走马灯：灯轮转动幕幕成戏

 fx-zoudeng

local ZouDeng = {}
local KEY = { PANELS = 4, RADIUS = 66 }

local ang, act = 0, 1

function ZD.Spin()
    SL:SetValue("spinning", true)
    SL:Schedule(function(dt)
        if not SL:GetValue("spinning") then SL:UnSchedule("zdRun") return end
        local spd = SL:GetValue("spinSpeed") or 50
        ang = ang + spd / 100 * 2.4 * dt
        -- 转满一圈: 换一幕
        if ang >= 6.28 then
            ang = ang - 6.28
            act = act % 4 + 1
            SL:ShowSystemTips("灯影轮换 · " .. SL:GetValue("actName", act))
        end
        -- 四面纸屏按深度排序后渲染
        local panels = {}
        for i = 1, KEY.PANELS do
            local a = ang + i / KEY.PANELS * 6.28
            panels[#panels + 1] = {
                i = i, depth = (math.cos(a) + 1) / 2, a = a
            }
        end
        table.sort(panels, function(x, y) return x.depth < y.depth end)
        for _, p in ipairs(panels) do
            local px = SL:GetValue("lampX") + math.sin(p.a) * KEY.RADIUS
            local alpha = 0.35 + p.depth * 0.5
            local w = 30 + p.depth * 26
            SL:DrawPanel(px, 160, w, 124, alpha,
                         SL:GetValue("actName", p.i))
        end
    end, 0.016, "zdRun")
end

return ZD