implemented en passant in legal moves

2025-02-02 23:13:37 +01:00 · 2025-02-02 23:13:37 +01:00 · 4c8fdfa3b4
commit 4c8fdfa3b4
parent 84c3af2bb1
1 changed files with 13 additions and 0 deletions
--- a/cpp/src/pieces/pawn.cpp
+++ b/cpp/src/pieces/pawn.cpp
@ -29,6 +29,19 @@ std::vector<Move> pawn_moves(const Board& b, const Coords xy) {
        }
    }

+    // -- Capture en passant
+    if (b.en_passant_target != -1) {
+        Coords c = Coords::from_index(b.en_passant_target);
+        int dy = my_colour == Colour::White ? -1 : 1;
+        if (c.y == xy.y + dy && (c.x == xy.x - 1 || c.x == xy.x + 1))
+            ret.push_back(Move{
+                xy.to_index(),
+                c.to_index(),
+                .is_capturing = true,
+                .en_passant = true
+            });
+    }
+
    // -- Promotion
    bool is_on_starting_rank =
        my_colour == Colour::White ? xy.y == 1 : xy.y == 6;