whisper.cpp/examples/wchess/libwchess/Chessboard.cpp

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#include "Chessboard.h"
#include <array>
#include <vector>
#include <algorithm>
#include <cstring>
#include <set>
#include <list>
#include <chrono>
namespace {
constexpr std::array<const char*, 64> positions = {
"a1", "b1", "c1", "d1", "e1", "f1", "g1", "h1",
"a2", "b2", "c2", "d2", "e2", "f2", "g2", "h2",
"a3", "b3", "c3", "d3", "e3", "f3", "g3", "h3",
"a4", "b4", "c4", "d4", "e4", "f4", "g4", "h4",
"a5", "b5", "c5", "d5", "e5", "f5", "g5", "h5",
"a6", "b6", "c6", "d6", "e6", "f6", "g6", "h6",
"a7", "b7", "c7", "d7", "e7", "f7", "g7", "h7",
"a8", "b8", "c8", "d8", "e8", "f8", "g8", "h8",
};
constexpr char INVALID_POS = positions.size();
constexpr int R = 0; // rank index
constexpr int F = 1; // file index
#define FILE (c[F] - '1')
#define RANK (c[R] - 'a')
constexpr char operator ""_P(const char * c, size_t size) {
return size < 2 || RANK < 0 || RANK > 7 ||
FILE < 0 || FILE > 7 ? INVALID_POS : FILE * 8 + RANK;
}
#undef FILE
#undef RANK
struct sview {
const char * ptr = nullptr;
size_t size = 0;
sview() = default;
sview(const char * p, size_t s) : ptr(p), size(s) {}
sview(const std::string& s) : ptr(s.data()), size(s.size()) {}
size_t find(char del, size_t pos) {
while (pos < size && ptr[pos] != del) ++pos;
return pos < size ? pos : std::string::npos;
}
};
std::vector<sview> split(sview str, char del) {
std::vector<sview> res;
size_t cur = 0;
size_t last = 0;
while (cur != std::string::npos) {
if (str.ptr[last] == ' ') {
++last;
continue;
}
cur = str.find(del, last);
size_t len = cur == std::string::npos ? str.size - last : cur - last;
res.emplace_back(str.ptr + last, len);
last = cur + 1;
}
return res;
}
char strToPos(sview str) {
return operator ""_P(str.ptr, str.size);
}
constexpr std::array<const char*, 6> pieceNames = {
"pawn", "knight", "bishop", "rook", "queen", "king",
};
static constexpr std::array<char, 6> blackShort = {
'p', 'n', 'b', 'r', 'q', 'k',
};
static constexpr std::array<char, 6> whiteShort = {
'P', 'N', 'B', 'R', 'Q', 'K',
};
char strToType(sview str) {
auto it = std::find_if(pieceNames.begin(), pieceNames.end(), [str] (const char* name) { return strncmp(name, str.ptr, str.size) == 0; });
return it != pieceNames.end() ? it - pieceNames.begin() : pieceNames.size();
}
// directions
using Direction = std::array<char, 2>;
constexpr Direction N = {(char) 0, (char) 1};
constexpr Direction NNE = {(char) 1, (char) 2};
constexpr Direction NE = {(char) 1, (char) 1};
constexpr Direction ENE = {(char) 2, (char) 1};
constexpr Direction E = {(char) 1, (char) 0};
constexpr Direction ESE = {(char) 2, (char) -1};
constexpr Direction SE = {(char) 1, (char) -1};
constexpr Direction SSE = {(char) 1, (char) -2};
constexpr Direction S = {(char) 0, (char) -1};
constexpr Direction SSW = {(char) -1, (char) -2};
constexpr Direction SW = {(char) -1, (char) -1};
constexpr Direction WSW = {(char) -2, (char) -1};
constexpr Direction W = {(char) -1, (char) 0};
constexpr Direction WNW = {(char) -2, (char) 1};
constexpr Direction NW = {(char) -1, (char) 1};
constexpr Direction NNW = {(char) -1, (char) 2};
char makeStep(char pos, const Direction& d) {
char next[2] = { char(positions[pos][R] + d[R]) , char(positions[pos][F] + d[F]) };
return strToPos(sview{next, sizeof(next)});
}
template<class Modifier>
char traverse(char pos, const Direction& d, const Modifier& m, int count = 8) {
while (--count >= 0) {
pos = makeStep(pos, d);
if (pos == INVALID_POS || m(pos)) break;
}
return pos;
}
Direction normalize(const Direction& distance) {
//return {char((distance[R] > 0) - (distance[R] < 0)), char((distance[F] > 0) - (distance[F] < 0))};
const int drp = distance[R] > 0 ? 1 : 0;
const int drn = distance[R] < 0 ? 1 : 0;
const int dfp = distance[F] > 0 ? 1 : 0;
const int dfn = distance[F] < 0 ? 1 : 0;
return {char(drp - drn), char(dfp - dfn)};
}
struct Pin {
Direction d;
Piece* pinner;
Piece* pinned;
};
using Pins = std::list<Pin>;
using Board = std::array<Piece*, 64>;
std::vector<Direction> filter(const Direction& pin, std::initializer_list<Direction> directions) {
if (pin[R] == 0 && pin[F] == 0) return directions;
std::vector<Direction> result;
for (auto& d : directions) {
if ((d[R] == pin[R] || d[R] == -pin[R]) && (d[F] == pin[F] || d[F] == -pin[F])) result.push_back(d);
}
return result;
}
}
class Piece {
public:
enum Types : char {
Pawn,
Knight,
Bishop,
Rook,
Queen,
King,
//
NUM_PIECES
};
enum Colors : char {
White,
Black,
};
const char* name() const;
char initial() const;
Types type() const { return m_type; }
Colors color() const { return m_color; }
char pos() const { return m_pos; }
void setPos(char pos) {
m_pos = pos;
invalidate();
}
const char* coord() const;
const std::set<char>& allowed() const { return m_allowed; }
bool canReach(char pos) const;
virtual bool movePattern(char pos) const = 0;
void take();
virtual void reinit(const State& state) = 0;
void invalidate();
protected:
Piece(Types type, Colors color, char pos, std::set<char> allowed)
: m_type(type), m_color(color), m_pos(pos), m_allowed(std::move(allowed)) {}
Piece(const Piece&) = delete;
~Piece() = default;
const Types m_type;
const Colors m_color;
char m_pos;
std::set<char> m_allowed;
bool m_update = false;
};
struct Pawn : public Piece {
Pawn(Colors color, char pos, std::set<char> next) : Piece(Types::Pawn, color, pos, std::move(next)) {}
bool is_first_move() const {
return m_color ? coord()[F] == '7' : coord()[F] == '2';
}
virtual bool movePattern(char pos) const override {
if (m_pos == INVALID_POS) return false;
auto cur = coord();
auto next = positions[pos];
Direction distance = {char(next[R] - cur[R]), char(next[F] - cur[F])};
char forward = m_color ? -1 : 1;
return (forward == distance[F] && distance[R] * distance[R] <= 1)
|| (is_first_move() && 2 * forward == distance[F] && distance[R] == 0);
}
virtual void reinit(const State& state) override;
};
struct Knight : public Piece {
Knight(Colors color, char pos, std::set<char> next) : Piece(Types::Knight, color, pos, std::move(next)) {}
virtual bool movePattern(char pos) const override {
if (m_pos == INVALID_POS) return false;
auto cur = coord();
auto next = positions[pos];
Direction diff = {char(next[R] - cur[R]), char(next[F] - cur[F])};
return diff[R]*diff[R] + diff[F]*diff[F] == 5;
}
virtual void reinit(const State& state) override;
};
struct Bishop : public Piece {
Bishop(Colors color, char pos) : Piece(Types::Bishop, color, pos, {}) {}
virtual bool movePattern(char pos) const override {
if (m_pos == INVALID_POS) return false;
auto cur = coord();
auto next = positions[pos];
return cur[R] - cur[F] == next[R] - next[F] || cur[R] + cur[F] == next[R] + next[F];
}
virtual void reinit(const State& state) override;
};
struct Rook : public Piece {
Rook(Colors color, char pos) : Piece(Types::Rook, color, pos, {}) {}
virtual bool movePattern(char pos) const override {
if (m_pos == INVALID_POS) return false;
auto cur = coord();
auto next = positions[pos];
return cur[R] == next[R] || cur[F] == next[F];
}
virtual void reinit(const State& state) override;
};
struct Queen : public Piece {
Queen(Colors color, char pos) : Piece(Types::Queen, color, pos, {}) {}
virtual bool movePattern(char pos) const override {
if (m_pos == INVALID_POS) return false;
auto cur = coord();
auto next = positions[pos];
return cur[R] == next[R] || cur[F] == next[F] || cur[R] - cur[F] == next[R] - next[F] || cur[R] + cur[F] == next[R] + next[F];
}
virtual void reinit(const State& state) override;
};
struct King : public Piece {
King(Colors color, char pos) : Piece(Types::King, color, pos, {}) {}
virtual bool movePattern(char pos) const override {
if (m_pos == INVALID_POS) return false;
auto cur = coord();
auto next = positions[pos];
Direction diff = {char(next[R] - cur[R]), char(next[F] - cur[F])};
return diff[R]*diff[R] + diff[F]*diff[F] <= 2;
}
virtual void reinit(const State& state) override;
};
struct PieceSet {
Piece* begin() { return &p1; }
Piece* end() { return &r2 + 1; }
const Piece* begin() const { return &p1; }
const Piece* end() const { return &r2 + 1; }
Piece& operator[](int i) { return *(begin() + i); }
const Piece& operator[](int i) const { return *(begin() + i); }
Pawn p1;
Pawn p2;
Pawn p3;
Pawn p4;
Pawn p5;
Pawn p6;
Pawn p7;
Pawn p8;
Rook r1;
Knight n1;
Bishop b1;
Queen q;
King k;
Bishop b2;
Knight n2;
Rook r2;
};
struct State {
State();
PieceSet blacks;
PieceSet whites;
Board board;
Pins blackPins;
Pins whitePins;
};
Direction findPin(const Piece& piece, const State& state) {
auto& pins = piece.color() ? state.blackPins : state.whitePins;
auto it = std::find_if(pins.begin(), pins.end(), [&] (const Pin& pin) { return pin.pinned == &piece; });
if (it != pins.end()) return it->d;
return {0, 0};
}
struct Find {
Find(const Board& board) : m_board(board) {}
bool operator() (char pos) const { return m_board[pos]; }
const Board& m_board;
};
struct Add {
Add(const Board& board, std::set<char>& moves, Piece::Colors color) : m_board(board), m_moves(moves), m_color(color) {}
bool operator() (char pos) const {
if (!m_board[pos] || m_board[pos]->color() != m_color) m_moves.insert(pos);
return m_board[pos];
}
const Board& m_board;
std::set<char>& m_moves;
Piece::Colors m_color;
};
void Pawn::reinit(const State& state) {
if (m_pos == INVALID_POS) return;
if (!m_update) return;
m_update = false;
m_allowed.clear();
auto pin = findPin(*this, state);
auto & left = m_color ? SW : NW;
auto & right = m_color ? SE : NE;
for (auto& direction : filter(pin, { left, right })) {
auto pos = makeStep(m_pos, direction);
if (pos != INVALID_POS && state.board[pos] && state.board[pos]->color() != m_color) m_allowed.insert(pos);
}
auto & forward = m_color ? S : N;
if (!filter(pin, {forward}).empty()) {
traverse(m_pos, forward, [&] (char pos) {
if (!state.board[pos]) m_allowed.insert(pos);
return state.board[pos] || !is_first_move();
}, 2);
}
}
void Knight::reinit(const State& state) {
if (m_pos == INVALID_POS) return;
if (!m_update) return;
m_update = false;
m_allowed.clear();
auto pin = findPin(*this, state);
if (pin[R] != 0 || pin[F] != 0) return;
for (auto& direction : { NNE, ENE, ESE, SSE, SSW, WSW, WNW, NNW }) {
auto pos = makeStep(m_pos, direction);
if (pos != INVALID_POS && (!state.board[pos] || state.board[pos]->color() != m_color)) m_allowed.insert(pos);
}
}
void Bishop::reinit(const State& state) {
if (m_pos == INVALID_POS) return;
if (!m_update) return;
m_update = false;
m_allowed.clear();
auto pin = findPin(*this, state);
for (auto& direction : filter(pin, { NE, SE, SW, NW })) {
traverse(m_pos, direction, Add(state.board, m_allowed, m_color));
}
}
void Rook::reinit(const State& state) {
if (m_pos == INVALID_POS) return;
if (!m_update) return;
m_update = false;
m_allowed.clear();
auto pin = findPin(*this, state);
for (auto& direction : filter(pin, { N, E, S, W })) {
traverse(m_pos, direction, Add(state.board, m_allowed, m_color));
}
}
void Queen::reinit(const State& state) {
if (m_pos == INVALID_POS) return;
if (!m_update) return;
m_update = false;
m_allowed.clear();
auto pin = findPin(*this, state);
for (auto& direction : filter(pin, { N, NE, E, SE, S, SW, W, NW })) {
traverse(m_pos, direction, Add(state.board, m_allowed, m_color));
}
}
void King::reinit(const State& state) {
if (m_pos == INVALID_POS) return;
if (!m_update) return;
m_update = false;
m_allowed.clear();
auto& enemyPieces = m_color ? state.whites : state.blacks;
auto& pawnAttackLeft = m_color ? SW : NW;
auto& pawnAttackRight = m_color ? SE : NE;
for (auto& direction : { N, NE, E, SE, S, SW, W, NW }) {
auto pos = makeStep(m_pos, direction);
bool accept = pos != INVALID_POS && !(state.board[pos] && state.board[pos]->color() == m_color);
if (accept) {
for (auto& p : enemyPieces) {
if (!p.movePattern(pos)) continue;
if (p.type() == Piece::Knight || p.type() == Piece::King) {
accept = false;
break;
}
else if (p.type() == Piece::Pawn) {
auto from = positions[pos];
auto to = p.coord();
Direction d {char(to[R] - from[R]), char(to[F] - from[F])};
if (d == pawnAttackLeft || d == pawnAttackRight) {
accept = false;
break;
}
}
else {
auto from = positions[pos];
auto to = p.coord();
Direction d = normalize({char(to[R] - from[R]), char(to[F] - from[F])});
auto reached = traverse(pos, d, Find(state.board));
if (p.pos() == reached) {
accept = false;
break;
}
}
}
}
if (accept) m_allowed.insert(pos);
}
}
const char* Piece::name() const {
static_assert(pieceNames.size() == Piece::NUM_PIECES, "Mismatch between piece names and types");
return pieceNames[m_type];
}
char Piece::initial() const {
static_assert(blackShort.size() == Piece::NUM_PIECES, "Mismatch between piece names and types");
static_assert(whiteShort.size() == Piece::NUM_PIECES, "Mismatch between piece names and types");
return m_color ? blackShort[m_type] : whiteShort[m_type];
}
void Piece::invalidate() {
m_update = true;
}
const char* Piece::coord() const {
if (m_pos == INVALID_POS) return "";
return positions[m_pos];
}
bool Piece::canReach(char pos) const {
return movePattern(pos) && m_allowed.count(pos);
}
void Piece::take() {
m_pos = INVALID_POS;
m_allowed = {};
}
State::State()
: blacks {
{Piece::Black, "a7"_P, {"a5"_P, "a6"_P} },
{Piece::Black, "b7"_P, {"b5"_P, "b6"_P} },
{Piece::Black, "c7"_P, {"c5"_P, "c6"_P} },
{Piece::Black, "d7"_P, {"d5"_P, "d6"_P} },
{Piece::Black, "e7"_P, {"e5"_P, "e6"_P} },
{Piece::Black, "f7"_P, {"f5"_P, "f6"_P} },
{Piece::Black, "g7"_P, {"g5"_P, "g6"_P} },
{Piece::Black, "h7"_P, {"h5"_P, "h6"_P} },
{Piece::Black, "a8"_P},
{Piece::Black, "b8"_P, {"a6"_P, "c6"_P} },
{Piece::Black, "c8"_P},
{Piece::Black, "d8"_P},
{Piece::Black, "e8"_P},
{Piece::Black, "f8"_P},
{Piece::Black, "g8"_P, {"f6"_P, "h6"_P} },
{Piece::Black, "h8"_P},
}
, whites {
{Piece::White, "a2"_P, {"a3"_P, "a4"_P} },
{Piece::White, "b2"_P, {"b3"_P, "b4"_P} },
{Piece::White, "c2"_P, {"c3"_P, "c4"_P} },
{Piece::White, "d2"_P, {"d3"_P, "d4"_P} },
{Piece::White, "e2"_P, {"e3"_P, "e4"_P} },
{Piece::White, "f2"_P, {"f3"_P, "f4"_P} },
{Piece::White, "g2"_P, {"g3"_P, "g4"_P} },
{Piece::White, "h2"_P, {"h3"_P, "h4"_P} },
{Piece::White, "a1"_P},
{Piece::White, "b1"_P, {"a3"_P, "c3"_P} },
{Piece::White, "c1"_P},
{Piece::White, "d1"_P},
{Piece::White, "e1"_P},
{Piece::White, "f1"_P},
{Piece::White, "g1"_P, {"f3"_P, "h3"_P} },
{Piece::White, "h1"_P},
}
, board {{
&whites[ 8], &whites[ 9], &whites[10], &whites[11], &whites[12], &whites[13], &whites[14], &whites[15],
&whites[ 0], &whites[ 1], &whites[ 2], &whites[ 3], &whites[ 4], &whites[ 5], &whites[ 6], &whites[ 7],
nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
&blacks[ 0], &blacks[ 1], &blacks[ 2], &blacks[ 3], &blacks[ 4], &blacks[ 5], &blacks[ 6], &blacks[ 7],
&blacks[ 8], &blacks[ 9], &blacks[10], &blacks[11], &blacks[12], &blacks[13], &blacks[14], &blacks[15],
}}
{}
Chessboard::Chessboard()
: m_state(new State())
{
setGrammar();
}
Chessboard::~Chessboard() = default;
void Chessboard::setPrompt(const std::string& prompt) {
m_prompt = prompt;
setGrammar();
}
void Chessboard::setGrammar() {
m_grammar.clear();
std::string result;
if (m_prompt.empty()) {
result += "move ::= \" \" ((piece | frompos) \" \" \"to \"?)? topos\n";
//result += "move ::= \" \" frompos \" \" \"to \"? topos\n";
}
else {
// result += "move ::= prompt \" \" ((piece | frompos) \" \" \"to \"?)? topos\n"
result += "move ::= prompt \" \" frompos \" \" \"to \"? topos\n"
"prompt ::= \" " + m_prompt + "\"\n";
}
std::set<Piece::Types> pieceTypes;
std::set<char> from_pos;
std::set<char> to_pos;
auto& pieces = m_moveCounter % 2 ? m_state->blacks : m_state->whites;
std::set<size_t> flags;
for (auto& p : pieces) {
if (p.allowed().empty()) continue;
bool addPiece = false;
if (!m_inCheck || p.type() == Piece::King) {
to_pos.insert(p.allowed().begin(), p.allowed().end());
addPiece = !p.allowed().empty();
}
else {
for (auto move : p.allowed()) {
if (m_allowedInCheck.count(move)) {
to_pos.insert(move);
addPiece = true;
}
}
}
if (addPiece) {
pieceTypes.insert(p.type());
from_pos.insert(p.pos());
}
}
if (pieceTypes.empty()) return;
result += "piece ::= (";
for (auto& p : pieceTypes) result += " \"" + std::string(pieceNames[p]) + "\" |";
result.pop_back();
result += ")\n\n";
result += "frompos ::= (";
for (auto& p : from_pos) result += " \"" + std::string(positions[p]) + "\" |";
result.pop_back();
result += ")\n";
result += "topos ::= (";
for (auto& p : to_pos) result += " \"" + std::string(positions[p]) + "\" |";
result.pop_back();
result += ")\n";
m_grammar = std::move(result);
}
std::string Chessboard::stringifyBoard() {
std::string result;
result.reserve(16 + 2 * 64 + 16);
for (char rank = 'a'; rank <= 'h'; ++rank) {
result.push_back(rank);
result.push_back(' ');
}
result.back() = '\n';
for (int i = 7; i >= 0; --i) {
for (int j = 0; j < 8; ++j) {
auto p = m_state->board[i * 8 + j];
if (p) result.push_back(p->initial());
else result.push_back((i + j) % 2 ? '.' : '*');
result.push_back(' ');
}
result.push_back('0' + i + 1);
result.push_back('\n');
}
return result;
}
std::string Chessboard::process(const std::string& command) {
const auto t_start = std::chrono::high_resolution_clock::now();
auto color = Piece::Colors(m_moveCounter % 2);
Piece* piece = nullptr;
auto pos_to = INVALID_POS;
if (!parseCommand(command, piece, pos_to)) return "";
auto pos_from = piece->pos();
if (!move(*piece, pos_to)) return "";
flagUpdates(pos_from, pos_to);
detectChecks();
auto& enemyPieces = color ? m_state->whites : m_state->blacks;
for (auto& p : enemyPieces) p.reinit(*m_state); // only enemy moves needed next
std::string result = {positions[pos_from][R], positions[pos_from][F], '-', positions[pos_to][R], positions[pos_to][F]};
++m_moveCounter;
setGrammar();
const auto t_end = std::chrono::high_resolution_clock::now();
auto t_ms = std::chrono::duration_cast<std::chrono::milliseconds>(t_end - t_start).count();
fprintf(stdout, "%s: Move '%s%s%s', (t = %d ms)\n", __func__, "\033[1m", result.data(), "\033[0m", (int) t_ms);
if (m_grammar.empty()) result.push_back('#');
return result;
}
bool Chessboard::parseCommand(const std::string& command, Piece*& piece, char& pos_to) {
auto color = Piece::Colors(m_moveCounter % 2);
fprintf(stdout, "%s: Command to %s: '%s%.*s%s'\n", __func__, (color ? "Black" : "White"), "\033[1m", int(command.size()), command.data(), "\033[0m");
if (command.empty()) return false;
auto tokens = split(command, ' ');
auto pos_from = INVALID_POS;
auto type = Piece::Types::NUM_PIECES;
if (tokens.size() == 1) {
type = Piece::Types::Pawn;
pos_to = strToPos(tokens.front());
}
else {
pos_from = strToPos(tokens.front());
if (pos_from == INVALID_POS) type = Piece::Types(strToType(tokens.front()));
pos_to = strToPos(tokens.back());
}
if (pos_to == INVALID_POS) return false;
if (pos_from == INVALID_POS) {
if (type == Piece::Types::NUM_PIECES) return false;
auto& pieces = color ? m_state->blacks : m_state->whites;
for (auto& p : pieces) {
if (p.type() == type && p.canReach(pos_to)) {
pos_from = p.pos();
break;
}
}
}
if (pos_from == INVALID_POS) return false;
if (m_state->board[pos_from] == nullptr) return false;
piece = m_state->board[pos_from];
if (piece->color() != color) return false;
return true;
}
void Chessboard::flagUpdates(char pos_from, char pos_to) {
auto color = Piece::Colors(m_moveCounter % 2);
auto& enemyPieces = color ? m_state->whites : m_state->blacks;
auto& ownPieces = color ? m_state->blacks : m_state->whites;
for (auto& p : enemyPieces) {
if (p.movePattern(pos_to) || p.movePattern(pos_from)) {
updatePins(p);
p.invalidate();
}
}
for (auto& p : ownPieces) {
if (p.movePattern(pos_to) || p.movePattern(pos_from)) {
updatePins(p);
p.invalidate();
}
}
}
void Chessboard::updatePins(Piece& piece) {
if (piece.type() == Piece::Pawn || piece.type() == Piece::Knight || piece.type() == Piece::King) return;
auto& enemyPieces = piece.color() ? m_state->whites : m_state->blacks;
auto& enemyPins = piece.color() ? m_state->whitePins : m_state->blackPins;
auto& king = enemyPieces.k;
auto it = std::find_if(enemyPins.begin(), enemyPins.end(), [&] (const Pin& pin) { return pin.pinner == &piece; });
if (it != enemyPins.end()) {
it->pinned->invalidate();
enemyPins.erase(it);
}
if (piece.movePattern(king.pos())) {
auto to = positions[king.pos()];
auto from = piece.coord();
Direction d = normalize({char(to[R] - from[R]), char(to[F] - from[F])});
auto reached = traverse(piece.pos(), d, Find(m_state->board));
auto foundPiece = m_state->board[reached];
if (&king == foundPiece) {
// check
king.invalidate();
}
else if (foundPiece && foundPiece->color() != piece.color()) {
reached = traverse(reached, d, Find(m_state->board));
if (&king == m_state->board[reached]) {
enemyPins.push_back({d, &piece, foundPiece});
foundPiece->invalidate();
}
}
}
}
void Chessboard::detectChecks() {
auto color = Piece::Colors(m_moveCounter % 2);
auto& enemyPieces = color ? m_state->whites : m_state->blacks;
auto& ownPieces = color ? m_state->blacks : m_state->whites;
auto& king = enemyPieces.k;
auto& pawnAttackLeft = color ? SW : NW;
auto& pawnAttackRight = color ? SE : NE;
for (auto& p : ownPieces) {
if (!p.movePattern(king.pos())) continue;
auto to = positions[king.pos()];
auto from = p.coord();
if (p.type() == Piece::Knight) {
if (!m_inCheck) {
m_allowedInCheck = { p.pos() };
}
else {
m_allowedInCheck.clear();
}
m_inCheck = true;
}
else if (p.type() == Piece::Pawn) {
Direction d {char(to[R] - from[R]), char(to[F] - from[F])};
if (d == pawnAttackLeft || d == pawnAttackRight) {
if (!m_inCheck) {
m_allowedInCheck = { p.pos() };
}
else {
m_allowedInCheck.clear();
}
m_inCheck = true;
}
}
else {
Direction d = normalize({char(to[R] - from[R]), char(to[F] - from[F])});
std::set<char> tmp;
auto pos = traverse(p.pos(), d, Add(m_state->board, tmp, king.color()));
if (pos == king.pos()) {
tmp.insert(p.pos());
if (!m_inCheck) {
m_allowedInCheck = std::move(tmp);
}
else {
m_allowedInCheck.clear();
}
m_inCheck = true;
}
}
}
}
bool Chessboard::move(Piece& piece, char pos_to) {
auto& allowed = piece.allowed();
if (allowed.count(pos_to) == 0 || (m_inCheck && piece.type() != Piece::King && m_allowedInCheck.count(pos_to) == 0)) return false;
if (m_state->board[pos_to] && m_state->board[pos_to]->color() == piece.color()) return false;
if (m_state->board[pos_to]) m_state->board[pos_to]->take();
m_state->board[piece.pos()] = nullptr;
m_state->board[pos_to] = &piece;
piece.setPos(pos_to);
m_inCheck = false;
m_allowedInCheck.clear();
return true;
}