segments(0), if(segments.length>=2) segments(1) else "")
}
val segments = command.split('(')
if( segments.length != 2 )
throw new IllegalStateException("invalid command: " + command)
val opcode = segments(0)
val params = segments(1).dropRight(1).split(',')
val keyValuePairs = params.map(splitParameterIntoKeyValue).toMap
(opcode, keyValuePairs)
}
}
// -------------------------------------------------------------------------------------------------
/** Utility class for managing 2D cell coordinates.
* The coordinate (0,0) corresponds to the top-left corner of the arena on screen.
* The direction (1,-1) points right and up.
*/
case class XY(x: Int, y: Int) {
override def toString = x + ":" + y
def isNonZero = x != 0 || y != 0
def isZero = x == 0 && y == 0
def isNonNegative = x >= 0 && y >= 0
def updateX(newX: Int) = XY(newX, y)
def updateY(newY: Int) = XY(x, newY)
def addToX(dx: Int) = XY(x + dx, y)
def addToY(dy: Int) = XY(x, y + dy)
def +(pos: XY) = XY(x + pos.x, y + pos.y)
def -(pos: XY) = XY(x - pos.x, y - pos.y)
def *(factor: Double) = XY((x * factor).intValue, (y * factor).intValue)
def distanceTo(pos: XY): Double = (this - pos).length // Phythagorean
def length: Double = math.sqrt(x * x + y * y) // Phythagorean
def stepsTo(pos: XY): Int = (this - pos).stepCount // steps to reach pos: max delta X or Y
def stepCount: Int = x.abs.max(y.abs) // steps from (0,0) to get here: max X or Y
def signum = XY(x.signum, y.signum)
def negate = XY(-x, -y)
def negateX = XY(-x, y)
def negateY = XY(x, -y)
/** Returns the direction index with 'Right' being index 0, then clockwise in 45 degree steps. */
def toDirection45: Int = {
val unit = signum
unit.x match {
case -1 =>
unit.y match {
case -1 =>
if(x < y * 3) Direction45.Left
else if(y < x * 3) Direction45.Up
else Direction45.UpLeft
case 0 =>
Direction45.Left
case 1 =>
if(-x > y * 3) Direction45.Left
else if(y > -x * 3) Direction45.Down
else Direction45.LeftDown
}
case 0 =>
unit.y match {
case 1 => Direction45.Down
case 0 => throw new IllegalArgumentException("cannot compute direction index for (0,0)")
case -1 => Direction45.Up
}
case 1 =>
unit.y match {
case -1 =>
if(x > -y * 3) Direction45.Right
else if(-y > x * 3) Direction45.Up
else Direction45.RightUp
case 0 =>
Direction45.Right
case 1 =>
if(x > y * 3) Direction45.Right
else if(y > x * 3) Direction45.Down
else Direction45.DownRight
}
}
}
def rotateCounterClockwise45 = XY.fromDirection45((signum.toDirection45 + 1) % 8)
def rotateCounterClockwise90 = XY.fromDirection45((signum.toDirection45 + 2) % 8)
def rotateClockwise45 = XY.fromDirection45((signum.toDirection45 + 7) % 8)
def rotateClockwise90 = XY.fromDirection45((signum.toDirection45 + 6) % 8)
def wrap(boardSize: XY) = {
val fixedX = if(x < 0) boardSize.x + x else if(x >= boardSize.x) x - boardSize.x else x
val fixedY = if(y < 0) boardSize.y + y else if(y >= boardSize.y) y - boardSize.y else y
if(fixedX != x || fixedY != y) XY(fixedX, fixedY) else this
}
}
object XY {
/** Parse an XY value from XY.toString format, e.g. "2:3". */
def apply(s: String) : XY = { val a = s.split(':'); XY(a(0).toInt,a(1).toInt) }
val Zero = XY(0, 0)
val One = XY(1, 1)
val Right = XY( 1, 0)
val RightUp = XY( 1, -1)
val Up = XY( 0, -1)
val UpLeft = XY(-1, -1)
val Left = XY(-1, 0)
val LeftDown = XY(-1, 1)
val Down = XY( 0, 1)
val DownRight = XY( 1, 1)
def fromDirection45(index: Int): XY = index match {
case Direction45.Right => Right
case Direction45.RightUp => RightUp
case Direction45.Up => Up
case Direction45.UpLeft => UpLeft
case Direction45.Left => Left
case Direction45.LeftDown => LeftDown
case Direction45.Down => Down
case Direction45.DownRight => DownRight
}
def fromDirection90(index: Int): XY = index match {
case Direction90.Right => Right
case Direction90.Up => Up
case Direction90.Left => Left
case Direction90.Down => Down
}
def apply(array: Array[Int]): XY = XY(array(0), array(1))
}
object Direction45 {
val Right = 0
val RightUp = 1
val Up = 2
val UpLeft = 3
val Left = 4
val LeftDown = 5
val Down = 6
val DownRight = 7
}
object Direction90 {
val Right = 0
val Up = 1
val Left = 2
val Down = 3
}
// -------------------------------------------------------------------------------------------------
case class View(cells: String) {
val size = math.sqrt(cells.length).toInt
val center = XY(size / 2, size / 2)
def apply(relPos: XY) = cellAtRelPos(relPos)
def indexFromAbsPos(absPos: XY) = absPos.x + absPos.y * size
def absPosFromIndex(index: Int) = XY(index % size, index / size)
def absPosFromRelPos(relPos: XY) = relPos + center
def cellAtAbsPos(absPos: XY) = cells.charAt(indexFromAbsPos(absPos))
def indexFromRelPos(relPos: XY) = indexFromAbsPos(absPosFromRelPos(relPos))
def relPosFromAbsPos(absPos: XY) = absPos - center
def relPosFromIndex(index: Int) = relPosFromAbsPos(absPosFromIndex(index))
def cellAtRelPos(relPos: XY) = cells.charAt(indexFromRelPos(relPos))
def offsetToNearest(c: Char) = {
val matchingXY = cells.view.zipWithIndex.filter(_._1 == c)
if( matchingXY.isEmpty )
None
else {
val nearest = matchingXY.map(p => relPosFromIndex(p._2)).minBy(_.length)
Some(nearest)
}
}
}
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