From 38d64422e4c893150227d203ad3199ae9faca48b Mon Sep 17 00:00:00 2001
From: Ahmet Fatih Cengiz <37782582+afc-afc0@users.noreply.github.com>
Date: Sun, 12 Apr 2026 02:37:10 -0400
Subject: [PATCH] bugfix(input): Fix touchpad upward scrolling in UI list boxes

Preserve wheel delta sign when normalizing for touchpad scroll direction
detection. Touchpad devices send small continuous deltas that were
truncated to 0 by integer division with MOUSE_WHEEL_DELTA, causing
upward scroll to be misidentified as downward scroll. Clamp the
normalized value to at least 1 or -1 based on the original sign.
---
 Core/GameEngine/Source/GameClient/Input/Mouse.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Core/GameEngine/Source/GameClient/Input/Mouse.cpp b/Core/GameEngine/Source/GameClient/Input/Mouse.cpp
index 67ceb096461..4abb1d44297 100644
--- a/Core/GameEngine/Source/GameClient/Input/Mouse.cpp
+++ b/Core/GameEngine/Source/GameClient/Input/Mouse.cpp
@@ -824,7 +824,9 @@ void Mouse::createStreamMessages()
 		{
 			msg = TheMessageStream->appendMessage( GameMessage::MSG_RAW_MOUSE_WHEEL );
 			msg->appendPixelArgument( m_currMouse.pos );
-			msg->appendIntegerArgument( m_currMouse.wheelPos / 120 );  // wheel delta
+			// TheSuperHackers @bugfix Preserve wheel delta sign for touchpad scroll direction detection
+			const Int wheelTicks = m_currMouse.wheelPos / MOUSE_WHEEL_DELTA;
+			msg->appendIntegerArgument( m_currMouse.wheelPos > 0 ? max( 1, wheelTicks ) : min( -1, wheelTicks ) );
 			msg->appendIntegerArgument( TheKeyboard->getModifierFlags() );
 		}