Function axisSelectionPolygons

docs/tests/v2/es6/js/sanddance.js:148988–149031

(axis, vertical, axisSelectionType, column)

}

function axisSelectionPolygons(axis, vertical, axisSelectionType, column) {
  const polygons = [];
  const size = 50;
  const getSearch = axisSelectionType === 'exact' ? (a, c, i) => ({
    expressions: [(0, _expression.selectExactAxis)(a, c, i)]
  }) : _expression.selectBetweenAxis;
  const {
    domain,
    ticks
  } = axis;

  if (ticks.length > 0 && domain) {
    const dim = vertical ? 1 : 0;
    const between = Math.abs(ticks[0].sourcePosition[dim] - domain.sourcePosition[dim]) > 1;
    let divisions;

    if (between) {
      divisions = [];

      for (let i = 1; i < ticks.length; i++) {
        divisions.push((ticks[i].sourcePosition[dim] + ticks[i - 1].sourcePosition[dim]) / 2);
      }
    } else {
      divisions = ticks.slice(1, -1).map(tick => tick.sourcePosition[dim]);
    }

    const add = (p2, i) => {
      var coords = [[p1, q1], [p2, q1], [p2, q2], [p1, q2]];
      polygons.push({
        search: getSearch(axis, column, i),
        polygon: vertical ? coords.map(xy => xy.reverse()) : coords
      });
      p1 = p2;
    };

    let p1 = domain.sourcePosition[dim];
    const q1 = domain.sourcePosition[vertical ? 0 : 1];
    const q2 = q1 - size;
    divisions.forEach(add);
    add(domain.targetPosition[dim], ticks.length - (between ? 1 : 2));
  }

  return polygons;
}

function facetSelectionPolygons(facetRects, facetColumn) {
  const polygons = [];