竹蜻蜓：搓得越快飞得越高

fx-bamboocopter

local BambooCopter = {}
local KEY = { GRAVITY = 140, DECAY = 9 }

local st = { spin = 0, released = false, y = 0, vy = 0, best = 0 }

function BC.Roll()
    if st.released then return end
    st.spin = math.min(100, st.spin + 16)
    SL:PlayBurst(SL:GetValue("handX") + 20, SL:GetValue("handY") - 10,
                 "spin_dust", 3)
    SL:PlaySfx("roll")
end

function BC.Release()
    if st.spin < 30 then
        SL:ShowSystemTips("转速不够 — 再搓几把")
        return
    end
    st.released = true
    st.vy = -st.spin * 2.6                 -- 初速 = 转速换算
    SL:ShowSystemTips("脱手放飞!")
end

function BC.Tick(dt)
    -- 叶片转速衰减
    st.spin = math.max(0, st.spin - KEY.DECAY * dt)
    if not st.released then return end
    local lift = st.spin * 3.2
    st.vy = st.vy + (KEY.GRAVITY - lift) * dt
    st.y = st.vy * dt + st.y
    local m = math.floor((SL:GetValue("handY") - 10 - st.y) / 10)
    if m > st.best then
        st.best = m
        SL:SetValue("bestM", m)
    end
    -- 落回手心
    if st.y >= 0 and st.vy > 0 then
        st.released = false
        st.spin = 0
        st.vy = 0
        SL:PlayBurst(SL:GetValue("handX") + 20,
                     SL:GetValue("handY") - 10, "landing_dust", 5)
        SL:ShowSystemTips("落回手心! 最高 " .. st.best .. "m")
    end
end

return BC