Augment moves of some fairy pieces

To get better disambiguation in variants that have to be played with
legality testing off, the Elephant is given also one-step moves (making
it a so-called Modern Elephant) in -variant fairy and great. The Dragon
King (Crowned Rook), which had no moves defined for it outside Shogi at
all, has been given Rook moves plus an orthogonal 2-jump, so that it
can get SAN moves when used as Dababba or Short Rook. (Illegal moves
currently aways force long algebraic notation...)

diff --git a/moves.c b/moves.c
index 89af9a0..d667113 100644 (file)
--- a/moves.c
+++ b/moves.c
@@ -418,6 +418,13 @@ void GenPseudoLegal(board, flags, callback, closure)
                           && !SameColor(board[rf][ff], board[rt][ft]))
                                callback(board, flags, NormalMove,
                                         rf, ff, rt, ft, closure);
+                      if(gameInfo.variant != VariantFairy && gameInfo.variant != VariantGreat) continue;
+                      rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
+                      ft = ff + fs;
+                      if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
+                          && !SameColor(board[rf][ff], board[rt][ft]))
+                               callback(board, flags, NormalMove,
+                                        rf, ff, rt, ft, closure);
                  }
                 break;
 
@@ -477,6 +484,19 @@ void GenPseudoLegal(board, flags, callback, closure)
               }
               break;
 
+            /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
+           case WhiteDragon:
+           case BlackDragon:
+              for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
+                for (s = -2; s <= 2; s += 4) {
+                     rt = rf + s * d;
+                     ft = ff + s * (1 - d);
+                      if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT || board[rf+rt>>1][ff+ft>>1] == EmptySquare) continue;
+                     if (SameColor(board[rf][ff], board[rt][ft])) continue;
+                     callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
+                 }
+              goto doRook;
+              
             /* Shogi Dragon King has to continue as Ferz after Rook moves */
             case SHOGI WhiteDragon:
             case SHOGI BlackDragon:
@@ -492,6 +512,7 @@ void GenPseudoLegal(board, flags, callback, closure)
             case SHOGI BlackRook:
            case WhiteRook:
            case BlackRook:
+          doRook:
               for (d = 0; d <= 1; d++)
                 for (s = -1; s <= 1; s += 2)
                  for (i = 1;; i++) {