Makers opening footprint

// Who absorbed the flow: the makers who opened positions at each price, from each fill's `makerWhy`.
// A taker sell fills a resting bid, so bid makers opening longs are on the left; a taker buy fills an
// ask, so ask makers opening shorts are on the right. The colours are the reverse of Bid × Ask: the
// left lane is buyers.
indicator('Makers opening footprint', { overlay: true, shortName: 'Makers opening' });

const tape = trades();
const fp = plot.footprint('Makers opening', {
  lanes: [
    { id: 'bidMakers', label: 'Bid makers opening longs', short: 'Bid makers', side: 'left', color: color.up },
    { id: 'askMakers', label: 'Ask makers opening shorts', short: 'Ask makers', side: 'right', color: color.down },
  ],
});

tape.onTrade((t) => {
  const why = t.makerWhy;
  if (t.side === 'sell' && (why === 'open_long' || why === 'flip_sl')) fp.add('bidMakers', t.price, t.size);
  else if (t.side === 'buy' && (why === 'open_short' || why === 'flip_ls')) fp.add('askMakers', t.price, t.size);
});