Description

Source code

function calculate(bars, ctx) {
  const last = bars.length - 1;
  if (last < 0) return;

  // ── Inputs ──
  const range = ctx.input('Range', 300, { min: 100, max: 1000, step: 100 });
  const showTodayOnly = ctx.input('Show Today Only', true);
  const centerRed80  = ctx.input('Center Red +80', true);
  const centerGrn35  = ctx.input('Center Green +35', true);
  const centerPnk64  = ctx.input('Center Pink +64', true);
  const centerPnk6   = ctx.input('Center Pink +06', true);
  const centerBlu0   = ctx.input('Center Blue +00', true);
  const centerBlu10  = ctx.input('Center Blue +10', true);
  const centerBlu20  = ctx.input('Center Blue +20', true);
  const centerBlu50  = ctx.input('Center Blue +50', true);
  const centerBlk47  = ctx.input('Center Black +47', true);
  const centerBlk72  = ctx.input('Center Black +72', true);
  const centerBlk86  = ctx.input('Center Black +86', true);
  const centerYel26  = ctx.input('Center Yellow +26', true);
  const centerYel42  = ctx.input('Center Yellow +42', true);
  const centerYel58  = ctx.input('Center Yellow +58', true);
  const centerYel94  = ctx.input('Center Yellow +94', true);
  const showBelow    = ctx.input('Show Below Base', true);
  const showAbove    = ctx.input('Show Above Base', true);

  // ── Determine today's date (using the last bar) ──
  const lastDate = new Date(bars[last].timestamp);
  const lastDateStr = lastDate.toDateString();

  // ── Find the daily close for the most recent complete day ──
  let firstBarOfToday = 0;
  for (let i = last; i >= 0; i--) {
    const d = new Date(bars[i].timestamp);
    if (d.toDateString() === lastDateStr) {
      firstBarOfToday = i;
    } else {
      break;
    }
  }

  // Daily close = close of the bar just before today's first bar
  const prevDayClose = firstBarOfToday > 0 ? bars[firstBarOfToday - 1].close : bars[last].close;

  // ── Compute base levels ──
  const baseCenter = Math.round(prevDayClose / 100) * 100;
  const baseBelow = baseCenter - 100;
  const baseAbove = baseCenter + 100;

  // ── Helper: draw a horizontal line across today's visible bars ──
  function drawHline(price, color, lineWidth, labelText) {
    ctx.line(firstBarOfToday, price, last, price, {
      color: color,
      lineWidth: lineWidth,
      extend: 'right',
      text: labelText || ''
    });
  }

  // ── Helper: draw a dashed horizontal line (for blue 00) ──
  function drawDashed(price, color, labelText) {
    ctx.line(firstBarOfToday, price, last, price, {
      color: color,
      lineWidth: 1,
      lineStyle: 'dashed',
      extend: 'right',
      text: labelText || ''
    });
  }

  // ── Helper: draw cross markers (for yellow volatility levels) ──
  function drawCross(price, color, labelText) {
    ctx.line(firstBarOfToday, price, last, price, {
      color: color,
      lineWidth: 2,
      lineStyle: 'dashed',
      extend: 'right',
      text: labelText || ''
    });
  }

  // ── Plot all levels (only today's bars if showTodayOnly) ──
  const startBar = showTodayOnly ? firstBarOfToday : 0;

  // ========== CENTER BASE ==========
  if (centerRed80) drawHline(baseCenter + 80, '#ff0000', 2, '+80');
  if (centerGrn35) drawHline(baseCenter + 35, '#00ff00', 2, '+35');
  if (centerPnk64) drawHline(baseCenter + 64, '#ff00ff', 1, '+64');
  if (centerPnk6)  drawHline(baseCenter + 6,  '#ff00ff', 1, '+06');
  if (centerBlu0)  drawDashed(baseCenter,      'rgba(0,0,255,0.3)', '+00');
  if (centerBlu10) drawHline(baseCenter + 10, '#0000ff', 1, '+10');
  if (centerBlu20) drawHline(baseCenter + 20, '#0000ff', 1, '+20');
  if (centerBlu50) drawHline(baseCenter + 50, '#0000ff', 1, '+50');
  if (centerBlk47) drawHline(baseCenter + 47, '#000000', 1, '+47');
  if (centerBlk72) drawHline(baseCenter + 72, '#000000', 1, '+72');
  if (centerBlk86) drawHline(baseCenter + 86, '#000000', 1, '+86');
  if (centerYel26) drawCross(baseCenter + 26, '#ffff00', '+26');
  if (centerYel42) drawCross(baseCenter + 42, '#ffff00', '+42');
  if (centerYel58) drawCross(baseCenter + 58, '#ffff00', '+58');
  if (centerYel94) drawCross(baseCenter + 94, '#ffff00', '+94');

  // ========== BASE BELOW ==========
  if (showBelow) {
    if (centerRed80) drawHline(baseBelow + 80, '#ff0000', 2, 'B-80');
    if (centerGrn35) drawHline(baseBelow + 35, '#00ff00', 2, 'B-35');
    if (centerPnk64) drawHline(baseBelow + 64, '#ff00ff', 1, 'B-64');
    if (centerPnk6)  drawHline(baseBelow + 6,  '#ff00ff', 1, 'B-06');
    if (centerBlu0)  drawDashed(baseBelow,     'rgba(0,0,255,0.3)', 'B-00');
    if (centerBlu10) drawHline(baseBelow + 10, '#0000ff', 1, 'B-10');
    if (centerBlu20) drawHline(baseBelow + 20, '#0000ff', 1, 'B-20');
    if (centerBlu50) drawHline(baseBelow + 50, '#0000ff', 1, 'B-50');
    if (centerBlk47) drawHline(baseBelow + 47, '#000000', 1, 'B-47');
    if (centerBlk72) drawHline(baseBelow + 72, '#000000', 1, 'B-72');
    if (centerBlk86) drawHline(baseBelow + 86, '#000000', 1, 'B-86');
    if (centerYel26) drawCross(baseBelow + 26, '#ffff00', 'B-26');
    if (centerYel42) drawCross(baseBelow + 42, '#ffff00', 'B-42');
    if (centerYel58) drawCross(baseBelow + 58, '#ffff00', 'B-58');
    if (centerYel94) drawCross(baseBelow + 94, '#ffff00', 'B-94');
  }

  // ========== BASE ABOVE ==========
  if (showAbove) {
    if (centerRed80) drawHline(baseAbove + 80, '#ff0000', 2, 'A-80');
    if (centerGrn35) drawHline(baseAbove + 35, '#00ff00', 2, 'A-35');
    if (centerPnk64) drawHline(baseAbove + 64, '#ff00ff', 1, 'A-64');
    if (centerPnk6)  drawHline(baseAbove + 6,  '#ff00ff', 1, 'A-06');
    if (centerBlu0)  drawDashed(baseAbove,     'rgba(0,0,255,0.3)', 'A-00');
    if (centerBlu10) drawHline(baseAbove + 10, '#0000ff', 1, 'A-10');
    if (centerBlu20) drawHline(baseAbove + 20, '#0000ff', 1, 'A-20');
    if (centerBlu50) drawHline(baseAbove + 50, '#0000ff', 1, 'A-50');
    if (centerBlk47) drawHline(baseAbove + 47, '#000000', 1, 'A-47');
    if (centerBlk72) drawHline(baseAbove + 72, '#000000', 1, 'A-72');
    if (centerBlk86) drawHline(baseAbove + 86, '#000000', 1, 'A-86');
    if (centerYel26) drawCross(baseAbove + 26, '#ffff00', 'A-26');
    if (centerYel42) drawCross(baseAbove + 42, '#ffff00', 'A-42');
    if (centerYel58) drawCross(baseAbove + 58, '#ffff00', 'A-58');
    if (centerYel94) drawCross(baseAbove + 94, '#ffff00', 'A-94');
  }
}