export function twoPointSpring()

in src/utils/animation.js [26:67]

• 32 lines of code
• 3 McCabe index (conditional complexity)

export function twoPointSpring(
  initialHoverValue,
  initialReferenceValue,
  scale,
  colorMap = () => 'black'
) {
  function ptToSpringValue(pt) {
    if (pt === undefined) return undefined;
    const out = { ...pt };
    Object.keys(out).forEach((k) => {
      out[k] = scale(out[k]);
    });
    return out;
  }

  const hovParams = { damping: 1, stiffness: 0.7 };
  const refParams = { damping: 0.55, stiffness: 1 };
  const leftValues = spring(ptToSpringValue(initialHoverValue), hovParams);
  const rightValues = spring(ptToSpringValue(initialReferenceValue), refParams);

  const dotsAndLines = derived([leftValues, rightValues], ([$left, $right]) => {
    if (!$left || !$right) return [];
    const dal = Object.keys($right).reduce((acc, k) => {
      const rightY = $right[k];
      const leftY = $left[k];
      const color = colorMap(k);
      acc[k] = { leftY, rightY, color };
      return acc;
    }, {});
    return dal;
  });
  return {
    transform: ptToSpringValue,
    subscribe: dotsAndLines.subscribe,
    setHover: (p, hard = false) => {
      leftValues.set(ptToSpringValue(p), { hard });
    },
    setReference: (p, hard = false) => {
      rightValues.set(ptToSpringValue(p), { hard });
    },
  };
}