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engine: create Node type for easier analysis

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This commit is contained in:
Adrien Abraham 2020-06-05 18:46:08 +02:00
parent 362e23e254
commit 21aae1d9ba
5 changed files with 243 additions and 209 deletions
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67
src/board.rs
View file

@ -30,43 +30,47 @@ pub const SQ_BL_Q: u8 = SQ_BL|SQ_Q;
pub const SQ_BL_K: u8 = SQ_BL|SQ_K;
#[inline]
pub fn has_flag(i: u8, flag: u8) -> bool { i & flag == flag }
pub const fn has_flag(i: u8, flag: u8) -> bool { i & flag == flag }
// Wrappers for clearer naming.
/// Get type of piece on square, without color.
#[inline]
pub fn get_type(square: u8) -> u8 { square & SQ_TYPE_MASK }
pub const fn get_type(square: u8) -> u8 { square & SQ_TYPE_MASK }
/// Return true if the piece on this square is of type `piece_type`.
#[inline]
pub fn is_type(square: u8, piece_type: u8) -> bool { get_type(square) == piece_type }
pub const fn is_type(square: u8, piece_type: u8) -> bool { get_type(square) == piece_type }
/// Return true if the piece on this square is the same as `piece`.
#[inline]
pub fn is_piece(square: u8, piece: u8) -> bool { has_flag(square, piece) }
pub const fn is_piece(square: u8, piece: u8) -> bool { has_flag(square, piece) }
/// Return true if the piece on this square has this color.
#[inline]
pub fn is_color(square: u8, color: u8) -> bool { has_flag(square, color) }
pub const fn is_color(square: u8, color: u8) -> bool { has_flag(square, color) }
/// Return true if this square has a white piece.
#[inline]
pub fn is_white(square: u8) -> bool { is_color(square, SQ_WH) }
pub const fn is_white(square: u8) -> bool { is_color(square, SQ_WH) }
/// Return true if this square has a black piece.
#[inline]
pub fn is_black(square: u8) -> bool { is_color(square, SQ_BL) }
pub const fn is_black(square: u8) -> bool { is_color(square, SQ_BL) }
/// Return the color of the piece on this square.
#[inline]
pub fn get_color(square: u8) -> u8 { square & SQ_COLOR_MASK }
pub const fn get_color(square: u8) -> u8 { square & SQ_COLOR_MASK }
/// Get opposite color.
#[inline]
pub fn opposite(color: u8) -> u8 { color ^ SQ_COLOR_MASK }
pub const fn opposite(color: u8) -> u8 { color ^ SQ_COLOR_MASK }
/// Minimum allowed value for stored Pos components.
pub const POS_MIN: i8 = 0;
/// Maximum allowed value for stored Pos components.
pub const POS_MAX: i8 = 7;
/// Coords (file, rank) of a square on a board, both components are in [0, 7].
pub type Pos = (i8, i8);
/// Check if a Pos component is in the [0, 7] range.
#[inline]
pub fn is_valid_pos_c(component: i8) -> bool { component >= 0 && component <= 7 }
/// Check if both `pos` components are valid.
#[inline]
pub fn is_valid_pos(pos: Pos) -> bool { is_valid_pos_c(pos.0) && is_valid_pos_c(pos.1) }
@ -75,7 +79,7 @@ pub fn is_valid_pos(pos: Pos) -> bool { is_valid_pos_c(pos.0) && is_valid_pos_c(
/// `s` has to be valid UTF8, or the very least ASCII because chars
/// are interpreted as raw bytes, and lowercase.
#[inline]
pub fn pos(s: &str) -> Pos {
pub const fn pos(s: &str) -> Pos {
let chars = s.as_bytes();
((chars[0] - 0x61) as i8, (chars[1] - 0x31) as i8)
}
@ -95,7 +99,7 @@ pub fn pos_string(p: &Pos) -> String {
pub type Board = [u8; 64];
/// Generate the board of a new game.
pub fn new() -> Board {
pub const fn new() -> Board {
[
/* 1 2 3 4 5 6 7 8 */
/* A */ SQ_WH_R, SQ_WH_P, SQ_E, SQ_E, SQ_E, SQ_E, SQ_BL_P, SQ_BL_R,
@ -110,7 +114,7 @@ pub fn new() -> Board {
}
/// Generate an empty board.
pub fn new_empty() -> Board {
pub const fn new_empty() -> Board {
[SQ_E; 64]
}
@ -147,7 +151,7 @@ pub fn eq(b1: &Board, b2: &Board) -> bool {
}
#[inline]
pub fn get_square(board: &Board, coords: &Pos) -> u8 {
pub const fn get_square(board: &Board, coords: &Pos) -> u8 {
board[(coords.0 * 8 + coords.1) as usize]
}
@ -162,7 +166,7 @@ pub fn clear_square(board: &mut Board, coords: &Pos) {
}
#[inline]
pub fn is_empty(board: &Board, coords: &Pos) -> bool {
pub const fn is_empty(board: &Board, coords: &Pos) -> bool {
get_square(board, coords) == SQ_E
}
@ -221,22 +225,6 @@ pub fn draw(board: &Board, f: &mut dyn std::io::Write) {
writeln!(f, " abcdefgh").unwrap();
}
/// A movement, with before/after positions and optional promotion.
pub type Move = (Pos, Pos, Option<u8>);
/// Apply a move `m` to a copy of `board`.
pub fn apply(board: &Board, m: &Move) -> Board {
let mut new_board = board.clone();
apply_into(&mut new_board, m);
new_board
}
/// Apply a move `m` into `board`.
pub fn apply_into(board: &mut Board, m: &Move) {
set_square(board, &m.1, get_square(board, &m.0));
clear_square(board, &m.0)
}
/// Storage for precomputed board pieces stats.
#[derive(Debug, Clone, PartialEq)]
pub struct BoardStats {
@ -253,7 +241,7 @@ pub struct BoardStats {
}
impl BoardStats {
pub fn new() -> BoardStats {
pub const fn new() -> BoardStats {
BoardStats {
num_pawns: 0, num_bishops: 0, num_knights: 0, num_rooks: 0, num_queens: 0,
num_kings: 0, num_doubled_pawns: 0, num_backward_pawns: 0, num_isolated_pawns: 0,
@ -458,23 +446,6 @@ mod tests {
assert_eq!(find_king(&b, SQ_BL), pos("e8"));
}
#[test]
fn test_apply_into() {
let mut b = new_empty();
// Put 2 enemy knights on board.
set_square(&mut b, &pos("d4"), SQ_WH_N);
set_square(&mut b, &pos("f4"), SQ_BL_N);
// Move white knight in a position attacked by black knight.
apply_into(&mut b, &(pos("d4"), pos("e6"), None));
assert_eq!(get_square(&b, &pos("d4")), SQ_E);
assert_eq!(get_square(&b, &pos("e6")), SQ_WH_N);
assert_eq!(num_pieces(&b), 2);
// Sack it with black knight
apply_into(&mut b, &(pos("f4"), pos("e6"), None));
assert_eq!(get_square(&b, &pos("e6")), SQ_BL_N);
assert_eq!(num_pieces(&b), 1);
}
#[test]
fn test_compute_stats() {
// Check that initial stats are correct.

195
src/engine.rs
View file

@ -14,7 +14,7 @@ pub struct Engine {
/// Debug mode, log some data.
debug: bool,
/// Current game state, starting point of further analysis.
state: GameState,
node: Node,
/// Communication mode.
mode: Mode,
/// If true, the engine is currently listening to incoming cmds.
@ -23,28 +23,33 @@ pub struct Engine {
working: Arc<atomic::AtomicBool>,
}
/// Representation of a game state that can cloned to analysis workers.
///
/// It does not include various parameters such as clocks so that they
/// can be passed separately using `WorkArgs`.
/// Analysis node: a board along with the game state and some stats.
#[derive(Clone)]
struct GameState {
struct Node {
/// Board for this node.
board: board::Board,
stats: (board::BoardStats, board::BoardStats), // white and black pieces stats.
color: u8,
castling: u8,
en_passant: Option<board::Pos>,
halfmove: i32,
fullmove: i32,
/// Game state.
game_state: rules::GameState,
/// White and black pieces stats; have to be recomputed if board changes.
stats: (board::BoardStats, board::BoardStats), // white and black pieces stats
}
impl std::fmt::Debug for GameState {
impl Node {
fn new() -> Node {
Node {
board: board::new_empty(),
game_state: rules::GameState::new(),
stats: (board::BoardStats::new(), board::BoardStats::new()),
}
}
}
impl std::fmt::Debug for Node {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(
f,
"GameState {{ board: [...], stats: {:?}, color: {:08b}, castling: {:08b}, \
en_passant: {:?}, halfmove: {}, fullmove: {} }}",
self.stats, self.color, self.castling, self.en_passant, self.halfmove, self.fullmove
"Node {{ board: [...], game_state: {:?}, stats: {:?} }}",
self.game_state, self.stats
)
}
}
@ -70,7 +75,7 @@ pub enum Cmd {
UciPosition(Vec<uci::PositionArgs>), // UCI "position" command.
UciGo(Vec<uci::GoArgs>), // UCI "go" command.
Stop, // Stop working ASAP.
TmpBestMove(Option<board::Move>), // Send best move found by analysis worker (TEMPORARY).
TmpBestMove(Option<rules::Move>), // Send best move found by analysis worker (TEMPORARY).
WorkerInfo(Vec<Info>), // Informations from a worker.
// Commands that can be sent by the engine.
@ -80,7 +85,7 @@ pub enum Cmd {
/// the message to be forwarded to whatever can log.
Log(String),
/// Report found best move.
BestMove(Option<board::Move>),
BestMove(Option<rules::Move>),
/// Report ongoing analysis information.
Info(Vec<Info>),
}
@ -98,7 +103,7 @@ struct WorkArgs {
/// Information to be transmitted back to whatever is listening.
#[derive(Debug, Clone)]
pub enum Info {
CurrentMove(board::Move),
CurrentMove(rules::Move),
}
/// General engine implementation.
@ -106,15 +111,7 @@ impl Engine {
pub fn new() -> Engine {
Engine {
debug: true,
state: GameState {
board: board::new_empty(),
stats: (board::BoardStats::new(), board::BoardStats::new()),
color: board::SQ_WH,
castling: rules::CASTLING_MASK,
en_passant: None,
halfmove: 0,
fullmove: 1,
},
node: Node::new(),
mode: Mode::No,
listening: false,
working: Arc::new(atomic::AtomicBool::new(false)),
@ -168,59 +165,41 @@ impl Engine {
///
/// For speed purposes, it assumes values are always valid.
fn apply_fen(&mut self, fen: &notation::Fen) {
self.set_fen_placement(&fen.placement);
self.set_fen_color(&fen.color);
self.set_fen_castling(&fen.castling);
self.set_fen_en_passant(&fen.en_passant);
self.set_fen_halfmove(&fen.halfmove);
self.set_fen_fullmove(&fen.fullmove);
}
fn set_fen_placement(&mut self, placement: &str) {
self.state.board = board::new_from_fen(placement);
}
fn set_fen_color(&mut self, color: &str) {
match color.chars().next().unwrap() {
'w' => self.state.color = board::SQ_WH,
'b' => self.state.color = board::SQ_BL,
// Placement.
self.node.board = board::new_from_fen(&fen.placement);
// Color.
match fen.color.chars().next().unwrap() {
'w' => self.node.game_state.color = board::SQ_WH,
'b' => self.node.game_state.color = board::SQ_BL,
_ => {}
}
}
fn set_fen_castling(&mut self, castling: &str) {
for c in castling.chars() {
};
// Castling.
for c in fen.castling.chars() {
match c {
'K' => self.state.castling |= rules::CASTLING_WH_K,
'Q' => self.state.castling |= rules::CASTLING_WH_Q,
'k' => self.state.castling |= rules::CASTLING_BL_K,
'q' => self.state.castling |= rules::CASTLING_BL_Q,
'K' => self.node.game_state.castling |= rules::CASTLING_WH_K,
'Q' => self.node.game_state.castling |= rules::CASTLING_WH_Q,
'k' => self.node.game_state.castling |= rules::CASTLING_BL_K,
'q' => self.node.game_state.castling |= rules::CASTLING_BL_Q,
_ => {}
}
}
}
fn set_fen_en_passant(&mut self, en_passant: &str) {
self.state.en_passant = match en_passant {
// En passant.
self.node.game_state.en_passant = match fen.en_passant.as_ref() {
"-" => None,
p => Some(board::pos(p)),
};
// Half moves.
self.node.game_state.halfmove = fen.halfmove.parse::<i32>().ok().unwrap();
// Full moves.
self.node.game_state.fullmove = fen.fullmove.parse::<i32>().ok().unwrap();
}
fn set_fen_halfmove(&mut self, halfmove: &str) {
self.state.halfmove = halfmove.parse::<i32>().ok().unwrap();
}
fn set_fen_fullmove(&mut self, fullmove: &str) {
self.state.fullmove = fullmove.parse::<i32>().ok().unwrap();
}
fn apply_moves(&mut self, moves: &Vec<board::Move>) {
fn apply_moves(&mut self, moves: &Vec<rules::Move>) {
moves.iter().for_each(|m| self.apply_move(m));
}
fn apply_move(&mut self, m: &board::Move) {
board::apply_into(&mut self.state.board, m);
fn apply_move(&mut self, m: &rules::Move) {
rules::apply_move_to(&mut self.node.board, &mut self.node.game_state, m);
}
/// Start working on board, returning the best move found.
@ -228,17 +207,17 @@ impl Engine {
/// Stop working after `movetime` ms, or go on forever if it's -1.
fn work(&mut self, args: &WorkArgs) {
if self.debug {
self.reply(Cmd::Log(format!("Current evaluation: {}", evaluate(&self.state.stats))));
self.reply(Cmd::Log(format!("Current evaluation: {}", evaluate(&self.node.stats))));
}
self.working.store(true, atomic::Ordering::Relaxed);
let state = self.state.clone();
let node = self.node.clone();
let args = args.clone();
let working = self.working.clone();
let tx = match &self.mode { Mode::Uci(_, _, tx) => tx.clone(), _ => return };
let debug = self.debug;
thread::spawn(move || {
analyze(&state, &args, working, tx, debug);
analyze(&node, &args, working, tx, debug);
});
}
@ -271,15 +250,10 @@ impl Engine {
},
uci::PositionArgs::Moves(moves) => {
self.apply_moves(&moves);
self.state.color = if moves.len() % 2 == 0 {
board::SQ_WH
} else {
board::SQ_BL
};
}
}
}
board::compute_stats_into(&self.state.board, &mut self.state.stats);
board::compute_stats_into(&self.node.board, &mut self.node.stats);
}
/// Start working using parameters passed with a "go" command.
@ -307,41 +281,43 @@ impl Engine {
}
fn analyze(
state: &GameState,
node: &Node,
_args: &WorkArgs,
wip: Arc<atomic::AtomicBool>,
working: Arc<atomic::AtomicBool>,
tx: mpsc::Sender<Cmd>,
debug: bool,
) {
if !wip.load(atomic::Ordering::Relaxed) {
if !working.load(atomic::Ordering::Relaxed) {
return;
}
let moves = rules::get_player_legal_moves(&state.board, state.color);
if debug {
let state_str = format!("Current state: {:?}", state);
let state_str = format!("Analysing node: {:?}", node);
tx.send(Cmd::Log(state_str)).unwrap();
let mut s = vec!();
board::draw(&state.board, &mut s);
board::draw(&node.board, &mut s);
let draw_str = String::from_utf8_lossy(&s).to_string();
tx.send(Cmd::Log(draw_str)).unwrap();
}
let moves = rules::get_player_legal_moves(&node.board, &node.game_state);
if debug {
let moves_str = format!("Legal moves: {}", notation::move_list_to_string(&moves));
tx.send(Cmd::Log(moves_str)).unwrap();
}
let mut best_e = if board::is_white(state.color) { -999.0 } else { 999.0 };
let mut best_e = if board::is_white(node.game_state.color) { -999.0 } else { 999.0 };
let mut best_move = None;
for m in moves {
// tx.send(Cmd::WorkerInfo(vec!(Info::CurrentMove(m)))).unwrap();
let mut board = state.board.clone();
board::apply_into(&mut board, &m);
let mut board = node.board.clone();
let mut game_state = node.game_state.clone();
rules::apply_move_to(&mut board, &mut game_state, &m);
let stats = board::compute_stats(&board);
let e = evaluate(&stats);
tx.send(Cmd::Log(format!("Move {} eval {}", notation::move_to_string(&m), e))).unwrap();
if
(board::is_white(state.color) && e > best_e) ||
(board::is_black(state.color) && e < best_e)
(board::is_white(game_state.color) && e > best_e) ||
(board::is_black(game_state.color) && e < best_e)
{
best_e = e;
best_move = Some(m.clone());
@ -363,20 +339,19 @@ fn analyze(
fn evaluate(stats: &(board::BoardStats, board::BoardStats)) -> f32 {
let (ws, bs) = stats;
(
200.0 * (ws.num_kings - bs.num_kings) as f32
+ 9.0 * (ws.num_queens - bs.num_queens) as f32
+ 5.0 * (ws.num_rooks - bs.num_rooks) as f32
+ 3.0 * (ws.num_bishops - bs.num_bishops) as f32
+ 3.0 * (ws.num_knights - bs.num_knights) as f32
+ (ws.num_pawns - bs.num_pawns) as f32
+ 0.5 * ( // FIXME
ws.num_doubled_pawns - bs.num_doubled_pawns +
ws.num_isolated_pawns - bs.num_isolated_pawns +
ws.num_backward_pawns - bs.num_backward_pawns
) as f32
+ 0.1 * (ws.mobility - bs.mobility) as f32
)
200.0 * (ws.num_kings - bs.num_kings) as f32
+ 9.0 * (ws.num_queens - bs.num_queens) as f32
+ 5.0 * (ws.num_rooks - bs.num_rooks) as f32
+ 3.0 * (ws.num_bishops - bs.num_bishops) as f32
+ 3.0 * (ws.num_knights - bs.num_knights) as f32
+ (ws.num_pawns - bs.num_pawns) as f32
+ 0.5 * ( // FIXME
ws.num_doubled_pawns - bs.num_doubled_pawns +
ws.num_isolated_pawns - bs.num_isolated_pawns +
ws.num_backward_pawns - bs.num_backward_pawns
) as f32
+ 0.1 * (ws.mobility - bs.mobility) as f32
}
#[cfg(test)]
@ -385,12 +360,16 @@ mod tests {
#[test]
fn test_evaluate() {
let mut b = board::new();
let stats = board::compute_stats(&b);
let mut node = Node::new();
let stats = board::compute_stats(&node.board);
assert_eq!(evaluate(&stats), 0.0);
board::apply_into(&mut b, &(notation::parse_move("d2d4")));
let stats = board::compute_stats(&b);
rules::apply_move_to_board(
&mut node.board,
&node.game_state,
&notation::parse_move("d2d4")
);
let stats = board::compute_stats(&node.board);
assert_eq!(evaluate(&stats), 0.0);
}
}

9
src/notation.rs
View file

@ -1,11 +1,12 @@
//! Functions using various notations.
use crate::board;
use crate::rules;
pub const NULL_MOVE: &str = "0000";
/// Create a string containing the UCI algebraic notation of this move.
pub fn move_to_string(m: &board::Move) -> String {
pub fn move_to_string(m: &rules::Move) -> String {
let mut move_string = String::new();
move_string.push_str(&board::pos_string(&m.0));
move_string.push_str(&board::pos_string(&m.1));
@ -21,8 +22,8 @@ pub fn move_to_string(m: &board::Move) -> String {
move_string
}
/// Parse an UCI move algebraic notation string to a board::Move.
pub fn parse_move(m_str: &str) -> board::Move {
/// Parse an UCI move algebraic notation string to a rules::Move.
pub fn parse_move(m_str: &str) -> rules::Move {
let prom = if m_str.len() == 5 {
Some(match m_str.as_bytes()[4] {
b'b' => board::SQ_B,
@ -38,7 +39,7 @@ pub fn parse_move(m_str: &str) -> board::Move {
}
/// Create a space-separated string of moves. Used for debugging.
pub fn move_list_to_string(moves: &Vec<board::Move>) -> String {
pub fn move_list_to_string(moves: &Vec<rules::Move>) -> String {
moves.iter().map(|m| move_to_string(m)).collect::<Vec<_>>().join(" ")
}

173
src/rules.rs
View file

@ -2,6 +2,31 @@
use crate::board::*;
/// Characteristics of the state of a game.
///
/// It does not include various parameters such as clocks that are
/// more aimed for engine analysis than typical rules checking.
#[derive(Debug, Clone)]
pub struct GameState {
pub color: u8,
pub castling: u8,
pub en_passant: Option<Pos>,
pub halfmove: i32,
pub fullmove: i32,
}
impl GameState {
pub const fn new() -> GameState {
GameState {
color: SQ_WH,
castling: CASTLING_MASK,
en_passant: None,
halfmove: 0,
fullmove: 1,
}
}
}
pub const CASTLING_WH_K: u8 = 0b00000001;
pub const CASTLING_WH_Q: u8 = 0b00000010;
pub const CASTLING_BL_K: u8 = 0b00000100;
@ -11,13 +36,41 @@ pub const CASTLING_MASK: u8 = 0b00001111;
pub const START_WH_K_POS: Pos = pos("e1");
pub const START_BL_K_POS: Pos = pos("e8");
/// A movement, with before/after positions and optional promotion.
pub type Move = (Pos, Pos, Option<u8>);
/// Apply a move `m` to copies to `board` and `game_state`.
pub fn apply_move(board: &Board, game_state: &GameState, m: &Move) -> (Board, GameState) {
let mut new_board = board.clone();
let mut new_state = game_state.clone();
apply_move_to(&mut new_board, &mut new_state, m);
(new_board, new_state)
}
pub fn apply_move_to(board: &mut Board, game_state: &mut GameState, m: &Move) {
apply_move_to_board(board, game_state, m);
apply_move_to_state(game_state, m);
}
/// Apply a move `m` into `board`.
pub fn apply_move_to_board(board: &mut Board, _game_state: &GameState, m: &Move) {
// TODO handle castling
set_square(board, &m.1, get_square(board, &m.0));
clear_square(board, &m.0)
}
pub fn apply_move_to_state(game_state: &mut GameState, _m: &Move) {
game_state.color = opposite(game_state.color);
// TODO handle castling
}
/// Get a list of legal moves for all pieces of this color.
pub fn get_player_legal_moves(board: &Board, color: u8, castling: u8) -> Vec<Move> {
filter_illegal_moves(board, color, get_player_moves(board, color, castling))
pub fn get_player_legal_moves(board: &Board, game_state: &GameState) -> Vec<Move> {
filter_illegal_moves(board, game_state, get_player_moves(board, game_state))
}
/// Get a list of moves for all pieces of this color.
pub fn get_player_moves(board: &Board, color: u8, castling: u8) -> Vec<Move> {
pub fn get_player_moves(board: &Board, game_state: &GameState) -> Vec<Move> {
let mut moves = vec!();
for r in 0..8 {
for f in 0..8 {
@ -25,8 +78,8 @@ pub fn get_player_moves(board: &Board, color: u8, castling: u8) -> Vec<Move> {
if is_empty(board, &p) {
continue
}
if is_color(get_square(board, &p), color) {
moves.append(&mut get_piece_moves(board, &p, castling));
if is_color(get_square(board, &p), game_state.color) {
moves.append(&mut get_piece_moves(board, &p, game_state));
}
}
}
@ -34,14 +87,14 @@ pub fn get_player_moves(board: &Board, color: u8, castling: u8) -> Vec<Move> {
}
/// Get a list of moves for the piece at position `at`.
pub fn get_piece_moves(board: &Board, at: &Pos, castling: u8) -> Vec<Move> {
pub fn get_piece_moves(board: &Board, at: &Pos, game_state: &GameState) -> Vec<Move> {
match get_square(board, at) {
p if is_piece(p, SQ_P) => get_pawn_moves(board, at, p),
p if is_piece(p, SQ_B) => get_bishop_moves(board, at, p),
p if is_piece(p, SQ_N) => get_knight_moves(board, at, p),
p if is_piece(p, SQ_R) => get_rook_moves(board, at, p),
p if is_piece(p, SQ_Q) => get_queen_moves(board, at, p),
p if is_piece(p, SQ_K) => get_king_moves(board, at, p, castling),
p if is_piece(p, SQ_K) => get_king_moves(board, at, p, game_state),
_ => vec!(),
}
}
@ -171,7 +224,7 @@ fn get_queen_moves(board: &Board, at: &Pos, piece: u8) -> Vec<Move> {
moves
}
fn get_king_moves(board: &Board, at: &Pos, piece: u8, castling: u8) -> Vec<Move> {
fn get_king_moves(board: &Board, at: &Pos, piece: u8, _game_state: &GameState) -> Vec<Move> {
let (f, r) = at;
let mut moves = vec!();
for offset in [(-1, 1), (0, 1), (1, 1), (-1, 0), (1, 0), (-1, -1), (0, -1), (1, -1)].iter() {
@ -211,24 +264,24 @@ fn move_on_enemy(piece1: u8, pos1: &Pos, piece2: u8, pos2: &Pos) -> Option<Move>
/// Return an iterator filtering out illegal moves from given list.
///
/// Pass color of moving player to avoid checking it for every move.
fn filter_illegal_moves(board: &Board, color: u8, castling: u8, moves: Vec<Move>) -> Vec<Move> {
let king_p = find_king(board, color);
fn filter_illegal_moves(board: &Board, game_state: &GameState, moves: Vec<Move>) -> Vec<Move> {
let king_p = find_king(board, game_state.color);
moves.into_iter().filter(|m| {
// If king moved, use its new position.
let king_p = if m.0 == king_p { m.1 } else { king_p };
let new_board = apply(board, m);
let (new_board, new_state) = apply_move(board, game_state, m);
// Check if the move makes the player king in check.
if is_attacked(&new_board, &king_p, castling) {
return false
}
true
!is_attacked(&new_board, &new_state, &king_p)
}).collect()
}
/// Return true if the piece at position `at` is attacked.
fn is_attacked(board: &Board, at: &Pos, castling: u8) -> bool {
let color = get_color(get_square(board, at));
let enemy_moves = get_player_moves(board, opposite(color), castling);
///
/// Beware that the game state must be coherent with the analysed
/// square, i.e. if the piece at `at` is white, the game state should
/// tell that it is black turn.
fn is_attacked(board: &Board, game_state: &GameState, at: &Pos) -> bool {
let enemy_moves = get_player_moves(board, game_state);
for m in enemy_moves.iter() {
if *at == m.1 {
return true
@ -241,26 +294,48 @@ fn is_attacked(board: &Board, at: &Pos, castling: u8) -> bool {
mod tests {
use super::*;
#[test]
fn test_apply_move_to_board() {
let mut b = new_empty();
let s = GameState::new();
// Put 2 enemy knights on board.
set_square(&mut b, &pos("d4"), SQ_WH_N);
set_square(&mut b, &pos("f4"), SQ_BL_N);
// Move white knight in a position attacked by black knight.
apply_move_to_board(&mut b, &s, &(pos("d4"), pos("e6"), None));
assert_eq!(get_square(&b, &pos("d4")), SQ_E);
assert_eq!(get_square(&b, &pos("e6")), SQ_WH_N);
assert_eq!(num_pieces(&b), 2);
// Sack it with black knight
apply_move_to_board(&mut b, &s, &(pos("f4"), pos("e6"), None));
assert_eq!(get_square(&b, &pos("e6")), SQ_BL_N);
assert_eq!(num_pieces(&b), 1);
}
#[test]
fn test_get_player_moves() {
let b = new();
let s = GameState::new();
// At first move, white has 16 pawn moves and 4 knight moves.
let moves = get_player_moves(&b, SQ_WH, CASTLING_MASK);
let moves = get_player_moves(&b, &s);
assert_eq!(moves.len(), 20);
}
#[test]
fn test_get_pawn_moves() {
let mut b = new_empty();
let s = GameState::new();
// Check that a pawn (here white queen's pawn) can move forward if the road is free.
set_square(&mut b, &pos("d3"), SQ_WH_P);
let moves = get_piece_moves(&b, &pos("d3"));
let moves = get_piece_moves(&b, &pos("d3"), &s);
assert!(moves.len() == 1 && moves.contains( &(pos("d3"), pos("d4"), None) ));
// Check that a pawn (here white king's pawn) can move 2 square forward on first move.
set_square(&mut b, &pos("e2"), SQ_WH_P);
let moves = get_piece_moves(&b, &pos("e2"));
let moves = get_piece_moves(&b, &pos("e2"), &s);
assert_eq!(moves.len(), 2);
assert!(moves.contains( &(pos("e2"), pos("e3"), None) ));
assert!(moves.contains( &(pos("e2"), pos("e4"), None) ));
@ -268,23 +343,23 @@ mod tests {
// Check that a pawn cannot move forward if a piece is blocking its path.
// 1. black pawn 2 square forward; only 1 square forward available from start pos.
set_square(&mut b, &pos("e4"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"));
let moves = get_piece_moves(&b, &pos("e2"), &s);
assert!(moves.len() == 1 && moves.contains( &(pos("e2"), pos("e3"), None) ));
// 2. black pawn 1 square forward; no square available.
set_square(&mut b, &pos("e3"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"));
let moves = get_piece_moves(&b, &pos("e2"), &s);
assert_eq!(moves.len(), 0);
// 3. remove the e4 black pawn; the white pawn should not be able to jump above e3 pawn.
clear_square(&mut b, &pos("e4"));
let moves = get_piece_moves(&b, &pos("e2"));
let moves = get_piece_moves(&b, &pos("e2"), &s);
assert_eq!(moves.len(), 0);
// Check that a pawn can take a piece diagonally.
set_square(&mut b, &pos("f3"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"));
let moves = get_piece_moves(&b, &pos("e2"), &s);
assert!(moves.len() == 1 && moves.contains( &(pos("e2"), pos("f3"), None) ));
set_square(&mut b, &pos("d3"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"));
let moves = get_piece_moves(&b, &pos("e2"), &s);
assert_eq!(moves.len(), 2);
assert!(moves.contains( &(pos("e2"), pos("f3"), None) ));
assert!(moves.contains( &(pos("e2"), pos("d3"), None) ));
@ -292,17 +367,18 @@ mod tests {
// Check that a pawn moving to the last rank leads to queen promotion.
// 1. by simply moving forward.
set_square(&mut b, &pos("a7"), SQ_WH_P);
let moves = get_piece_moves(&b, &pos("a7"));
let moves = get_piece_moves(&b, &pos("a7"), &s);
assert!(moves.len() == 1 && moves.contains( &(pos("a7"), pos("a8"), Some(SQ_Q)) ));
}
#[test]
fn test_get_bishop_moves() {
let mut b = new_empty();
let s = GameState::new();
// A bishop has maximum range when it's in a center square.
set_square(&mut b, &pos("d4"), SQ_WH_B);
let moves = get_piece_moves(&b, &pos("d4"));
let moves = get_piece_moves(&b, &pos("d4"), &s);
assert_eq!(moves.len(), 13);
// Going top-right.
assert!(moves.contains( &(pos("d4"), pos("e5"), None) ));
@ -324,89 +400,96 @@ mod tests {
// When blocking sight to one square with friendly piece, lose 2 moves.
set_square(&mut b, &pos("b2"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 11);
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 11);
// When blocking sight to one square with enemy piece, lose only 1 move.
set_square(&mut b, &pos("b2"), SQ_BL_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 12);
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 12);
}
#[test]
fn test_get_knight_moves() {
let mut b = new_empty();
let s = GameState::new();
// A knight never has blocked sight; if it's in the center of the board, it can have up to
// 8 moves.
set_square(&mut b, &pos("d4"), SQ_WH_N);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 8);
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 8);
// If on a side if has only 4 moves.
set_square(&mut b, &pos("a4"), SQ_WH_N);
assert_eq!(get_piece_moves(&b, &pos("a4")).len(), 4);
assert_eq!(get_piece_moves(&b, &pos("a4"), &s).len(), 4);
// And in a corner, only 2 moves.
set_square(&mut b, &pos("a1"), SQ_WH_N);
assert_eq!(get_piece_moves(&b, &pos("a1")).len(), 2);
assert_eq!(get_piece_moves(&b, &pos("a1"), &s).len(), 2);
// Add 2 friendly pieces and it is totally blocked.
set_square(&mut b, &pos("b3"), SQ_WH_P);
set_square(&mut b, &pos("c2"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("a1")).len(), 0);
assert_eq!(get_piece_moves(&b, &pos("a1"), &s).len(), 0);
}
#[test]
fn test_get_rook_moves() {
let mut b = new_empty();
let s = GameState::new();
set_square(&mut b, &pos("d4"), SQ_WH_R);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 14);
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 14);
set_square(&mut b, &pos("d6"), SQ_BL_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 12);
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 12);
set_square(&mut b, &pos("d6"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 11);
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 11);
}
#[test]
fn test_get_queen_moves() {
let mut b = new_empty();
let s = GameState::new();
set_square(&mut b, &pos("d4"), SQ_WH_Q);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 14 + 13); // Bishop + rook moves.
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 14 + 13); // Bishop + rook moves.
}
#[test]
fn test_get_king_moves() {
let mut b = new_empty();
let s = GameState::new();
set_square(&mut b, &pos("d4"), SQ_WH_K);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 8);
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 8);
set_square(&mut b, &pos("e5"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 7);
assert_eq!(get_piece_moves(&b, &pos("d4"), &s).len(), 7);
}
#[test]
fn test_filter_illegal_moves() {
let mut b = new_empty();
let s = GameState::new();
// Place white's king on first rank.
set_square(&mut b, &pos("e1"), SQ_WH_K);
// Place black rook in second rank: king can only move left or right.
set_square(&mut b, &pos("h2"), SQ_BL_R);
let all_wh_moves = get_piece_moves(&b, &pos("e1"));
let all_wh_moves = get_piece_moves(&b, &pos("e1"), &s);
assert_eq!(all_wh_moves.len(), 5);
assert_eq!(filter_illegal_moves(&b, SQ_WH, all_wh_moves).len(), 2);
assert_eq!(filter_illegal_moves(&b, &s, all_wh_moves).len(), 2);
}
#[test]
fn test_is_attacked() {
let mut b = new_empty();
let mut s = GameState::new();
s.color = SQ_BL;
// Place a black rook in white pawn's file.
set_square(&mut b, &pos("d4"), SQ_WH_P);
set_square(&mut b, &pos("d6"), SQ_BL_R);
assert!(is_attacked(&b, &pos("d4")));
assert!(is_attacked(&b, &s, &pos("d4")));
// Move the rook on another file, no more attack.
apply_into(&mut b, &(pos("d6"), pos("e6"), None));
assert!(!is_attacked(&b, &pos("d4")));
apply_move_to(&mut b, &mut s, &(pos("d6"), pos("e6"), None));
assert!(!is_attacked(&b, &s, &pos("d4")));
}
}

8
src/uci.rs
View file

@ -5,9 +5,9 @@ use std::io::{self, Write};
use std::sync::mpsc;
use std::thread;
use crate::board;
use crate::engine;
use crate::notation;
use crate::rules;
const VATU_NAME: &str = env!("CARGO_PKG_NAME");
const VATU_AUTHORS: &str = env!("CARGO_PKG_AUTHORS");
@ -57,13 +57,13 @@ pub enum UciCmd {
pub enum PositionArgs {
Startpos,
Fen(notation::Fen),
Moves(Vec<board::Move>),
Moves(Vec<rules::Move>),
}
/// Arguments for the go remote commands.
#[derive(Debug, Clone)]
pub enum GoArgs {
SearchMoves(Vec<board::Move>),
SearchMoves(Vec<rules::Move>),
Ponder,
WTime(i32),
BTime(i32),
@ -249,7 +249,7 @@ impl Uci {
}
/// Send best move.
fn send_bestmove(&mut self, m: &Option<board::Move>) {
fn send_bestmove(&mut self, m: &Option<rules::Move>) {
let move_str = match m {
Some(m) => notation::move_to_string(m),
None => notation::NULL_MOVE.to_string(),