From d2c61a81b5b9302ad01eaa8ad64637f5c15e90bd Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Sun, 24 Jul 2022 16:31:26 +0200
Subject: [PATCH] Make use of generated move tables

---
 src/build.rs               |  3 ++
 src/movegen/magic/mod.rs   |  5 +++
 src/movegen/magic/moves.rs | 71 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)
 create mode 100644 src/movegen/magic/moves.rs

diff --git a/src/build.rs b/src/build.rs
index e05410d..29265f5 100644
--- a/src/build.rs
+++ b/src/build.rs
@@ -131,5 +131,8 @@ fn main() -> Result<()> {
         print_boards(&mut out, "QUEEN_SIDE_CASTLE_BLOCKERS", &queen_blockers)?;
     }
 
+    // Include the generated files now that the build script has run.
+    println!("cargo:rustc-cfg=generated_boards");
+
     Ok(())
 }
diff --git a/src/movegen/magic/mod.rs b/src/movegen/magic/mod.rs
index 251a5d9..8b3f605 100644
--- a/src/movegen/magic/mod.rs
+++ b/src/movegen/magic/mod.rs
@@ -19,3 +19,8 @@ impl Magic {
         base_index + self.offset
     }
 }
+
+#[cfg(generated_boards)]
+mod moves;
+#[cfg(generated_boards)]
+pub use moves::*;
diff --git a/src/movegen/magic/moves.rs b/src/movegen/magic/moves.rs
new file mode 100644
index 0000000..2901b28
--- /dev/null
+++ b/src/movegen/magic/moves.rs
@@ -0,0 +1,71 @@
+use super::Magic;
+use crate::board::{Bitboard, Color, Square};
+
+include!(concat!(env!("OUT_DIR"), "/magic_tables.rs"));
+
+pub fn quiet_pawn_moves(color: Color, square: Square, blockers: Bitboard) -> Bitboard {
+    // If there is a piece in front of the pawn, it can't advance
+    if !(color.backward_direction().move_board(blockers) & square).is_empty() {
+        return Bitboard::EMPTY;
+    }
+    // SAFETY: we know the values are in-bounds
+    unsafe {
+        *PAWN_MOVES
+            .get_unchecked(color.index())
+            .get_unchecked(square.index())
+    }
+}
+
+pub fn pawn_moves(color: Color, square: Square, blockers: Bitboard) -> Bitboard {
+    // SAFETY: we know the values are in-bounds
+    let attacks = unsafe {
+        *PAWN_ATTACKS
+            .get_unchecked(color.index())
+            .get_unchecked(square.index())
+    };
+    quiet_pawn_moves(color, square, blockers) | attacks
+}
+
+pub fn knight_moves(square: Square) -> Bitboard {
+    // SAFETY: we know the values are in-bounds
+    unsafe { *KNIGHT_MOVES.get_unchecked(square.index()) }
+}
+
+pub fn bishop_moves(square: Square, blockers: Bitboard) -> Bitboard {
+    // SAFETY: we know the values are in-bounds
+    unsafe {
+        let index = BISHOP_MAGICS
+            .get_unchecked(square.index())
+            .get_index(blockers);
+        *BISHOP_MOVES.get_unchecked(index)
+    }
+}
+
+pub fn rook_moves(square: Square, blockers: Bitboard) -> Bitboard {
+    // SAFETY: we know the values are in-bounds
+    unsafe {
+        let index = ROOK_MAGICS
+            .get_unchecked(square.index())
+            .get_index(blockers);
+        *ROOK_MOVES.get_unchecked(index)
+    }
+}
+
+pub fn queen_moves(square: Square, blockers: Bitboard) -> Bitboard {
+    bishop_moves(square, blockers) | rook_moves(square, blockers)
+}
+
+pub fn king_moves(square: Square) -> Bitboard {
+    // SAFETY: we know the values are in-bounds
+    unsafe { *KING_MOVES.get_unchecked(square.index()) }
+}
+
+pub fn king_side_castle_blockers(color: Color) -> Bitboard {
+    // SAFETY: we know the values are in-bounds
+    unsafe { *KING_SIDE_CASTLE_BLOCKERS.get_unchecked(color.index()) }
+}
+
+pub fn queen_side_castle_blockers(color: Color) -> Bitboard {
+    // SAFETY: we know the values are in-bounds
+    unsafe { *QUEEN_SIDE_CASTLE_BLOCKERS.get_unchecked(color.index()) }
+}