GLua math functions for regular Lua

-- This is some of math functions that available in GLua but missing in vanilla Lua.

math.Clamp = math.Clamp or function(val, lower, upper)
    assert(val and lower and upper, "not very useful error message here")
    if lower > upper then lower, upper = upper, lower end -- swap if boundaries supplied the wrong way
    return math.max(lower, math.min(upper, val))
end

math.Round = math.Round or function(num, numDecimalPlaces)
    local mult = 10^(numDecimalPlaces or 0)
    return math.floor(num * mult + 0.5) / mult
end