From 0e8b870e7d0deb9f51483ed72d2116ef0f6af700 Mon Sep 17 00:00:00 2001
From: Blixibon <acj3017@gmail.com>
Date: Wed, 27 Oct 2021 17:05:19 -0500
Subject: [PATCH] Re-enabled NPC gesture turning with a cvar to toggle it

---
 sp/src/game/server/ai_basenpc_schedule.cpp | 10 ++++++++++
 sp/src/game/server/ai_blended_movement.cpp |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/sp/src/game/server/ai_basenpc_schedule.cpp b/sp/src/game/server/ai_basenpc_schedule.cpp
index 7fc1c13b..bcb54c81 100644
--- a/sp/src/game/server/ai_basenpc_schedule.cpp
+++ b/sp/src/game/server/ai_basenpc_schedule.cpp
@@ -4317,6 +4317,15 @@ void CAI_BaseNPC::SetTurnActivity ( void )
 	float flYD;
 	flYD = GetMotor()->DeltaIdealYaw();
 
+#ifdef MAPBASE
+	// Allow AddTurnGesture() to decide this
+	if (GetMotor()->AddTurnGesture( flYD ))
+	{
+		SetIdealActivity( ACT_IDLE );
+		Remember( bits_MEMORY_TURNING );
+		return;
+	}
+#else
 	// FIXME: unknown case, update yaw should catch these
 	/*
 	if (GetMotor()->AddTurnGesture( flYD ))
@@ -4326,6 +4335,7 @@ void CAI_BaseNPC::SetTurnActivity ( void )
 		return;
 	}
 	*/
+#endif
 
 	if( flYD <= -80 && flYD >= -100 && SelectWeightedSequence( ACT_90_RIGHT ) != ACTIVITY_NOT_AVAILABLE )
 	{
diff --git a/sp/src/game/server/ai_blended_movement.cpp b/sp/src/game/server/ai_blended_movement.cpp
index d1b32d14..0a11c915 100644
--- a/sp/src/game/server/ai_blended_movement.cpp
+++ b/sp/src/game/server/ai_blended_movement.cpp
@@ -1640,10 +1640,17 @@ void CAI_BlendedMotor::MaintainTurnActivity( void )
 
 ConVar scene_flatturn( "scene_flatturn", "1" );
 
+#ifdef MAPBASE
+ConVar ai_turning_enabled( "ai_turning_enabled", "1", FCVAR_NONE, "Enables NPC turning, which was previously disabled by Valve at some point after 2004 due to a now-unknown major issue." );
+#endif
+
 bool CAI_BlendedMotor::AddTurnGesture( float flYD )
 {
 
 	// some funky bug with human turn gestures, disable for now
+#ifdef MAPBASE
+	if (!ai_turning_enabled.GetBool())
+#endif
 	return false;
 
 	// try using a turn gesture