Add pawn, knight, and king attack move caches

test/base.py

@@ -0,0 +1,79 @@
+import ctypes
+import platform
+import unittest
+from pathlib import Path
+
+
+WHITE, BLACK = 0, 1
+FILES = {c:i for i,c in enumerate("abcdefgh")}
+
+
+def sq(name: str) -> int:
+    f = FILES[name[0].lower()]
+    r = int(name[1]) - 1
+    return f + 8 * r
+
+
+def bb_from(*algebraic):
+    m = 0
+    for s in algebraic:
+        m |= (1 << sq(s))
+    return m
+
+
+def popcount(x: int) -> int:
+    return x.bit_count()
+
+
+def draw_bb(mask: int, origin: int | None = None) -> str:
+    print("\n")
+    lines = []
+    for r in range(7, -1, -1):
+        row = []
+        for f in range(8):
+            sqi = r * 8 + f
+            bit = (mask >> sqi) & 1
+            if origin is not None and sqi == origin:
+                ch = 'O'
+            elif bit:
+                ch = 'x'
+            else:
+                ch = '.'
+            row.append(ch)
+        lines.append(f"{r+1} " + " ".join(row))
+    lines.append("  " + " ".join(FILES))
+    lines = "\n".join(lines)
+    print(lines, "\n")
+
+
+class ChessLibTestBase(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        root = Path(__file__).resolve().parents[1]
+        libname = "libchess.so"
+        libpath = root / "build" / libname
+        cls.lib = ctypes.CDLL(str(libpath))
+
+        attack_cache_functions = [
+            "create_knight_attack_cache",
+            "create_pawn_attack_cache",
+            "create_king_attack_cache",
+        ]
+
+        # init functions
+        for fn in attack_cache_functions:
+            getattr(cls.lib, fn).argtypes = []
+            getattr(cls.lib, fn).restype = None
+     
+        cls.lib.create_knight_attack_cache()
+        cls.lib.create_pawn_attack_cache()
+        cls.lib.create_king_attack_cache()
+
+        KnightArr = ctypes.c_uint64 * 64
+        KingArr   = ctypes.c_uint64 * 64
+        PawnRow   = ctypes.c_uint64 * 64
+        PawnArr   = PawnRow * 2
+
+        cls.KNIGHT_ATTACKS = KnightArr.in_dll(cls.lib, "KNIGHT_ATTACKS")
+        cls.KING_ATTACKS   = KingArr.in_dll(cls.lib, "KING_ATTACKS")
+        cls.PAWN_ATTACKS   = PawnArr.in_dll(cls.lib, "PAWN_ATTACKS")

test/test_piece_attack_cache.py

@@ -0,0 +1,83 @@
+from test.base import ChessLibTestBase
+from test.base import bb_from
+from test.base import draw_bb
+from test.base import sq
+from test.base import BLACK, WHITE
+
+
+class KnightFixedCases(ChessLibTestBase):
+    def test_knight_a1(self):
+        expected = bb_from("b3", "c2")
+        self.assertEqual(int(self.KNIGHT_ATTACKS[sq("a1")]), expected)
+
+
+    def test_knight_d4(self):
+        expected = bb_from("b5","b3","c6","e6","f5","f3","c2","e2")
+        actual = int(self.KNIGHT_ATTACKS[sq("d4")])
+        self.assertEqual(actual, expected)
+
+
+    def test_knight_h8(self):
+        expected = bb_from("f7","g6")
+        actual = int(self.KNIGHT_ATTACKS[sq("h8")])
+        self.assertEqual(actual, expected)
+
+
+class PawnFixedCases(ChessLibTestBase):
+    def test_white_pawn_a2(self):
+        expected = bb_from("b3")
+        actual = int(self.PAWN_ATTACKS[WHITE][sq("a2")])
+        self.assertEqual(actual, expected)
+
+
+    def test_white_pawn_b2(self):
+        expected = bb_from("a3", "c3")
+        actual = int(self.PAWN_ATTACKS[WHITE][sq("b2")])
+        self.assertEqual(actual, expected)
+
+
+    def test_black_pawn_a2(self):
+        expected = bb_from("b6")
+        actual = int(self.PAWN_ATTACKS[BLACK][sq("a7")])
+        self.assertEqual(actual, expected)
+
+
+    def test_black_pawn_b2(self):
+        expected = bb_from("a6", "c6")
+        actual = int(self.PAWN_ATTACKS[BLACK][sq("b7")])
+        self.assertEqual(actual, expected)
+
+
+class KingFixedCases(ChessLibTestBase):
+    def test_king_a1(self):
+        expected = bb_from("a2", "b1", "b2")
+        actual = int(self.KING_ATTACKS[sq("a1")])
+        self.assertEqual(actual, expected)
+
+
+    def test_king_a8(self):
+        expected = bb_from("a7", "b8", "b7")
+        actual = int(self.KING_ATTACKS[sq("a8")])
+        self.assertEqual(actual, expected)
+
+
+    def test_king_h1(self):
+        expected = bb_from("h2", "g1", "g2")
+        actual = int(self.KING_ATTACKS[sq("h1")])
+        self.assertEqual(actual, expected)
+
+
+    def test_king_h8(self):
+        expected = bb_from("h7", "g7", "g8")
+        actual = int(self.KING_ATTACKS[sq("h8")])
+        self.assertEqual(actual, expected)
+
+
+    def test_king_d4(self):
+        expected = bb_from(
+            "c3", "d3", "e3",
+            "c4", "e4",
+            "c5", "d5", "e5",
+        )
+        actual = int(self.KING_ATTACKS[sq("d4")])
+        self.assertEqual(actual, expected)