Mercurial > hg > terminal-chess / file revision
src/game.c@faec61c4901f
src/game.c
Wed, 26 Mar 2014 14:12:59 +0100
- author
- Mike Becker <universe@uap-core.de>
- date
- Wed, 26 Mar 2014 14:12:59 +0100
- changeset 13
- faec61c4901f
- parent 12
- 84880c7e1ea6
- child 14
- 970748b9a73b
- permissions
- -rw-r--r--
completed eval_move
1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2014 Mike Becker. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 *
28 */
30 #include "game.h"
31 #include "input.h"
32 #include "rules/rules.h"
33 #include <ncurses.h>
34 #include <string.h>
36 static const uint8_t boardx = 10, boardy = 10;
38 static void draw_board(Board board, uint8_t mycolor) {
40 for (uint8_t y = 0 ; y < 8 ; y++) {
41 for (uint8_t x = 0 ; x < 8 ; x++) {
42 uint8_t col = board[y][x] & COLOR_MASK;
43 uint8_t piece = board[y][x] & PIECE_MASK;
44 char piecec = ' ';
45 switch (piece) {
46 case PAWN: piecec = 'P'; break;
47 case ROOK: piecec = 'R'; break;
48 case KNIGHT: piecec = 'N'; break;
49 case BISHOP: piecec = 'B'; break;
50 case QUEEN: piecec = 'Q'; break;
51 case KING: piecec = 'K'; break;
52 }
54 attrset((col == WHITE ? A_BOLD : A_DIM) |
55 COLOR_PAIR((y&1)==(x&1) ? COL_WB : COL_BW));
57 int cy = mycolor == WHITE ? boardy-y : boardy-7+y;
58 int cx = mycolor == WHITE ? boardx+x*3 : boardx+21-x*3;
59 mvaddch(cy, cx, ' ');
60 mvaddch(cy, cx+1, piecec);
61 mvaddch(cy, cx+2, ' ');
62 }
63 }
65 attrset(A_NORMAL);
66 for (uint8_t i = 0 ; i < 8 ; i++) {
67 int x = mycolor == WHITE ? boardx+i*3+1 : boardx+22-i*3;
68 int y = mycolor == WHITE ? boardy-i : boardy-7+i;
69 mvaddch(boardy+1, x, 'a'+i);
70 mvaddch(y, boardx-2, '1'+i);
71 }
72 }
74 /**
75 * Applies a move and deletes captured pieces.
76 *
77 * @param board the current board state
78 * @param move the move to apply
79 */
80 static void apply_move(Board board, Move *move) {
81 board[move->fromrow][move->fromfile] = 0;
82 // TODO: care for en passant capture
83 board[move->torow][move->tofile] = move->piece;
85 /* castling */
86 if ((move->piece & PIECE_MASK) == KING &&
87 move->fromfile == fileidx('e')) {
88 uint8_t color = move->piece & COLOR_MASK;
90 if (move->tofile == fileidx('g')) {
91 board[move->torow][fileidx('h')] = 0;
92 board[move->torow][fileidx('f')] = color|ROOK;
93 } else if (move->tofile == fileidx('c')) {
94 board[move->torow][fileidx('a')] = 0;
95 board[move->torow][fileidx('d')] = color|ROOK;
96 }
97 }
98 }
100 /**
101 * Validates move by applying chess rules.
102 * @param board the current board state
103 * @param move the move to validate
104 * @return TRUE, if the move complies to chess rules, FALSE otherwise
105 */
106 static _Bool validate_move(Board board, Move *move) {
107 _Bool result;
109 /* validate indices (don't trust opponent) */
110 if (!chkidx(move)) {
111 return FALSE;
112 }
114 /* does piece exist */
115 result = board[move->fromrow][move->fromfile] == move->piece;
117 switch (move->piece & PIECE_MASK) {
118 case PAWN:
119 result = result && pawn_chkrules(board, move);
120 result = result && !pawn_isblocked(board, move);
121 break;
122 case ROOK:
123 result = result && rook_chkrules(board, move);
124 result = result && !rook_isblocked(board, move);
125 break;
126 case KNIGHT:
127 result = result && knight_chkrules(board, move);
128 result = result && !knight_isblocked(board, move);
129 break;
130 case BISHOP:
131 result = result && bishop_chkrules(board, move);
132 result = result && !bishop_isblocked(board, move);
133 break;
134 case QUEEN:
135 result = result && queen_chkrules(board, move);
136 result = result && !queen_isblocked(board, move);
137 break;
138 case KING:
139 result = result && king_chkrules(board, move);
140 result = result && !king_isblocked(board, move);
141 break;
142 default:
143 result = FALSE;
144 }
146 /* is piece pinned */
147 // TODO: make it so
149 /* correct check and checkmate flags */
150 // TODO: make it so
152 return result;
153 }
155 /**
156 * Maps a character to a piece.
157 *
158 * Does not work for pawns, since they don't have a character.
159 *
160 * @param c one of R,N,B,Q,K
161 * @return numeric value for the specified piece
162 */
163 static uint8_t getpiece(char c) {
164 switch (c) {
165 case 'R': return ROOK;
166 case 'N': return KNIGHT;
167 case 'B': return BISHOP;
168 case 'Q': return QUEEN;
169 case 'K': return KING;
170 default: return 0;
171 }
172 }
174 /**
175 * Guesses the location of a piece for short algebraic notation.
176 *
177 * @param board the current state of the board
178 * @param move the move date to operate on
179 * @return TRUE if the location could be retrieved, FALSE if the location is
180 * ambiguous
181 */
182 static _Bool getlocation(Board board, Move *move) {
183 uint8_t piece = move->piece & PIECE_MASK;
184 switch (piece) {
185 case PAWN: return pawn_getlocation(board, move);
186 case ROOK: return rook_getlocation(board, move);
187 case KNIGHT: return knight_getlocation(board, move);
188 case BISHOP: return bishop_getlocation(board, move);
189 case QUEEN: return queen_getlocation(board, move);
190 case KING: return king_getlocation(board, move);
191 default: return FALSE;
192 }
193 }
195 /**
196 * Evaluates a move syntactically and stores the move data in the specified
197 * object.
198 *
199 * @param board the current state of the board
200 * @param mycolor the color of the current player
201 * @param mstr the input string to parse
202 * @param move a pointer to object where the move data shall be stored
203 * @return TRUE, if the move is syntactically valid, FALSE otherwise
204 */
205 static _Bool eval_move(Board board, uint8_t mycolor, char *mstr, Move *move) {
206 memset(move, 0, sizeof(Move));
207 move->fromfile = POS_UNSPECIFIED;
208 move->fromrow = POS_UNSPECIFIED;
210 size_t len = strlen(mstr);
212 /* evaluate check/checkmate flags */
213 if (mstr[len-1] == '+') {
214 len--; mstr[len] = '\0';
215 move->check = TRUE;
216 } else if (mstr[len-1] == '#') {
217 len--; mstr[len] = '\0';
218 move->checkmate = TRUE;
219 }
221 if (len == 2) {
222 /* pawn move (e.g. "e4") */
223 move->piece = PAWN;
224 move->tofile = fileidx(mstr[0]);
225 move->torow = rowidx(mstr[1]);
226 } else if (len == 3) {
227 if (strcmp(mstr, "O-O") == 0) {
228 /* king side castling */
229 move->piece = KING;
230 move->fromfile = fileidx('e');
231 move->tofile = fileidx('g');
232 move->fromrow = move->torow = mycolor == WHITE ? 0 : 7;
233 } else {
234 /* move (e.g. "Nf3") */
235 move->piece = getpiece(mstr[0]);
236 move->tofile = fileidx(mstr[1]);
237 move->torow = rowidx(mstr[2]);
238 }
240 } else if (len == 4) {
241 move->piece = getpiece(mstr[0]);
242 if (mstr[1] == 'x') {
243 /* capture (e.g. "Nxf3", "dxe5") */
244 move->capture = TRUE;
245 if (!move->piece) {
246 move->piece = PAWN;
247 move->fromfile = fileidx(mstr[0]);
248 }
249 } else {
250 /* move (e.g. "Ndf3") */
251 move->fromfile = fileidx(mstr[1]);
252 }
253 move->tofile = fileidx(mstr[2]);
254 move->torow = rowidx(mstr[3]);
255 } else if (len == 5) {
256 if (strcmp(mstr, "O-O-O") == 0) {
257 /* queen side castling "O-O-O" */
258 move->piece = KING;
259 move->fromfile = fileidx('e');
260 move->tofile = fileidx('c');
261 move->fromrow = move->torow = mycolor == WHITE ? 0 : 7;
262 } else {
263 move->piece = getpiece(mstr[0]);
264 if (mstr[2] == 'x') {
265 move->capture = TRUE;
266 if (move->piece) {
267 /* capture (e.g. "Ndxf3") */
268 move->fromfile = fileidx(mstr[1]);
269 } else {
270 /* long notation capture (e.g. "e5xf6") */
271 move->piece = PAWN;
272 move->fromfile = fileidx(mstr[0]);
273 move->fromrow = rowidx(mstr[1]);
274 }
275 } else {
276 /* long notation move (e.g. "Nc5a4") */
277 move->fromfile = fileidx(mstr[1]);
278 move->fromrow = rowidx(mstr[2]);
279 }
280 move->tofile = fileidx(mstr[3]);
281 move->torow = rowidx(mstr[4]);
282 }
283 } else if (len == 6) {
284 /* long notation capture (e.g. "Nc5xf3") */
285 if (mstr[3] == 'x') {
286 move->capture = TRUE;
287 move->piece = getpiece(mstr[0]);
288 move->fromfile = fileidx(mstr[1]);
289 move->fromrow = rowidx(mstr[2]);
290 move->tofile = fileidx(mstr[4]);
291 move->torow = rowidx(mstr[5]);
292 }
293 }
296 if (move->piece) {
297 move->piece |= mycolor;
298 if (move->fromfile == POS_UNSPECIFIED
299 || move->fromrow == POS_UNSPECIFIED) {
300 return getlocation(board, move) && chkidx(move);
301 } else {
302 return chkidx(move);
303 }
304 } else {
305 return FALSE;
306 }
307 // TODO: return status code to indicate the error type
308 }
310 static int sendmove(Board board, uint8_t mycolor, int opponent) {
311 const size_t buflen = 8;
312 char movestr[buflen];
313 _Bool remisrejected = FALSE;
314 uint8_t code;
316 while (1) {
317 move(boardy+3, 0);
318 if (remisrejected) {
319 printw(
320 "Use chess notation to enter your move.\n"
321 "Remis offer rejected - type 'surr' to surrender. \n\n"
322 "Type your move: ");
323 } else {
324 printw(
325 "Use chess notation to enter your move.\n"
326 "Or type 'surr' to surrender or 'remis' to offer remis.\n\n"
327 "Type your move: ");
328 }
329 clrtoeol();
330 refresh();
331 getnstr(movestr, buflen);
333 if (strncmp(movestr, "surr", buflen) == 0) {
334 printw("You surrendered!");
335 refresh();
336 net_send_code(opponent, NETCODE_SURRENDER);
337 return 1;
338 } else if (strncmp(movestr, "remis", buflen) == 0) {
339 if (!remisrejected) {
340 net_send_code(opponent, NETCODE_REMIS);
341 printw("Remis offer sent - waiting for acceptance...");
342 refresh();
343 if (net_recieve_code(opponent) == NETCODE_ACCEPT) {
344 printw("\rRemis accepted!");
345 clrtoeol();
346 refresh();
347 return 1;
348 } else {
349 remisrejected = TRUE;
350 }
351 }
352 } else {
353 Move move;
354 if (eval_move(board, mycolor, movestr, &move)) {
355 net_send_code(opponent, NETCODE_MOVE);
356 net_send_data(opponent, &move, sizeof(Move));
357 code = net_recieve_code(opponent);
358 move.check = code == NETCODE_CHECK;
359 move.checkmate = code == NETCODE_CHECKMATE;
360 // TODO: record move
361 if (code == NETCODE_DECLINE) {
362 printw("Invalid move.");
363 clrtoeol();
364 } else {
365 apply_move(board, &move);
366 if (move.checkmate) {
367 printw("Checkmate!");
368 return 1;
369 }
370 }
371 } else {
372 printw("Can't interpret move - please use algebraic notation.");
373 }
374 }
375 }
376 }
378 static int recvmove(Board board, int opponent) {
380 while (1) {
381 move(boardy+3, 0);
382 printw("Awaiting opponent move...");
383 clrtoeol();
384 refresh();
386 // TODO: nonblocking
387 uint32_t code = net_recieve_code(opponent);
389 Move move;
390 switch (code) {
391 case NETCODE_SURRENDER:
392 printw("\rYour opponent surrendered!");
393 clrtoeol();
394 return 1;
395 case NETCODE_REMIS:
396 if (prompt_yesno(
397 "\rYour opponent offers remis - do you accept")) {
398 printw("\rRemis accepted!");
399 clrtoeol();
400 net_send_code(opponent, NETCODE_ACCEPT);
401 return 1;
402 } else {
403 net_send_code(opponent, NETCODE_DECLINE);
404 }
405 break;
406 case NETCODE_MOVE:
407 net_recieve_data(opponent, &move, sizeof(Move));
408 if (validate_move(board, &move)) {
409 apply_move(board, &move);
410 // TODO: record move
411 if (move.check) {
412 net_send_code(opponent, NETCODE_CHECK);
413 } else if (move.checkmate) {
414 net_send_code(opponent, NETCODE_CHECKMATE);
415 } else {
416 net_send_code(opponent, NETCODE_ACCEPT);
417 }
418 return 0;
419 } else {
420 net_send_code(opponent, NETCODE_DECLINE);
421 }
422 }
423 }
424 }
426 void game_start(Settings *settings, int opponent) {
427 _Bool myturn = is_server(settings) ==
428 (settings->gameinfo.servercolor == WHITE);
429 uint8_t mycolor = myturn ? WHITE:BLACK;
431 _Bool running;
433 Board board = {
434 {WROOK, WKNIGHT, WBISHOP, WQUEEN, WKING, WBISHOP, WKNIGHT, WROOK},
435 {WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN},
436 {0, 0, 0, 0, 0, 0, 0, 0},
437 {0, 0, 0, 0, 0, 0, 0, 0},
438 {0, 0, 0, 0, 0, 0, 0, 0},
439 {0, 0, 0, 0, 0, 0, 0, 0},
440 {BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN},
441 {BROOK, BKNIGHT, BBISHOP, BQUEEN, BKING, BBISHOP, BKNIGHT, BROOK}
442 };
444 do {
445 clear();
446 draw_board(board, mycolor);
447 if (myturn) {
448 running = !sendmove(board, mycolor, opponent);
449 } else {
450 running = !recvmove(board, opponent);
451 flushinp(); // flush any input the user hacked in while waiting
452 }
453 myturn ^= TRUE;
454 } while (running);
456 mvaddstr(getmaxy(tchess_window)-1, 0,
457 "Game has ended. Press any key to leave...");
458 getch();
459 }
