// check the victim pieces returned by the move to determine if it's a
// game-over situation. If so, also calculate the score depending on
// the pov (which player's point of view)
static bool is_game_over(victims_t victims, int pov, int ply) {
tbassert(ptype_of(victims.stomped) != KING, "Stomped a king.\n");
if (ptype_of(victims.zapped) == KING) {
return true;
}
return false;
}
// MOBILITY heuristic: safe squares around king of color color.
int mobility(position_t *p, color_t color) {
char* laser_map;
if (color == WHITE) {
laser_map = laser_map_black;
} else {
laser_map = laser_map_white;
}
int mobility = 0;
square_t king_sq = p->kloc[color];
tbassert(ptype_of(p->board[king_sq]) == KING,
"ptype: %d\n", ptype_of(p->board[king_sq]));
tbassert(color_of(p->board[king_sq]) == color,
"color: %d\n", color_of(p->board[king_sq]));
if (laser_map[king_sq] == 0) {
mobility++;
}
for (int d = 0; d < 8; ++d) {
square_t sq = king_sq + dir_of(d);
if (laser_map[sq] == 0) {
mobility++;
}
}
return mobility;
}
// KAGGRESSIVE heuristic: bonus for King with more space to back
ev_score_t kaggressive_old(position_t *p, fil_t f, rnk_t r) {
square_t sq = square_of(f, r);
piece_t x = p->board[sq];
color_t c = color_of(x);
tbassert(ptype_of(x) == KING, "ptype_of(x) = %d\n", ptype_of(x));
square_t opp_sq = p->kloc[opp_color(c)];
fil_t of = fil_of(opp_sq);
rnk_t _or = (rnk_t) rnk_of(opp_sq);
int delta_fil = of - f;
int delta_rnk = _or - r;
int bonus = 0;
if (delta_fil >= 0 && delta_rnk >= 0) {
bonus = (f + 1) * (r + 1);
} else if (delta_fil <= 0 && delta_rnk >= 0) {
bonus = (BOARD_WIDTH - f) * (r + 1);
} else if (delta_fil <= 0 && delta_rnk <= 0) {
bonus = (BOARD_WIDTH - f) * (BOARD_WIDTH - r);
} else if (delta_fil >= 0 && delta_rnk <= 0) {
bonus = (f + 1) * (BOARD_WIDTH - r);
}
return (KAGGRESSIVE * bonus) / (BOARD_WIDTH * BOARD_WIDTH);
}
// KAGGRESSIVE heuristic: bonus for King with more space to back
ev_score_t kaggressive(position_t *p, rnk_t r, fil_t f, full_board_t* board) {
piece_t x = get_piece(p, r, f, board);
color_t c = color_of(x);
tbassert(ptype_of(x) == KING, "ptype_of(x) = %d\n", ptype_of(x));
square_t opp_sq = board->pieces[opp_color(c)][0];
fil_t of = fil_of(opp_sq);
rnk_t _or = (rnk_t) rnk_of(opp_sq);
int delta_fil = of - f;
int delta_rnk = _or - r;
int bonus = 0;
if (delta_fil >= 0 && delta_rnk >= 0) {
bonus = (f + 1) * (r + 1);
} else if (delta_fil <= 0 && delta_rnk >= 0) {
bonus = (BOARD_WIDTH - f) * (r + 1);
} else if (delta_fil <= 0 && delta_rnk <= 0) {
bonus = (BOARD_WIDTH - f) * (BOARD_WIDTH - r);
} else if (delta_fil >= 0 && delta_rnk <= 0) {
bonus = (f + 1) * (BOARD_WIDTH - r);
}
return (KAGGRESSIVE * bonus) / (BOARD_WIDTH * BOARD_WIDTH);
}
// Marks the path of the laser until it hits a piece or goes off the board.
// Returns the number of unpinned pawns.
//
// p : current board state
// laser_map : end result will be stored here. Every square on the
// path of the laser is marked with mark_mask
// c : color of king shooting laser
// mark_mask: what each square is marked with
int mark_laser_path(position_t *p, char *laser_map, color_t c,
char mark_mask) {
int pinned_pawns = 0;
uint8_t total_pawns;
color_t color = opp_color(c);
square_t o_king_sq = p->kloc[color];
if (c == WHITE) { // opposing king pins our pawns
total_pawns = p->pawn_count[BLACK];
} else {
total_pawns = p->pawn_count[WHITE];
}
// Fire laser, recording in laser_map
square_t sq = p->kloc[c];
int bdir = ori_of(p->board[sq]);
int beam = beam_of(bdir);
tbassert(ptype_of(p->board[sq]) == KING,
"ptype: %d\n", ptype_of(p->board[sq]));
laser_map[sq] |= mark_mask;
// we update h_attackable here
h_attackable = h_dist(sq, o_king_sq);
while (true) {
sq += beam;
laser_map[sq] |= mark_mask;
tbassert(sq < ARR_SIZE && sq >= 0, "sq: %d\n", sq);
switch (ptype_of(p->board[sq])) {
case EMPTY: // empty square
h_attackable += h_dist(sq, o_king_sq);
break;
case PAWN: // Pawn
h_attackable += h_dist(sq, o_king_sq);
if (color_of(p->board[sq]) == color) {
pinned_pawns += 1;
}
bdir = reflect_of(bdir, ori_of(p->board[sq]));
if (bdir < 0) { // Hit back of Pawn
return total_pawns - pinned_pawns;
}
beam = beam_of(bdir);
break;
case KING: // King
h_attackable += h_dist(sq, o_king_sq);
return total_pawns - pinned_pawns;
break;
case INVALID: // Ran off edge of board
return total_pawns - pinned_pawns;
break;
default: // Shouldna happen, man!
tbassert(false, "Not cool, man. Not cool.\n");
break;
}
}
}
// Translate a position struct into a fen string
// NOTE: When you use the test framework in search.c, you should modify this
// function to match your optimized board representation in move_gen.c
//
// Input: (populated) position struct
// empty string where FEN characters will be written
// Output: null
int pos_to_fen(position_t *p, char *fen) {
int pos = 0;
int i;
for (rnk_t r = BOARD_WIDTH - 1; r >=0 ; --r) {
int empty_in_a_row = 0;
for (fil_t f = 0; f < BOARD_WIDTH; ++f) {
piece_t piece = get_piece(p, r, f, &base_board);
if (ptype_of(piece) == INVALID) { // invalid square
tbassert(false, "Bad news, yo.\n"); // This is bad!
}
if (ptype_of(piece) == EMPTY) { // empty square
empty_in_a_row++;
continue;
} else {
if (empty_in_a_row) fen[pos++] = '0' + empty_in_a_row;
empty_in_a_row = 0;
int ori = ori_of(piece); // orientation
color_t c = color_of(piece);
if (ptype_of(piece) == KING) {
for (i = 0; i < 2; i++) fen[pos++] = king_ori_to_rep[c][ori][i];
continue;
}
if (ptype_of(piece) == PAWN) {
for (i = 0; i < 2; i++) fen[pos++] = pawn_ori_to_rep[c][ori][i];
continue;
}
}
}
// assert: for larger boards, we need more general solns
tbassert(BOARD_WIDTH <= 10, "BOARD_WIDTH = %d\n", BOARD_WIDTH);
if (empty_in_a_row == 10) {
fen[pos++] = '1';
fen[pos++] = '0';
} else if (empty_in_a_row) {
fen[pos++] = '0' + empty_in_a_row;
}
if (r) fen[pos++] = '/';
}
fen[pos++] = ' ';
fen[pos++] = 'W';
fen[pos++] = '\0';
return pos;
}
// MOBILITY heuristic: safe squares around king of color color.
int mobility(position_t *p, color_t color, char* laser_map, full_board_t* board) {
int mobility = 0;
square_t king_sq = board->pieces[color][0];
tbassert(ptype_of(board->board[king_sq]) == KING,
"ptype: %d\n", ptype_of(board->board[king_sq]));
tbassert(color_of(board->board[king_sq]) == color,
"color: %d\n", color_of(board->board[king_sq]));
if (laser_map[king_sq] == 0) {
mobility++;
}
for (int d = 0; d < 8; ++d) {
square_t sq = king_sq + dir_of(d);
if (in_bounds(sq) && laser_map[sq] == 0) {
mobility++;
}
}
return mobility;
}
int pawnpin(position_t *p, color_t color, square_t* laser_list, int laser_list_len, full_board_t* board) {
int unpinned_pawns = board->pawn_count[color];
for(int i = 1; i < laser_list_len; i++) {
if (color_of(board->board[laser_list[i]]) == color && ptype_of(board->board[laser_list[i]]) == PAWN) {
unpinned_pawns--;
}
}
return unpinned_pawns;
}
// H_SQUARES_ATTACKABLE heuristic: for shooting the enemy king
int h_squares_attackable(position_t *p, color_t c) {
char* laser_map;
if (c == WHITE) {
laser_map = laser_map_white;
} else {
laser_map = laser_map_black;
}
square_t o_king_sq = p->kloc[opp_color(c)];
tbassert(ptype_of(p->board[o_king_sq]) == KING,
"ptype: %d\n", ptype_of(p->board[o_king_sq]));
tbassert(color_of(p->board[o_king_sq]) != c,
"color: %d\n", color_of(p->board[o_king_sq]));
float h_attackable_temp = 0;
for (fil_t f = 0; f < BOARD_WIDTH; f++) {
for (rnk_t r = 0; r < BOARD_WIDTH; r++) {
square_t sq = square_of(f, r);
if (laser_map[sq] != 0) {
h_attackable_temp += h_dist(sq, o_king_sq);
}
}
}
return h_attackable_temp;
}
static score_t get_game_over_score(victims_t victims, int pov, int ply) {
tbassert(ptype_of(victims.stomped) != KING, "Stomped a king.\n");
score_t score;
if (color_of(victims.zapped) == WHITE) {
score = -WIN * pov;
} else {
score = WIN * pov;
}
if (score < 0) {
score += ply;
} else {
score -= ply;
}
return score;
}
int check_pawn_counts(position_t *p) {
int live_pawn_count = 0;
for (fil_t f = 0; f < BOARD_WIDTH; f++) {
square_t sq = (FIL_ORIGIN + f) * ARR_WIDTH + RNK_ORIGIN;
for (rnk_t r = 0; r < BOARD_WIDTH; r++, sq++) {
if (ptype_of(p->board[sq]) == PAWN) {
live_pawn_count++;
}
}
}
int ploc_count = 0;
for (int i = 0; i < NUM_PAWNS; i++) {
if (p->ploc[i] != 0) {
ploc_count++;
}
}
if (ploc_count == live_pawn_count) {
return 1;
}
return 0;
}
int check_position_integrity(position_t *p) {
for (fil_t f = 0; f < BOARD_WIDTH; f++) {
square_t sq = (FIL_ORIGIN + f) * ARR_WIDTH + RNK_ORIGIN;
for (rnk_t r = 0; r < BOARD_WIDTH; r++, sq++) {
if (ptype_of(p->board[sq]) == PAWN) {
int pawn_found = 0;
for (int i = 0; i < NUM_PAWNS; i++) {
if (p->ploc[i] == sq) {
pawn_found = 1;
break;
}
}
if (pawn_found == 0) {
return 0;
}
}
}
}
return 1;
}
static score_t get_game_over_score(victims_t* victims, int pov, int ply) {
tbassert(ptype_of(victims->stomped) != KING, "Stomped a king.\n");
// score negative when victims.zapped == WHITE
score_t score = -1*(1 - 2*(color_of(victims->zapped)))*WIN*pov;
return score + (1 - 2*(score >= 0))*ply;
}
// check the victim pieces returned by the move to determine if it's a
// game-over situation. If so, also calculate the score depending on
// the pov (which player's point of view)
static bool is_game_over(victims_t* victims, int pov, int ply) {
tbassert(ptype_of(victims->stomped) != KING, "Stomped a king.\n");
return ptype_of(victims->zapped) == KING;
}
// Static evaluation. Returns score
score_t eval(position_t *p, bool verbose) {
// seed rand_r with a value of 1, as per
// http://linux.die.net/man/3/rand_r
static __thread unsigned int seed = 1;
// verbose = true: print out components of score
ev_score_t score[2] = { 0, 0 };
// int corner[2][2] = { {INF, INF}, {INF, INF} };
ev_score_t bonus;
//char buf[MAX_CHARS_IN_MOVE];
color_t c;
for (fil_t f = 0; f < BOARD_WIDTH; f++) {
for (rnk_t r = 0; r < BOARD_WIDTH; r++) {
square_t sq = square_of(f, r);
piece_t x = p->board[sq];
//if (verbose) {
// square_to_str(sq, buf, MAX_CHARS_IN_MOVE);
//}
switch (ptype_of(x)) {
case EMPTY:
break;
case PAWN:
c = color_of(x);
// MATERIAL heuristic: Bonus for each Pawn
bonus = PAWN_EV_VALUE;
// if (verbose) {
// printf("MATERIAL bonus %d for %s Pawn on %s\n", bonus, color_to_str(c), buf);
// }
score[c] += bonus;
// PBETWEEN heuristic
bonus = pbetween(p, f, r);
// if (verbose) {
// printf("PBETWEEN bonus %d for %s Pawn on %s\n", bonus, color_to_str(c), buf);
// }
score[c] += bonus;
// PCENTRAL heuristic
bonus = pcentral(f, r);
// if (verbose) {
// printf("PCENTRAL bonus %d for %s Pawn on %s\n", bonus, color_to_str(c), buf);
// }
score[c] += bonus;
break;
case KING:
c = color_of(x);
// KFACE heuristic
bonus = kface(p, f, r);
// if (verbose) {
// printf("KFACE bonus %d for %s King on %s\n", bonus,
// color_to_str(c), buf);
// }
score[c] += bonus;
// KAGGRESSIVE heuristic
color_t othercolor = opp_color(c);
square_t otherking = p->kloc[othercolor];
fil_t otherf = fil_of(otherking);
rnk_t otherr = rnk_of(otherking);
bonus = kaggressive(f, r, otherf, otherr);
assert(bonus == kaggressive_old(p, f, r));
// if (verbose) {
// printf("KAGGRESSIVE bonus %d for %s King on %s\n", bonus, color_to_str(c), buf);
// }
score[c] += bonus;
break;
case INVALID:
break;
default:
tbassert(false, "Jose says: no way!\n"); // No way, Jose!
}
laser_map_black[sq] = 0;
laser_map_white[sq] = 0;
}
}
int black_pawns_unpinned = mark_laser_path(p, laser_map_white, WHITE, 1); // 1 = path of laser with no moves
ev_score_t w_hattackable = HATTACK * (int) h_attackable;
score[WHITE] += w_hattackable;
// if (verbose) {
// printf("HATTACK bonus %d for White\n", w_hattackable);
// }
// PAWNPIN Heuristic --- is a pawn immobilized by the enemy laser.
int b_pawnpin = PAWNPIN * black_pawns_unpinned;
score[BLACK] += b_pawnpin;
int b_mobility = MOBILITY * mobility(p, BLACK);
score[BLACK] += b_mobility;
// if (verbose) {
// printf("MOBILITY bonus %d for Black\n", b_mobility);
// }
int white_pawns_unpinned = mark_laser_path(p, laser_map_black, BLACK, 1); // 1 = path of laser with no moves
ev_score_t b_hattackable = HATTACK * (int) h_attackable;
score[BLACK] += b_hattackable;
// if (verbose) {
// printf("HATTACK bonus %d for Black\n", b_hattackable);
// }
int w_mobility = MOBILITY * mobility(p, WHITE);
score[WHITE] += w_mobility;
// if (verbose) {
// printf("MOBILITY bonus %d for White\n", w_mobility);
// }
int w_pawnpin = PAWNPIN * white_pawns_unpinned;
score[WHITE] += w_pawnpin;
// score from WHITE point of view
ev_score_t tot = score[WHITE] - score[BLACK];
if (RANDOMIZE) {
ev_score_t z = rand_r(&seed) % (RANDOMIZE*2+1);
tot = tot + z - RANDOMIZE;
}
if (color_to_move_of(p) == BLACK) {
tot = -tot;
}
return tot / EV_SCORE_RATIO;
}
// Static evaluation. Returns score
score_t eval(position_t *p, bool verbose, full_board_t* board) {
// seed rand_r with a value of 1, as per
// http://linux.die.net/man/3/rand_r
static __thread unsigned int seed = 1;
// verbose = true: print out components of score
ev_score_t score[2] = { 0, 0 };
// int corner[2][2] = { {INF, INF}, {INF, INF} };
ev_score_t bonus;
color_t c = WHITE;
while (true) {
for (pnum_t pnum = 0; pnum <= board->pawn_count[c]; pnum++) {
square_t sq = board->pieces[c][pnum];
rnk_t r = rnk_of(sq);
fil_t f = fil_of(sq);
piece_t x = board->board[sq];
switch (ptype_of(x)) {
case EMPTY:
tbassert(false, "Jose says: no way!\n"); // No way, Jose!
case PAWN:
// PBETWEEN heuristic
bonus = pbetween(p, r, f, board);
score[c] += bonus;
// PCENTRAL heuristic
bonus = pcentral(r, f);
score[c] += bonus;
break;
case KING:
// KFACE heuristic
bonus = kface(p, r, f, board);
score[c] += bonus;
// KAGGRESSIVE heuristic
bonus = kaggressive(p, r, f, board);
score[c] += bonus;
break;
case INVALID:
tbassert(false, "Jose says: no way!\n"); // No way, Jose!
default:
tbassert(false, "Jose says: no way!\n"); // No way, Jose!
}
}
if (c == BLACK)
break;
c = BLACK;
}
score[WHITE] += board->pawn_count[WHITE] * PAWN_EV_VALUE;
score[BLACK] += board->pawn_count[BLACK] * PAWN_EV_VALUE;
square_t white_laser_list[MAX_NUM_PIECES];
square_t black_laser_list[MAX_NUM_PIECES];
int whitePathCount = get_laser_path_list(p, white_laser_list, WHITE, board);
int blackPathCount = get_laser_path_list(p, black_laser_list, BLACK, board);
ev_score_t w_hattackable = HATTACK * h_squares_attackable(p, WHITE, white_laser_list, whitePathCount, board);
score[WHITE] += w_hattackable;
ev_score_t b_hattackable = HATTACK * h_squares_attackable(p, BLACK, black_laser_list, blackPathCount, board);
score[BLACK] += b_hattackable;
int w_mobility_list = MOBILITY * mobility_list(p, WHITE, black_laser_list, blackPathCount, board);
score[WHITE] += w_mobility_list;
int b_mobility_list = MOBILITY * mobility_list(p, BLACK, white_laser_list, whitePathCount, board);
score[BLACK] += b_mobility_list;
// PAWNPIN Heuristic --- is a pawn immobilized by the enemy laser.
int w_pawnpin = PAWNPIN * pawnpin(p, WHITE, black_laser_list, blackPathCount, board); //use other color's laser map
score[WHITE] += w_pawnpin;
int b_pawnpin = PAWNPIN * pawnpin(p, BLACK, white_laser_list, whitePathCount, board); //use other color's laser map
score[BLACK] += b_pawnpin;
// score from WHITE point of view
ev_score_t tot = score[WHITE] - score[BLACK];
if (RANDOMIZE) {
ev_score_t z = rand_r(&seed) % (RANDOMIZE*2+1);
tot = tot + z - RANDOMIZE;
}
if (color_to_move_of(p) == BLACK) {
tot = -tot;
}
return tot / EV_SCORE_RATIO;
}
// Translate a fen string into a board position struct
//
int fen_to_pos(position_t *p, char *fen) {
static position_t dmy1, dmy2;
// these sentinels simplify checking previous
// states without stepping past null pointers.
dmy1.key = 0;
dmy1.victims.stomped = 1;
dmy1.victims.zapped = 1;
dmy1.history = NULL;
dmy2.key = 0;
dmy2.victims.stomped = 1;
dmy2.victims.zapped = 1;
dmy2.history = &dmy1;
p->key = 0; // hash key
p->victims.stomped = 0; // piece destroyed by stomper
p->victims.zapped = 0; // piece destroyed by shooter
p->history = &dmy2; // history
memset(&base_board, 0, sizeof(full_board_t));
if (fen[0] == '\0') { // Empty FEN => use starting position
fen = "ss3nw5/3nw2nw3/2nw7/1nw6SE1/nw9/9SE/1nw6SE1/7SE2/3SE2SE3/5SE3NN W";
}
int c_count = 0; // Invariant: fen[c_count] is next char to be read
for (int i = 0; i < ARR_SIZE; ++i) {
base_board.board[i] = INVALID_PIECE;
}
c_count = parse_fen_board(p, fen);
if (!c_count) {
return 1; // parse error of board
}
// King check
int Kings[2] = {0, 0};
for (fil_t f = 0; f < BOARD_WIDTH; ++f) {
for (rnk_t r = 0; r < BOARD_WIDTH; ++r) {
square_t sq = square_of(r, f);
piece_t x = base_board.board[sq];
ptype_t typ = ptype_of(x);
if (typ == KING) {
Kings[color_of(x)]++;
}
}
}
if (Kings[WHITE] == 0) {
fen_error(fen, c_count, "No White Kings");
return 1;
} else if (Kings[WHITE] > 1) {
fen_error(fen, c_count, "Too many White Kings");
return 1;
} else if (Kings[BLACK] == 0) {
fen_error(fen, c_count, "No Black Kings");
return 1;
} else if (Kings[BLACK] > 1) {
fen_error(fen, c_count, "Too many Black Kings");
return 1;
}
char c;
bool done = false;
// Look for color to move and set ply accordingly
while (!done && (c = fen[c_count++]) != '\0') {
switch (c) {
// ignore whitespace until the end
case ' ':
case '\t':
case '\n':
case '\r':
break;
// White to move
case 'W':
case 'w':
p->ply = 0;
base_board.ply = 0;
done = true;
break;
// Black to move
case 'B':
case 'b':
p->ply = 1;
base_board.ply = 1;
done = true;
break;
default:
fen_error(fen, c_count, "Must specify White (W) or Black (B) to move");
return 1;
break;
}
}
// Look for last move, if it exists
int lm_from_sq, lm_to_sq, lm_rot;
if (get_sq_from_str(fen, &c_count, &lm_from_sq) != 0) { // parse error
return 1;
}
if (lm_from_sq == 0) { // from-square of last move
p->last_move = 0; // no last move specified
p->key = compute_zob_key(p, &base_board);
return 0;
}
c = fen[c_count];
switch (c) {
case 'R':
case 'r':
lm_to_sq = lm_from_sq;
lm_rot = RIGHT;
break;
case 'U':
case 'u':
lm_to_sq = lm_from_sq;
lm_rot = UTURN;
break;
case 'L':
case 'l':
lm_to_sq = lm_from_sq;
lm_rot = LEFT;
break;
default: // Not a rotation
lm_rot = NONE;
if (get_sq_from_str(fen, &c_count, &lm_to_sq) != 0) {
return 1;
}
break;
}
p->last_move = move_of(EMPTY, lm_rot, lm_from_sq, lm_to_sq);
p->key = compute_zob_key(p, &base_board);
return 0; // everything is okay
}
