adding a create move helper function

1 files changed, 42 insertions, 0 deletions

diff --git a/src/board/board.cpp b/src/board/board.cpp
index 9d0ef47..3b1383a 100644
--- a/src/board/board.cpp
+++ b/src/board/board.cpp
@@ -10,6 +10,48 @@
 
 int PositionToIndex(Position i) { return (i.rank * 8) + i.file; }
 
+uint16_t CreateMove(uint8_t from, uint8_t to, PieceType promotion) {
+  if (from >= 64 || to >= 64) {
+    std::cout << "expected a valid chess piece position 0-63";
+    assert(false);
+  }
+  uint16_t move = 0;
+  bool firstPromotionFlag = false;
+  bool secondPromotionFlag = false;
+  switch (promotion) {
+  case NONEPIECE:
+  case KNIGHT:
+    firstPromotionFlag = false;
+    secondPromotionFlag = false;
+    break;
+  case QUEEN:
+    firstPromotionFlag = true;
+    secondPromotionFlag = false;
+    break;
+  case ROOK:
+    firstPromotionFlag = false;
+    secondPromotionFlag = true;
+    break;
+  case BISHOP:
+    firstPromotionFlag = true;
+    secondPromotionFlag = true;
+    break;
+  default:
+    std::cout << "unexpected promotion type";
+    assert(false);
+    exit(1);
+  }
+  if (firstPromotionFlag) {
+    move |= (1 << 1);
+  }
+  if (secondPromotionFlag) {
+    move |= (1 << 0);
+  }
+  move |= (from << 2);
+  move |= (to << 8);
+  return move;
+};
+
 PieceType getPromotionTypeFromMove(uint16_t move) {
   bool firstFlag = (move & (1 << 1)) != 0;
   bool secondFlag = (move & (1 << 0)) != 0;