Allow mods to blacklist vanilla roles

MiraAPI/Patches/Options/LobbyViewPanePatches.cs

@@ -185,7 +185,8 @@ public static class LobbyViewPanePatches
                 __instance.settingsInfo.Add(categoryHeaderRoleVariant.gameObject);
                 num -= 0.696f;
                 var roles = RoleManager.Instance.AllRoles.ToArray().Where(x =>
-                    x is not ICustomRole && x.Role != RoleTypes.Crewmate && x.Role != RoleTypes.Impostor &&
+                    x is not ICustomRole && !x.IsRoleBlacklisted() && x.Role != RoleTypes.Crewmate &&
+                    x.Role != RoleTypes.Impostor &&
                     x.Role != RoleTypes.CrewmateGhost && x.Role != RoleTypes.ImpostorGhost).ToList();
                 for (int j = 0; j < roles.Count; j++)
                 {

MiraAPI/Patches/Options/RoleSettingMenuPatches.cs

@@ -74,10 +74,10 @@ public static class RoleSettingMenuPatches
             var num = 0.662f;
 
             var list = CustomRoleManager.AllRoles.Where(
-                r => !r.IsCustomRole() && r.TeamType == RoleTeamTypes.Crewmate && r.Role != RoleTypes.Crewmate &&
+                r => !r.IsCustomRole() && !r.IsRoleBlacklisted() && r.TeamType == RoleTeamTypes.Crewmate && r.Role != RoleTypes.Crewmate &&
                      r.Role != RoleTypes.CrewmateGhost).ToList();
             var list2 = CustomRoleManager.AllRoles.Where(
-                r => !r.IsCustomRole() && r.TeamType == RoleTeamTypes.Impostor && r.Role != RoleTypes.Impostor &&
+                r => !r.IsCustomRole() && !r.IsRoleBlacklisted() && r.TeamType == RoleTeamTypes.Impostor && r.Role != RoleTypes.Impostor &&
                      r.Role != RoleTypes.ImpostorGhost).ToList();
 
             if (__instance.roleTabs == null || __instance.roleTabs.Count == 0)

MiraAPI/Utilities/Helpers.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
+using AmongUs.GameOptions;
 using HarmonyLib;
 using Il2CppInterop.Runtime.InteropTypes.Arrays;
 using MiraAPI.Roles;
@@ -536,4 +537,19 @@ public static class Helpers
         }
         return role.NiceName;
     }
+
+    /// <summary>
+    /// Returns whether the role is blacklisted from appearing and spawning. (Only applicable to vanilla roles)
+    /// </summary>
+    /// <param name="role">The role to check.</param>
+    /// <returns>The role's blacklist status.</returns>
+    public static bool IsRoleBlacklisted(this RoleBehaviour role)
+    {
+        // This should be patchable by mods when a vanilla role is meant to be replaced by a custom role.
+        if (role.Role is RoleTypes.Engineer)
+        {
+            return true;
+        }
+        return false;
+    }
 }