Set up Board

Right now, your TutorialChess.kt should look like this:

package tutorial

import boards.Board2D
import gameTypes.chess.AbstractChess2D

open class TutorialChess : AbstractChess2D(
                                  listOf(),
                                  listOf()
{
  override val board: Board2D = TODO()
  override val name = "Tutorial Chess"

  override fun initBoard() {
      TODO()
  }
}

Step 1: Creating a board

Since our variant uses a 2D rectangular based board, we can use the Board2D interface to create the board. Our restriction for the board is that the centre square is out of bounds. This can be defined by a coordinate region like so:

private val outOfBoundsRegion = CoordinateRegion(3, 3)

Our variant uses a 7x7 board, and therefore can be defined like so:

private val outOfBoundsRegion = CoordinateRegion(3, 3)
override val board: Board2D = Board2D(7, 7, outOfBoundsRegion)

Step 2: Implementing initBoard()

This function should setup the initial piece placements and is called everytime this game is started. Put each player into a variable for ease of use.

override fun initBoard() {
    val player1 = players[0]
    val player2 = players[1]
}

1. Adding Pawns

We can add the Berlin Pawns to the board with a for loop like so:

override fun initBoard() {
    val player1 = players[0]
    val player2 = players[1]
    for (i in 0..6) {
        board.addPiece(Coordinate2D(i, 1), BerlinWhitePawn(player1))
        board.addPiece(Coordinate2D(i, 5), BerlinBlackPawn(player2))
    }
}

2. Adding the backline pieces

The rest of the pieces can be added using FEN notation using the FEN chess notation.

rbakbar/ppppppp/7/7/7/PPPPPPP/RBAKBAR

This represents the inital positions of pieces in this variant. As the Berlin pawn and Alfil are fairy pieces, we must add them to the FEN mapping.

We then initialise the board using FEN notation.

override fun initBoard() {
  val fen = FenUtility("rbakbar/ppppppp/7/7/7/PPPPPPP/RBAKBAR")

  fen.extendFenPieces('a', ::Alfil)
  fen.extendFenPiecesCaseSensitive('p', ::BerlinWhitePawn, ::BerlinBlackPawn)

  fen.initBoardWithFEN(board, players[0], players[1])
}

Step 3: Overall

package tutorial

import boards.Board2D
import coordinates.Coordinate2D
import gameTypes.chess.AbstractChess
import pieces.chess.*
import regions.CoordinateRegion

open class TutorialChess : AbstractChess2D(
                                  listOf(),
                                  listOf()
{
    private val outOfBoundsRegion = CoordinateRegion(3, 3)
    override val board: Board2D = Board2D(7, 7, outOfBoundsRegion)
    override val name = "Tutorial Chess"

      override fun initBoard() {
        val fen = FenUtility("rbakbar/ppppppp/7/7/7/PPPPPPP/RBAKBAR")

        fen.extendFenPieces('a', ::Alfil)
        fen.extendFenPiecesCaseSensitive('p', ::BerlinWhitePawn, ::BerlinBlackPawn)

        fen.initBoardWithFEN(board, players[0], players[1])
      }
}