Add a cheat to allow dual-wielding all guns. The cheat's name is "Gameplay/(Two-Handed)"

src/game/cheats.c

@@ -100,6 +100,9 @@ struct cheat g_Cheats[] = {
 	{ L_MPWEAPONS_114, WEAPON_DMC,        0,                             0,       CHEATFLAG_FIRINGRANGE                        }, // DMC
 	{ L_MPWEAPONS_115, WEAPON_AR53,       0,                             0,       CHEATFLAG_FIRINGRANGE                        }, // AR53
 	{ L_MPWEAPONS_116, WEAPON_RCP45,      0,                             0,       CHEATFLAG_FIRINGRANGE                        }, // RC-P45
+#ifndef PLATFORM_N64
+	{ L_MPWEAPONS_215, 0,                 SOLOSTAGEINDEX_EXTRACTION,     DIFF_A,  CHEATFLAG_COMPLETION                         }, // dual wield all guns cheat
+#endif
 };
 
 u32 cheatIsUnlocked(s32 cheat_id)
@@ -1090,6 +1093,16 @@ struct menuitem g_CheatsGameplayMenuItems[] = {
 		0,
 		cheatCheckboxMenuHandler,
 	},
+#ifndef PLATFORM_N64
+	{
+		MENUITEMTYPE_CHECKBOX,
+		CHEAT_DUALWIELDALLGUNS,
+		0,
+		(uintptr_t)&cheatGetNameIfUnlocked,
+		0,
+		cheatCheckboxMenuHandler,
+	},
+#endif
 	{
 		MENUITEMTYPE_SEPARATOR,
 		0,

src/game/game_0b0fd0.c

@@ -286,7 +286,12 @@ void currentPlayerZoomIn(f32 fovpersec)
 bool weaponHasFlag(s32 itemid, u32 flag)
 {
 	struct weapon *weapon = weaponFindById(itemid);
-
+#ifndef PLATFORM_N64 //always return, that weapon is dual-wieldable if player sets the cheat. 
+	if (cheatIsActive(CHEAT_DUALWIELDALLGUNS) && (flag == WEAPONFLAG_DUALWIELD))
+	{
+		return true;
+	}
+#endif
 	if (!weapon) {
 		return false;
 	}

src/game/inv.c

@@ -510,6 +510,17 @@ s32 invGiveWeaponsByProp(struct prop *prop)
 			weapon = prop->weapon;
 			weaponnum = weapon->weaponnum;
 			otherweaponnum;
+#ifndef PLATFORM_N64
+			//This piece of code makes the cheat work in singleplayer. 
+			if (cheatIsActive(CHEAT_DUALWIELDALLGUNS) && !g_Vars.normmplayerisrunning)
+			{
+				if(invHasSingleWeaponExcAllGuns(weaponnum) && (invHasDoubleWeaponExcAllGuns(weapon->weaponnum, weapon->weaponnum)==0))
+				{
+					invGiveDoubleWeapon(weaponnum, weaponnum);
+					numgiven = 2;
+				}
+			}
+#endif
 
 			if (cheatIsActive(CHEAT_PERFECTDARKNESS) && weaponnum == WEAPON_NIGHTVISION) {
 				return 1;

src/include/constants.h

@@ -449,6 +449,7 @@
 #define CHEAT_DMC                    39
 #define CHEAT_AR53                   40
 #define CHEAT_RCP45                  41
+#define CHEAT_DUALWIELDALLGUNS       42
 
 #define CHEATFLAG_TIMED       0
 #define CHEATFLAG_ALWAYSON    1