Chess: Fix AI moving king into attacked squares

This commit is contained in:
Wuzzy 2023-07-11 17:59:06 +02:00
parent d834d41c41
commit 077b7d66b8

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@ -52,6 +52,80 @@ local piece_values = {
king = 900 king = 900
} }
local rowDirs = {-1, -1, -1, 0, 0, 1, 1, 1}
local colDirs = {-1, 0, 1, -1, 1, -1, 0, 1}
local rowDirsKnight = { 2, 1, 2, 1, -2, -1, -2, -1}
local colDirsKnight = {-1, -2, 1, 2, 1, 2, -1, -2}
local bishopThreats = {true, false, true, false, false, true, false, true}
local rookThreats = {false, true, false, true, true, false, true, false}
local queenThreats = {true, true, true, true, true, true, true, true}
local kingThreats = {true, true, true, true, true, true, true, true}
local function attacked(color, idx, board)
local threatDetected = false
local kill = color == "white"
local pawnThreats = {kill, false, kill, false, false, not kill, false, not kill}
for dir = 1, 8 do
if not threatDetected then
local col, row = index_to_xy(idx)
col, row = col + 1, row + 1
for step = 1, 8 do
row = row + rowDirs[dir]
col = col + colDirs[dir]
if row >= 1 and row <= 8 and col >= 1 and col <= 8 then
local square = get_square(row, col)
local square_name = board[square]
local piece, pieceColor = square_name:match(":(%w+)_(%w+)")
if piece then
if pieceColor ~= color then
if piece == "bishop" and bishopThreats[dir] then
threatDetected = true
elseif piece == "rook" and rookThreats[dir] then
threatDetected = true
elseif piece == "queen" and queenThreats[dir] then
threatDetected = true
else
if step == 1 then
if piece == "pawn" and pawnThreats[dir] then
threatDetected = true
end
if piece == "king" and kingThreats[dir] then
threatDetected = true
end
end
end
end
break
end
end
end
local colK, rowK = index_to_xy(idx)
colK, rowK = colK + 1, rowK + 1
rowK = rowK + rowDirsKnight[dir]
colK = colK + colDirsKnight[dir]
if rowK >= 1 and rowK <= 8 and colK >= 1 and colK <= 8 then
local square = get_square(rowK, colK)
local square_name = board[square]
local piece, pieceColor = square_name:match(":(%w+)_(%w+)")
if piece and pieceColor ~= color and piece == "knight" then
threatDetected = true
end
end
end
end
return threatDetected
end
local function get_possible_moves(board, from_idx) local function get_possible_moves(board, from_idx)
local piece, color = board[from_idx]:match(":(%w+)_(%w+)") local piece, color = board[from_idx]:match(":(%w+)_(%w+)")
if not piece then if not piece then
@ -414,6 +488,10 @@ local function get_possible_moves(board, from_idx)
if dx > 1 or dy > 1 then if dx > 1 or dy > 1 then
moves[to_idx] = nil moves[to_idx] = nil
end end
if attacked(color, xy_to_index(to_x, to_y), board) then
moves[to_idx] = nil
end
end end
end end
@ -461,80 +539,6 @@ local function best_move(moves)
return tonumber(choice_from), choice_to return tonumber(choice_from), choice_to
end end
local rowDirs = {-1, -1, -1, 0, 0, 1, 1, 1}
local colDirs = {-1, 0, 1, -1, 1, -1, 0, 1}
local rowDirsKnight = { 2, 1, 2, 1, -2, -1, -2, -1}
local colDirsKnight = {-1, -2, 1, 2, 1, 2, -1, -2}
local bishopThreats = {true, false, true, false, false, true, false, true}
local rookThreats = {false, true, false, true, true, false, true, false}
local queenThreats = {true, true, true, true, true, true, true, true}
local kingThreats = {true, true, true, true, true, true, true, true}
local function attacked(color, idx, board)
local threatDetected = false
local kill = color == "white"
local pawnThreats = {kill, false, kill, false, false, not kill, false, not kill}
for dir = 1, 8 do
if not threatDetected then
local col, row = index_to_xy(idx)
col, row = col + 1, row + 1
for step = 1, 8 do
row = row + rowDirs[dir]
col = col + colDirs[dir]
if row >= 1 and row <= 8 and col >= 1 and col <= 8 then
local square = get_square(row, col)
local square_name = board[square]
local piece, pieceColor = square_name:match(":(%w+)_(%w+)")
if piece then
if pieceColor ~= color then
if piece == "bishop" and bishopThreats[dir] then
threatDetected = true
elseif piece == "rook" and rookThreats[dir] then
threatDetected = true
elseif piece == "queen" and queenThreats[dir] then
threatDetected = true
else
if step == 1 then
if piece == "pawn" and pawnThreats[dir] then
threatDetected = true
end
if piece == "king" and kingThreats[dir] then
threatDetected = true
end
end
end
end
break
end
end
end
local colK, rowK = index_to_xy(idx)
colK, rowK = colK + 1, rowK + 1
rowK = rowK + rowDirsKnight[dir]
colK = colK + colDirsKnight[dir]
if rowK >= 1 and rowK <= 8 and colK >= 1 and colK <= 8 then
local square = get_square(rowK, colK)
local square_name = board[square]
local piece, pieceColor = square_name:match(":(%w+)_(%w+)")
if piece and pieceColor ~= color and piece == "knight" then
threatDetected = true
end
end
end
end
return threatDetected
end
local function locate_kings(board) local function locate_kings(board)
local Bidx, Widx local Bidx, Widx
for i = 1, 64 do for i = 1, 64 do