tmp: save progress from @black-pearltmp

1 files changed, 26 insertions, 0 deletions

diff --git a/src/bitboard.c b/src/bitboard.c
index e53e3ed..96f220d 100644
--- a/src/bitboard.c
+++ b/src/bitboard.c
@@ -35,3 +35,29 @@ inline int bitscanAndReset(Bitboard* bb) {
   *bb &= *bb - 1;
   return idx;
 }
+
+
+/* These 4 blindly copied from chessprogramming.org TODO: rewrite */
+U64 rankMask(enumSquare sq) {
+  return  C64(0xff) << (sq & 56);
+}
+
+U64 fileMask(enumSquare sq) {
+  return C64(0x0101010101010101) << (sq & 7);
+}
+
+U64 diagonalMask(enumSquare sq) {
+   const U64 maindia = C64(0x8040201008040201);
+   int diag =8*(sq & 7) - (sq & 56);
+   int nort = -diag & ( diag >> 31);
+   int sout =  diag & (-diag >> 31);
+   return (maindia >> sout) << nort;
+}
+
+U64 antiDiagMask(enumSquare sq) {
+   const U64 maindia = C64(0x0102040810204080);
+   int diag =56- 8*(sq&7) - (sq&56);
+   int nort = -diag & ( diag >> 31);
+   int sout =  diag & (-diag >> 31);
+   return (maindia >> sout) << nort;
+}