Many traders consider “round” levels (to be more exact, the levels, the vertical coordinate of which (in points) ends with “00”) as the levels of resistance/support. Example: the levels of 1.5800 and 1.5900 for EURUSD. Indicator RoundLevels draws two “round” nearest levels above and below the current price level.
The indicator is rather created to facilitate manual trading. It has 4 buffers that store the values of vertical coordinates of these levels. However, in this present realization, only the last value of each buffer has an exact sense.
The external variable LineWidth says for the thickness of lines composing the “round” levels. The variable KeepTraces regulates whether to keep the buffer values calculated on the preceding candlesticks.