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chess restructuring: changed order of functions
This commit is contained in:
TiynGER
parent
0ceb567048
commit
c91bf64047
423
src/chess.nim
423
src/chess.nim
@ -109,8 +109,7 @@ const
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(0, 1, 0, 0, 0), # bishop only
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(0, 2, 0, 0, 0) # 2 knights
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] ## `InsufficientMaterial` describes the pieces where no checkmate can be
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## forced.
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## forced
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let
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PieceChar = {
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@ -144,47 +143,65 @@ let
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# `FileChar` maps the files of the chessboard to numbers for better
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# conversion.
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proc checkInsufficientMaterial(board: Board): bool =
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## Checks for combinations of pieces on a `board`, where no checkmate can be
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## forced.
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## Returns true if no player can force a checkmate to the other.
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var wp = 0
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var wn = 0
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var wb = 0
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var wr = 0
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var wq = 0
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var bp = 0
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var bn = 0
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var bb = 0
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var br = 0
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var bq = 0
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for field in board.low..board.high:
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case board[field]:
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of WPawn:
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wp = wp + 1
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of BPawn:
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bp = bp + 1
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of WKnight:
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wn = wn + 1
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of BKnight:
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bn = bn + 1
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of WBishop:
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wb = wb + 1
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of BBishop:
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bb = bb + 1
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of WRook:
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wr = wr + 1
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of BRook:
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br = br + 1
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of WQueen:
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wq = wq + 1
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of BQueen:
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bq = bq + 1
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else:
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continue
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let wpieces: PieceAmount = (wp, wn, wb, wr, wq)
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let bpieces: PieceAmount = (bp, bn, bb, br, bq)
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return (wpieces in InsufficientMaterial) and (bpieces in InsufficientMaterial)
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proc fieldToInd*(file: string, line: int): int =
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## Calculate and return board index from `file` and `line` of a chess board.
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## Returns -1 if the `field` was not input correct.
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try:
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return 1+(line+1)*10+FileChar[file]
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except IndexDefect, ValueError:
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return -1
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proc fieldToInd*(field: string): int =
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## Calculate and return board index from `field` of a chess board.
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## Returns -1 if the `field` was not input correct.
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try:
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return fieldToInd($field[0], parseInt($field[1]))
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except IndexDefect, ValueError:
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return -1
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proc indToField*(ind: int): string =
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## Calculate and returns field name from board index `ind`.
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let line = (int)ind/10-1
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let file_ind = (ind)%%10-1
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for file, i in FileChar:
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if FileChar[file] == file_ind:
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return $file & $line
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proc getMove*(start: int, dest: int, prom: int, color: Color): Move =
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## Get a move object of the `color` player from `start` to `dest` with an
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## eventual promition to `prom`.
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var move = Move(start: start, dest: dest, prom: prom * ord(color), color: color)
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if (WKnight > prom or WQueen < prom):
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move.prom = WQueen
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return move
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proc getMove*(start: int, dest: int, color: Color): Move =
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## Get a move object of the `color` player from `start` to `dest` with
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## automatic promition to queen.
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var move = Move(start: start, dest: dest, prom: WQueen * ord(color), color: color)
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return move
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proc notationToMove*(notation: string, color: Color): Move =
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## Convert and return simplified algebraic chess `notation` to a move object,
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## color of player is `color`.
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var move: Move
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var start = fieldToInd(notation[0..1])
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var dest = fieldToInd(notation[2..3])
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move = getMove(start, dest, color)
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if (len(notation) > 4):
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var promStr = $notation[4]
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var prom: int
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case promStr:
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of "Q":
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prom = WQueen * ord(color)
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of "R":
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prom = WRook * ord(color)
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of "B":
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prom = WBishop * ord(color)
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of "N":
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prom = WKnight * ord(color)
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move = getMove(start, dest, prom, color)
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return move
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proc initBoard(): Board =
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## Create and return a board with pieces in starting position.
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@ -256,20 +273,6 @@ proc initGame*(board: array[0..63, int], color: Color): Game =
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fiftyMoveCounter: 0)
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return game
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proc getMove*(start: int, dest: int, prom: int, color: Color): Move =
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## Get a move object of the `color` player from `start` to `dest` with an
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## eventual promition to `prom`.
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var move = Move(start: start, dest: dest, prom: prom * ord(color), color: color)
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if (WKnight > prom or WQueen < prom):
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move.prom = WQueen
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return move
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proc getMove*(start: int, dest: int, color: Color): Move =
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## Get a move object of the `color` player from `start` to `dest` with
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## automatic promition to queen.
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var move = Move(start: start, dest: dest, prom: WQueen * ord(color), color: color)
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return move
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proc echoBoard*(game: Game, color: Color) =
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## Prints out the given `board` with its pieces as characters and line
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## indices from perspecive of `color`.
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@ -293,30 +296,6 @@ proc echoBoard*(game: Game, color: Color) =
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echo line_str
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echo "a b c d e f g h"
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proc fieldToInd*(file: string, line: int): int =
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## Calculate and return board index from `file` and `line` of a chess board.
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## Returns -1 if the `field` was not input correct.
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try:
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return 1+(line+1)*10+FileChar[file]
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except IndexDefect, ValueError:
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return -1
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proc fieldToInd*(field: string): int =
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## Calculate and return board index from `field` of a chess board.
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## Returns -1 if the `field` was not input correct.
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try:
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return fieldToInd($field[0], parseInt($field[1]))
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except IndexDefect, ValueError:
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return -1
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proc indToField*(ind: int): string =
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## Calculate and returns field name from board index `ind`.
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let line = (int)ind/10-1
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let file_ind = (ind)%%10-1
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for file, i in FileChar:
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if FileChar[file] == file_ind:
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return $file & $line
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proc genCastleRights(moved: Moved): CastleRights =
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## Generate and return rights to castle from given `moved`
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let wk = not moved[fieldToInd("e1")] and not moved[fieldToInd("h1")]
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@ -325,27 +304,84 @@ proc genCastleRights(moved: Moved): CastleRights =
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let bq = not moved[fieldToInd("e8")] and not moved[fieldToInd("a8")]
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return (wk, wq, bk, bq)
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proc notationToMove*(notation: string, color: Color): Move =
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## Convert and return simplified algebraic chess `notation` to a move object,
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## color of player is `color`.
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var move: Move
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var start = fieldToInd(notation[0..1])
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var dest = fieldToInd(notation[2..3])
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move = getMove(start, dest, color)
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if (len(notation) > 4):
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var promStr = $notation[4]
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var prom: int
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case promStr:
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of "Q":
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prom = WQueen * ord(color)
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of "R":
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prom = WRook * ord(color)
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of "B":
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prom = WBishop * ord(color)
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of "N":
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prom = WKnight * ord(color)
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move = getMove(start, dest, prom, color)
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return move
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proc genPawnAttackDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible attack destinations for a pawn with specific `color`
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## located at index `field` of `game`.
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## Returns a sequence of possible indices to move to.
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if (not field in game.board.low..game.board.high):
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return @[]
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var res = newSeq[int]()
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var dest: int
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var target: int
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for attacks in Pawn_Moves_White_Attack:
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dest = field + (attacks * ord(color))
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if (not dest in game.board.low..game.board.high):
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continue
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target = game.board[dest]
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if (target == 999 or ord(color) * target >= 0):
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continue
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res.add(dest)
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return res
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proc genPawnDoubleDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible double destinations for a pawn with specific `color`
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## located at index `field` of `game`.
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## Returns a sequence of possible indices to move to.
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if (not field in game.board.low..game.board.high):
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return @[]
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var res = newSeq[int]()
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var dest: int
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var target: int
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for doubles in Pawn_Moves_White_Double:
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dest = field + doubles * ord(color)
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if (not dest in game.board.low..game.board.high):
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continue
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target = game.board[dest]
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if (game.moved[field] or (target != 0) or (
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game.board[dest+(S*ord(color))] != 0)):
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continue
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res.add(dest)
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return res
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proc genPawnDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible destinations for a pawn with specific `color` located at
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## index `field` of `game`.
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## Returns a sequence of possible indices to move to.
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if (not field in game.board.low..game.board.high):
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return @[]
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var res = newSeq[int]()
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var dest: int
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var target: int
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for move in Pawn_Moves_White:
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dest = field + move * ord(color)
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if (not dest in game.board.low..game.board.high):
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continue
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target = game.board[dest]
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if (target != 0 and target != ord(color) * WEnPassant):
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continue
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res.add(dest)
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res.add(game.genPawnAttackDests(field, color))
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res.add(game.genPawnDoubleDests(field, color))
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return res
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proc genKnightDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible destinations for a knight with specific `color` located
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## at index `field` of `game`.
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## Returns a sequence of possible indices to move to.
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if (not field in game.board.low..game.board.high):
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return @[]
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var res = newSeq[int]()
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var dest: int
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var target: int
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for move in Knight_Moves:
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dest = field + move
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if (not dest in game.board.low..game.board.high):
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continue
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target = game.board[dest]
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if (target == 999 or (ord(color) * target > 0 and ord(color) * target != WEnPassant)):
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continue
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res.add(dest)
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return res
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proc genBishopDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible destinations for a bishop with specific `color` located
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@ -461,85 +497,6 @@ proc genKingDests(game: Game, field: int, color: Color): seq[int] =
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res.add(game.genKingCastleDest(field, color))
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return res
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proc genKnightDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible destinations for a knight with specific `color` located
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## at index `field` of `game`.
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## Returns a sequence of possible indices to move to.
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if (not field in game.board.low..game.board.high):
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return @[]
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var res = newSeq[int]()
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var dest: int
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var target: int
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for move in Knight_Moves:
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dest = field + move
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if (not dest in game.board.low..game.board.high):
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continue
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target = game.board[dest]
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if (target == 999 or (ord(color) * target > 0 and ord(color) * target != WEnPassant)):
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continue
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res.add(dest)
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return res
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proc genPawnAttackDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible attack destinations for a pawn with specific `color`
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## located at index `field` of `game`.
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## Returns a sequence of possible indices to move to.
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if (not field in game.board.low..game.board.high):
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return @[]
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var res = newSeq[int]()
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var dest: int
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var target: int
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for attacks in Pawn_Moves_White_Attack:
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dest = field + (attacks * ord(color))
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if (not dest in game.board.low..game.board.high):
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continue
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target = game.board[dest]
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if (target == 999 or ord(color) * target >= 0):
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continue
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res.add(dest)
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return res
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proc genPawnDoubleDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible double destinations for a pawn with specific `color`
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## located at index `field` of `game`.
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## Returns a sequence of possible indices to move to.
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if (not field in game.board.low..game.board.high):
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return @[]
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var res = newSeq[int]()
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var dest: int
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var target: int
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for doubles in Pawn_Moves_White_Double:
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dest = field + doubles * ord(color)
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if (not dest in game.board.low..game.board.high):
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continue
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target = game.board[dest]
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if (game.moved[field] or (target != 0) or (
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game.board[dest+(S*ord(color))] != 0)):
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continue
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res.add(dest)
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return res
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proc genPawnDests(game: Game, field: int, color: Color): seq[int] =
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## Generate possible destinations for a pawn with specific `color` located at
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## index `field` of `game`.
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## Returns a sequence of possible indices to move to.
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if (not field in game.board.low..game.board.high):
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return @[]
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var res = newSeq[int]()
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var dest: int
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var target: int
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for move in Pawn_Moves_White:
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dest = field + move * ord(color)
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if (not dest in game.board.low..game.board.high):
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continue
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target = game.board[dest]
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if (target != 0 and target != ord(color) * WEnPassant):
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continue
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res.add(dest)
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res.add(game.genPawnAttackDests(field, color))
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res.add(game.genPawnDoubleDests(field, color))
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return res
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proc pieceOn(game: Game, color: Color, sequence: seq[int],
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pieceID: int): bool =
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## Returns true if the `PieceID` of a given `color` is in `sequence` else
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@ -593,11 +550,31 @@ proc moveLeadsToCheck(game: Game, start: int, dest: int,
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check.uncheckedMove(start, dest)
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return check.isInCheck(color)
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proc removeEnPassant(board: var Board, color: Color): void =
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## Removes every en passant of given `color` from the `board`.
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for field in board.low..board.high:
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if board[field] == ord(color) * WEnPassant:
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board[field] = 0
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proc genPawnPromotion(move: Move, color: Color): seq[Move] =
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## Generate all possible promotions of a `move` by `color`.
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var promotions = newSeq[Move]()
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let start = move.start
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let dest = move.dest
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if (90 < dest and dest < 99) or (20 < dest and dest < 29):
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for piece in WKnight..WQueen:
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promotions.add(getMove(start, dest, piece, color))
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return promotions
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proc genLegalPawnMoves(game: Game, field: int, color: Color): seq[Move] =
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## Generates all legal pawn moves in a `game` starting from `field` for a
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## `color`.
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if game.board[field] != WPawn * ord(color):
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return @[]
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var res = newSeq[Move]()
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var moves = game.genPawnDests(field, color)
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for dest in moves:
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if not game.moveLeadsToCheck(field, dest, color):
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var promotions = genPawnPromotion(getMove(field, dest, color), color)
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if promotions != @[]:
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res.add(promotions)
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else:
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res.add(getMove(field, dest, color))
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return res
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proc genLegalKnightMoves(game: Game, field: int, color: Color): seq[Move] =
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## Generates all legal knight moves in a `game` starting from `field` for a
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@ -663,32 +640,6 @@ proc genLegalKingMoves(game: Game, field: int, color: Color): seq[Move] =
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res.add(getMove(field, dest, color))
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return res
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proc genPawnPromotion(move: Move, color: Color): seq[Move] =
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## Generate all possible promotions of a `move` by `color`.
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var promotions = newSeq[Move]()
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let start = move.start
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let dest = move.dest
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if (90 < dest and dest < 99) or (20 < dest and dest < 29):
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for piece in WKnight..WQueen:
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promotions.add(getMove(start, dest, piece, color))
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return promotions
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proc genLegalPawnMoves(game: Game, field: int, color: Color): seq[Move] =
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## Generates all legal pawn moves in a `game` starting from `field` for a
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## `color`.
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if game.board[field] != WPawn * ord(color):
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return @[]
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var res = newSeq[Move]()
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var moves = game.genPawnDests(field, color)
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for dest in moves:
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if not game.moveLeadsToCheck(field, dest, color):
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var promotions = genPawnPromotion(getMove(field, dest, color), color)
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if promotions != @[]:
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res.add(promotions)
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else:
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res.add(getMove(field, dest, color))
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return res
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proc genLegalMoves*(game: Game, field: int, color: Color): seq[Move] =
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## Generates all legal moves in a `game` starting from `field` for a `color`.
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var legal_moves = newSeq[Move]()
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@ -756,6 +707,12 @@ proc castling(game: var Game, kstart: int, dest_kingside: bool,
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return true
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return false
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proc removeEnPassant(board: var Board, color: Color): void =
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## Removes every en passant of given `color` from the `board`.
|
||||
for field in board.low..board.high:
|
||||
if board[field] == ord(color) * WEnPassant:
|
||||
board[field] = 0
|
||||
|
||||
proc checkedMove*(game: var Game, move: Move): bool {.discardable.} =
|
||||
## Tries to make a `move` in a given `game``.
|
||||
## This process checks for the legality of the move and performs the switch
|
||||
@ -833,6 +790,48 @@ proc isDrawClaimable*(game: Game): bool =
|
||||
## Returns true if a draw is claimable by either player.
|
||||
return game.threeMoveRep() or game.fiftyMoveRule()
|
||||
|
||||
proc checkInsufficientMaterial(board: Board): bool =
|
||||
## Checks for combinations of pieces on a `board`, where no checkmate can be
|
||||
## forced.
|
||||
## Returns true if no player can force a checkmate to the other.
|
||||
var wp = 0
|
||||
var wn = 0
|
||||
var wb = 0
|
||||
var wr = 0
|
||||
var wq = 0
|
||||
var bp = 0
|
||||
var bn = 0
|
||||
var bb = 0
|
||||
var br = 0
|
||||
var bq = 0
|
||||
for field in board.low..board.high:
|
||||
case board[field]:
|
||||
of WPawn:
|
||||
wp = wp + 1
|
||||
of BPawn:
|
||||
bp = bp + 1
|
||||
of WKnight:
|
||||
wn = wn + 1
|
||||
of BKnight:
|
||||
bn = bn + 1
|
||||
of WBishop:
|
||||
wb = wb + 1
|
||||
of BBishop:
|
||||
bb = bb + 1
|
||||
of WRook:
|
||||
wr = wr + 1
|
||||
of BRook:
|
||||
br = br + 1
|
||||
of WQueen:
|
||||
wq = wq + 1
|
||||
of BQueen:
|
||||
bq = bq + 1
|
||||
else:
|
||||
continue
|
||||
let wpieces: PieceAmount = (wp, wn, wb, wr, wq)
|
||||
let bpieces: PieceAmount = (bp, bn, bb, br, bq)
|
||||
return (wpieces in InsufficientMaterial) and (bpieces in InsufficientMaterial)
|
||||
|
||||
proc isStalemate*(game: Game, color: Color): bool =
|
||||
## Returns true if the `color` player is stalemate in a `game`.
|
||||
return (game.hasNoMoves(color) and not game.isInCheck(color)) or
|
||||
|
||||
@ -1,6 +1,3 @@
|
||||
from strutils import parseInt
|
||||
import rdstdin
|
||||
|
||||
import ./chess
|
||||
|
||||
proc runGame*(): void =
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user