From b99cda9530a54e459eb49b50cf1922b38c7432ec Mon Sep 17 00:00:00 2001
From: eug-vs <eugene@eug-vs.xyz>
Date: Tue, 30 Aug 2022 23:04:19 +0300
Subject: feaT: add pawn promotions

---
 src/main.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

(limited to 'src/main.c')

diff --git a/src/main.c b/src/main.c
index 2b7275f..4471c37 100644
--- a/src/main.c
+++ b/src/main.c
@@ -233,6 +233,17 @@ int apply_move(Move move, int* board) {
     // printf("Captured %s\n", pieces[target_piece]);
   }
 
+  if ((piece & NO_COLOR) == PAWN) {
+    int rank = move.destination / 16;
+    if (rank == 0) {
+      board[move.destination] = QUEEN | BLACK;
+      return target_piece | PROMOTION_HAPPENED;
+    } else if (rank == 7) {
+      board[move.destination] = QUEEN | WHITE;
+      return target_piece | PROMOTION_HAPPENED;
+    }
+  }
+
   if ((piece & NO_COLOR) == KING && abs(move.destination - move.origin) == 2) {
     // CASTLE!
     if (move.destination == 2) {
@@ -260,6 +271,14 @@ int apply_move(Move move, int* board) {
 void reverse_move(Move move, int captured_piece, int* board) {
   int piece = board[move.destination];
 
+  if (captured_piece & PROMOTION_HAPPENED) {
+    board[move.destination] = captured_piece ^ PROMOTION_HAPPENED;
+    if (piece % 2 == WHITE) {
+      board[move.origin] = PAWN | WHITE;
+    } else board[move.origin] = PAWN | BLACK;
+    return;
+  }
+
   board[move.origin] = piece;
   board[move.destination] = captured_piece;
 
-- 
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