二段跳：一跃再跃踏空而过

if P.jumps == 1 then P.vy = -380; P.jumps = 2 end

fx-doublejump

local DoubleJump = {}
local KEY = { JUMP1 = 420, JUMP2 = 380, GRAVITY = 900 }

local st = { vy = 0, jumps = 0, grounded = true }

function DJ.Press()
    if st.grounded then
        -- 第一跳
        st.vy = -KEY.JUMP1
        st.jumps = 1
        st.grounded = false
        SL:PlayBurst(SL:GetValue("actorX"), SL:GetValue("actorY"), "dust", 6)
        SL:PlayActorAct("player", "run")
    elseif st.jumps == 1 then
        -- 二段跳: 空中再蹬一脚, 并重置下坠速度
        st.vy = -KEY.JUMP2
        st.jumps = 2
        SL:PlayFxAt("air_ring", SL:GetValue("actorX"), SL:GetValue("actorY"))
        SL:PlaySfx("double_jump")
    end
    -- 第二次二段跳的输入被忽略: jumps 已是 2
end

function DJ.Tick(dt)
    if st.grounded then return end
    st.vy = st.vy + KEY.GRAVITY * dt
    local y = SL:GetValue("actorY") + st.vy * dt
    if y >= SL:GetValue("groundY") then
        y = SL:GetValue("groundY")
        st.grounded = true
        st.vy = 0
        st.jumps = 0
        SL:PlayActorAct("player", "idle")
    end
    SL:SetActorY("player", y)
end

return DJ