存档
保存与读取

保存
不知道为什么,我一开始不想马上做这个,甚至担心它会很难。但因为我已经做了几个测试场景,能保存游戏会方便得多。当然也要能读取。
为此我在 engine3 里创建了一个类,也就是 serialization.lua,它是对 binser 的封装。
这样就能正确地保存对象数据了。
然后我在游戏里写了一个 state.lua 类,大致是这样的。
function State:saveEntities()
for _, entity in pairs(entityManager.entities) do
if entity.saveEntity then
entity:saveEntity()
end
end
end
---@param file string Where to save the data
function State:save(file, force)
-- Check if it is possible to save right now
if action:isProcessWorking() and force ~= true then
print("saving is not possible now, a action is still working")
return false
end
local data = {}
-- Create a save state for all entities that are needed
self:saveEntities()
-- We don't need all session data.
-- @warning keep this up to date if you want to add something
local sessionData = session:getData()
local validSessionKeyNamePatterns = {
"^actor-.*",
"^item-.*",
"^animation-.*",
"^scene-.*",
"action",
"^entity_delete",
"^entity_properties",
"^currentSceneUkey"
}
for sessionKeyName, sessionValue in pairs(sessionData) do
-- I don't know how to create multi patterns ... [x|y] don't work
local check = false
for _, pattern in pairs(validSessionKeyNamePatterns) do
if string.match(sessionKeyName, pattern) ~= nil then
if self.config.log.state then
print("[SESSION.SET." .. sessionKeyName .. "]")
end
data[sessionKeyName] = sessionValue
check = true
break
end
end
if check == false and self.config.log.state then
print("[SESSION.INFO." .. sessionKeyName .. "] don't match any save pattern")
end
end
local success, message = love.filesystem.write(file, Serialization.serialize(data))
if success == false then
error("Cannot save data, " .. message)
end
end
---@param file string What file data to load
function State:load(file)
local data = love.filesystem.read(file)
if data then
local results, len = Serialization.deserialize(data)
-- at the moment we only use one object in each file
if len == 1 then
-- set the session data
session:setData(results[1])
end
end
end
使用
现在每个 entity 类都可以(可选地)创建两个函数,在保存和读取游戏时使用。下面是角色 entity 的一个简要示例。这种做法的好处是将来可以往任何方向扩展,而且文件也非常小。
-- special function that will execute when saving the game
function Actor:saveEntity()
-- maybe a extend class did create some data
local data = session:get("actor-" .. self.ukey) or {}
data.sceneUkey = self.sceneUkey
data.lastMove = self.lastMove
data.movableByUserInput = self.movableByUserInput
if self.activeFrameset then
data.startPositionX = self.activeFrameset:getX()
data.startPositionY = self.activeFrameset:getY()
end
-- maybe the actor did change the frameset (using a hat)
data.frameset = {}
for index, frameset in pairs(self.frameset) do
data.frameset[index] = frameset.name
end
session:set("actor-" .. self.ukey, data)
end
function Actor:loadEntity()
local restoreData = session:get("actor-" .. self.ukey)
if restoreData == nil then
return
end
if restoreData.sceneUkey ~= nil then
self:setSceneUkey(restoreData.sceneUkey)
end
if restoreData.movableByUserInput ~= nil then
self:setMovableByUserInput(restoreData.movableByUserInput)
end
-- maybe the actor did change the frameset (using a hat)
if restoreData.frameset then
for index, framesetName in pairs(restoreData.frameset) do
self:setFrameset(index, framesetName)
end
end
if restoreData.startPositionX and restoreData.startPositionY then
self.movable.vPosition.x = restoreData.startPositionX
self.movable.vPosition.y = restoreData.startPositionY
self:setXY(self.movable.vPosition.x, self.movable.vPosition.y)
end
if restoreData.lastMove then
-- what will be the new activeFrameset (index)
self:setActiveFrameset(restoreData.lastMove)
end
-- when load scene is used, we don't set the player position
-- @warning we do this after setXY, because that function will show the player
local currentSceneUkey = session:get("currentSceneUkey")
if currentSceneUkey and self.sceneUkey ~= currentSceneUkey then
self:hide()
end
end
最后
如你所见,你只需要确保只保存真正需要的数据。其他数据都是多余的,还会让调试几乎变得不可能。这样的系统不要拖太久,反正你迟早都得做。
上面的代码目前是通过一个按钮触发的,会截取一张游戏截图,然后选中的角色会说保存成功了。
self.buttonSave.callbackAfterMousePressedEvent["btnSave"] = function(button)
local currentTime = os.time()
local saveGameName = "savegame" .. currentTime .. ".data"
local saveGameScreenshot = "screenshot" .. currentTime .. ".png"
-- create a screenshot without the state menu (write it to the save directory (love default))
love.graphics.captureScreenshot(saveGameScreenshot)
-- save the game
State():save(saveGameName)
-- say that the save the game was correct
local activeActor = entityManager:find({ movableByUserInput = true }, "Player")
if #activeActor == 1 then
local actionSay = ActionSay()
actionSay:execute(
{
action = action.SAY,
initiator = activeActor[1]
},
{
text = i18n:s("Save game done!")
},
nil,
{},
{},
nil
)
end
self.buttonLoad:setIsVisible(true)
return { preventDefault = true }
end