// KFACE heuristic: bonus (or penalty) for King facing toward the other King
ev_score_t kface(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);
square_t opp_sq = board->pieces[opp_color(c)][0];
int delta_fil = fil_of(opp_sq) - f;
int delta_rnk = rnk_of(opp_sq) - r;
int bonus;
switch (ori_of(x)) {
case NN:
bonus = delta_rnk;
break;
case EE:
bonus = delta_fil;
break;
case SS:
bonus = -delta_rnk;
break;
case WW:
bonus = -delta_fil;
break;
default:
bonus = 0;
tbassert(false, "Illegal King orientation.\n");
}
return (bonus * KFACE) / (abs(delta_rnk) + abs(delta_fil));
}
// 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);
}
// KFACE heuristic: bonus (or penalty) for King facing toward the other King
ev_score_t kface(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);
square_t opp_sq = p->kloc[opp_color(c)];
int delta_fil = fil_of(opp_sq) - f;
int delta_rnk = rnk_of(opp_sq) - r;
int bonus;
switch (ori_of(x)) {
case NN:
bonus = delta_rnk;
break;
case EE:
bonus = delta_fil;
break;
case SS:
bonus = -delta_rnk;
break;
case WW:
bonus = -delta_fil;
break;
default:
bonus = 0;
tbassert(false, "Illegal King orientation.\n");
}
return (bonus * KFACE) / (abs(delta_rnk) + abs(delta_fil));
}
// 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);
}
// 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;
}
}
}
// H_SQUARES_ATTACKABLE heuristic: for shooting the enemy king
float h_squares_attackable(position_t *p, color_t c,
square_t* laser_list, int laser_list_length, full_board_t* board) {
square_t o_king_sq = board->pieces[opp_color(c)][0];
rnk_t k_rnk = rnk_of(o_king_sq);
fil_t k_fil = fil_of(o_king_sq);
float h_attackable = 0;
for (int i = 0; i < laser_list_length - 1; i++) {
h_attackable += fast_h_dist(laser_list[i], laser_list[i+1], k_rnk, k_fil);
}
if (in_bounds(laser_list[laser_list_length - 1])) {
h_attackable += fast_h_dist(laser_list[laser_list_length - 1], laser_list[laser_list_length - 1] + 1, k_rnk, k_fil);
}
return h_attackable;
}
// 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 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;
}
