From 10efa56c58dd2aad821eb9ba53c6bd775c7e8ebf Mon Sep 17 00:00:00 2001
From: Kawe Mazidjatari <48657826+Mauler125@users.noreply.github.com>
Date: Mon, 16 Sep 2024 16:27:02 +0200
Subject: [PATCH] Engine: don't run NVIDIA Reflex if -gfx_disableLowLatency was
 specified

This command line argument should fully disable NVIDIA Reflex, AMD Anti-Lag 2 and PCL statistics.
---
 src/engine/sys_dll2.cpp                |  2 +-
 src/geforce/reflex.cpp                 | 25 ++++++++++++++++++++++---
 src/geforce/reflex.h                   |  5 ++++-
 src/materialsystem/cmaterialsystem.cpp |  5 ++++-
 src/radeon/antilag.cpp                 |  2 ++
 5 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/src/engine/sys_dll2.cpp b/src/engine/sys_dll2.cpp
index 522ccb4d..ee99a5e5 100644
--- a/src/engine/sys_dll2.cpp
+++ b/src/engine/sys_dll2.cpp
@@ -234,7 +234,7 @@ void CEngineAPI::UpdateLowLatencyParameters()
 void CEngineAPI::RunLowLatencyFrame()
 {
 #ifndef DEDICATED
-    if (GeForce_IsLowLatencySDKEnabled())
+    if (GeForce_IsLowLatencySDKAvailable())
     {
         if (GeForce_HasPendingLowLatencyParameterUpdates())
         {
diff --git a/src/geforce/reflex.cpp b/src/geforce/reflex.cpp
index f157be08..f6db3894 100644
--- a/src/geforce/reflex.cpp
+++ b/src/geforce/reflex.cpp
@@ -9,6 +9,8 @@
 
 static bool s_LowLatencySDKEnabled = false;
 
+static bool s_LowLatencyAvailable = false;
+
 // If false, the system will call 'NvAPI_D3D_SetSleepMode' to update the parameters.
 static bool s_ReflexModeInfoUpToDate = false;
 
@@ -31,9 +33,9 @@ void GeForce_EnableLowLatencySDK(const bool enable)
 //-----------------------------------------------------------------------------
 // Purpose: whether we should run the low latency SDK
 //-----------------------------------------------------------------------------
-bool GeForce_IsLowLatencySDKEnabled(void)
+bool GeForce_IsLowLatencySDKAvailable(void)
 {
-	if (!s_LowLatencySDKEnabled)
+	if (!s_LowLatencySDKEnabled || !s_LowLatencyAvailable)
 		return false;
 
 	const MaterialAdapterInfo_t& adapterInfo = g_pMaterialAdapterMgr->GetAdapterInfo();
@@ -42,6 +44,23 @@ bool GeForce_IsLowLatencySDKEnabled(void)
 	return adapterInfo.m_VendorID == NVIDIA_VENDOR_ID;
 }
 
+//-----------------------------------------------------------------------------
+// Purpose: initialize the low latency SDK
+//-----------------------------------------------------------------------------
+bool GeForce_InitLowLatencySDK(void)
+{
+	s_LowLatencyAvailable = true;
+	return s_LowLatencyAvailable;
+}
+
+//-----------------------------------------------------------------------------
+// Purpose: shutdown the low latency SDK
+//-----------------------------------------------------------------------------
+void GeForce_ShutdownLowLatencySDK(void)
+{
+	s_LowLatencyAvailable = false;
+}
+
 //-----------------------------------------------------------------------------
 // Purpose: mark the parameters as out-of-date; force update next frame
 //-----------------------------------------------------------------------------
@@ -126,7 +145,7 @@ void GeForce_SetLatencyMarker(IUnknown* const device,
 {
 	Assert(device);
 
-	if (GeForce_ParameterUpdateWasSuccessful() && GeForce_IsLowLatencySDKEnabled())
+	if (GeForce_ParameterUpdateWasSuccessful() && GeForce_IsLowLatencySDKAvailable())
 	{
 		NV_LATENCY_MARKER_PARAMS params = {};
 		params.version = NV_LATENCY_MARKER_PARAMS_VER1;
diff --git a/src/geforce/reflex.h b/src/geforce/reflex.h
index 696f745d..07d8ae38 100644
--- a/src/geforce/reflex.h
+++ b/src/geforce/reflex.h
@@ -4,7 +4,10 @@
 extern bool g_PCLStatsAvailable;
 
 void GeForce_EnableLowLatencySDK(const bool enable);
-bool GeForce_IsLowLatencySDKEnabled(void);
+bool GeForce_IsLowLatencySDKAvailable(void);
+
+bool GeForce_InitLowLatencySDK(void);
+void GeForce_ShutdownLowLatencySDK(void);
 
 void GeForce_MarkLowLatencyParametersOutOfDate(void);
 bool GeForce_HasPendingLowLatencyParameterUpdates(void);
diff --git a/src/materialsystem/cmaterialsystem.cpp b/src/materialsystem/cmaterialsystem.cpp
index 158705f4..d0402221 100644
--- a/src/materialsystem/cmaterialsystem.cpp
+++ b/src/materialsystem/cmaterialsystem.cpp
@@ -11,6 +11,7 @@
 #include "rtech/pak/pakstate.h"
 #include "engine/cmodel_bsp.h"
 #include "engine/sys_engine.h"
+#include "engine/sys_dll2.h"
 #include "geforce/reflex.h"
 #include "radeon/antilag.h"
 #ifndef MATERIALSYSTEM_NODX
@@ -61,9 +62,10 @@ InitReturnVal_t CMaterialSystem::Init(CMaterialSystem* thisptr)
 
 	if (s_useLowLatency)
 	{
+		GeForce_InitLowLatencySDK();
 		Radeon_InitLowLatencySDK();
-		PCLSTATS_INIT(0);
 
+		PCLSTATS_INIT(0);
 		g_PCLStatsAvailable = true;
 	}
 
@@ -83,6 +85,7 @@ int CMaterialSystem::Shutdown(CMaterialSystem* thisptr)
 			PCLSTATS_SHUTDOWN();
 
 		Radeon_ShutdownLowLatencySDK();
+		GeForce_ShutdownLowLatencySDK();
 	}
 #endif
 
diff --git a/src/radeon/antilag.cpp b/src/radeon/antilag.cpp
index 453cddff..907fa640 100644
--- a/src/radeon/antilag.cpp
+++ b/src/radeon/antilag.cpp
@@ -28,6 +28,8 @@ void Radeon_EnableLowLatencySDK(const bool enable)
 //-----------------------------------------------------------------------------
 bool Radeon_IsLowLatencySDKAvailable(void)
 {
+	// NOTE: don't check on s_LowLatencySDKEnabled here as this needs to be
+	// provided to the driver itself.
 	if (!s_LowLatencyAvailable)
 		return false;