started work on the movement logic

src/chess.h

@@ -21,6 +21,8 @@
 // type abstractions
 typedef int board_t[BOARD_HORIZONTAL][BOARD_VERTICAL];
 
+#define PIECE_COUNT 7 // how many unique pieces are there
+#define MAX_PIECE_MOVE_COUNT 27 // the max possible num of options where to move in one moment
 typedef enum {
     NONE,
     PAWN,
@@ -47,6 +49,11 @@ typedef struct {
     pos_t to;
 } move_t;
 
+typedef struct {
+    int dirx;
+    int diry; 
+} relative_move_t;
+
 // the default arrangment of pieces on the board
 #define BOARD_DEFAULT_CONFIG \
 (board_t){\
@@ -59,6 +66,24 @@ typedef struct {
     {2,3,4,5,6,4,3,2}\
 }
 
+typedef struct {
+    piece_e piece;
+    unsigned int piece_move_count;
+    relative_move_t moves[MAX_PIECE_MOVE_COUNT];
+} valid_move_t;
+
+/** FIXME: ALSO DEPENDS ON THE STATE OF THE GAME - e.g. a pawn cannot move two places in the middle of the game but can in the first round */
+#define DEFAULT_VALID_MOVES \
+(valid_move_t[PIECE_COUNT]){\
+    .piece = NONE, .count = 0, .moves = {}\
+    .piece = PAWN, .count = 0, .moves = {}\
+    .piece = ROOK, .count = 0, .moves = {}\
+    .piece = KNIGHT, .count = 0, .moves = {}\
+    .piece = BISHOP, .count = 0, .moves = {}\
+    .piece = QUEEN, .count = 0, .moves = {}\
+    .piece = KING, .count = 0, .moves = {}\
+}
+
 typedef enum {
     CHECKMATE,
     STALEMATE