Lua数字滚动：旧值到新值的缓动翻牌

flowchart TD
A[记下旧值和新值] --> B[计时从零到一]
B --> C[缓动曲线折算进度]
C --> D[显示值 = 旧值加差值乘进度]
D --> E{计满了吗}
E -- 否 --> B
E -- 是 --> F[显示值钉死新值]

 fx-numroll

-- @file NumberRoll.lua
-- 数字滚动 —— 旧值到新值的缓动翻牌

local NumberRoll = {}

local CONST = {
    ROLL_LIFE     = 1.0,
    PULSE_SCALE   = 0.06,

    COLOR_NUM     = "#c9d1d9",
    COLOR_PANEL   = "#161b22",

    ZORDER_ROLL   = 150,
    AUTOINC_BASE  = 1152000,
}

local _shown     = 0
local _from      = 0
local _to        = 0
local _rollT     = 0
local _rolling   = false
local _label     = nil
local _scheduler = nil
local _autoInc   = 0

local function GenID(prefix)
    _autoInc = _autoInc + 1
    return string.format("%s_%d", prefix or "NRL",
        CONST.AUTOINC_BASE + _autoInc)
end

local function ShowTip(msg)
    if msg and msg ~= "" then SL:ShowSystemTips(msg) end
end

local function EaseOutCubic(k)
    return 1 - math.pow(1 - k, 3)
end

function NumberRoll.Shown()
    return _shown
end

-- 滚动发起：记旧记新，开滚
function NumberRoll.RollTo(target)
    _from = _shown
    _to = target
    _rollT = 0
    _rolling = true
end

-- 上屏输出：缓动折算的显示值逐拍刷新
if not _scheduler then
    _scheduler = SL:Schedule(function(dt)
        if not _rolling then return end
        _rollT = _rollT + dt
        local k = math.min(1, _rollT / CONST.ROLL_LIFE)
        _shown = math.floor(
            _from + (_to - _from) * EaseOutCubic(k))
        if _label and not GUI:Widget_IsNull(_label) then
            GUI:setText(_label,
                tostring(string.format("%d", _shown)))
        end
        if k >= 1 then
            _rolling = false
            _shown = _to
            ShowTip("滚完——稳稳停在 " .. _to)
        end
    end, 0.02)
end

function NumberRoll.Bind(label)
    SafeRemove(label)
    _label = label
end

local function SafeRemove(node)
    if node and not GUI:Widget_IsNull(node) then
        GUI:removeFromParent(node)
    end
end

SL:ScheduleOnce(function()
    NumberRoll.Bind(GUI:GetCashLabel())
    ShowTip("技能已加载: 数字滚动 (调试按钮触发)")
end, 1.0)

function NumberRoll.Unload()
    if _scheduler then SL:Unschedule(_scheduler) end
    SafeRemove(_label)
    _rolling = false
end

return NumberRoll