eschac

src/rays.rs

@@ -0,0 +1,44 @@
+use crate::bitboard::*;
+use crate::board::*;
+
+pub(crate) struct Rays(BySquare<ByDirection<Bitboard>>);
+
+impl Rays {
+    pub(crate) fn new() -> Self {
+        Self(BySquare::new(|square| {
+            ByDirection::new(|direction| {
+                let mut square = square;
+                let mut res = Bitboard::new();
+                while let Some(x) = square.trans(direction) {
+                    square = x;
+                    res |= square.bitboard();
+                }
+                res
+            })
+        }))
+    }
+
+    #[inline]
+    pub(crate) fn ray(&self, square: Square, direction: Direction) -> Bitboard {
+        *self.0.get(square).get(direction)
+    }
+
+    pub(crate) fn blocked(
+        &self,
+        square: Square,
+        direction: Direction,
+        blockers: Bitboard,
+    ) -> Bitboard {
+        let blockers = blockers & *self.0.get(square).get(direction);
+        let square2 = if (direction as u8) < 4 {
+            blockers.first()
+        } else {
+            blockers.last()
+        };
+        *self.0.get(square).get(direction)
+            & !match square2 {
+                Some(square2) => *self.0.get(square2).get(direction),
+                None => Bitboard::new(),
+            }
+    }
+}