one/dist/esm/link/prefetchIntent.js

One is a new React Framework that makes Vite serve both native and web.

function createPrefetchIntent(options) {
  const { onPrefetch, maxReach = 500, perpWeight = 5, minSpeed = 8 } = options, done = /* @__PURE__ */ new Set();
  let rects = [], px = 0, py = 0, vx = 0, vy = 0, moveCount = 0, lastPrefetchMove = 0;
  function setRects(newRects) {
    rects = newRects.filter((r) => !done.has(r.h));
  }
  function move(x, y, dx, dy) {
    moveCount++;
    const smooth = moveCount < 3 ? 0.3 : 0.6;
    vx = vx * smooth + dx * (1 - smooth), vy = vy * smooth + dy * (1 - smooth), px = x, py = y;
    const speed = Math.sqrt(vx * vx + vy * vy);
    if (speed < minSpeed) return;
    const ux = vx / speed, uy = vy / speed;
    let best = 1 / 0, href = "";
    for (const { r, h } of rects) {
      const cx = (r.left + r.right) / 2 - px, cy = (r.top + r.bottom) / 2 - py, dist = Math.sqrt(cx * cx + cy * cy), along = cx * ux + cy * uy;
      if (along < 0) continue;
      const perpX = cx - along * ux, perpY = cy - along * uy, perp = Math.sqrt(perpX * perpX + perpY * perpY), baseRadius = Math.max(r.width, r.height) / 2 + 30, distanceFactor = Math.max(0.2, 1 - dist / 1e3), radius = baseRadius * distanceFactor + 20;
      if (perp > radius) continue;
      const score = along + perp * perpWeight;
      score < best && (best = score, href = h);
    }
    href && best < maxReach && moveCount - lastPrefetchMove > 1 && (done.add(href), rects = rects.filter((r) => r.h !== href), lastPrefetchMove = moveCount, onPrefetch(href));
  }
  const nodes = /* @__PURE__ */ new Map();
  function observe(el, href) {
    return nodes.set(el, href), () => {
      nodes.delete(el), done.delete(href);
    };
  }
  return { setRects, move, observe, nodes, done };
}
let instance = null, started = !1;
function startPrefetchIntent(onPrefetch) {
  if (started) return instance;
  started = !0, instance = createPrefetchIntent({ onPrefetch });
  let frame = 0, px = 0, py = 0;
  function measure() {
    if (!instance.nodes.size) return setTimeout(measure, 300);
    const io = new IntersectionObserver((entries) => {
      io.disconnect(), instance.setRects(
        entries.filter((e) => e.isIntersecting).map((e) => ({
          r: e.boundingClientRect,
          h: instance.nodes.get(e.target)
        })).filter((x) => x.h)
      ), setTimeout(measure, 300);
    });
    instance.nodes.forEach((_, el) => io.observe(el));
  }
  return measure(), document.addEventListener(
    "mousemove",
    (e) => {
      if (++frame % 4) return;
      const dx = e.clientX - px, dy = e.clientY - py;
      px = e.clientX, py = e.clientY, instance.move(px, py, dx, dy);
    },
    { passive: !0 }
  ), instance;
}
function observePrefetchIntent(el, href) {
  return instance ? instance.observe(el, href) : () => {
  };
}
export {
  createPrefetchIntent,
  observePrefetchIntent,
  startPrefetchIntent
};
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