Chess: Add en passant detection for possible moves
This commit is contained in:
Wuzzy
parent
db80dd58db
commit
da68b34c49
@ -126,6 +126,12 @@ local function attacked(color, idx, board)
|
||||
return threatDetected
|
||||
end
|
||||
|
||||
local function get_current_halfmove(meta)
|
||||
local moves_raw = meta:get_string("moves_raw")
|
||||
local mrsplit = string.split(moves_raw, ";")
|
||||
return #mrsplit
|
||||
end
|
||||
|
||||
-- Returns all theoretically possible moves from a given
|
||||
-- square, according to the piece it occupies. Ignores restrictions like check, etc.
|
||||
-- If the square is empty, no moves are returned.
|
||||
@ -136,7 +142,7 @@ end
|
||||
-- Any key with a numeric value is a possible destination.
|
||||
-- The numeric value is a move rating for AI and is 0 by default.
|
||||
-- Example: { [4] = 0, [9] = 0 } -- can move to squares 4 and 9
|
||||
local function get_theoretical_moves_from(board, from_idx)
|
||||
local function get_theoretical_moves_from(meta, board, from_idx)
|
||||
local piece, color = board[from_idx]:match(":(%w+)_(%w+)")
|
||||
if not piece then
|
||||
return {}
|
||||
@ -160,6 +166,7 @@ local function get_theoretical_moves_from(board, from_idx)
|
||||
if piece == "pawn" then
|
||||
if color == "white" then
|
||||
local pawnWhiteMove = board[xy_to_index(from_x, from_y - 1)]
|
||||
local en_passant = false
|
||||
-- white pawns can go up only
|
||||
if from_y - 1 == to_y then
|
||||
if from_x == to_x then
|
||||
@ -167,7 +174,26 @@ local function get_theoretical_moves_from(board, from_idx)
|
||||
moves[to_idx] = nil
|
||||
end
|
||||
elseif from_x - 1 == to_x or from_x + 1 == to_x then
|
||||
if not pieceTo:find("black") then
|
||||
local can_capture = false
|
||||
if pieceTo:find("black") then
|
||||
can_capture = true
|
||||
else
|
||||
-- en passant
|
||||
local inv = meta:get_inventory()
|
||||
local enPassantPiece = inv:get_stack("board", xy_to_index(to_x, from_y))
|
||||
local epp_meta = enPassantPiece:get_meta()
|
||||
local epp_name = enPassantPiece:get_name()
|
||||
if epp_name:find("black") and epp_name:sub(11,14) == "pawn" then
|
||||
local pawn_no = epp_name:sub(-1)
|
||||
local double_step_halfmove = meta:get_int("doublePawnStepB"..pawn_no)
|
||||
local current_halfmove = get_current_halfmove(meta)
|
||||
if double_step_halfmove ~= 0 and double_step_halfmove == current_halfmove then
|
||||
can_capture = true
|
||||
en_passant = true
|
||||
end
|
||||
end
|
||||
end
|
||||
if not can_capture then
|
||||
moves[to_idx] = nil
|
||||
end
|
||||
else
|
||||
@ -195,7 +221,7 @@ local function get_theoretical_moves_from(board, from_idx)
|
||||
moves[to_idx] = nil
|
||||
end
|
||||
elseif from_x - 1 == to_x or from_x + 1 == to_x then
|
||||
if not pieceTo:find("black") then
|
||||
if not pieceTo:find("black") and not en_passant then
|
||||
moves[to_idx] = nil
|
||||
end
|
||||
else
|
||||
@ -204,6 +230,7 @@ local function get_theoretical_moves_from(board, from_idx)
|
||||
|
||||
elseif color == "black" then
|
||||
local pawnBlackMove = board[xy_to_index(from_x, from_y + 1)]
|
||||
local en_passant = false
|
||||
-- black pawns can go down only
|
||||
if from_y + 1 == to_y then
|
||||
if from_x == to_x then
|
||||
@ -211,7 +238,26 @@ local function get_theoretical_moves_from(board, from_idx)
|
||||
moves[to_idx] = nil
|
||||
end
|
||||
elseif from_x - 1 == to_x or from_x + 1 == to_x then
|
||||
if not pieceTo:find("white") then
|
||||
local can_capture = false
|
||||
if pieceTo:find("white") then
|
||||
can_capture = true
|
||||
else
|
||||
-- en passant
|
||||
local inv = meta:get_inventory()
|
||||
local enPassantPiece = inv:get_stack("board", xy_to_index(to_x, from_y))
|
||||
local epp_meta = enPassantPiece:get_meta()
|
||||
local epp_name = enPassantPiece:get_name()
|
||||
if epp_name:find("white") and epp_name:sub(11,14) == "pawn" then
|
||||
local pawn_no = epp_name:sub(-1)
|
||||
local double_step_halfmove = meta:get_int("doublePawnStepW"..pawn_no)
|
||||
local current_halfmove = get_current_halfmove(meta)
|
||||
if double_step_halfmove ~= 0 and double_step_halfmove == current_halfmove then
|
||||
can_capture = true
|
||||
en_passant = true
|
||||
end
|
||||
end
|
||||
end
|
||||
if not can_capture then
|
||||
moves[to_idx] = nil
|
||||
end
|
||||
else
|
||||
@ -239,7 +285,7 @@ local function get_theoretical_moves_from(board, from_idx)
|
||||
moves[to_idx] = nil
|
||||
end
|
||||
elseif from_x - 1 == to_x or from_x + 1 == to_x then
|
||||
if not pieceTo:find("white") then
|
||||
if not pieceTo:find("white") and not en_passant then
|
||||
moves[to_idx] = nil
|
||||
end
|
||||
else
|
||||
@ -536,10 +582,10 @@ end
|
||||
-- origin_index is the board index for the square to start the piece from (as string)
|
||||
-- and this is the key for a list of destination indixes.
|
||||
-- r1, r2, r3 ... are numeric values (normally 0) to "rate" this square for AI.
|
||||
local function get_theoretical_moves_for(board, player)
|
||||
local function get_theoretical_moves_for(meta, board, player)
|
||||
local moves = {}
|
||||
for i = 1, 64 do
|
||||
local possibleMoves = get_theoretical_moves_from(board, i)
|
||||
local possibleMoves = get_theoretical_moves_from(meta, board, i)
|
||||
if next(possibleMoves) then
|
||||
local stack_name = board[i]
|
||||
if stack_name:find(player) then
|
||||
@ -949,8 +995,8 @@ local function update_game_result(meta)
|
||||
local blackCanMove = false
|
||||
local whiteCanMove = false
|
||||
|
||||
local blackMoves = get_theoretical_moves_for(board_t, "black")
|
||||
local whiteMoves = get_theoretical_moves_for(board_t, "white")
|
||||
local blackMoves = get_theoretical_moves_for(meta, board_t, "black")
|
||||
local whiteMoves = get_theoretical_moves_for(meta, board_t, "white")
|
||||
local b = 0
|
||||
for k,v in pairs(blackMoves) do
|
||||
b = b + 1
|
||||
@ -1207,10 +1253,8 @@ function realchess.move(pos, from_list, from_index, to_list, to_index, player)
|
||||
if epp_name:find("black") and epp_name:sub(11,14) == "pawn" then
|
||||
local pawn_no = epp_name:sub(-1)
|
||||
local double_step_halfmove = meta:get_int("doublePawnStepB"..pawn_no)
|
||||
local moves_raw = meta:get_string("moves_raw")
|
||||
local mrsplit = string.split(moves_raw, ";")
|
||||
local current_halfmove = #mrsplit + 1
|
||||
if double_step_halfmove ~= 0 and double_step_halfmove == current_halfmove - 1 then
|
||||
local current_halfmove = get_current_halfmove(meta)
|
||||
if double_step_halfmove ~= 0 and double_step_halfmove == current_halfmove then
|
||||
can_capture = true
|
||||
inv:set_stack(to_list, xy_to_index(to_x, from_y), "")
|
||||
end
|
||||
@ -1291,10 +1335,8 @@ function realchess.move(pos, from_list, from_index, to_list, to_index, player)
|
||||
if epp_name:find("white") and epp_name:sub(11,14) == "pawn" then
|
||||
local pawn_no = epp_name:sub(-1)
|
||||
local double_step_halfmove = meta:get_int("doublePawnStepW"..pawn_no)
|
||||
local moves_raw = meta:get_string("moves_raw")
|
||||
local mrsplit = string.split(moves_raw, ";")
|
||||
local current_halfmove = #mrsplit + 1
|
||||
if double_step_halfmove ~= 0 and double_step_halfmove == current_halfmove - 1 then
|
||||
local current_halfmove = get_current_halfmove(meta)
|
||||
if double_step_halfmove ~= 0 and double_step_halfmove == current_halfmove then
|
||||
can_capture = true
|
||||
inv:set_stack(to_list, xy_to_index(to_x, from_y), "")
|
||||
end
|
||||
@ -1696,7 +1738,7 @@ local function ai_move(inv, meta)
|
||||
if (lastMove == opponentColor or (aiColor == "white" and lastMove == "")) and gameResult == "" then
|
||||
update_formspec(meta)
|
||||
|
||||
local moves = get_theoretical_moves_for(board_t, aiColor)
|
||||
local moves = get_theoretical_moves_for(meta, board_t, aiColor)
|
||||
|
||||
local choice_from, choice_to = best_move(moves)
|
||||
if choice_from == nil then
|
||||
|
||||
Loading…
Reference in New Issue
Block a user