Mercurial > hg > terminal-chess / file comparison
comparison: src/chess/rules.c
src/chess/rules.c
- changeset 139
- fa10bee331ac
- parent 137
- 43d1b3c33369
equal
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| 138:bcd6100373ef | 139:fa10bee331ac |
|---|---|
| 262 case 'K': return KING; | 262 case 'K': return KING; |
| 263 default: return 0; | 263 default: return 0; |
| 264 } | 264 } |
| 265 } | 265 } |
| 266 | 266 |
| 267 // TODO: check if we really need this "simulate" flag for performance | |
| 267 static void apply_move_impl(GameState *gamestate, Move *move, bool simulate) { | 268 static void apply_move_impl(GameState *gamestate, Move *move, bool simulate) { |
| 268 /* format move before moving (s.t. ambiguities can be resolved) */ | 269 /* format move before moving (s.t. ambiguities can be resolved) */ |
| 269 if (!simulate) { | 270 if (!simulate) { |
| 270 if (!move->string[0]) { | 271 if (!move->string[0]) { |
| 271 format_move(gamestate, move); | 272 format_move(gamestate, move); |
| 450 if (move->check) { | 451 if (move->check) { |
| 451 /* determine possible escape fields */ | 452 /* determine possible escape fields */ |
| 452 bool canescape = false; | 453 bool canescape = false; |
| 453 for (int dr = -1 ; dr <= 1 && !canescape ; dr++) { | 454 for (int dr = -1 ; dr <= 1 && !canescape ; dr++) { |
| 454 for (int df = -1 ; df <= 1 && !canescape ; df++) { | 455 for (int df = -1 ; df <= 1 && !canescape ; df++) { |
| 455 if (!(dr == 0 && df == 0) && | 456 if (dr == 0 && df == 0) continue; |
| 456 isidx(opkingrow + dr) && isidx(opkingfile + df)) { | 457 if (!isidx(opkingrow + dr)) continue; |
| 457 /* escape field neither occupied nor covered */ | 458 if (!isidx(opkingfile + df)) continue; |
| 458 canescape = | 459 uint8_t er = opkingrow + dr; |
| 459 !simulation.board[opkingrow + dr][opkingfile + df] && | 460 uint8_t ef = opkingfile + df; |
| 460 !is_covered(&simulation, | 461 |
| 461 opkingrow + dr, opkingfile + df, piececolor); | 462 /* check if escape field is already covered (threatened) */ |
| 463 if (is_covered(&simulation, er, ef, piececolor)) | |
| 464 continue; | |
| 465 | |
| 466 /* check if piece of the king's color blocks the field */ | |
| 467 if ((simulation.board[er][ef] & COLOR_MASK) == oppcolor) | |
| 468 continue; | |
| 469 | |
| 470 /* check if an attacking piece blocks the field */ | |
| 471 if ((simulation.board[er][ef] & COLOR_MASK) == piececolor) { | |
| 472 /* test if the king can fight back */ | |
| 473 GameState sim_retaliate = gamestate_copy_sim(&simulation); | |
| 474 Move move_retaliate = {0}; | |
| 475 move_retaliate.piece = (oppcolor|KING); | |
| 476 move_retaliate.fromrow = opkingrow; | |
| 477 move_retaliate.fromfile = opkingfile; | |
| 478 move_retaliate.torow = er; | |
| 479 move_retaliate.tofile = ef; | |
| 480 move_retaliate.capture = 1; | |
| 481 apply_move_impl(&sim_retaliate, &move_retaliate, true); | |
| 482 canescape = !is_covered(&sim_retaliate, er, ef, piececolor); | |
| 483 gamestate_cleanup(&sim_retaliate); | |
| 484 } else { | |
| 485 /* the field is not covered and unoccupied */ | |
| 486 canescape = true; | |
| 462 } | 487 } |
| 463 } | 488 } |
| 464 } | 489 } |
| 465 /* can't escape, can he capture? */ | 490 |
| 491 /* can't escape, can the king be rescued? */ | |
| 466 if (!canescape && threatcount == 1) { | 492 if (!canescape && threatcount == 1) { |
| 467 /* TODO: this is bugged - we actually need distinguish two cases | 493 canescape = is_protected(&simulation, |
| 468 * 1. another piece can rescue the king | |
| 469 * (this is what is implemented now) | |
| 470 * 2. the king can kill the attacker | |
| 471 * - in this case, the threatcount is irrelevant, because | |
| 472 * the king moves out of the current threat | |
| 473 * - we must verify that the king can actually kill the | |
| 474 * attacker without running into a new check | |
| 475 */ | |
| 476 canescape = is_attacked(&simulation, | |
| 477 threats[0].fromrow, threats[0].fromfile, oppcolor); | 494 threats[0].fromrow, threats[0].fromfile, oppcolor); |
| 478 } | 495 } |
| 479 | 496 |
| 480 /* can't capture, can he block? */ | 497 /* can't capture, can he block? */ |
| 481 if (!canescape && threatcount == 1) { | 498 if (!canescape && threatcount == 1) { |
