Save states I guess

docs/src/includes/_globals.md

@@ -1515,6 +1515,15 @@ Retrieves the current value of the performance counter, which is a high resoluti
 
 Retrieves the frequency of the performance counter. The frequency of the performance counter is fixed at system boot and is consistent across all processors. Therefore, the frequency need only be queried upon application initialization, and the result can be cached.
 
+### get_save_state
+
+
+> Search script examples for [get_save_state](https://github.com/spelunky-fyi/overlunky/search?l=Lua&q=get_save_state)
+
+#### [StateMemory](#StateMemory) get_save_state(int slot)
+
+Get [StateMemory](#StateMemory) from a save_state slot.
+
 ### get_setting
 
 
@@ -1681,6 +1690,15 @@ Immediately ends the run with the death screen, also calls the [save_progress](#
 
 Immediately load a screen based on [state](#state).screen_next and stuff
 
+### load_state
+
+
+> Search script examples for [load_state](https://github.com/spelunky-fyi/overlunky/search?l=Lua&q=load_state)
+
+#### nil load_state(int slot)
+
+Load level state from slot 1..4, if a save_state was made in this level.
+
 ### lowbias32
 
 
@@ -1762,6 +1780,15 @@ Saves the game to savegame.sav, unless game saves are blocked in the settings. A
 
 Runs the [ON](#ON).SAVE callback. Fails and returns false, if you're trying to save too often (2s).
 
+### save_state
+
+
+> Search script examples for [save_state](https://github.com/spelunky-fyi/overlunky/search?l=Lua&q=save_state)
+
+#### nil save_state(int slot)
+
+Save current level state to slot 1..4. These save states are invalid after you exit the level, but can be used to rollback to an earlier state in the same level. You probably definitely shouldn't use save state functions during an update, and sync them to the same event outside an update (i.e. GUIFRAME, POST_UPDATE).
+
 ### script_enabled
 
 

examples/barrymod.lua

@@ -1,130 +1,56 @@
 meta.name = 'Barrymod'
-meta.version = 'WIP'
-meta.description = 'Restarts the current level on death or manually like nothing happened. Not everything from Inventory is implemented, cause it\'s not in the api yet. Sometimes also gets the level gen wrong and atm screws up journal progress by design.'
+meta.version = '1.0'
+meta.description = 'Creates checkpoints and restarts the current level on death like nothing happened.'
 meta.author = 'Dregu'
 
-local status = {}
-local restart = false
+register_option_bool('save_early', 'Multiverse of Madness Mode',
+    'Rerolls the level generation on death,\nbut keeps quest state and inventory.',
+    false)
 
-local vars = {
-    state = {'seed', 'level_count', 'time_total', 'shoppie_aggro', 'shoppie_aggro_next', 'merchant_aggro', 'kali_favor', 'kali_status', 'kali_altars_destroyed', 'level_flags', 'quest_flags', 'journal_flags', 'presence_flags', 'special_visibility_flags', 'kills_npc', 'damage_taken', 'time_last_level', 'saved_dogs', 'saved_cats', 'saved_hamsters', 'money_last_levels', 'money_shop_total', 'correct_ushabti'},
-    quests = {'yang_state', 'jungle_susters_flags', 'van_horsing_state', 'sparrow_state', 'madame_tusk_state', 'beg_state'},
-    inventory = {'health', 'bombs', 'ropes', 'held_item', 'held_item_metadata', 'kapala_blood_amount', 'poison_tick_timer', 'cursed', 'elixir_buff', 'mount_type', 'mount_metadata', 'kills_level', 'kills_total', 'collected_money_total'}
-}
-
-local names = {}
-for i,v in pairs(ENT_TYPE) do
-  names[v] = i
-end
-
-local function save(from, arr)
-    for i,v in ipairs(arr) do
-        status[v] = from[v]
-    end
-    print("Saved state")
-end
-
-local function load(to, arr)
-    for i,v in ipairs(arr) do
-        if status[v] ~= nil then
-            to[v] = status[v]
-        end
-    end
-    print("Loaded state")
-end
-
-local function clear()
-    status = {}
-    status.back = -1
-    status.power = {}
-    status.rng = {}
-    print("Cleared state")
-end
-
-local function restart_level()
-    restart = true
-    state.screen_next = SCREEN.LEVEL
-    state.screen_last = SCREEN.TRANSITION
-    state.world_next = state.world
-    state.level_next = state.level
-    state.theme_next = state.theme
-    state.quest_flags = 1
-    state.loading = 2
-end
-
-register_option_button('restart', 'Restart level', function()
-    restart_level()
+register_option_callback('buttons', nil, function(ctx)
+    if ctx:win_button('Quick Save') then save_state(1) end
+    ctx:win_inline()
+    if ctx:win_button('Quick Load') then load_state(1) end
 end)
 
 set_callback(function()
-    if state.items.player_inventory[1].health < 1 then
-        state.items.player_inventory[1].health = 4
+    if not options.save_early then
+        save_state(1)
+    end
+    for _, p in pairs(players) do
+        set_on_player_instagib(p.uid, function(e)
+            -- can't load_state directly here, cause we're still in the middle of an update
+            restart = true
+        end)
     end
+end, ON.LEVEL)
 
-    if restart then
-        if status.rng then
-            for i,v in pairs(status.rng) do
-                    prng:set_pair(i, v.a, v.b)
-            end
-        end
-        load(state, vars.state)
-        load(state.quests, vars.quests)
-        load(state.items.player_inventory[1], vars.inventory)
-    else
-        if not status.rng then
-            status.rng = {}
-        end
-        for i=0,9 do
-            local a,b = prng:get_pair(i)
-            status.rng[i] = { a=a, b=b }
-        end
-        save(state, vars.state)
-        save(state.quests, vars.quests)
-        save(state.items.player_inventory[1], vars.inventory)
+set_callback(function()
+    if options.save_early then
+        -- for whatever prng related reason, loading a save created at this point will reroll the level rng, which is a neat I guess
+        save_state(1)
     end
 end, ON.PRE_LEVEL_GENERATION)
 
 set_callback(function()
-    local ent = players[1]
     if restart then
-        if status.power then
-            for i,v in ipairs(status.power) do
-                local m = string.find(names[v], 'PACK')
-                if not m and not ent:has_powerup(v) then
-                    ent:give_powerup(v)
-                end
-            end
-        end
-        if status.back and status.back ~= -1 and ent:worn_backitem() == -1 then
-            pick_up(ent.uid, spawn(status.back, 0, 0, LAYER.PLAYER, 0, 0))
-        end
-    else
-        status.back = -1
-        local backitem = worn_backitem(players[1].uid)
-        if backitem ~= -1 then
-            status.back = get_entity(backitem).type.id
-        end
-
-        status.power = {}
-        for i,v in ipairs(players[1]:get_powerups()) do
-            status.power[i] = v
-        end
+        restart = nil
+        -- load the save state we made earlier, after updates to not mess with the running state
+        load_state(1)
     end
-
-    set_on_kill(ent.uid, function()
-        restart_level()
-    end)
-
-    set_on_destroy(ent.uid, function()
-        restart_level()
-    end)
-
-    restart = false
-end, ON.LEVEL)
+end, ON.POST_UPDATE)
 
 set_callback(function()
-    local tile = get_grid_entity_at(6, 121, LAYER.FRONT)
+    if state.screen ~= SCREEN.TRANSITION then return end
+    local tile = get_entity(get_grid_entity_at(6, 121, LAYER.FRONT))
     if tile then
-        get_entity(tile):destroy()
+        tile:remove()
+        tile = get_entity(get_grid_entity_at(6, 120, LAYER.FRONT))
+        if tile then
+            tile:decorate_internal()
+        end
+    else
+        tile = get_entity(spawn_grid_entity(ENT_TYPE.FLOOR_GENERIC, 6, 121, LAYER.FRONT))
+        tile:decorate_internal()
     end
-end, ON.TRANSITION)
+end, ON.POST_LEVEL_GENERATION)

src/game_api/rpc.cpp

@@ -1903,3 +1903,53 @@ void init_seeded(std::optional<uint32_t> seed)
     auto* state = State::get().ptr();
     isf(state, seed.value_or(state->seed));
 }
+
+void copy_state(int from, int to)
+{
+    size_t arr = get_address("save_states");
+    size_t iterIdx = 1;
+    size_t fromBaseState = memory_read<size_t>(arr + (from - 1) * 8);
+    size_t toBaseState = memory_read<size_t>(arr + (to - 1) * 8);
+    do
+    {
+        size_t copyContent = *(size_t*)((fromBaseState - 8) + iterIdx * 8);
+        // variable used to fix pointers that point somewhere in the same Thread
+        size_t diff = toBaseState - fromBaseState;
+        if (copyContent >= fromBaseState + 0x2000000 || copyContent <= fromBaseState)
+        {
+            diff = 0;
+        }
+        *(size_t*)(toBaseState + iterIdx * 8 + -8) = diff + copyContent;
+
+        // Almost same code as before, but on the next value, idk why
+        copyContent = *(size_t*)(fromBaseState + iterIdx * 8);
+        diff = toBaseState - fromBaseState;
+        if (copyContent >= fromBaseState + 0x2000000 || copyContent <= fromBaseState)
+        {
+            diff = 0;
+        }
+        *(size_t*)(toBaseState + iterIdx * 8) = diff + copyContent;
+
+        iterIdx = iterIdx + 2;
+    } while (iterIdx != 0x400001);
+};
+
+StateMemory* get_save_state(int slot)
+{
+    size_t arr = get_address("save_states");
+    size_t base = memory_read<size_t>(arr + (slot - 1) * 8);
+    auto state = reinterpret_cast<StateMemory*>(base + 0x4a0);
+    if (state->screen)
+        return state;
+    return nullptr;
+}
+
+void invalidate_save_states()
+{
+    for (int i = 1; i <= 4; ++i)
+    {
+        auto state = get_save_state(i);
+        if (state)
+            state->screen = 0;
+    }
+}

src/game_api/rpc.hpp

@@ -137,3 +137,6 @@ void set_speedhack(std::optional<float> multiplier);
 float get_speedhack();
 void init_adventure();
 void init_seeded(std::optional<uint32_t> seed);
+void copy_state(int from, int to);
+StateMemory* get_save_state(int slot);
+void invalidate_save_states();

src/game_api/script/events.cpp

@@ -78,7 +78,10 @@ bool pre_unload_level()
             return !block;
         });
     if (!block)
+    {
         g_level_loaded = false;
+        invalidate_save_states();
+    }
     return block;
 }
 bool pre_init_level()

src/game_api/script/lua_vm.cpp

@@ -2249,6 +2249,28 @@ end
     /// Initializes some seedeed run related values and loads the character select screen, as if starting a new seeded run after entering the seed.
     lua["play_seeded"] = init_seeded;
 
+    /// Save current level state to slot 1..4. These save states are invalid after you exit the level, but can be used to rollback to an earlier state in the same level. You probably definitely shouldn't use save state functions during an update, and sync them to the same event outside an update (i.e. GUIFRAME, POST_UPDATE).
+    lua["save_state"] = [](int slot)
+    {
+        if (slot >= 1 && slot <= 4)
+            copy_state(5, slot);
+    };
+
+    /// Load level state from slot 1..4, if a save_state was made in this level.
+    lua["load_state"] = [](int slot)
+    {
+        if (slot >= 1 && slot <= 4 && get_save_state(slot))
+            copy_state(slot, 5);
+    };
+
+    /// Get StateMemory from a save_state slot.
+    lua["get_save_state"] = [](int slot) -> StateMemory*
+    {
+        if (slot >= 1 && slot <= 5)
+            return get_save_state(slot);
+        return nullptr;
+    };
+
     lua.create_named_table("INPUTS", "NONE", 0x0, "JUMP", 0x1, "WHIP", 0x2, "BOMB", 0x4, "ROPE", 0x8, "RUN", 0x10, "DOOR", 0x20, "MENU", 0x40, "JOURNAL", 0x80, "LEFT", 0x100, "RIGHT", 0x200, "UP", 0x400, "DOWN", 0x800);
 
     lua.create_named_table("MENU_INPUT", "NONE", 0x0, "SELECT", 0x1, "BACK", 0x2, "DELETE", 0x4, "RANDOM", 0x8, "JOURNAL", 0x10, "LEFT", 0x20, "RIGHT", 0x40, "UP", 0x80, "DOWN", 0x100);

src/game_api/search.cpp

@@ -2110,6 +2110,11 @@ std::unordered_map<std::string_view, AddressRule> g_address_rules{
         PatternCommandBuffer{}
             .from_exe_base(0x22b7ca10) // TODO
     },
+    {
+        "save_states"sv,
+        PatternCommandBuffer{}
+            .from_exe_base(0x22e0d1d0) // TODO
+    },
 };
 std::unordered_map<std::string_view, size_t> g_cached_addresses;