MAME Lua插件：替换弃用函数emu.register_start/register_stop遇阻求助

问题描述 #

我开发了一款用于MAME的Lua插件，通过两个PowerShell脚本实现物理屏幕在横竖方向间切换。原脚本使用emu.register_start()和emu.register_stop()能稳定运行，但这两个函数已被废弃，官方推荐使用emu.add_machine_reset_notifier和emu.add_machine_stop_notifier替代。我替换后代码无法正常工作，寻求修复方案。

原代码 #

local exports = {}
exports.name = "screenrotator"
exports.version = "0.0.1"
exports.description = "Rotate Display"
exports.license = "The BSD 3-Clause License"
exports.author = { name = "Daren" }

-- Define file locations for portrait and landscape scripts
local portraitScript = "D:\\Games\\MAME\\mame0263b_64bit\\plugins\\ScreenRotator\\portrait.ps1"
local landscapeScript = "D:\\Games\\MAME\\mame0263b_64bit\\plugins\\ScreenRotator\\landscape.ps1"

-- Flag to track if the plugin start function has been called
local startCalled = false

-- Define the plugin functions
function exports.startplugin()
    -- Check if the start function has already been called
    if not startCalled then
        -- Set flag to true to indicate that the start function has been called
        startCalled = true
        
        emu.register_start(function()
            local screenrotation = manager.machine.system.orientation
            print(screenrotation)
            if screenrotation == "rot270" or screenrotation == "rot90" then
                print("Vertical game. Rotating...")
                os.execute("powershell.exe -file " .. portraitScript)
            else
                print("Horizontal game. Not Rotating...")
            end
        end)

        emu.register_stop(function()
            local screenrotation = manager.machine.system.orientation
            print(screenrotation)
            if screenrotation == "rot270" or screenrotation == "rot90" then
                print("Vertical game. Rotating back...")
                os.execute("powershell.exe -file " .. landscapeScript)
            else
                print("Horizontal game. No need to rotate back.")
            end
        end)
    else
        print("Start function already called. Skipping...")
    end
end

-- Call the plugin initialization function
exports.startplugin()

return exports

修复后的代码 #

local exports = {}
exports.name = "screenrotator"
exports.version = "0.0.1"
exports.description = "Rotate Display"
exports.license = "The BSD 3-Clause License"
exports.author = { name = "Daren" }

-- Define file locations for portrait and landscape scripts
local portraitScript = "D:\\Games\\MAME\\mame0263b_64bit\\plugins\\ScreenRotator\\portrait.ps1"
local landscapeScript = "D:\\Games\\MAME\\mame0263b_64bit\\plugins\\ScreenRotator\\landscape.ps1"

-- Flag to track if the plugin start function has been called
local startCalled = false

-- Define the plugin functions
function exports.startplugin()
    if not startCalled then
        startCalled = true
        
        -- 替换废弃的emu.register_start，使用机器重置通知（启动时触发）
        emu.add_machine_reset_notifier(function()
            local screenrotation = manager.machine.system.orientation
            print(screenrotation)
            if screenrotation == "rot270" or screenrotation == "rot90" then
                print("Vertical game. Rotating...")
                os.execute("powershell.exe -file " .. portraitScript)
            else
                print("Horizontal game. Not Rotating...")
            end
        end)

        -- 替换废弃的emu.register_stop，使用机器停止通知
        emu.add_machine_stop_notifier(function(machine)
            -- 直接使用回调传入的machine实例获取方向，比manager.machine更可靠
            local screenrotation = machine.system.orientation
            print(screenrotation)
            if screenrotation == "rot270" or screenrotation == "rot90" then
                print("Vertical game. Rotating back...")
                os.execute("powershell.exe -file " .. landscapeScript)
            else
                print("Horizontal game. No need to rotate back.")
            end
        end)
    else
        print("Start function already called. Skipping...")
    end
end

exports.startplugin()

return exports

关键修复点 #

1. 启动回调替换：emu.register_start()被emu.add_machine_reset_notifier()替代，该函数会在机器启动或重置时触发，与原函数的触发时机完全匹配。
2. 停止回调替换：emu.register_stop()被emu.add_machine_stop_notifier()替代，回调函数会接收当前机器实例作为参数，推荐直接使用该参数获取系统方向，避免依赖全局的manager.machine。
3. 逻辑保留：原有的屏幕方向判断、PowerShell脚本执行逻辑完全保留，确保功能不变。

验证注意事项 #

• 确认你的MAME版本（0.246及以上）支持这两个新函数（你使用的0.263版本完全兼容）。
• 检查PowerShell脚本路径是否正确，确保MAME有权限执行PowerShell命令。

内容的提问来源于stack exchange，提问作者Daren Page