1  local M = {}
 2  
 3  M.clamp = function(x, min, max)
 4    return x < min and min or (x > max and max or x)
 5  end
 6  
 7  M.round = function(x, increment)
 8    if increment then
 9      return M.round(x / increment) * increment
10    end
11    return x >= 0 and math.floor(x + 0.5) or math.ceil(x - 0.5)
12  end
13  
14  return M