From 1951db07202d4102fbfc0e40a3569ba05bed06f1 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Fri, 22 Jul 2022 10:37:56 +0200
Subject: [PATCH] Add magic mask generation

---
 src/movegen/mod.rs           |  3 +++
 src/movegen/wizardry/mask.rs | 41 ++++++++++++++++++++++++++++++++++++
 src/movegen/wizardry/mod.rs  |  1 +
 3 files changed, 45 insertions(+)
 create mode 100644 src/movegen/wizardry/mask.rs
 create mode 100644 src/movegen/wizardry/mod.rs

diff --git a/src/movegen/mod.rs b/src/movegen/mod.rs
index d379194..3d22eb0 100644
--- a/src/movegen/mod.rs
+++ b/src/movegen/mod.rs
@@ -8,3 +8,6 @@ mod king;
 mod knight;
 mod pawn;
 mod rook;
+
+// Magic bitboard generation
+mod wizardry;
diff --git a/src/movegen/wizardry/mask.rs b/src/movegen/wizardry/mask.rs
new file mode 100644
index 0000000..af1b8fa
--- /dev/null
+++ b/src/movegen/wizardry/mask.rs
@@ -0,0 +1,41 @@
+use crate::board::{Bitboard, File, Rank, Square};
+use crate::movegen::bishop::bishop_moves;
+use crate::movegen::rook::rook_moves;
+
+/// Compute the relevancy mask for a bishop on a given [Square].
+#[allow(unused)] // FIXME: remove once used
+pub fn generate_bishop_mask(square: Square) -> Bitboard {
+    let rays = bishop_moves(square, Bitboard::EMPTY);
+
+    let mask = File::A.into_bitboard()
+        | File::H.into_bitboard()
+        | Rank::First.into_bitboard()
+        | Rank::Eighth.into_bitboard();
+
+    rays - mask
+}
+
+/// Compute the relevancy mask for a rook on a given [Square].
+#[allow(unused)] // FIXME: remove once used
+pub fn generate_rook_mask(square: Square) -> Bitboard {
+    let rays = rook_moves(square, Bitboard::EMPTY);
+
+    let mask = {
+        let mut mask = Bitboard::EMPTY;
+        if square.file() != File::A {
+            mask = mask | File::A.into_bitboard()
+        };
+        if square.file() != File::H {
+            mask = mask | File::H.into_bitboard()
+        };
+        if square.rank() != Rank::First {
+            mask = mask | Rank::First.into_bitboard()
+        };
+        if square.rank() != Rank::Eighth {
+            mask = mask | Rank::Eighth.into_bitboard()
+        };
+        mask
+    };
+
+    rays - mask
+}
diff --git a/src/movegen/wizardry/mod.rs b/src/movegen/wizardry/mod.rs
new file mode 100644
index 0000000..f6053c6
--- /dev/null
+++ b/src/movegen/wizardry/mod.rs
@@ -0,0 +1 @@
+mod mask;