From a6df3ae0dd73db228fdee2af67253644362a6112 Mon Sep 17 00:00:00 2001
From: AnnaSnoeijs <anna.snoeijs@hotmail.com>
Date: Fri, 6 Jun 2025 21:31:59 +0200
Subject: [PATCH] Made logic a bit faster for boards with many columns

---
 connect4.c |  2 +-
 logic.c    | 39 +++++++++++++++++++++++++--------------
 logic.h    |  3 ++-
 3 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/connect4.c b/connect4.c
index 536c327..dd75c83 100644
--- a/connect4.c
+++ b/connect4.c
@@ -166,7 +166,7 @@ int main( int argc, char *argv[] ){
 		move_t move = askMove();
 		int column = askColumn( playboard, move );
 		playMove( &playboard, move, column );
-		calcWins( &wins, playboard );
+		calcWins( &wins, playboard, column );
 		updateBoard( wins, playboard, move, column );
 	}
 }
diff --git a/logic.c b/logic.c
index 8651e2b..456c98f 100644
--- a/logic.c
+++ b/logic.c
@@ -58,23 +58,24 @@ void playMove(
 
 void calcWins(
 	wins_t *wins,
-	const board_t board
+	const board_t board,
+	const int column
 ){
 	// First the simplest win, the humble tower
 	wins->count0.vertical = 0;
 	wins->count1.vertical = 0;
+	// Check for lil towers
+	wins->same.vertical2 [ column ] =
+		~( board.column [ column ]
+		^ board.column [ column ] >> 1 )
+		& safeHeightMask( board.height [ column ] - 1 );
+	// Actually check for win
+	wins->same.vertical4 [ column ] =
+		wins->same.vertical2 [ column ]
+		& wins->same.vertical2 [ column ] >> 1
+		& wins->same.vertical2 [ column ] >> 2;
+	// Count 'em
 	for( int i = 0; i < board.columns; i++ ){
-		// Check for lil towers
-		wins->same.vertical2 [ i ] =
-			~( board.column [ i ]
-			^ board.column [ i ] >> 1 )
-			& safeHeightMask( board.height [ i ] - 1 );
-		// Actually check for win
-		wins->same.vertical4 [ i ] =
-			wins->same.vertical2 [ i ]
-			& wins->same.vertical2 [ i ] >> 1
-			& wins->same.vertical2 [ i ] >> 2;
-		// Count 'em
 		wins->count0.vertical += __builtin_popcount(
 			wins->same.vertical4 [ i ] & ~board.column [ i ]
 		);
@@ -90,7 +91,11 @@ void calcWins(
 	wins->count0.diagonalDown = 0;
 	wins->count1.diagonalDown = 0;
 	// First connect 2
-	for( int i = 0; i < board.columns - 1; i++ ){
+	for(
+		int i = top( column - 1, 0 );
+		i < bottom( column + 1, board.columns - 1 );
+		i++
+	){
 		wins->same.horizontal2 [ i ] =
 			~( board.column [ i ]
 			^ board.column [ i + 1 ] )
@@ -115,7 +120,11 @@ void calcWins(
 			& ~1; // A diagonal line down ain't starts at the floor innit?
 	}
 	// Then stitch the twos together and count
-	for( int i = 0; i < board.columns - 3; i++ ){
+	for(
+		int i = top( column - 3, 0 );
+		i < bottom( column + 1, board.columns - 3 );
+		i++
+	){
 		wins->same.horizontal4 [ i ] =
 			wins->same.horizontal2 [ i ]
 			& wins->same.horizontal2 [ i + 1 ]
@@ -128,6 +137,8 @@ void calcWins(
 			wins->same.diagonalDown2 [ i ]
 			& wins->same.diagonalDown2 [ i + 1 ] << 1
 			& wins->same.diagonalDown2 [ i + 2 ] << 2;
+	}
+	for( int i = 0; i < board.columns - 3; i++ ){
 		wins->count0.horizontal += __builtin_popcount(
 			wins->same.horizontal4 [ i ] & ~board.column [ i ]
 		);
diff --git a/logic.h b/logic.h
index 744f01c..ccf712d 100644
--- a/logic.h
+++ b/logic.h
@@ -12,5 +12,6 @@ extern void playMove(
 
 extern void calcWins(
 	wins_t *wins,
-	const board_t board
+	const board_t board,
+	const int column
 );