Fully implement "disable-mod-detection" setting

- Catch exceptions in OnPausedChanged
- Unhide "disable-mod-detection" setting
- Add error message for unsupported modifications
- Change memory modification lookup to contain functions
- Don't (re)enable mod detection automatically
- Add memory.lua library that allows to change the protection of memory regions.

files/libraries/memory.lua

@@ -0,0 +1,58 @@
+-- Copyright (c) 2022 David Vogel
+--
+-- This software is released under the MIT License.
+-- https://opensource.org/licenses/MIT
+
+local ffi = require("ffi")
+
+local Memory = {}
+
+if ffi.abi'64bit' then
+	ffi.cdef([[
+		typedef uint64_t __uint3264;
+	]])
+else
+	ffi.cdef([[
+		typedef uint32_t __uint3264;
+	]])
+end
+
+ffi.cdef([[
+	typedef void            VOID;
+	typedef VOID            *LPVOID;
+	typedef int             BOOL;
+	typedef __uint3264      ULONG_PTR, *PULONG_PTR;
+	typedef ULONG_PTR       SIZE_T, *PSIZE_T;
+	typedef unsigned long   DWORD;
+	typedef DWORD           *PDWORD;
+
+	BOOL VirtualProtect(LPVOID lpAddress, SIZE_T dwSize, DWORD flNewProtect, PDWORD lpflOldProtect);
+]])
+
+Memory.PAGE_NOACCESS          = 0x01
+Memory.PAGE_READONLY          = 0x02
+Memory.PAGE_READWRITE         = 0x04
+Memory.PAGE_WRITECOPY         = 0x08
+Memory.PAGE_EXECUTE           = 0x10
+Memory.PAGE_EXECUTE_READ      = 0x20
+Memory.PAGE_EXECUTE_READWRITE = 0x40
+Memory.PAGE_EXECUTE_WRITECOPY = 0x80
+Memory.PAGE_GUARD             = 0x100
+Memory.PAGE_NOCACHE           = 0x200
+Memory.PAGE_WRITECOMBINE      = 0x400
+
+---Changes the protection on a region of committed pages in the virtual address space of the calling process.
+---@param addr ffi.cdata*
+---@param size integer
+---@param newProtect integer
+---@return ffi.cdata* oldProtect
+function Memory.VirtualProtect(addr, size, newProtect)
+	local oldprotect = ffi.new('DWORD[1]')
+	if not ffi.C.VirtualProtect(addr, size, newProtect, oldprotect) then
+		error(string.format("failed to call VirtualProtect(%s, %s, %s)", addr, size, newProtect))
+	end
+
+	return oldprotect
+end
+
+return Memory

files/message.lua

@@ -176,3 +176,21 @@ function Message:ShowGeneralInstallationProblem(...)
 		Lines = { ... },
 	}
 end
+
+---Tell the user that some modifications couldn't be applied because it is unsupported.
+---@param realm "config"|"magicNumbers"|"processMemory"|"filePatches"
+---@param name string
+---@param value any
+function Message:ShowModificationUnsupported(realm, name, value)
+	self.List = self.List or {}
+
+	self.List["ModificationFailed"] = {
+		Type = "warning",
+		Lines = {
+			string.format("Couldn't modify %q in %q realm.", name, realm),
+			" ",
+			"This simply means that this modification is not supported for the Noita version you are using.",
+			"Feel free to open an issue at https://github.com/Dadido3/noita-mapcap.",
+		},
+	}
+end

files/modification.lua

@@ -19,6 +19,7 @@
 local CameraAPI = require("noita-api.camera")
 local Coords = require("coordinates")
 local ffi = require("ffi")
+local Memory = require("memory")
 local NXML = require("luanxml.nxml")
 local Utils = require("noita-api.utils")
 local Vec2 = require("noita-api.vec2")
@@ -92,38 +93,40 @@ end
 ---@param memory table
 function Modification.SetMemoryOptions(memory)
 	-- Lookup table with the following hierarchy:
-	-- DevBuild -> OS -> BuildDate -> Option -> Address.
+	-- DevBuild -> OS -> BuildDate -> Option -> ModFunc.
 	local lookup = {
 		[true] = {
 			Windows = {
 				[0x00F77B0C] = { _BuildString = "Build Apr 23 2021 18:36:55", -- GOG dev build.
-					mPostFxDisabled = 0x010E3B6C,
-					mGuiDisabled = 0x010E3B6D,
-					mGuiHalfSize = 0x010E3B6E,
-					mFogOfWarOpenEverywhere = 0x010E3B6F,
-					mTrailerMode = 0x010E3B70,
-					mDayTimeRotationPause = 0x010E3B71,
-					mPlayerNeverDies = 0x010E3B72,
-					mFreezeAI = 0x010E3B73,
+					mPostFxDisabled = function(value) ffi.cast("char*", 0x010E3B6C)[0] = value end,
+					mGuiDisabled = function(value) ffi.cast("char*", 0x010E3B6D)[0] = value end,
+					mGuiHalfSize = function(value) ffi.cast("char*", 0x010E3B6E)[0] = value end,
+					mFogOfWarOpenEverywhere = function(value) ffi.cast("char*", 0x010E3B6F)[0] = value end,
+					mTrailerMode = function(value) ffi.cast("char*", 0x010E3B70)[0] = value end,
+					mDayTimeRotationPause = function(value) ffi.cast("char*", 0x010E3B71)[0] = value end,
+					mPlayerNeverDies = function(value) ffi.cast("char*", 0x010E3B72)[0] = value end,
+					mFreezeAI = function(value) ffi.cast("char*", 0x010E3B73)[0] = value end,
 				},
 				[0x00F80384] = { _BuildString = "Build Apr 23 2021 18:40:40", -- Steam dev build.
-					mPostFxDisabled = 0x010EDEBC,
-					mGuiDisabled = 0x010EDEBD,
-					mGuiHalfSize = 0x010EDEBE,
-					mFogOfWarOpenEverywhere = 0x010EDEBF,
-					mTrailerMode = 0x010EDEC0,
-					mDayTimeRotationPause = 0x010EDEC1,
-					mPlayerNeverDies = 0x010EDEC2,
-					mFreezeAI = 0x010EDEC3,
+					mPostFxDisabled = function(value) ffi.cast("char*", 0x010EDEBC)[0] = value end,
+					mGuiDisabled = function(value) ffi.cast("char*", 0x010EDEBD)[0] = value end,
+					mGuiHalfSize = function(value) ffi.cast("char*", 0x010EDEBE)[0] = value end,
+					mFogOfWarOpenEverywhere = function(value) ffi.cast("char*", 0x010EDEBF)[0] = value end,
+					mTrailerMode = function(value) ffi.cast("char*", 0x010EDEC0)[0] = value end,
+					mDayTimeRotationPause = function(value) ffi.cast("char*", 0x010EDEC1)[0] = value end,
+					mPlayerNeverDies = function(value) ffi.cast("char*", 0x010EDEC2)[0] = value end,
+					mFreezeAI = function(value) ffi.cast("char*", 0x010EDEC3)[0] = value end,
 				},
 			},
 		},
 		[false] = {
 			Windows = {
 				[0x00E1C550] = { _BuildString = "Build Apr 23 2021 18:44:24", -- Steam build.
-					--enableModDetection = 0x0063D8AD, -- This basically just changes the value that Noita forces to the "mods_have_been_active_during_this_run" member of the WorldStateComponent when any mod is enabled.
-					-- The page this is in is not writable, so this will crash Noita.
-					-- This modification can be applied manually with some other tool that changes the permission prior to writing, like Cheat Engine.
+					enableModDetection = function(value)
+						local ptr = ffi.cast("char*", 0x0063D8AD)
+						Memory.VirtualProtect(ptr, 1, Memory.PAGE_EXECUTE_READWRITE)
+						ptr[0] = value -- This basically just changes the value that Noita forces to the "mods_have_been_active_during_this_run" member of the WorldStateComponent when any mod is enabled.
+					end,
 				},
 			},
 		},
@@ -132,10 +135,10 @@ function Modification.SetMemoryOptions(memory)
 	-- Look up the tree and set options accordingly.
 
 	local level1 = lookup[DebugGetIsDevBuild()]
-	if level1 == nil then return end
+	level1 = level1 or {}
 
 	local level2 = level1[ffi.os]
-	if level2 == nil then return end
+	level2 = level2 or {}
 
 	local level3
 	for k, v in pairs(level2) do
@@ -146,9 +149,11 @@ function Modification.SetMemoryOptions(memory)
 	end
 
 	for k, v in pairs(memory) do
-		local address = level3[k]
-		if address ~= nil then
-			ffi.cast("char*", address)[0] = v
+		local modFunc = level3[k]
+		if modFunc ~= nil then
+			modFunc(v)
+		else
+			Message:ShowModificationUnsupported("processMemory", k, v)
 		end
 	end
 end
@@ -243,7 +248,8 @@ function Modification.RequiredChanges()
 	if ModSettingGet("noita-mapcap.disable-mod-detection") then
 		memory["enableModDetection"] = 0
 	else
-		memory["enableModDetection"] = 1
+		-- Don't actively (re)enable mod detection.
+		--memory["enableModDetection"] = 1
 	end
 
 	-- Disables or hides most of the UI.

init.lua

@@ -150,10 +150,13 @@ end
 ---@param isPaused boolean
 ---@param isInventoryPause boolean
 function OnPausedChanged(isPaused, isInventoryPause)
+	Message:CatchException("OnPausedChanged", function()
 		-- Set some stuff based on mod settings.
 		-- Normally this would be in `OnModSettingsChanged`, but that doesn't seem to be called.
 		local config, magic, memory, patches = Modification.RequiredChanges()
 		Modification.SetMemoryOptions(memory)
+
+	end)
 end
 
 ---Will be called when the game is unpaused, if player changed any mod settings while the game was paused.

settings.lua

@@ -318,7 +318,6 @@ modSettings = {
 				id = "disable-mod-detection",
 				ui_name = "  Disable mod detection",
 				ui_description = "If enabled, Noita will behave as if no mods are enabled.\nTherefore secrets like the cauldron will be generated.",
-				hidden = true,
 				value_default = false,
 				scope = MOD_SETTING_SCOPE_RUNTIME,
 			},