done rook and bishop

assignment1-18/chessboard.c

@@ -65,13 +65,13 @@ void print_chessboard(struct chessboard * cb) {
 
 }
 
-void cb_move(struct chessboard* cb, int from_row, int from_col, int to_row,
+inline void cb_move(struct chessboard* cb, int from_row, int from_col, int to_row,
              int to_col) {
     cb->position[to_row][to_col] = cb->position[from_row][from_col];
     cb->position[from_row][from_col] = EMPTY;
 }
 
-bool is_empty(struct chessboard* cb, int row, int col) {
+inline bool is_empty(struct chessboard* cb, int row, int col) {
     return cb->position[row][col] == EMPTY;
 }
 
@@ -79,6 +79,11 @@ inline enum player player(struct chessboard* cb, int row, int col) {
      return cb->position[row][col] < 7 ? WHITE : BLACK;
 }
 
+
+inline int sign(int n) {
+    return n == 0 ? 0 : (n > 0 ? 1 : -1);
+}
+
 enum mstatus move_pawn(struct chessboard* cb, enum player p, int from_row,
                        int from_col, int to_row, int to_col) {
     // two forward if in the starting position, no capture is valid
@@ -109,6 +114,40 @@ enum mstatus move_pawn(struct chessboard* cb, enum player p, int from_row,
     }
 }
 
+enum mstatus check_empty_paths(struct chessboard* cb, int from_row,
+     int from_col, int to_row, int to_col) {
+     int ii = sign(to_row - from_row), jj = sign(to_col - from_col);
+     int i = from_row + ii, j = from_col + jj;
+     for(; i != to_col || j != to_row; i += ii; j += jj) {
+         if (!is_empty(cb, i, j)) {
+             return INVALID;
+         }
+     }
+
+     cb_move(cb, from_row, from_col, to_row, to_col);
+     return VALID;
+}
+
+enum mstatus move_rook(struct chessboard* cb, enum player p, int from_row,
+                       int from_col, int to_row, int to_col) {
+    if (to_row != from_row && to_col != from_col) {
+        return INVALID;
+    }
+
+    return check_empty_paths(cb, from_row, from_col, to_row, to_col);
+}
+
+enum mstatus move_bishop(struct chessboard* cb, enum player p, int from_row,
+                       int from_col, int to_row, int to_col) {
+    if (from_row - to_row == from_col - to_col && from_row != to_row) {
+        return INVALID;
+    }
+
+    return check_empty_paths(cb, from_row, from_col, to_row, to_col);
+}
+
+
+
 enum mstatus move(
         struct chessboard * cb, enum player p,
         const char * from, const char * to)
@@ -124,12 +163,12 @@ enum mstatus move(
     int from_col = from[1] - '1', to_col = to[0] - '1';
 
     // if you are moving thin air, EH VOLEVIH
-    if (cb->position[from_row][from_col] == EMPTY) {
+    if (is_empty(cb, from_row, from_col)) {
         return INVALID;
     }
 
     // if you are moving someone else's pieces, "thou shall not steal"
-    if (cb->position[from_row][from_col] / 7 != p) {
+    if (player(cb, from_row, from_col) != p) {
         return INVALID;
     }
 
@@ -141,13 +180,23 @@ enum mstatus move(
         return INVALID;
     }
 
+    // if you try to move on the same spot, don't do it you buffoon
+    if (from_row == to_row && from_col == to_col) {
+        return INVALID;
+    }
+
     // try to understand which piece we are moving
     switch (cb->position[from_row][from_col]) {
     case WHITE_PAWN:
     case BLACK_PAWN:
         return move_pawn(cb, p, from_row, from_col, to_row, to_col);
+    case WHITE_ROOK:
+    case BLACK_ROOK:
+        return move_rook(cb, p, from_row, from_col, to_row, to_col);
+    case WHITE_BISHOP:
+    case BLACK_BISHOP:
+        return move_bishop(cb, p, from_row, from_col, to_row, to_col);
     default:
         return INVALID;
     }
 }
-