1.1 --- a/src/chess/rules.c Thu Apr 03 16:07:04 2014 +0200
1.2 +++ b/src/chess/rules.c Fri Apr 04 17:36:42 2014 +0200
1.3 @@ -90,12 +90,14 @@
1.4 }
1.5 }
1.6
1.7 -_Bool is_covered(GameState *gamestate,uint8_t row,uint8_t file,uint8_t color) {
1.8 +_Bool get_any_threat_for(GameState *gamestate, uint8_t row, uint8_t file,
1.9 + uint8_t color, Move *threat) {
1.10 Move threats[16];
1.11 int threatcount = 0;
1.12 for (uint8_t r = 0 ; r < 8 ; r++) {
1.13 for (uint8_t f = 0 ; f < 8 ; f++) {
1.14 if ((gamestate->board[r][f] & COLOR_MASK) == color) {
1.15 + memset(&(threats[threatcount]), 0, sizeof(Move));
1.16 threats[threatcount].piece = gamestate->board[r][f];
1.17 threats[threatcount].fromrow = r;
1.18 threats[threatcount].fromfile = f;
1.19 @@ -108,6 +110,9 @@
1.20
1.21 for (int i = 0 ; i < threatcount ; i++) {
1.22 if (validate_move(gamestate, &(threats[i]))) {
1.23 + if (threat) {
1.24 + *threat = threats[i];
1.25 + }
1.26 return 1;
1.27 }
1.28 }
1.29 @@ -158,7 +163,7 @@
1.30 gamestate->board[move->torow][fileidx('d')] = color|ROOK;
1.31 }
1.32 }
1.33 -
1.34 +
1.35 addmove(gamestate, move);
1.36 }
1.37
1.38 @@ -179,8 +184,8 @@
1.39 result = msrc(gamestate->board, move) == move->piece;
1.40
1.41 /* can't capture own pieces */
1.42 - if ((mdst(gamestate->board, move) & COLOR_MASK)
1.43 - == (move->piece & COLOR_MASK)) {
1.44 + uint8_t piececolor = (move->piece & COLOR_MASK);
1.45 + if ((mdst(gamestate->board, move) & COLOR_MASK) == piececolor) {
1.46 return 0;
1.47 }
1.48
1.49 @@ -219,13 +224,70 @@
1.50 return 0;
1.51 }
1.52
1.53 - /* is piece pinned */
1.54 - // TODO: make it so
1.55 + /* find kings for check validation */
1.56 + uint8_t mykingfile = 0, mykingrow = 0, opkingfile = 0, opkingrow = 0;
1.57 + for (uint8_t row = 0 ; row < 8 ; row++) {
1.58 + for (uint8_t file = 0 ; file < 8 ; file++) {
1.59 + if (gamestate->board[row][file] ==
1.60 + (piececolor == WHITE?WKING:BKING)) {
1.61 + mykingfile = file;
1.62 + mykingrow = row;
1.63 + } else if (gamestate->board[row][file] ==
1.64 + (piececolor == WHITE?BKING:WKING)) {
1.65 + opkingfile = file;
1.66 + opkingrow = row;
1.67 + }
1.68 + }
1.69 + }
1.70 +
1.71 + /* simulation move for check validation */
1.72 + GameState simulation;
1.73 + memcpy(&simulation, gamestate, sizeof(GameState));
1.74 + apply_move(&simulation, move);
1.75 +
1.76 + /* don't move into or stay in check position */
1.77 + if (is_covered(&simulation, mykingrow, mykingfile,
1.78 + opponent_color(piececolor))) {
1.79 + return 0;
1.80 + }
1.81
1.82 /* correct check and checkmate flags (move is still valid) */
1.83 - // TODO: make it so
1.84 + Move threat;
1.85 + move->check = get_any_threat_for(&simulation, opkingrow, opkingfile,
1.86 + piececolor, &threat);
1.87
1.88 - return result;
1.89 + if (move->check) {
1.90 + /* determine possible escape fields */
1.91 + _Bool canescape = 0;
1.92 + for (int dr = -1 ; dr <= 1 && !canescape ; dr++) {
1.93 + for (int df = -1 ; df <= 1 && !canescape ; df++) {
1.94 + if (!(dr == 0 && df == 0) &&
1.95 + isidx(opkingrow + dr) && isidx(opkingfile + df)) {
1.96 +
1.97 + /* escape field neither blocked nor covered */
1.98 + if ((simulation.board[opkingrow + dr][opkingfile + df]
1.99 + & COLOR_MASK) != opponent_color(piececolor)) {
1.100 + canescape |= !is_covered(&simulation,
1.101 + opkingrow + dr, opkingfile + df, piececolor);
1.102 + }
1.103 + }
1.104 + }
1.105 + }
1.106 + /* can't escape, can we capture? */
1.107 + if (!canescape) {
1.108 + canescape = is_covered(&simulation, threat.fromrow,
1.109 + threat.fromfile, opponent_color(piececolor));
1.110 +
1.111 + /* can't capture, can we block? */
1.112 + // TODO: make it so
1.113 +
1.114 + if (!canescape) {
1.115 + gamestate->checkmate = 1;
1.116 + }
1.117 + }
1.118 + }
1.119 +
1.120 + return 1;
1.121 }
1.122
1.123 int eval_move(GameState *gamestate, char *mstr, Move *move) {
