Warn user about unsupported FOV value

src/game/client/neo/ui/neo_root.cpp

@@ -1099,7 +1099,14 @@ void CNeoRoot::MainLoopSettings(const MainLoopParam param)
 					if (NeoUI::Button(NeoUI::HintAlt(L"Accept (F8)", L"Accept (START)")).bPressed
 							|| NeoUI::Bind(BTNCODES_ACCEPT, ARRAYSIZE(BTNCODES_ACCEPT)))
 					{
-						NeoSettingsSave(&m_ns);
+						if (m_ns.general.iFov > maxSupportedFov)
+						{
+							m_state = STATE_CONFIRMSETTINGS;
+						}
+						else
+						{
+							NeoSettingsSave(&m_ns);
+						}
 					}
 				}
 			}
@@ -2291,6 +2298,17 @@ void CNeoRoot::MainLoopPopup(const MainLoopParam param)
 						L"Settings changed: Do you want to apply the settings?" :
 						L"Error: Invalid settings, cannot save.");
 				NeoUI::SwapFont(NeoUI::FONT_NTNORMAL);
+
+				if (m_ns.general.iFov > maxSupportedFov)
+				{
+					wchar_t warning[77+1];
+					V_snwprintf(warning, ARRAYSIZE(warning),
+						L"WARNING: Current FOV value is %d%cvalues above %d may cause visual artifacts!",
+						m_ns.general.iFov, wint_t(8212) /* em dash */, maxSupportedFov);
+					NeoUI::Label(warning);
+					g_uiCtx.iLayoutY += (g_uiCtx.layout.iRowTall / 2);
+				}
+
 				NeoUI::SetPerRowLayout(3);
 				{
 					g_uiCtx.iLayoutX = (g_uiCtx.iMarginX / 2);

src/game/client/neo/ui/neo_root_settings.cpp

@@ -1006,7 +1006,7 @@ void NeoSettings_General(NeoSettings *ns)
 		NeoUI::EndOverrideFgColor();
 	}
 
-	NeoUI::SliderInt(L"FOV", &pGeneral->iFov, 75, 110);
+	NeoUI::SliderInt(L"FOV", &pGeneral->iFov, MIN_FOV, MAX_FOV);
 	NeoUI::SliderInt(L"Viewmodel FOV Offset", &pGeneral->iViewmodelFov, -20, 40);
 	NeoUI::RingBoxBool(L"Reload empty", &pGeneral->bReloadEmpty);
 	NeoUI::RingBoxBool(L"Right hand viewmodel", &pGeneral->bViewmodelRighthand);

src/game/client/neo/ui/neo_root_settings.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "shareddefs.h"
 #include "tier1/convar.h"
 #include "neo_player_shared.h"
 #include "neo_hud_crosshair.h"
@@ -37,6 +38,12 @@ enum XHairExportNotify
 
 #define NEO_BINDS_TOTAL 96
 
+// Note that this is not necessarily the same as "neo_fov" cvar max value.
+// We are restricted to supporting a max of 90 due to an engine limitation.
+constexpr auto maxSupportedFov = 90;
+static_assert(MIN_FOV <= maxSupportedFov);
+static_assert(MAX_FOV >= maxSupportedFov);
+
 struct NeoSettings
 {
 	enum EquipUtilityPriorityType

src/game/client/view.cpp

@@ -60,6 +60,7 @@
 #endif
 
 #ifdef NEO
+#include "neo/ui/neo_root_settings.h"
 #include "vgui_controls/pch_vgui_controls.h"
 #endif // NEO
 
@@ -75,7 +76,14 @@ extern ConVar default_fov;
 extern bool g_bRenderingScreenshot;
 
 #ifdef NEO
-ConVar neo_fov("neo_fov", V_STRINGIFY(DEFAULT_FOV), FCVAR_ARCHIVE | FCVAR_USERINFO, "Set the normal FOV.", true, static_cast<float>(MIN_FOV), true, static_cast<float>(MAX_FOV));
+ConVar neo_fov("neo_fov", V_STRINGIFY(DEFAULT_FOV), FCVAR_ARCHIVE | FCVAR_USERINFO, "Set the normal FOV.", true, static_cast<float>(MIN_FOV), true, static_cast<float>(MAX_FOV),
+	[](IConVar* var, const char* pOldValue, float flOldValue) {
+		int newVal = ((ConVar*)var)->GetInt();
+		if (newVal > maxSupportedFov)
+		{
+			Warning("Current FOV value is %d - values above %d may cause visual artifacts!\n", newVal, maxSupportedFov);
+		}
+	});
 ConVar neo_fov_relay_spec("neo_fov_relay_spec", "0", FCVAR_ARCHIVE | FCVAR_USERINFO,
 		"If enabled, during first-person spectating, it will relay the target player's neo_fov to the spectator."
 		" This ConVar is controlled by the spectator, not the target player.", true, 0.0f, true, 1.0f);