//@version=5
indicator("Trendlines with Breaks [LuxAlgo]", "LuxAlgo - Trendlines with Breaks", overlay = true)
//------------------------------------------------------------------------------
//Settings
//-----------------------------------------------------------------------------{
length = input.int(14, 'Swing Detection Lookback')
mult = input.float(1., 'Slope', minval = 0, step = .1)
calcMethod = input.string('Atr', 'Slope Calculation Method', options = ['Atr','Stdev','Linreg'])
backpaint = input(true, tooltip = 'Backpainting offset displayed elements in the past. Disable backpainting to see real time information returned by the indicator.')
//Style
upCss = input.color(color.teal, 'Up Trendline Color', group = 'Style')
dnCss = input.color(color.red, 'Down Trendline Color', group = 'Style')
showExt = input(true, 'Show Extended Lines')
//-----------------------------------------------------------------------------}
//Calculations
//-----------------------------------------------------------------------------{
var upper = 0.
var lower = 0.
var slope_ph = 0.
var slope_pl = 0.
var offset = backpaint ? length : 0
n = bar_index
src = close
ph = ta.pivothigh(length, length)
pl = ta.pivotlow(length, length)
//Slope Calculation Method
slope = switch calcMethod
'Atr' => ta.atr(length) / length * mult
'Stdev' => ta.stdev(src,length) / length * mult
'Linreg' => math.abs(ta.sma(src * n, length) - ta.sma(src, length) * ta.sma(n, length)) / ta.variance(n, length) / 2 * mult
//Get slopes and calculate trendlines
slope_ph := ph ? slope : slope_ph
slope_pl := pl ? slope : slope_pl
upper := ph ? ph : upper - slope_ph
lower := pl ? pl : lower + slope_pl
var upos = 0
var dnos = 0
upos := ph ? 0 : close > upper - slope_ph * length ? 1 : upos
dnos := pl ? 0 : close < lower + slope_pl * length ? 1 : dnos
//-----------------------------------------------------------------------------}
//Extended Lines
//-----------------------------------------------------------------------------{
var uptl = line.new(na,na,na,na, color = upCss, style = line.style_dashed, extend = extend.right)
var dntl = line.new(na,na,na,na, color = dnCss, style = line.style_dashed, extend = extend.right)
if ph and showExt
uptl.set_xy1(n-offset, backpaint ? ph : upper - slope_ph * length)
uptl.set_xy2(n-offset+1, backpaint ? ph - slope : upper - slope_ph * (length+1))
if pl and showExt
dntl.set_xy1(n-offset, backpaint ? pl : lower + slope_pl * length)
dntl.set_xy2(n-offset+1, backpaint ? pl + slope : lower + slope_pl * (length+1))
//-----------------------------------------------------------------------------}
//Plots
//-----------------------------------------------------------------------------{
plot(backpaint ? upper : upper - slope_ph * length, 'Upper', color = ph ? na : upCss, offset = -offset)
plot(backpaint ? lower : lower + slope_pl * length, 'Lower', color = pl ? na : dnCss, offset = -offset)
//Breakouts
plotshape(upos > upos[1] ? low : na, "Upper Break"
, shape.labelup
, location.absolute
, upCss
, text = "B"
, textcolor = color.white
, size = size.tiny)
plotshape(dnos > dnos[1] ? high : na, "Lower Break"
, shape.labeldown
, location.absolute
, dnCss
, text = "B"
, textcolor = color.white
, size = size.tiny)
//-----------------------------------------------------------------------------}
//Alerts
//-----------------------------------------------------------------------------{
alertcondition(upos > upos[1], 'Upward Breakout', 'Price broke the down-trendline upward')
alertcondition(dnos > dnos[1], 'Downward Breakout', 'Price broke the up-trendline downward')
//-----------------------------------------------------------------------------}
