合击技能：双人出手时差半秒内算同步

-- 错误：要求同一秒，几乎无法触发
local function canCombo(t1, t2)
    return os.date("%S", t1) == os.date("%S", t2)
end

local WINDOW = 0.5
local function canCombo(t1, t2)
    return math.abs(t1 - t2) <= WINDOW
end
local function onCast(p, mate)
    local now = os.time()
    local mt = tonumber(getplayvar(mate, "lastCast") or "0")
    if canCombo(now, mt)
        and getplayvar(p, "MAP") == getplayvar(mate, "MAP") then
        setplayvar(p, "lastCast", 0)
        setplayvar(mate, "lastCast", 0)
        sendcentermsg(0, "合击技触发")
    else
        setplayvar(p, "lastCast", now)
    end
end