bpaul-chess

commit ed6793101504aebf59c0fcb98d1ea78466e154dd
parent 5a93117d3877330488326b0feea20e42e0bdba45
Author: benjamin paul <bpaul@bpaul.xyz>
Date:   Sat, 23 Oct 2021 22:20:46 +1000

Printing the board plus fix everything that was broken that was found in the process

Diffstat:
M
src/main.c
 | 
36
+++++++++++++++++++++++-------------
M
src/pos.c
 | 
45
++++++++++++++++++++++++++++++++++++++++-----
M
src/pos.h
 | 
33
+++++++++++++++++++++++++++------

3 files changed, 90 insertions(+), 24 deletions(-)
diff --git a/src/main.c b/src/main.c
@@ -2,6 +2,12 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "bb.h"
+#include "pos.h"
+
+#define BUFSIZE 8192
+#define START_FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
+
 #define VERSION "v0.0.1"
 
 /* sizeof magically gets the length of the string! (plus \0) */
@@ -9,21 +15,15 @@
 
 int
 main() {
-	/* If your computer does not have enough RAM to support a 2KiB buffer, it
-	 * probably wont be able to run the program.
-	 *
-	 * A 2048 character buffer may be too small for a position command, a
-	 * setoption command or a go searchmoves command. The position command is
-	 * the only command out of these which may be used in an actual setting.
-	 * For it to be the case that the command is too big, there must be
-	 * (2048-23)/5 moves made being the buffer size minus the length of
-	 * "position startpos moves" divided by the size of a move, being 4
-	 * characters and a space. This means that with this buffer size, a game
-	 * cannot go on for longer than 405 moves. */
-	char buf[2048];
+	char buf[BUFSIZE];
+
+	/* Create a position structure */
+	pos p;
+
+	parse_fen(&p, START_FEN);
 
 	for (;;) {
-		fgets(buf, 2048, stdin);
+		fgets(buf, BUFSIZE, stdin);
 
 		if (CMD("uci")) {
 			puts("id name bpaul-chess " VERSION);
@@ -33,7 +33,17 @@ main() {
 			puts("readyok");
 		} else if (CMD("quit")) {
 			break;
+		} else if (CMD("position startpos")) {
+			/* Still would need to do the moves section of this command :( */
+			parse_fen(&p, START_FEN);
+		} else if (CMD("position fen")) {
+			parse_fen(&p, buf + 11);
+		}
+#ifndef NDEBUG /* Debug commands! */
+		else if (CMD("print")) {
+			print_board(&p);
 		}
+#endif
 	}
 
 	return 0;
diff --git a/src/pos.c b/src/pos.c
@@ -1,5 +1,6 @@
 #include <assert.h>
 #include <stdbool.h>
+#include <stdio.h>
 
 #include "bb.h"
 #include "pos.h"
@@ -23,10 +24,26 @@ void
 setpiece(pos *p, unsigned char pc, unsigned char sq) {
 	setbit(&p->sides[side(pc)], sq);
 	setbit(&p->pieces[piece(pc)], sq);
+	p->mailbox[sq] = pc;
 }
 
 void
-parsefen(pos *p, char *fen) {
+reset_board(pos *p) {
+	int i;
+	for (i = 0; i < 2; i++) p->sides[i] = 0;
+	for (i = 0; i < 6; i++) p->pieces[i] = 0;
+	for (i = 0; i < 64; i++) p->mailbox[i] = nP;
+	p->castle = 0;
+	p->enpas = NO_SQ;
+	p->fifty = 0;
+	p->game_length = 0;
+	p->turn = WHITE;
+}
+
+void
+parse_fen(pos *p, char *fen) {
+	reset_board(p);
+
 	char phase, sq;
 
 	phase = 0;
@@ -63,6 +80,7 @@ parsefen(pos *p, char *fen) {
 					 * character which is a number gives the integer value of
 					 * the number. For example, '8' - '0' = 8. */
 					sq += *fen - '0';
+					break;
 
 				case '/':
 					/* This should only occur after we have moved past the last
@@ -72,13 +90,17 @@ parsefen(pos *p, char *fen) {
 					 * by 2 rows downwards. */
 					assert(sq % 8 == 0);
 					sq -= 16;
+					break;
+
+				case ' ':
+					phase = 1;
+					fen++;
+					break;
 
 				default:
 					/* There was an error in the fen */
-					assert(0);
+					printf("Fen error, character %c, sq %d", *fen, sq);
 			}
-
-			if (sq < 0) { phase++; fen += 2; }
 		}
 
 		/* Turn */
@@ -105,7 +127,7 @@ parsefen(pos *p, char *fen) {
 
 				/* If it is not one of these characters there is
 				 * something wrong with the fen */
-				default: assert(0);
+				default: printf("Fen error");
 			}
 		} else if (phase == 2) phase++;
 
@@ -132,3 +154,16 @@ parsefen(pos *p, char *fen) {
 		fen++;
 	}
 }
+
+#ifndef NDEBUG
+void
+print_board(pos *p) {
+	int r,c;
+	for (r = 7; r >= 0; r--) {
+		for (c = 0; c <= 7; c++) {
+			putchar("pnbrqk  PNBRQK."[p->mailbox[square(r,c)]]);
+		}
+		puts("");
+	}
+}
+#endif
diff --git a/src/pos.h b/src/pos.h
@@ -1,19 +1,35 @@
 #ifndef POS_H
 #define POS_H
 
-enum { WHITE, BLACK, SIDE_CNT };
+enum { WHITE, BLACK };
 
-enum { PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING, PIECE_CNT };
+enum { PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING };
 
 /* Please format this better! */
 enum {  wP,     wN, wB, wR, wQ, wK,
-	bP = 8, bN, bB, bR, bQ, bK };
+	bP = 8, bN, bB, bR, bQ, bK,
+    nP /* No piece */
+};
+
+/* Square names enum */
+enum {
+	A1, B1, C1, D1, E1, F1, G1, H1,
+    A2, B2, C2, D2, E2, F2, G2, H2,
+    A3, B3, C3, D3, E3, F3, G3, H3,
+    A4, B4, C4, D4, E4, F4, G4, H4,
+    A5, B5, C5, D5, E5, F5, G5, H5,
+    A6, B6, C6, D6, E6, F6, G6, H6,
+    A7, B7, C7, D7, E7, F7, G7, H7,
+    A8, B8, C8, D8, E8, F8, G8, H8,
+    NO_SQ
+};
 
 typedef struct pos pos;
 
 struct pos {
-	bb sides[SIDE_CNT];
-	bb pieces[PIECE_CNT];
+	bb sides[2];
+	bb pieces[6];
+	char mailbox[64]; /* Array of piece positions used for square lookup */
 	char castle;	/* Castling permissions flags */
 	char enpas;	/* En passant square */
 	unsigned char fifty;	/* Tracker for 50 move rule */
@@ -21,5 +37,10 @@ struct pos {
 	char turn;
 };
 
-void parsefen(pos *, char *);
+void reset_board(pos *);
+void parse_fen(pos *, char *);
+#ifndef NDEBUG
+void print_board(pos *);
+#endif
+
 #endif