refactor: use 0x88 board representation

1 files changed, 33 insertions, 33 deletions

diff --git a/src/main.c b/src/main.c
index 931d1df..5c8e7de 100644
--- a/src/main.c
+++ b/src/main.c
@@ -6,11 +6,11 @@
 #include "pieces.h"
 
 
-void print_board(int board[BOARD_SIZE][BOARD_SIZE]) {
-  for (int rank = BOARD_SIZE - 1; rank >= 0; rank--) {
+void print_board(int board[128]) {
+  for (int rank = 7; rank >= 0; rank--) {
     printf("%i|", rank + 1);
-    for (int file = 0; file < BOARD_SIZE; file++) {
-      int piece = board[rank][file];
+    for (int file = 0; file < 8; file++) {
+      int piece = board[rank * 16 + file];
       printf("%s ", pieces[piece]);
     }
     printf("\n");
@@ -18,7 +18,7 @@ void print_board(int board[BOARD_SIZE][BOARD_SIZE]) {
   printf("  a b c d e f g h\n");
 }
 
-void parse_FEN(char* FEN, int board[BOARD_SIZE][BOARD_SIZE]) {
+void parse_FEN(char* FEN, int board[128]) {
   // TODO: parse everything, not position only
   int rank = 7;
   int file = 0;
@@ -28,45 +28,45 @@ void parse_FEN(char* FEN, int board[BOARD_SIZE][BOARD_SIZE]) {
     if (FEN[k] > '0' && FEN[k] <= '8') {
       int last_file = file + FEN[k] - '0';
       for (file; file < last_file; file++) {
-        board[rank][file] = EMPTY;
+        board[rank * 16 + file] = EMPTY;
       }
     } else {
       switch (FEN[k]) {
         case 'r':
-          board[rank][file] = BLACK | ROOK;
+          board[rank * 16 + file] = BLACK | ROOK;
           break;
         case 'R':
-          board[rank][file] = ROOK;
+          board[rank * 16 + file] = ROOK;
           break;
         case 'n':
-          board[rank][file] = BLACK | KNIGHT;
+          board[rank * 16 + file] = BLACK | KNIGHT;
           break;
         case 'N':
-          board[rank][file] = KNIGHT;
+          board[rank * 16 + file] = KNIGHT;
           break;
         case 'b':
-          board[rank][file] = BLACK | BISHOP;
+          board[rank * 16 + file] = BLACK | BISHOP;
           break;
         case 'B':
-          board[rank][file] = BISHOP;
+          board[rank * 16 + file] = BISHOP;
           break;
         case 'q':
-          board[rank][file] = BLACK | QUEEN;
+          board[rank * 16 + file] = BLACK | QUEEN;
           break;
         case 'Q':
-          board[rank][file] = QUEEN;
+          board[rank * 16 + file] = QUEEN;
           break;
         case 'k':
-          board[rank][file] = BLACK | KING;
+          board[rank * 16 + file] = BLACK | KING;
           break;
         case 'K':
-          board[rank][file] = KING;
+          board[rank * 16 + file] = KING;
           break;
         case 'p':
-          board[rank][file] = BLACK | PAWN;
+          board[rank * 16 + file] = BLACK | PAWN;
           break;
         case 'P':
-          board[rank][file] = PAWN;
+          board[rank * 16 + file] = PAWN;
           break;
         case '/':
           rank--;
@@ -75,30 +75,30 @@ void parse_FEN(char* FEN, int board[BOARD_SIZE][BOARD_SIZE]) {
         case ' ':
           return;
         default:
-          board[rank][file] = KNIGHT;
+          board[rank * 16 + file] = KNIGHT;
       }
       file++;
     }
   }
 }
 
-int notation_to_position(int file, int rank) {
-  return ((rank - 1) << 3) + (file - 'a');
+int notation_to_index(int file, int rank) {
+  return (rank - 1) * 16 + (file - 'a');
 }
 
-void position_to_notation(int position, char notation[2]) {
-  notation[0] = (position & FILE_MASK) + 'a';
-  notation[1] = (position >> 3) + '1';
+void index_to_notation(int index, char notation[2]) {
+  notation[0] = (index & FILE_MASK) + 'a';
+  notation[1] = (index >> 4) + '1';
 }
 
 int positions_to_move(int origin, int destination) {
-  return (origin << 6) + destination;
+  return (origin << 8) + destination;
 };
 
 void print_move(int move) {
-  char move_in_notation[5] = "xy XY";
-  position_to_notation(move >> 6, move_in_notation);
-  position_to_notation(move & DESTINATION_MASK, move_in_notation + 3);
+  char move_in_notation[] = "xy XY";
+  index_to_notation(move >> 8, move_in_notation);
+  index_to_notation(move & DESTINATION_MASK, move_in_notation + 3);
   printf("%s\n", move_in_notation);
 };
 
@@ -110,14 +110,14 @@ int input_move() {
 
   scanf(" %c%i %c%i", &file, &rank, &file_destination, &rank_destination);
 
-  int pos = notation_to_position(file, rank);
-  int pos_destination = notation_to_position(file_destination, rank_destination);
+  int pos = notation_to_index(file, rank);
+  int pos_destination = notation_to_index(file_destination, rank_destination);
 
   return positions_to_move(pos, pos_destination);
 };
 
 void apply_move(int move, int* board) {
-  int origin = move >> 6;
+  int origin = move >> 8;
   int destination = move & DESTINATION_MASK;
 
   board[destination] = board[origin];
@@ -125,14 +125,14 @@ void apply_move(int move, int* board) {
 }
 
 int main() {
-  int board[BOARD_SIZE][BOARD_SIZE];
+  int board[128];
   parse_FEN(DEFAULT_FEN, board);
   print_board(board);
 
   int move;
   while (1) {
     move = input_move();
-    apply_move(move, (int *)board);
+    apply_move(move, board);
     print_board(board);
   }