Checkers-Lib

An npm package for Checkers/Draughts.

Features

• Functions to get all avaiable moves
• A manager to play moves
• An ai to get the best moves

Available Functions

function getMoves(position, pieceType = "w", forcedCaptures = false, canCaptureBackwards = false, flyingKing = false, maxCaptures = false)
// get all posible moves in a position for a certain color
// returns { "moves": moves, "hasToCapture": hasToCapture }

function getPieceMoves(position, x, y, hasToCapture = false, forcedCaptures = false, canCaptureBackwards = false, flyingKing = false, maxCaptures = false)
// get all moves for piece at a certain position
// returns { "moves": moves, "hasToCapture": hasToCapture }

function getPeasantMoves(position, x, y, pieceType = "w", hasToCapture = false, forcedCaptures = false, canCaptureBackwards = false)
// gets all peasant moves at a position
// returns { "moves": moves, "hasToCapture": hasToCapture }

function getKingMoves(position, x, y, pieceType = "w", hasToCapture = false, forcedCaptures = false, flyingKing = false)
// gets all king moves at a position
// returns { "moves": moves, "hasToCapture": hasToCapture }

function makeMove(oldPosition, move)
// makes a move in position
// returns newPosition

function unmakeMove(newPosition, move)
// undoes a move from a position
// returns oldPosition

function getBestMove(position, player = "w", forcedCaptures = false, canCaptureBackwards = false, flyingKing = false, maxCaptures = false, depth = 6)
// gets the best move by performing a minimax search to a certain depth
// returns bestMove

Values

position - a 2d array of all the pieces. Black moves down white moves up.
Example position at the start of game:

[["*", "b", "*", "b", "*", "b", "*", "b"],
 ["b", "*", "b", "*", "b", "*", "b", "*"],
 ["*", "b", "*", "b", "*", "b", "*", "b"],
 ["*", "*", "*", "*", "*", "*", "*", "*"],
 ["*", "*", "*", "*", "*", "*", "*", "*"],
 ["w", "*", "w", "*", "w", "*", "w", "*"],
 ["*", "w", "*", "w", "*", "w", "*", "w"],
 ["w", "*", "w", "*", "w", "*", "w", "*"]]

move - How does the board change after a move.
Move formatting: {["x": x, "y": y, "originalPiece": originalPiece], ["x": x1, "y": y1, "originalPiece": originalPiece] ...}.
Some examples:

{["x": 2, "y": 5, "originalPiece": "w"], ["x": 1, "y": 4, "originalPiece": "*"]} // white moves a Peasant one square
{["x": 0, "y": 3, "originalPiece": "b"], ["x": 1, "y": 4, "originalPiece": "W"], ["x": 2, "y": 5, "originalPiece": "*"]} // black captures a White King
{["x": 1, "y": 4, "originalPiece": "W"], ["x": 3, "y": 6, "originalPiece": "*"]} // the White King moves two spaces

hasToCapture - whether only captures should be returned
forcedCaptures - GameRule: whether pieces are forced to capture
canCaptureBackwards - GameRule: can Peasants capture backwards
flyingKing - GameRule: can Kings move any number of squares
maxCaptures - GameRule: whether pieces are forced to make the max number of captures