From 6b70cad6e1fc8d161e893f4e118f4e20d14e1622 Mon Sep 17 00:00:00 2001
From: arookas <arookas@outlook.com>
Date: Tue, 24 Mar 2020 23:21:26 -0400
Subject: [PATCH] Add option to invert mouse x

---
 src/d_main.cpp            | 6 +++++-
 src/g_game.cpp            | 1 +
 wadsrc/static/menudef.txt | 1 +
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/d_main.cpp b/src/d_main.cpp
index 163c9824f0..bf2eb02df1 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -171,6 +171,7 @@ EXTERN_CVAR (Bool, freelook)
 EXTERN_CVAR (Float, m_pitch)
 EXTERN_CVAR (Float, m_yaw)
 EXTERN_CVAR (Bool, invertmouse)
+EXTERN_CVAR (Bool, invertmousex)
 EXTERN_CVAR (Bool, lookstrafe)
 EXTERN_CVAR (Int, screenblocks)
 EXTERN_CVAR (Bool, sv_cheats)
@@ -449,7 +450,10 @@ void D_PostEvent (const event_t *ev)
 		}
 		if (!buttonMap.ButtonDown(Button_Strafe) && !lookstrafe)
 		{
-			G_AddViewAngle (int(ev->x * m_yaw * mouse_sensitivity * 8.0), true);
+			int turn = int(ev->x * m_yaw * mouse_sensitivity * 8.0);
+			if (invertmousex)
+				turn = -turn;
+			G_AddViewAngle (turn, true);
 			events[eventhead].x = 0;
 		}
 		if ((events[eventhead].x | events[eventhead].y) == 0)
diff --git a/src/g_game.cpp b/src/g_game.cpp
index 0bf7812604..b29f67d6bf 100644
--- a/src/g_game.cpp
+++ b/src/g_game.cpp
@@ -202,6 +202,7 @@ int				lookspeed[2] = {450, 512};
 
 CVAR (Bool,		cl_run,			false,	CVAR_GLOBALCONFIG|CVAR_ARCHIVE)		// Always run?
 CVAR (Bool,		invertmouse,	false,	CVAR_GLOBALCONFIG|CVAR_ARCHIVE)		// Invert mouse look down/up?
+CVAR (Bool,		invertmousex,	false,	CVAR_GLOBALCONFIG|CVAR_ARCHIVE)		// Invert mouse look left/right?
 CVAR (Bool,		freelook,		true,	CVAR_GLOBALCONFIG|CVAR_ARCHIVE)		// Always mlook?
 CVAR (Bool,		lookstrafe,		false,	CVAR_GLOBALCONFIG|CVAR_ARCHIVE)		// Always strafe with mouse?
 CVAR (Float,	m_pitch,		1.f,	CVAR_GLOBALCONFIG|CVAR_ARCHIVE)		// Mouse speeds
diff --git a/wadsrc/static/menudef.txt b/wadsrc/static/menudef.txt
index b59af595f4..e7803545ef 100644
--- a/wadsrc/static/menudef.txt
+++ b/wadsrc/static/menudef.txt
@@ -734,6 +734,7 @@ OptionMenu "MouseOptions" protected
 	Slider "$MOUSEMNU_STRAFESPEED",		"m_side", 0, 2.5, 0.1
 	StaticText 	""
 	Option "$MOUSEMNU_ALWAYSMOUSELOOK",	"freelook", "OnOff"
+	Option "$MOUSEMNU_INVERTMOUSEX",		"invertmousex", "OnOff"
 	Option "$MOUSEMNU_INVERTMOUSE",		"invertmouse", "OnOff"
 	Option "$MOUSEMNU_LOOKSPRING",		"lookspring", "OnOff"
 	Option "$MOUSEMNU_LOOKSTRAFE",		"lookstrafe", "OnOff"