dece/Vatu
Archived
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

rules: find basic illegal moves

Browse source
This commit is contained in:
dece 2020-05-31 19:00:56 +02:00
parent ce16748258
commit 2a4f46e5aa
3 changed files with 249 additions and 107 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

BIN
src/.rules.rs.swp
View file

Binary file not shown.

122
src/board.rs
View file

@ -10,8 +10,9 @@ pub const SQ_Q: u8 = 0b00010000;
pub const SQ_K: u8 = 0b00100000;
// Piece color flags.
pub const SQ_WH: u8 = 0b01000000;
pub const SQ_BL: u8 = 0b10000000;
pub const SQ_WH: u8 = 0b01000000;
pub const SQ_BL: u8 = 0b10000000;
pub const SQ_COLOR_MASK: u8 = 0b11000000;
// Piece flags helpers.
pub const SQ_WH_P: u8 = SQ_WH|SQ_P;
@ -40,6 +41,13 @@ pub fn is_white(square: u8) -> bool { is_color(square, SQ_WH) }
#[inline]
pub fn is_black(square: u8) -> bool { is_color(square, SQ_BL) }
/// Get piece color.
#[inline]
pub 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 POS_MIN: i8 = 0;
pub const POS_MAX: i8 = 7;
/// Coords (file, rank) of a square on a board, both components are in [0, 7].
@ -54,7 +62,7 @@ pub fn is_valid_pos(pos: Pos) -> bool { is_valid_pos_c(pos.0) && is_valid_pos_c(
/// Convert string coordinates to Pos.
///
/// `s` has to be valid UTF8, or the very least ASCII because chars
/// are interpreted as raw bytes.
/// are interpreted as raw bytes, and lowercase.
#[inline]
pub fn pos(s: &str) -> Pos {
let chars = s.as_bytes();
@ -86,31 +94,69 @@ pub fn new_empty() -> Board {
}
#[inline]
pub fn get_square(board: &Board, coords: Pos) -> u8 {
pub fn get_square(board: &Board, coords: &Pos) -> u8 {
board[(coords.0 * 8 + coords.1) as usize]
}
#[inline]
pub fn set_square(board: &mut Board, coords: Pos, piece: u8) {
pub fn set_square(board: &mut Board, coords: &Pos, piece: u8) {
board[(coords.0 * 8 + coords.1) as usize] = piece;
}
#[inline]
pub fn clear_square(board: &mut Board, coords: Pos) {
pub fn clear_square(board: &mut Board, coords: &Pos) {
set_square(board, coords, SQ_E);
}
#[inline]
pub fn is_empty(board: &Board, coords: Pos) -> bool { get_square(board, coords) == SQ_E }
pub fn is_empty(board: &Board, coords: &Pos) -> bool { get_square(board, coords) == SQ_E }
/// Count number of pieces on board
pub fn num_pieces(board: &Board) -> u8 {
let mut count = 0;
for i in board.iter() {
if *i != SQ_E {
count += 1;
}
}
count
}
/// Find the king of `color`.
pub fn find_king(board: &Board, color: u8) -> Pos {
for f in 0..8 {
for r in 0..8 {
let s = get_square(board, &(f, r));
if is_color(s, color) && is_piece(s, SQ_K) {
return (f, r)
}
}
}
eprintln!("No king on board!");
(0, 0)
}
/// A movement, with before/after positions.
pub type Move = (Pos, Pos);
/// 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)
}
pub fn draw(board: &Board) {
for r in (0..8).rev() {
let mut rank = String::with_capacity(8);
for f in 0..8 {
let s = get_square(board, (f, r));
let s = get_square(board, &(f, r));
let piece =
if is_piece(s, SQ_P) { 'p' }
else if is_piece(s, SQ_B) { 'b' }
@ -130,6 +176,12 @@ pub fn draw(board: &Board) {
mod tests {
use super::*;
#[test]
fn test_opposite() {
assert_eq!(opposite(SQ_WH), SQ_BL);
assert_eq!(opposite(SQ_BL), SQ_WH);
}
#[test]
fn test_pos() {
assert_eq!(pos("a1"), (0, 0));
@ -142,24 +194,54 @@ mod tests {
#[test]
fn test_get_square() {
let b = new();
assert_eq!(get_square(&b, pos("a1")), SQ_WH_R);
assert_eq!(get_square(&b, pos("a2")), SQ_WH_P);
assert_eq!(get_square(&b, pos("a3")), SQ_E);
assert_eq!(get_square(&b, &pos("a1")), SQ_WH_R);
assert_eq!(get_square(&b, &pos("a2")), SQ_WH_P);
assert_eq!(get_square(&b, &pos("a3")), SQ_E);
assert_eq!(get_square(&b, pos("a7")), SQ_BL_P);
assert_eq!(get_square(&b, pos("a8")), SQ_BL_R);
assert_eq!(get_square(&b, &pos("a7")), SQ_BL_P);
assert_eq!(get_square(&b, &pos("a8")), SQ_BL_R);
assert_eq!(get_square(&b, pos("d1")), SQ_WH_Q);
assert_eq!(get_square(&b, pos("d8")), SQ_BL_Q);
assert_eq!(get_square(&b, pos("e1")), SQ_WH_K);
assert_eq!(get_square(&b, pos("e8")), SQ_BL_K);
assert_eq!(get_square(&b, &pos("d1")), SQ_WH_Q);
assert_eq!(get_square(&b, &pos("d8")), SQ_BL_Q);
assert_eq!(get_square(&b, &pos("e1")), SQ_WH_K);
assert_eq!(get_square(&b, &pos("e8")), SQ_BL_K);
}
#[test]
fn test_is_empty() {
let b = new();
assert_eq!(is_empty(&b, pos("a1")), false);
assert_eq!(is_empty(&b, pos("a2")), false);
assert_eq!(is_empty(&b, pos("a3")), true);
assert_eq!(is_empty(&b, &pos("a1")), false);
assert_eq!(is_empty(&b, &pos("a2")), false);
assert_eq!(is_empty(&b, &pos("a3")), true);
}
#[test]
fn test_num_pieces() {
assert_eq!(num_pieces(&new_empty()), 0);
assert_eq!(num_pieces(&new()), 32);
}
#[test]
fn test_find_king() {
let b = new();
assert_eq!(find_king(&b, SQ_WH), pos("e1"));
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"))));
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"))));
assert_eq!(get_square(&b, &pos("e6")), SQ_BL_N);
assert_eq!(num_pieces(&b), 1);
}
}

234
src/rules.rs
View file

@ -2,34 +2,38 @@
use crate::board::*;
/// Get a list of legal moves for all pieces of either white or black.
pub fn get_legal_player_moves(board: &Board, color: u8) -> Vec<Move> {
/// Get a list of moves for all pieces of either white or black.
pub fn get_player_moves(board: &Board, color: u8) -> Vec<Move> {
let mut moves = vec!();
for r in 0..8 {
for f in 0..8 {
if is_color(get_square(board, (f, r)), color) {
moves.append(&mut get_legal_piece_moves(board, (f, r)));
let p = (f, r);
if is_empty(board, &p) {
continue
}
if is_color(get_square(board, &p), color) {
moves.append(&mut get_piece_moves(board, &p));
}
}
}
moves
}
/// Get a list of legal moves for the piece at position `at`.
pub fn get_legal_piece_moves(board: &Board, at: Pos) -> Vec<Move> {
/// Get a list of moves for the piece at position `at`.
pub fn get_piece_moves(board: &Board, at: &Pos) -> Vec<Move> {
match get_square(board, at) {
p if is_piece(p, SQ_P) => get_legal_pawn_moves(board, at, p),
p if is_piece(p, SQ_B) => get_legal_bishop_moves(board, at, p),
p if is_piece(p, SQ_N) => get_legal_knight_moves(board, at, p),
p if is_piece(p, SQ_R) => get_legal_rook_moves(board, at, p),
p if is_piece(p, SQ_Q) => get_legal_queen_moves(board, at, p),
p if is_piece(p, SQ_K) => get_legal_king_moves(board, at, p),
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),
_ => vec!(),
}
}
fn get_legal_pawn_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
let (f, r) = at;
fn get_pawn_moves(board: &Board, at: &Pos, piece: u8) -> Vec<Move> {
let (f, r) = *at;
let mut moves = vec!();
let movement: i8 = if is_white(piece) { 1 } else { -1 };
// Check 1 or 2 square forward.
@ -43,22 +47,22 @@ fn get_legal_pawn_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
return moves
}
let forward: Pos = (f, forward_r);
if is_empty(board, forward) {
moves.push((at, forward))
if is_empty(board, &forward) {
moves.push((*at, forward))
}
// Check diagonals for pieces to attack.
if i == 1 {
let df = f - 1;
if df >= POS_MIN {
let diag: Pos = (df, forward_r);
if let Some(m) = move_on_enemy(piece, at, get_square(board, diag), diag) {
if let Some(m) = move_on_enemy(piece, at, get_square(board, &diag), &diag) {
moves.push(m);
}
}
let df = f + 1;
if df <= POS_MAX {
let diag: Pos = (df, forward_r);
if let Some(m) = move_on_enemy(piece, at, get_square(board, diag), diag) {
if let Some(m) = move_on_enemy(piece, at, get_square(board, &diag), &diag) {
moves.push(m);
}
}
@ -68,7 +72,7 @@ fn get_legal_pawn_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
moves
}
fn get_legal_bishop_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
fn get_bishop_moves(board: &Board, at: &Pos, piece: u8) -> Vec<Move> {
let (f, r) = at;
let mut sight = [true; 4]; // Store diagonals where a piece blocks sight.
let mut moves = vec!();
@ -81,10 +85,10 @@ fn get_legal_bishop_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
if !is_valid_pos(p) {
continue
}
if is_empty(board, p) {
moves.push((at, p));
if is_empty(board, &p) {
moves.push((*at, p));
} else {
if let Some(m) = move_on_enemy(piece, at, get_square(board, p), p) {
if let Some(m) = move_on_enemy(piece, at, get_square(board, &p), &p) {
moves.push(m);
}
sight[dir] = false; // Stop looking in that direction.
@ -94,7 +98,7 @@ fn get_legal_bishop_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
moves
}
fn get_legal_knight_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
fn get_knight_moves(board: &Board, at: &Pos, piece: u8) -> Vec<Move> {
let (f, r) = at;
let mut moves = vec!();
for offset in [(1, 2), (2, 1), (2, -1), (1, -2), (-1, -2), (-2, -1), (-2, 1), (-1, 2)].iter() {
@ -102,16 +106,16 @@ fn get_legal_knight_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
if !is_valid_pos(p) {
continue
}
if is_empty(board, p) {
moves.push((at, p));
} else if let Some(m) = move_on_enemy(piece, at, get_square(board, p), p) {
if is_empty(board, &p) {
moves.push((*at, p));
} else if let Some(m) = move_on_enemy(piece, at, get_square(board, &p), &p) {
moves.push(m);
}
}
moves
}
fn get_legal_rook_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
fn get_rook_moves(board: &Board, at: &Pos, piece: u8) -> Vec<Move> {
let (f, r) = at;
let mut moves = vec!();
let mut sight = [true; 4]; // Store lines where a piece blocks sight.
@ -124,10 +128,10 @@ fn get_legal_rook_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
if !is_valid_pos(p) {
continue
}
if is_empty(board, p) {
moves.push((at, p));
if is_empty(board, &p) {
moves.push((*at, p));
} else {
if let Some(m) = move_on_enemy(piece, at, get_square(board, p), p) {
if let Some(m) = move_on_enemy(piece, at, get_square(board, &p), &p) {
moves.push(m);
}
sight[dir] = false; // Stop looking in that direction.
@ -137,15 +141,15 @@ fn get_legal_rook_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
moves
}
fn get_legal_queen_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
fn get_queen_moves(board: &Board, at: &Pos, piece: u8) -> Vec<Move> {
let mut moves = vec!();
// Easy way to get queen moves, but may be a bit quicker if everything was rewritten here.
moves.append(&mut get_legal_bishop_moves(board, at, piece));
moves.append(&mut get_legal_rook_moves(board, at, piece));
moves.append(&mut get_bishop_moves(board, at, piece));
moves.append(&mut get_rook_moves(board, at, piece));
moves
}
fn get_legal_king_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
fn get_king_moves(board: &Board, at: &Pos, piece: u8) -> 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() {
@ -153,9 +157,9 @@ fn get_legal_king_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
if !is_valid_pos(p) {
continue
}
if is_empty(board, p) {
moves.push((at, p));
} else if let Some(m) = move_on_enemy(piece, at, get_square(board, p), p) {
if is_empty(board, &p) {
moves.push((*at, p));
} else if let Some(m) = move_on_enemy(piece, at, get_square(board, &p), &p) {
moves.push(m);
}
}
@ -164,70 +168,100 @@ fn get_legal_king_moves(board: &Board, at: Pos, piece: u8) -> Vec<Move> {
}
/// 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> {
if (is_white(piece1) && is_black(piece2)) || (is_black(piece1) && is_white(piece2)) {
Some((pos1, pos2))
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)) {
Some((*pos1, *pos2))
} else {
None
}
}
/// 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, moves: Vec<Move>) -> Vec<Move> {
let king_p = find_king(board, 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);
// Check if the move makes the player king in check.
if is_attacked(&new_board, &king_p) {
return false
}
true
}).collect()
}
/// Return true if the piece at position `at` is attacked.
fn is_attacked(board: &Board, at: &Pos) -> bool {
let color = get_color(get_square(board, at));
let enemy_moves = get_player_moves(board, opposite(color));
for m in enemy_moves.iter() {
if *at == m.1 {
return true
}
}
false
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_get_legal_player_moves() {
fn test_get_player_moves() {
let b = new();
// At first move, white has 16 pawn moves and 4 knight moves.
let moves = get_legal_player_moves(&b, SQ_WH);
let moves = get_player_moves(&b, SQ_WH);
assert_eq!(moves.len(), 20);
}
#[test]
fn test_get_legal_pawn_moves() {
fn test_get_pawn_moves() {
let mut b = new_empty();
// 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_legal_piece_moves(&b, pos("d3"));
set_square(&mut b, &pos("d3"), SQ_WH_P);
let moves = get_piece_moves(&b, &pos("d3"));
assert!(moves.len() == 1 && moves.contains( &(pos("d3"), pos("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_legal_piece_moves(&b, pos("e2"));
set_square(&mut b, &pos("e2"), SQ_WH_P);
let moves = get_piece_moves(&b, &pos("e2"));
assert_eq!(moves.len(), 2);
assert!(moves.contains( &(pos("e2"), pos("e3")) ));
assert!(moves.contains( &(pos("e2"), pos("e4")) ));
// Check that a pawn cannot move forward if a piece is blocking its path.
// 1. black pawn 2 square forward:
set_square(&mut b, pos("e4"), SQ_BL_P);
let moves = get_legal_piece_moves(&b, pos("e2"));
set_square(&mut b, &pos("e4"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"));
assert!(moves.len() == 1 && moves.contains( &(pos("e2"), pos("e3")) ));
// 2. black pawn 1 square forward:
set_square(&mut b, pos("e3"), SQ_BL_P);
let moves = get_legal_piece_moves(&b, pos("e2"));
set_square(&mut b, &pos("e3"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"));
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_legal_piece_moves(&b, pos("e2"));
set_square(&mut b, &pos("f3"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"));
assert!(moves.len() == 1 && moves.contains( &(pos("e2"), pos("f3")) ));
set_square(&mut b, pos("d3"), SQ_BL_P);
let moves = get_legal_piece_moves(&b, pos("e2"));
set_square(&mut b, &pos("d3"), SQ_BL_P);
let moves = get_piece_moves(&b, &pos("e2"));
assert_eq!(moves.len(), 2);
assert!(moves.contains( &(pos("e2"), pos("f3")) ));
assert!(moves.contains( &(pos("e2"), pos("d3")) ));
}
#[test]
fn test_get_legal_bishop_moves() {
fn test_get_bishop_moves() {
let mut b = new_empty();
// A bishop has maximum range when it's in a center square.
set_square(&mut b, pos("d4"), SQ_WH_B);
let moves = get_legal_piece_moves(&b, pos("d4"));
set_square(&mut b, &pos("d4"), SQ_WH_B);
let moves = get_piece_moves(&b, &pos("d4"));
assert_eq!(moves.len(), 13);
// Going top-right.
assert!(moves.contains( &(pos("d4"), pos("e5")) ));
@ -248,64 +282,90 @@ mod tests {
assert!(moves.contains( &(pos("d4"), pos("a7")) ));
// When blocking sight to one square with friendly piece, lose 2 moves.
set_square(&mut b, pos("b2"), SQ_WH_P);
assert_eq!(get_legal_piece_moves(&b, pos("d4")).len(), 11);
set_square(&mut b, &pos("b2"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).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_legal_piece_moves(&b, pos("d4")).len(), 12);
set_square(&mut b, &pos("b2"), SQ_BL_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 12);
}
#[test]
fn test_get_legal_knight_moves() {
fn test_get_knight_moves() {
let mut b = new_empty();
// 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_legal_piece_moves(&b, pos("d4")).len(), 8);
set_square(&mut b, &pos("d4"), SQ_WH_N);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 8);
// If on a side if has only 4 moves.
set_square(&mut b, pos("a4"), SQ_WH_N);
assert_eq!(get_legal_piece_moves(&b, pos("a4")).len(), 4);
set_square(&mut b, &pos("a4"), SQ_WH_N);
assert_eq!(get_piece_moves(&b, &pos("a4")).len(), 4);
// And in a corner, only 2 moves.
set_square(&mut b, pos("a1"), SQ_WH_N);
assert_eq!(get_legal_piece_moves(&b, pos("a1")).len(), 2);
set_square(&mut b, &pos("a1"), SQ_WH_N);
assert_eq!(get_piece_moves(&b, &pos("a1")).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_legal_piece_moves(&b, pos("a1")).len(), 0);
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);
}
#[test]
fn test_get_legal_rook_moves() {
fn test_get_rook_moves() {
let mut b = new_empty();
set_square(&mut b, pos("d4"), SQ_WH_R);
assert_eq!(get_legal_piece_moves(&b, pos("d4")).len(), 14);
set_square(&mut b, pos("d6"), SQ_BL_P);
assert_eq!(get_legal_piece_moves(&b, pos("d4")).len(), 12);
set_square(&mut b, pos("d6"), SQ_WH_P);
assert_eq!(get_legal_piece_moves(&b, pos("d4")).len(), 11);
set_square(&mut b, &pos("d4"), SQ_WH_R);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 14);
set_square(&mut b, &pos("d6"), SQ_BL_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 12);
set_square(&mut b, &pos("d6"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 11);
}
#[test]
fn test_get_legal_queen_moves() {
fn test_get_queen_moves() {
let mut b = new_empty();
set_square(&mut b, pos("d4"), SQ_WH_Q);
assert_eq!(get_legal_piece_moves(&b, pos("d4")).len(), 14 + 13); // Bishop + rook moves.
set_square(&mut b, &pos("d4"), SQ_WH_Q);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 14 + 13); // Bishop + rook moves.
}
#[test]
fn test_get_legal_king_moves() {
fn test_get_king_moves() {
let mut b = new_empty();
set_square(&mut b, pos("d4"), SQ_WH_K);
assert_eq!(get_legal_piece_moves(&b, pos("d4")).len(), 8);
set_square(&mut b, pos("e5"), SQ_WH_P);
assert_eq!(get_legal_piece_moves(&b, pos("d4")).len(), 7);
set_square(&mut b, &pos("d4"), SQ_WH_K);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 8);
set_square(&mut b, &pos("e5"), SQ_WH_P);
assert_eq!(get_piece_moves(&b, &pos("d4")).len(), 7);
}
#[test]
fn test_filter_illegal_moves() {
let mut b = new_empty();
// 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"));
assert_eq!(all_wh_moves.len(), 5);
assert_eq!(filter_illegal_moves(&b, SQ_WH, all_wh_moves).len(), 2);
}
#[test]
fn test_is_attacked() {
let mut b = new_empty();
// 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")));
// Move the rook on another file, no more attack.
apply_into(&mut b, &(pos("d6"), pos("e6")));
assert!(!is_attacked(&b, &pos("d4")));
}
}