CommonFun.GetElementRate
function CommonFun.GetElementRate(srcUser, srcAtkElement, targetUser, targetDefElement, params, damageParam)
  local ElementRate = GameConfig.ElementRestrain[srcAtkElement][targetDefElement]
  local srcAtkLevel = CommonFun.GetUserAtkLevel(srcUser, srcAtkElement, params, damageParam)
  local tarDefLevel = CommonFun.GetUserDefLevel(targetUser, targetDefElement)
  if 3 <= tarDefLevel then
    ElementRate = ElementRate + (srcAtkLevel - 1) * 0.25 - 0.25 - (tarDefLevel - 2) * 0.125
  elseif 2 <= tarDefLevel and tarDefLevel < 3 then
    ElementRate = ElementRate + (srcAtkLevel - 1) * 0.25 - 0.25
  else
    ElementRate = ElementRate + (srcAtkLevel - 1) * 0.25
  end
  if ElementRate < 0 then
    ElementRate = 0
  end
  return ElementRate
end