--- a/src/chess/rules.h Tue May 26 15:29:00 2026 +0200
+++ b/src/chess/rules.h Thu May 28 12:15:26 2026 +0200
@@ -30,8 +30,6 @@
#ifndef RULES_H
#define RULES_H
-#include "game-info.h"
-
#include <stdint.h>
#include <stdbool.h>
@@ -48,6 +46,94 @@
#define ENPASSANT_THREAT 0x40
+#define WHITE 0x10
+#define BLACK 0x20
+#define opponent_color(color) ((color)==WHITE?BLACK:WHITE)
+
+#define PIECE_MASK 0x0F
+#define COLOR_MASK 0x30
+
+#define PAWN 0x01
+#define ROOK 0x02
+#define KNIGHT 0x03
+#define BISHOP 0x04
+#define QUEEN 0x05
+#define KING 0x06
+
+#define WPAWN (WHITE|PAWN)
+#define WROOK (WHITE|ROOK)
+#define WKNIGHT (WHITE|KNIGHT)
+#define WBISHOP (WHITE|BISHOP)
+#define WQUEEN (WHITE|QUEEN)
+#define WKING (WHITE|KING)
+#define BPAWN (BLACK|PAWN)
+#define BROOK (BLACK|ROOK)
+#define BKNIGHT (BLACK|KNIGHT)
+#define BBISHOP (BLACK|BISHOP)
+#define BQUEEN (BLACK|QUEEN)
+#define BKING (BLACK|KING)
+
+typedef uint8_t Board[8][8];
+
+struct movetimeval {
+ uint64_t tv_sec;
+ int32_t tv_usec;
+};
+
+typedef struct {
+ uint8_t piece;
+ uint8_t fromfile;
+ uint8_t fromrow;
+ uint8_t tofile;
+ uint8_t torow;
+ uint8_t promotion;
+ uint8_t check;
+ uint8_t capture;
+ struct movetimeval timestamp;
+ struct movetimeval movetime;
+ char string[8];
+} Move;
+
+typedef struct {
+ uint8_t servercolor;
+ uint8_t timecontrol;
+ uint16_t time;
+ uint16_t addtime;
+} GameInfo;
+
+/** The buffer length for player names in GameInfo structures. */
+#define PLAYER_NAME_BUFLEN 32
+
+typedef struct {
+ Board board;
+ Move* moves;
+ /** optional name of the white player */
+ char wname[PLAYER_NAME_BUFLEN];
+ /** optional name of the black player */
+ char bname[PLAYER_NAME_BUFLEN];
+ /** capacity of the move array */
+ unsigned movecapacity;
+ /** number of (half-)moves (counting BOTH colors) */
+ unsigned int movecount;
+ /** a premove that shall be evaluated next time it's our turn */
+ char premove[8];
+ bool checkmate;
+ bool stalemate;
+ bool remis;
+ bool wresign;
+ bool bresign;
+ /** this flag is only supposed to be set when the opponent disconnects */
+ bool ragequit;
+ bool review;
+} GameState;
+
+#define is_game_running(gamestate) !((gamestate)->checkmate || \
+ (gamestate)->wresign || (gamestate)->bresign || \
+ (gamestate)->stalemate || (gamestate)->remis || (gamestate)->review)
+
+#define last_move(gamestate) \
+ ((gamestate)->moves[(gamestate)->movecount-1])
+
#define POS_UNSPECIFIED UINT8_MAX
#define mdst(b,m) b[(m)->torow][(m)->tofile]
#define msrc(b,m) b[(m)->fromrow][(m)->fromfile]
@@ -71,6 +157,19 @@
#define fileidx_s(c) (isfile(c)?fileidx(c):POS_UNSPECIFIED)
#define rowidx_s(c) (isrow(c)?rowidx(c):POS_UNSPECIFIED)
+
+/**
+ * Initializes a game state and prepares the chess board.
+ * @param gamestate the game state to initialize
+ */
+void gamestate_init(GameState *gamestate);
+
+/**
+ * Cleans up a game state and frees the memory for the movement list.
+ * @param gamestate the game state to clean up
+ */
+void gamestate_cleanup(GameState *gamestate);
+
/**
* Maps a character to a piece.
* 