Function computeFlexCategoryTraits

src/controllers/controller.bar.js:89–115

* Computes an "optimal" category that globally arranges bars side by side (no gap when * percentage options are 1), based on the previous and following categories. This mode * generates bars with different widths when data are not evenly spaced. * @private

(index, ruler, options, stackCount)

 * @private
 */
function computeFlexCategoryTraits(index, ruler, options, stackCount) {
  const pixels = ruler.pixels;
  const curr = pixels[index];
  let prev = index > 0 ? pixels[index - 1] : null;
  let next = index < pixels.length - 1 ? pixels[index + 1] : null;
  const percent = options.categoryPercentage;

  if (prev === null) {
    // first data: its size is double based on the next point or,
    // if it's also the last data, we use the scale size.
    prev = curr - (next === null ? ruler.end - ruler.start : next - curr);
  }

  if (next === null) {
    // last data: its size is also double based on the previous point.
    next = curr + curr - prev;
  }

  const start = curr - (curr - Math.min(prev, next)) / 2 * percent;
  const size = Math.abs(next - prev) / 2 * percent;

  return {
    chunk: size / stackCount,
    ratio: options.barPercentage,
    start
  };
}

function parseFloatBar(entry, item, vScale, i) {
  const startValue = vScale.parse(entry[0], i);