--- a/src/chess/rules.c Wed May 28 15:47:57 2014 +0200
+++ b/src/chess/rules.c Wed Jun 11 15:38:01 2014 +0200
@@ -33,6 +33,17 @@
#include <stdlib.h>
#include <sys/time.h>
+static GameState gamestate_copy_sim(GameState *gamestate) {
+ GameState simulation = *gamestate;
+ if (simulation.lastmove) {
+ MoveList *lastmovecopy = malloc(sizeof(MoveList));
+ *lastmovecopy = *(simulation.lastmove);
+ simulation.movelist = simulation.lastmove = lastmovecopy;
+ }
+
+ return simulation;
+}
+
void gamestate_cleanup(GameState *gamestate) {
MoveList *elem;
elem = gamestate->movelist;
@@ -145,67 +156,75 @@
addmove(gamestate, move);
}
-static _Bool validate_move_rules(GameState *gamestate, Move *move) {
+static int validate_move_rules(GameState *gamestate, Move *move) {
/* validate indices (don't trust opponent) */
if (!chkidx(move)) {
- return 0;
+ return INVALID_POSITION;
}
/* must move */
if (move->fromfile == move->tofile && move->fromrow == move->torow) {
- return 0;
+ return INVALID_MOVE_SYNTAX;
}
/* does piece exist */
if ((msrc(gamestate->board, move)&(PIECE_MASK|COLOR_MASK))
!= (move->piece&(PIECE_MASK|COLOR_MASK))) {
- return 0;
+ return INVALID_POSITION;
}
/* can't capture own pieces */
if ((mdst(gamestate->board, move) & COLOR_MASK)
== (move->piece & COLOR_MASK)) {
- return 0;
+ return RULES_VIOLATED;
}
/* must capture, if and only if destination is occupied */
if ((mdst(gamestate->board, move) == 0 && move->capture) ||
(mdst(gamestate->board, move) != 0 && !move->capture)) {
- return 0;
+ return INVALID_MOVE_SYNTAX;
}
/* validate individual rules */
+ _Bool chkrules;
switch (move->piece & PIECE_MASK) {
case PAWN:
- return pawn_chkrules(gamestate, move) &&
+ chkrules = pawn_chkrules(gamestate, move) &&
!pawn_isblocked(gamestate, move);
+ break;
case ROOK:
- return rook_chkrules(move) &&
+ chkrules = rook_chkrules(move) &&
!rook_isblocked(gamestate, move);
+ break;
case KNIGHT:
- return knight_chkrules(move); /* knight is never blocked */
+ chkrules = knight_chkrules(move); /* knight is never blocked */
+ break;
case BISHOP:
- return bishop_chkrules(move) &&
+ chkrules = bishop_chkrules(move) &&
!bishop_isblocked(gamestate, move);
+ break;
case QUEEN:
- return queen_chkrules(move) &&
+ chkrules = queen_chkrules(move) &&
!queen_isblocked(gamestate, move);
+ break;
case KING:
- return king_chkrules(gamestate, move) &&
+ chkrules = king_chkrules(gamestate, move) &&
!king_isblocked(gamestate, move);
+ break;
default:
- return 0;
+ return INVALID_MOVE_SYNTAX;
}
+
+ return chkrules ? VALID_MOVE_SEMANTICS : RULES_VIOLATED;
}
-_Bool validate_move(GameState *gamestate, Move *move) {
- // TODO: provide more details via a return code
+int validate_move(GameState *gamestate, Move *move) {
- _Bool result = validate_move_rules(gamestate, move);
+ int result = validate_move_rules(gamestate, move);
/* cancel processing to save resources */
- if (!result) {
- return 0;
+ if (result != VALID_MOVE_SEMANTICS) {
+ return result;
}
/* find kings for check validation */
@@ -226,15 +245,23 @@
}
}
- /* simulation move for check validation */
- GameState simulation = *gamestate;
+ /* simulate move for check validation */
+ GameState simulation = gamestate_copy_sim(gamestate);
Move simmove = *move;
apply_move(&simulation, &simmove);
/* don't move into or stay in check position */
if (is_covered(&simulation, mykingrow, mykingfile,
opponent_color(piececolor))) {
- return 0;
+
+ gamestate_cleanup(&simulation);
+ if ((move->piece & PIECE_MASK) == KING) {
+ return KING_MOVES_INTO_CHECK;
+ } else {
+ /* last move is always not null in this case */
+ return gamestate->lastmove->move.check ?
+ KING_IN_CHECK : PIECE_PINNED;
+ }
}
/* correct check and checkmate flags (move is still valid) */
@@ -315,7 +342,9 @@
}
}
- return 1;
+ gamestate_cleanup(&simulation);
+
+ return VALID_MOVE_SEMANTICS;
}
_Bool get_threats(GameState *gamestate, uint8_t row, uint8_t file,
@@ -351,7 +380,8 @@
_Bool result = 0;
for (int i = 0 ; i < candidatecount ; i++) {
- if (validate_move_rules(gamestate, &(candidates[i]))) {
+ if (validate_move_rules(gamestate, &(candidates[i]))
+ == VALID_MOVE_SEMANTICS) {
result = 1;
if (threats && threatcount) {
threats[(*threatcount)++] = candidates[i];
@@ -375,10 +405,14 @@
}
}
- GameState simulation = *gamestate;
+ GameState simulation = gamestate_copy_sim(gamestate);
Move simmove = *move;
apply_move(&simulation, &simmove);
- return is_covered(&simulation, kingrow, kingfile, opponent_color(color));
+ _Bool covered = is_covered(&simulation,
+ kingrow, kingfile, opponent_color(color));
+ gamestate_cleanup(&simulation);
+
+ return covered;
}
_Bool get_real_threats(GameState *gamestate, uint8_t row, uint8_t file,
@@ -404,7 +438,7 @@
}
for (uint8_t i = 0 ; i < candidatecount ; i++) {
- GameState simulation = *gamestate;
+ GameState simulation = gamestate_copy_sim(gamestate);
Move simmove = candidates[i];
apply_move(&simulation, &simmove);
if (!is_covered(&simulation, kingrow, kingfile,
@@ -414,6 +448,7 @@
threats[(*threatcount)++] = candidates[i];
}
}
+ gamestate_cleanup(&simulation);
}
return result;
@@ -421,7 +456,7 @@
return 0;
}
}
-#include <ncurses.h>
+
static int getlocation(GameState *gamestate, Move *move) {
uint8_t color = move->piece & COLOR_MASK;
@@ -473,6 +508,9 @@
move->fromrow = POS_UNSPECIFIED;
size_t len = strlen(mstr);
+ if (len < 1 || len > 6) {
+ return INVALID_MOVE_SYNTAX;
+ }
/* evaluate check/checkmate flags */
if (mstr[len-1] == '+') {
@@ -513,7 +551,6 @@
move->tofile = fileidx(mstr[1]);
move->torow = rowidx(mstr[2]);
}
-
} else if (len == 4) {
move->piece = getpiece(mstr[0]);
if (!move->piece) {