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rules: use new structures

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This commit is contained in:
dece 2020-06-19 19:29:10 +02:00
parent 91e1fbbe21
commit 4cea0e34e9
4 changed files with 371 additions and 304 deletions
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15
src/board.rs
View file

@ -103,6 +103,18 @@ pub const H6: Square = 61;
pub const H7: Square = 62;
pub const H8: Square = 63;
/// Get square from file and rank, both starting from 0.
#[inline]
pub const fn sq(file: i8, rank: i8) -> Square { file * 8 + rank }
/// Get file from square.
#[inline]
pub const fn sq_file(square: Square) -> i8 { square / 8 }
/// Get rank from square.
#[inline]
pub const fn sq_rank(square: Square) -> i8 { square % 8 }
/// Get bit mask of `p` in a bitboard.
#[inline]
pub const fn bit_pos(square: Square) -> u64 { 1 << square }
@ -299,7 +311,6 @@ impl Board {
#[cfg(test)]
mod tests {
use super::*;
use crate::notation;
#[test]
fn test_opposite() {
@ -327,7 +338,7 @@ mod tests {
#[test]
fn test_new_from_fen() {
let b1 = Board::new();
let b2 = Board::new_from_fen(notation::FEN_START);
let b2 = Board::new_from_fen(crate::fen::FEN_START);
assert!(b1 == b2);
}

4
src/node.rs
View file

@ -1,7 +1,7 @@
use std::fmt;
use crate::board;
use crate::movement::{self, Move};
use crate::movement::Move;
use crate::rules;
use crate::stats;
@ -25,7 +25,7 @@ impl Node {
/// Apply a move to this node.
pub fn apply_move(&mut self, m: &Move) {
movement::apply_move_to(&mut self.board, &mut self.game_state, m);
m.apply_to(&mut self.board, &mut self.game_state);
}
/// Return player moves from this node.

465
src/rules.rs
View file

@ -2,8 +2,11 @@
use crate::board::*;
use crate::castling::*;
use crate::movement::{self, Move};
use crate::notation;
use crate::fen;
use crate::movement::Move;
const POS_MIN: i8 = 0;
const POS_MAX: i8 = 7;
/// Characteristics of the state of a game.
///
@ -46,7 +49,7 @@ impl std::fmt::Display for GameState {
- halfmove: {}\n\
- fullmove: {}",
color_to_string(self.color), self.castling,
notation::en_passant_to_string(self.en_passant),
fen::en_passant_to_string(self.en_passant),
self.halfmove, self.fullmove
)
}
@ -67,49 +70,57 @@ pub fn get_player_moves(
let mut moves = Vec::with_capacity(256);
for r in 0..8 {
for f in 0..8 {
let p = (f, r);
if is_empty(board, &p) {
let square = sq(f, r);
if board.is_empty(square) {
continue
}
if is_color(get_square(board, &p), game_state.color) {
moves.append(&mut get_piece_moves(board, &p, game_state, commit));
if board.get_color(square) == game_state.color {
moves.append(
&mut get_piece_moves(board, game_state, square, game_state.color, commit)
);
}
}
}
moves
}
/// Get a list of moves for the piece at position `at`.
/// Get a list of moves for the piece of `color` on `square`.
///
/// Use `board` and `game_state` to get the moves. `color` is the color
/// of the piece on `square`; it could technically be found from the
/// board but that would require an additional lookup and this function
/// is always called in a context where the piece color is known.
pub fn get_piece_moves(
board: &Board,
at: &Pos,
game_state: &GameState,
square: Square,
color: Color,
commit: bool,
) -> Vec<Move> {
match get_square(board, at) {
p if is_piece(p, SQ_P) => get_pawn_moves(board, at, p, game_state, commit),
p if is_piece(p, SQ_B) => get_bishop_moves(board, at, p, game_state, commit),
p if is_piece(p, SQ_N) => get_knight_moves(board, at, p, game_state, commit),
p if is_piece(p, SQ_R) => get_rook_moves(board, at, p, game_state, commit),
p if is_piece(p, SQ_Q) => get_queen_moves(board, at, p, game_state, commit),
p if is_piece(p, SQ_K) => get_king_moves(board, at, p, game_state, commit),
match board.get_piece(square) {
PAWN => get_pawn_moves(board, game_state, square, color, commit),
BISHOP => get_bishop_moves(board, game_state, square, color, commit),
KNIGHT => get_knight_moves(board, game_state, square, color, commit),
ROOK => get_rook_moves(board, game_state, square, color, commit),
QUEEN => get_queen_moves(board, game_state, square, color, commit),
KING => get_king_moves(board, game_state, square, color, commit),
_ => vec!(),
}
}
fn get_pawn_moves(
board: &Board,
at: &Pos,
piece: u8,
game_state: &GameState,
square: Square,
color: Color,
commit: bool,
) -> Vec<Move> {
let (f, r) = *at;
let (f, r) = (sq_file(square), sq_rank(square));
let mut moves = vec!();
// Direction: positive for white, negative for black.
let dir: i8 = if is_white(piece) { 1 } else { -1 };
let dir = if color == WHITE { 1 } else { -1 };
// Check 1 or 2 square forward.
let move_len = if (is_white(piece) && r == 1) || (is_black(piece) && r == 6) { 2 } else { 1 };
let move_len = if (color == WHITE && r == 1) || (color == BLACK && r == 6) { 2 } else { 1 };
for i in 1..=move_len {
let forward_r = r + dir * i;
if dir > 0 && forward_r > POS_MAX {
@ -118,16 +129,14 @@ fn get_pawn_moves(
if dir < 0 && forward_r < POS_MIN {
return moves
}
let forward: Pos = (f, forward_r);
let forward: Square = sq(f, forward_r);
// If forward square is empty (and we are not jumping over an occupied square), add it.
if is_empty(board, &forward) && (i == 1 || is_empty(board, &(f, forward_r - dir))) {
if board.is_empty(forward) && (i == 1 || board.is_empty(sq(f, forward_r - dir))) {
let mut m = Move::new(square, forward);
// Pawns that get to the opposite rank automatically promote as queens.
let prom = if (dir > 0 && forward_r == POS_MAX) || (dir < 0 && forward_r == POS_MIN) {
Some(SQ_Q)
} else {
None
};
let m = (*at, forward, prom);
if (dir > 0 && forward_r == POS_MAX) || (dir < 0 && forward_r == POS_MIN) {
m.promotion = Some(QUEEN)
}
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
@ -136,19 +145,26 @@ fn get_pawn_moves(
if i == 1 {
// First diagonal.
if f - 1 >= POS_MIN {
let diag: Pos = (f - 1, forward_r);
if let Some(m) = move_on_enemy(piece, at, get_square(board, &diag), &diag) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
let diag = sq(f - 1, forward_r);
if !board.is_empty(diag) {
let diag_color = board.get_color(diag);
if let Some(m) = move_if_enemy(color, square, diag_color, diag, true) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
}
}
}
// Second diagonal.
if f + 1 <= POS_MAX {
let diag: Pos = (f + 1, forward_r);
if let Some(m) = move_on_enemy(piece, at, get_square(board, &diag), &diag) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
let diag = sq(f + 1, forward_r);
if !board.is_empty(diag) {
let diag_color = board.get_color(diag);
if let Some(m) = move_if_enemy(color, square, diag_color, diag, true) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
}
}
}
@ -160,12 +176,12 @@ fn get_pawn_moves(
fn get_bishop_moves(
board: &Board,
at: &Pos,
piece: u8,
game_state: &GameState,
square: Square,
color: Color,
commit: bool,
) -> Vec<Move> {
let (f, r) = at;
let (f, r) = (sq_file(square), sq_rank(square));
let mut views = [true; 4]; // Store diagonals where a piece blocks commit.
let mut moves = Vec::with_capacity(8);
for dist in 1..=7 {
@ -173,24 +189,33 @@ fn get_bishop_moves(
if !views[dir] {
continue
}
let p = (f + offset.0 * dist, r + offset.1 * dist);
// If this position is out of the board, stop looking in that direction.
if !is_valid_pos(p) {
let ray_f = f + offset.0 * dist;
if ray_f <= POS_MIN || ray_f >= POS_MAX {
views[dir] = false;
continue
}
if is_empty(board, &p) {
let m = (*at, p, None);
let ray_r = r + offset.1 * dist;
if ray_r <= POS_MIN || ray_r >= POS_MAX {
views[dir] = false;
continue
}
let ray_square = sq(ray_f, ray_r);
if board.is_empty(ray_square) {
let m = Move::new(square, ray_square);
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
} else {
if let Some(m) = move_on_enemy(piece, at, get_square(board, &p), &p) {
let ray_color = board.get_color(ray_square);
if let Some(m) = move_if_enemy(color, square, ray_color, ray_square, false) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
}
views[dir] = false; // Stop looking in that direction.
views[dir] = false;
}
}
}
@ -199,26 +224,35 @@ fn get_bishop_moves(
fn get_knight_moves(
board: &Board,
at: &Pos,
piece: u8,
game_state: &GameState,
square: Square,
color: Color,
commit: bool,
) -> Vec<Move> {
let (f, r) = at;
let (f, r) = (sq_file(square), sq_rank(square));
let mut moves = Vec::with_capacity(8);
for offset in [(1, 2), (2, 1), (2, -1), (1, -2), (-1, -2), (-2, -1), (-2, 1), (-1, 2)].iter() {
let p = (f + offset.0, r + offset.1);
if !is_valid_pos(p) {
let ray_f = f + offset.0;
if ray_f <= POS_MIN || ray_f >= POS_MAX {
continue
}
if is_empty(board, &p) {
let m = (*at, p, None);
let ray_r = r + offset.1;
if ray_r <= POS_MIN || ray_r >= POS_MAX {
continue
}
let ray_square = sq(ray_f, ray_r);
if board.is_empty(ray_square) {
let m = Move::new(square, ray_square);
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
} else if let Some(m) = move_on_enemy(piece, at, get_square(board, &p), &p) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
} else {
let ray_color = board.get_color(ray_square);
if let Some(m) = move_if_enemy(color, square, ray_color, ray_square, false) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
}
}
}
@ -227,12 +261,12 @@ fn get_knight_moves(
fn get_rook_moves(
board: &Board,
at: &Pos,
piece: u8,
game_state: &GameState,
square: Square,
color: Color,
commit: bool,
) -> Vec<Move> {
let (f, r) = at;
let (f, r) = (sq_file(square), sq_rank(square));
let mut moves = Vec::with_capacity(8);
let mut views = [true; 4]; // Store lines where a piece blocks commit.
for dist in 1..=7 {
@ -240,19 +274,27 @@ fn get_rook_moves(
if !views[dir] {
continue
}
let p = (f + offset.0 * dist, r + offset.1 * dist);
// If this position is out of the board, stop looking in that direction.
if !is_valid_pos(p) {
let ray_f = f + offset.0 * dist;
if ray_f <= POS_MIN || ray_f >= POS_MAX {
views[dir] = false;
continue
}
if is_empty(board, &p) {
let m = (*at, p, None);
let ray_r = r + offset.1 * dist;
if ray_r <= POS_MIN || ray_r >= POS_MAX {
views[dir] = false;
continue
}
let ray_square = sq(ray_f, ray_r);
if board.is_empty(ray_square) {
let m = Move::new(square, ray_square);
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
} else {
if let Some(m) = move_on_enemy(piece, at, get_square(board, &p), &p) {
let ray_color = board.get_color(ray_square);
if let Some(m) = move_if_enemy(color, square, ray_color, ray_square, false) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
@ -266,40 +308,49 @@ fn get_rook_moves(
fn get_queen_moves(
board: &Board,
at: &Pos,
piece: u8,
game_state: &GameState,
commit: bool
square: Square,
color: Color,
commit: bool,
) -> Vec<Move> {
let mut moves = vec!();
let mut moves = Vec::with_capacity(16);
// Easy way to get queen moves, but may be a bit quicker if everything was rewritten here.
moves.append(&mut get_bishop_moves(board, at, piece, game_state, commit));
moves.append(&mut get_rook_moves(board, at, piece, game_state, commit));
moves.append(&mut get_bishop_moves(board, game_state, square, color, commit));
moves.append(&mut get_rook_moves(board, game_state, square, color, commit));
moves
}
fn get_king_moves(
board: &Board,
at: &Pos,
piece: u8,
game_state: &GameState,
commit: bool
square: Square,
color: Color,
commit: bool,
) -> Vec<Move> {
let (f, r) = at;
let mut moves = vec!();
let (f, r) = (sq_file(square), sq_rank(square));
let mut moves = Vec::with_capacity(8);
for offset in [(-1, 1), (0, 1), (1, 1), (-1, 0), (1, 0), (-1, -1), (0, -1), (1, -1)].iter() {
let p = (f + offset.0, r + offset.1);
if !is_valid_pos(p) {
let ray_f = f + offset.0;
if ray_f <= POS_MIN || ray_f >= POS_MAX {
continue
}
if is_empty(board, &p) {
let m = (*at, p, None);
let ray_r = r + offset.1;
if ray_r <= POS_MIN || ray_r >= POS_MAX {
continue
}
let ray_square = sq(ray_f, ray_r);
if board.is_empty(ray_square) {
let m = Move::new(square, ray_square);
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
} else if let Some(m) = move_on_enemy(piece, at, get_square(board, &p), &p) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
} else {
let ray_color = board.get_color(ray_square);
if let Some(m) = move_if_enemy(color, square, ray_color, ray_square, false) {
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
}
}
}
@ -318,7 +369,7 @@ fn get_king_moves(
// 6. The king does not end up in check.
// First get the required castling rank and color mask for the player.
let (castling_rank, castling_color_mask) = if is_white(game_state.color) {
let (castling_rank, castling_color_mask) = if game_state.color == WHITE {
(0, CASTLING_WH_MASK)
} else {
(7, CASTLING_BL_MASK)
@ -327,8 +378,8 @@ fn get_king_moves(
// Check for castling if the king is on its castling rank (R1)
// and is not in check (R4).
if
*r == castling_rank &&
!is_attacked(board, game_state, at)
r == castling_rank &&
!is_attacked(board, game_state, square)
{
// Check for both castling sides.
for (path_files, opt_empty_file, castling_side_mask) in CASTLING_SIDES.iter() {
@ -337,8 +388,10 @@ fn get_king_moves(
// Check that squares in the king's path are empty and not attacked (R3.1, R5, R6).
let mut path_is_clear = true;
for path_f in path_files {
let p = (*path_f, castling_rank);
if !is_empty(board, &p) || is_illegal(board, game_state, &(*at, p, None)) {
let path_square = sq(*path_f, castling_rank);
if
!board.is_empty(path_square)
|| is_illegal(board, game_state, &Move::new(square, path_square)) {
path_is_clear = false;
break;
}
@ -348,13 +401,13 @@ fn get_king_moves(
}
// Check that rook jumps over an empty square on queen-side (R3.2).
if let Some(rook_path_f) = opt_empty_file {
let p = (*rook_path_f, castling_rank);
if !is_empty(board, &p) {
let rook_path_square = sq(*rook_path_f, castling_rank);
if !board.is_empty(rook_path_square) {
continue;
}
}
let castle = castling_side_mask & castling_color_mask;
let m = movement::get_castle_move(castle);
let m = Move::get_castle_move(castle);
if can_register(commit, board, game_state, &m) {
moves.push(m);
}
@ -375,20 +428,25 @@ fn can_register(commit: bool, board: &Board, game_state: &GameState, m: &Move) -
!commit || !is_illegal(board, game_state, m)
}
/// Return a move from pos1 to pos2 if piece1 & piece2 are enemies.
fn move_on_enemy(piece1: u8, pos1: &Pos, piece2: u8, pos2: &Pos) -> Option<Move> {
let color1 = get_color(piece1);
if is_color(piece2, opposite(color1)) {
/// Return a move from `square1` to `square2` if colors are opposite.
fn move_if_enemy(
color1: Color,
square1: Square,
color2: Color,
square2: Square,
is_pawn: bool,
) -> Option<Move> {
if color2 == opposite(color1) {
// Automatic queen promotion for pawns moving to the opposite rank.
let prom = if
is_piece(piece1, SQ_P) &&
((is_white(piece1) && pos2.1 == POS_MAX) || (is_black(piece1) && pos2.1 == POS_MIN))
Some(if
is_pawn
&& (color1 == WHITE && sq_rank(square2) == POS_MAX)
|| (color1 == BLACK && sq_rank(square2) == POS_MIN)
{
Some(SQ_Q)
Move::new_promotion(square1, square2, QUEEN)
} else {
None
};
Some((*pos1, *pos2, prom))
Move::new(square1, square2)
})
} else {
None
}
@ -396,36 +454,38 @@ fn move_on_enemy(piece1: u8, pos1: &Pos, piece2: u8, pos2: &Pos) -> Option<Move>
/// Check if a move is illegal.
fn is_illegal(board: &Board, game_state: &GameState, m: &Move) -> bool {
if let Some(king_p) = find_king(board, game_state.color) {
if let Some(mut king_square) = board.find_king(game_state.color) {
// Rule 1: a move is illegal if the king ends up in check.
// If king moves, use its new position.
let king_p = if m.0 == king_p { m.1 } else { king_p };
if m.source == king_square {
king_square = m.dest
}
let mut hypothetic_board = board.clone();
movement::apply_move_to_board(&mut hypothetic_board, m);
m.apply_to_board(&mut hypothetic_board);
// Check if the move makes the player king in check.
if is_attacked(&hypothetic_board, &game_state, &king_p) {
if is_attacked(&hypothetic_board, &game_state, king_square) {
return true
}
}
false
}
/// Return true if the piece at position `at` is attacked.
/// Return true if the piece on `square` is attacked.
///
/// Check all possible enemy moves and return true when one of them
/// ends up attacking the position.
///
/// 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 white turn. If the square at `at` is empty, simply
/// square, i.e. if the piece on `square` is white, the game state
/// should tell that it is white turn. If `square` is empty, simply
/// check if it is getting attacked by the opposite player.
fn is_attacked(board: &Board, game_state: &GameState, at: &Pos) -> bool {
fn is_attacked(board: &Board, game_state: &GameState, square: Square) -> bool {
let mut enemy_game_state = game_state.clone();
enemy_game_state.color = opposite(game_state.color);
// Do not attempt to commit moves, just check for attacked squares.
let enemy_moves = get_player_moves(board, &enemy_game_state, false);
for m in enemy_moves.iter() {
if *at == m.1 {
if square == m.dest {
return true
}
}
@ -435,11 +495,10 @@ fn is_attacked(board: &Board, game_state: &GameState, at: &Pos) -> bool {
#[cfg(test)]
mod tests {
use super::*;
use crate::notation::parse_move;
#[test]
fn test_get_player_moves() {
let b = new();
let b = Board::new();
let gs = GameState::new();
// At first move, white has 16 pawn moves and 4 knight moves.
@ -449,132 +508,132 @@ mod tests {
#[test]
fn test_get_pawn_moves() {
let mut b = new_empty();
let mut b = Board::new_empty();
let gs = 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"), &gs, true);
assert!(moves.len() == 1 && moves.contains( &parse_move("d3d4") ));
b.set_square(D3, WHITE, PAWN);
let moves = get_piece_moves(&b, &gs, D3, WHITE, true);
assert!(moves.len() == 1 && moves.contains(&Move::new(D3, D4)));
// 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"), &gs, true);
b.set_square(E2, WHITE, PAWN);
let moves = get_piece_moves(&b, &gs, E2, WHITE, true);
assert_eq!(moves.len(), 2);
assert!(moves.contains( &parse_move("e2e3") ));
assert!(moves.contains( &parse_move("e2e4") ));
assert!(moves.contains(&Move::new(E2, E3)));
assert!(moves.contains(&Move::new(E2, E4)));
// 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"), &gs, true);
assert!(moves.len() == 1 && moves.contains( &parse_move("e2e3") ));
b.set_square(E4, BLACK, PAWN);
let moves = get_piece_moves(&b, &gs, E2, WHITE, true);
assert!(moves.len() == 1 && moves.contains(&Move::new(E2, E3)));
// 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"), &gs, true);
b.set_square(E3, BLACK, PAWN);
let moves = get_piece_moves(&b, &gs, E2, WHITE, true);
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"), &gs, true);
b.clear_square(E4);
let moves = get_piece_moves(&b, &gs, E2, WHITE, true);
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"), &gs, true);
assert!(moves.len() == 1 && moves.contains( &parse_move("e2f3") ));
set_square(&mut b, &pos("d3"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"), &gs, true);
b.set_square(F3, BLACK, PAWN);
let moves = get_piece_moves(&b, &gs, E2, WHITE, true);
assert!(moves.len() == 1 && moves.contains(&Move::new(E2, F3)));
b.set_square(D3, BLACK, PAWN);
let moves = get_piece_moves(&b, &gs, E2, WHITE, true);
assert_eq!(moves.len(), 2);
assert!(moves.contains( &parse_move("e2f3") ));
assert!(moves.contains( &parse_move("e2d3") ));
assert!(moves.contains( &Move::new(E2, F3) ));
assert!(moves.contains( &Move::new(E2, D3) ));
// 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"), &gs, true);
assert!(moves.len() == 1 && moves.contains( &parse_move("a7a8q") ));
b.set_square(A7, WHITE, PAWN);
let moves = get_piece_moves(&b, &gs, A7, WHITE, true);
assert!(moves.len() == 1 && moves.contains(&Move::new_promotion(A7, A8, QUEEN)));
}
#[test]
fn test_get_bishop_moves() {
let mut b = new_empty();
let mut b = Board::new_empty();
let gs = 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"), &gs, true);
b.set_square(D4, WHITE, BISHOP);
let moves = get_piece_moves(&b, &gs, D4, WHITE, true);
assert_eq!(moves.len(), 13);
// Going top-right.
assert!(moves.contains( &parse_move("d4e5") ));
assert!(moves.contains( &parse_move("d4f6") ));
assert!(moves.contains( &parse_move("d4g7") ));
assert!(moves.contains( &parse_move("d4h8") ));
assert!(moves.contains(&Move::new(D4, E5)));
assert!(moves.contains(&Move::new(D4, F6)));
assert!(moves.contains(&Move::new(D4, G7)));
assert!(moves.contains(&Move::new(D4, H8)));
// Going bottom-right.
assert!(moves.contains( &parse_move("d4e3") ));
assert!(moves.contains( &parse_move("d4f2") ));
assert!(moves.contains( &parse_move("d4g1") ));
assert!(moves.contains(&Move::new(D4, E3)));
assert!(moves.contains(&Move::new(D4, F2)));
assert!(moves.contains(&Move::new(D4, G1)));
// Going bottom-left.
assert!(moves.contains( &parse_move("d4c3") ));
assert!(moves.contains( &parse_move("d4b2") ));
assert!(moves.contains( &parse_move("d4a1") ));
assert!(moves.contains(&Move::new(D4, C3)));
assert!(moves.contains(&Move::new(D4, B2)));
assert!(moves.contains(&Move::new(D4, A1)));
// Going top-left.
assert!(moves.contains( &parse_move("d4c5") ));
assert!(moves.contains( &parse_move("d4b6") ));
assert!(moves.contains( &parse_move("d4a7") ));
assert!(moves.contains(&Move::new(D4, C5)));
assert!(moves.contains(&Move::new(D4, B6)));
assert!(moves.contains(&Move::new(D4, A7)));
// When blocking commit 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"), &gs, true).len(), 11);
b.set_square(B2, WHITE, PAWN);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).len(), 11);
// When blocking commit 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"), &gs, true).len(), 12);
b.set_square(B2, BLACK, PAWN);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).len(), 12);
}
#[test]
fn test_get_knight_moves() {
let mut b = new_empty();
let mut b = Board::new_empty();
let gs = GameState::new();
// A knight never has blocked commit; 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"), &gs, true).len(), 8);
b.set_square(D4, WHITE, KNIGHT);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).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"), &gs, true).len(), 4);
b.set_square(A4, WHITE, KNIGHT);
assert_eq!(get_piece_moves(&b, &gs, A4, WHITE, true).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"), &gs, true).len(), 2);
b.set_square(A1, WHITE, KNIGHT);
assert_eq!(get_piece_moves(&b, &gs, A1, WHITE, true).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"), &gs, true).len(), 0);
b.set_square(B3, WHITE, PAWN);
b.set_square(C2, WHITE, PAWN);
assert_eq!(get_piece_moves(&b, &gs, A1, WHITE, true).len(), 0);
}
#[test]
fn test_get_rook_moves() {
let mut b = new_empty();
let mut b = Board::new_empty();
let gs = GameState::new();
set_square(&mut b, &pos("d4"), SQ_WH_R);
assert_eq!(get_piece_moves(&b, &pos("d4"), &gs, true).len(), 14);
set_square(&mut b, &pos("d6"), SQ_BL_P);
assert_eq!(get_piece_moves(&b, &pos("d4"), &gs, true).len(), 12);
set_square(&mut b, &pos("d6"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("d4"), &gs, true).len(), 11);
b.set_square(D4, WHITE, ROOK);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).len(), 14);
b.set_square(D6, BLACK, PAWN);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).len(), 12);
b.set_square(D6, WHITE, PAWN);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).len(), 11);
}
#[test]
fn test_get_queen_moves() {
let mut b = new_empty();
let mut b = Board::new_empty();
let gs = GameState::new();
set_square(&mut b, &pos("d4"), SQ_WH_Q);
assert_eq!(get_piece_moves(&b, &pos("d4"), &gs, true).len(), 14 + 13);
b.set_square(D4, WHITE, QUEEN);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).len(), 14 + 13);
}
#[test]
@ -582,54 +641,54 @@ mod tests {
let mut gs = GameState::new();
// King can move 1 square in any direction.
let mut b = new_empty();
set_square(&mut b, &pos("d4"), SQ_WH_K);
assert_eq!(get_piece_moves(&b, &pos("d4"), &gs, true).len(), 8);
set_square(&mut b, &pos("e5"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("d4"), &gs, true).len(), 7);
let mut b = Board::new_empty();
b.set_square(D4, WHITE, KING);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).len(), 8);
b.set_square(E5, WHITE, PAWN);
assert_eq!(get_piece_moves(&b, &gs, D4, WHITE, true).len(), 7);
// If castling is available, other moves are possible: 5 moves + 2 castles.
let mut b = new_empty();
set_square(&mut b, &pos("e1"), SQ_WH_K);
set_square(&mut b, &pos("a1"), SQ_WH_R);
set_square(&mut b, &pos("h1"), SQ_WH_R);
assert_eq!(get_piece_moves(&b, &pos("e1"), &gs, true).len(), 5 + 2);
let mut b = Board::new_empty();
b.set_square(E1, WHITE, KING);
b.set_square(A1, WHITE, ROOK);
b.set_square(H1, WHITE, ROOK);
assert_eq!(get_piece_moves(&b, &gs, E1, WHITE, true).len(), 5 + 2);
// Castling works as well for black.
gs.color = SQ_BL;
set_square(&mut b, &pos("e8"), SQ_BL_K);
set_square(&mut b, &pos("a8"), SQ_BL_R);
set_square(&mut b, &pos("h8"), SQ_BL_R);
assert_eq!(get_piece_moves(&b, &pos("e8"), &gs, true).len(), 5 + 2);
gs.color = BLACK;
b.set_square(E8, BLACK, KING);
b.set_square(A8, BLACK, ROOK);
b.set_square(H8, BLACK, ROOK);
assert_eq!(get_piece_moves(&b, &gs, E8, BLACK, true).len(), 5 + 2);
}
#[test]
fn test_filter_illegal_moves() {
let mut b = new_empty();
let mut b = Board::new_empty();
let mut gs = GameState::new();
// Place white's king on first rank.
set_square(&mut b, &pos("e1"), SQ_WH_K);
b.set_square(E1, WHITE, KING);
// Place black rook in second rank: king can only move left or right.
set_square(&mut b, &pos("h2"), SQ_BL_R);
b.set_square(H2, BLACK, ROOK);
// No castling available.
gs.castling = 0;
// 5 moves in absolute but only 2 are legal.
let all_wh_moves = get_piece_moves(&b, &pos("e1"), &gs, true);
let all_wh_moves = get_piece_moves(&b, &gs, E1, WHITE, true);
assert_eq!(all_wh_moves.len(), 2);
}
#[test]
fn test_is_attacked() {
let mut b = new_empty();
let mut b = Board::new_empty();
let gs = GameState::new();
// 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, &gs, &pos("d4")));
b.set_square(D4, WHITE, PAWN);
b.set_square(D6, BLACK, ROOK);
assert!(is_attacked(&b, &gs, D4));
// Move the rook on another file, no more attack.
movement::apply_move_to_board(&mut b, &parse_move("d6e6"));
assert!(!is_attacked(&b, &gs, &pos("d4")));
Move::new(D6, E6).apply_to_board(&mut b);
assert!(!is_attacked(&b, &gs, D4));
}
}

191
src/stats.rs
View file

@ -1,7 +1,7 @@
//! Board statistics used for heuristics.
use crate::board::*;
use crate::rules;
use crate::rules::GameState;
/// Storage for board pieces stats.
#[derive(Debug, Clone, PartialEq)]
@ -39,6 +39,98 @@ impl BoardStats {
self.num_isolated_pawns = 0;
self.mobility = 0;
}
/// Fill `stats` from given `board` and `game_state`.
///
/// Only the current playing side stats are created,
/// prepare the game_state accordingly.
pub fn compute(&mut self, board: &Board, game_state: &GameState) {
self.reset();
let color = game_state.color;
// Compute mobility for all pieces.
self.mobility = rules::get_player_moves(board, game_state, true).len() as i32;
// Compute amount of each piece.
for (piece, p) in get_piece_iterator(board) {
let (pos_f, pos_r) = p;
if piece == SQ_E || !is_color(piece, color) {
continue
}
match get_type(piece) {
SQ_R => stats.num_rooks += 1,
SQ_N => stats.num_knights += 1,
SQ_B => stats.num_bishops += 1,
SQ_Q => stats.num_queens += 1,
SQ_K => stats.num_kings += 1,
SQ_P => {
stats.num_pawns += 1;
let mut doubled = false;
let mut isolated = true;
let mut backward = true;
for r in 0..8 {
// Check for doubled pawns.
if
!doubled &&
is_piece(get_square(board, &(pos_f, r)), color|SQ_P) && r != pos_r
{
doubled = true;
}
// Check for isolated pawns.
if
isolated &&
(
// Check on the left file if not on a-file...
(
pos_f > POS_MIN &&
is_piece(get_square(board, &(pos_f - 1, r)), color|SQ_P)
) ||
// Check on the right file if not on h-file...
(
pos_f < POS_MAX &&
is_piece(get_square(board, &(pos_f + 1, r)), color|SQ_P)
)
)
{
isolated = false;
}
// Check for backward pawns.
if backward {
if color == SQ_WH && r <= pos_r {
if (
pos_f > POS_MIN &&
is_type(get_square(board, &(pos_f - 1, r)), SQ_P)
) || (
pos_f < POS_MAX &&
is_type(get_square(board, &(pos_f + 1, r)), SQ_P)
) {
backward = false;
}
} else if color == SQ_BL && r >= pos_r {
if (
pos_f > POS_MIN &&
is_type(get_square(board, &(pos_f - 1, r)), SQ_P)
) || (
pos_f < POS_MAX &&
is_type(get_square(board, &(pos_f + 1, r)), SQ_P)
) {
backward = false;
}
}
}
}
if doubled {
stats.num_doubled_pawns += 1;
}
if isolated {
stats.num_isolated_pawns += 1;
}
if backward {
stats.num_backward_pawns += 1;
}
},
_ => {}
}
}
}
}
impl std::fmt::Display for BoardStats {
@ -57,7 +149,7 @@ impl std::fmt::Display for BoardStats {
/// Create two new BoardStats objects from the board, for both sides.
///
/// See `compute_stats_into` for details.
pub fn compute_stats(board: &Board, game_state: &rules::GameState) -> (BoardStats, BoardStats) {
pub fn compute_stats(board: &Board, game_state: &GameState) -> (BoardStats, BoardStats) {
let mut stats = (BoardStats::new(), BoardStats::new());
compute_stats_into(board, game_state, &mut stats);
stats
@ -78,101 +170,6 @@ pub fn compute_stats_into(
compute_color_stats_into(board, &gs, &mut stats.1);
}
/// Fill `stats` from given `board` and `game_state`.
///
/// Only the current playing side stats are created,
/// prepare the game_state accordingly.
pub fn compute_color_stats_into(
board: &Board,
game_state: &rules::GameState,
stats: &mut BoardStats,
) {
stats.reset();
let color = game_state.color;
// Compute mobility for all pieces.
stats.mobility = rules::get_player_moves(board, game_state, true).len() as i32;
// Compute amount of each piece.
for (piece, p) in get_piece_iterator(board) {
let (pos_f, pos_r) = p;
if piece == SQ_E || !is_color(piece, color) {
continue
}
match get_type(piece) {
SQ_R => stats.num_rooks += 1,
SQ_N => stats.num_knights += 1,
SQ_B => stats.num_bishops += 1,
SQ_Q => stats.num_queens += 1,
SQ_K => stats.num_kings += 1,
SQ_P => {
stats.num_pawns += 1;
let mut doubled = false;
let mut isolated = true;
let mut backward = true;
for r in 0..8 {
// Check for doubled pawns.
if
!doubled &&
is_piece(get_square(board, &(pos_f, r)), color|SQ_P) && r != pos_r
{
doubled = true;
}
// Check for isolated pawns.
if
isolated &&
(
// Check on the left file if not on a-file...
(
pos_f > POS_MIN &&
is_piece(get_square(board, &(pos_f - 1, r)), color|SQ_P)
) ||
// Check on the right file if not on h-file...
(
pos_f < POS_MAX &&
is_piece(get_square(board, &(pos_f + 1, r)), color|SQ_P)
)
)
{
isolated = false;
}
// Check for backward pawns.
if backward {
if color == SQ_WH && r <= pos_r {
if (
pos_f > POS_MIN &&
is_type(get_square(board, &(pos_f - 1, r)), SQ_P)
) || (
pos_f < POS_MAX &&
is_type(get_square(board, &(pos_f + 1, r)), SQ_P)
) {
backward = false;
}
} else if color == SQ_BL && r >= pos_r {
if (
pos_f > POS_MIN &&
is_type(get_square(board, &(pos_f - 1, r)), SQ_P)
) || (
pos_f < POS_MAX &&
is_type(get_square(board, &(pos_f + 1, r)), SQ_P)
) {
backward = false;
}
}
}
}
if doubled {
stats.num_doubled_pawns += 1;
}
if isolated {
stats.num_isolated_pawns += 1;
}
if backward {
stats.num_backward_pawns += 1;
}
},
_ => {}
}
}
}
#[cfg(test)]
mod tests {