// DriftWall — ported from React Bits (reactbits.dev) to plain JSX. Columns of tiles drift past
// a tilted 3D plane, the plane leans toward the pointer, and a hovered tile lifts out of it.
// Drives the About page's wall of Maria's certificates.
//
// Deviations from upstream, all deliberate:
//
// * **The frame loop only runs while the wall is on screen.** Upstream starts a
// `requestAnimationFrame` loop on mount and never stops it — it keeps animating a wall
// nobody is looking at, on a page that already runs a WebGL backdrop. An
// IntersectionObserver starts and stops it, and `visibilitychange` stops it for a
// backgrounded tab. Same arrangement as SideRays and Aurora.
// * **Under `prefers-reduced-motion` there is no loop at all.** Upstream keeps the rAF
// running even when reduced — it skips the drift but still animates the pointer lean every
// frame. Here the plane is positioned once and the columns stand still, so the wall becomes
// a static montage. Tiles still lift on hover, which is a transition rather than motion.
// * **`elementFromPoint` is rAF-throttled.** Upstream hit-tests the document on every single
// `pointermove`; the active tile can only change once per painted frame.
// * **Tiles take `srcSet`/`sizes`**, so the wall uses this site's own derivatives instead of
// one full-size URL per tile — it renders each item several times over, so a single large
// source would be downloaded once but painted at every copy.
// * **`object-fit: contain` on a paper ground, not upstream's `cover`.** These tiles are
// documents. `cover` at tile size crops a certificate to an illegible fragment of itself;
// contained, the whole page reads as a miniature, which is the only honest way to show one.
// * Colours come from the site's tokens. Upstream's `#060010` overlay and `#0b0b12` tile
// ground are built for a near-black page and would sit as dark rectangles on this cream one.
// * **Tiles size themselves from each image's aspect ratio.** Upstream gives every tile one
// fixed `tileHeight`, which for documents of two different shapes means letterboxing the
// portrait ones inside landscape boxes. Each item carries a `ratio` and the tile takes
// `tileWidth / ratio`, so a certificate's box *is* the certificate. The loop maths follows:
// a column's `copyHeight` is the sum of its own tiles rather than `count * tileHeight`, or
// the wrap point drifts out of step and the column visibly jumps.
// * **Clicking a tile opens it**, via an `onSelect` callback — upstream only supports an
// `href` per tile, which would navigate away from the page.
// * Track refs are indexed, never pushed — React re-invokes an inline ref callback on every
// update, and a pushed array doubles up on a language switch.
const DW_reduced = () =>
typeof window !== "undefined" && window.matchMedia
&& window.matchMedia("(prefers-reduced-motion: reduce)").matches;
// How much taller than its container each column's track has to be. The plane is scaled 1.18
// and pitched on two axes, so its projection reaches well past the container box.
const DW_COVER = 2.2;
// Upstream's golden-ratio jitter, so neighbouring columns never share a speed.
const dwColumnFactor = (index, variance) => {
const pseudo = ((index * 0.6180339887 + 0.35) % 1) * 2 - 1;
return 1 + variance * pseudo;
};
const DriftWall = ({
items = [],
columns = 5,
tileWidth = 200,
tileHeight = 132,
gap = 18,
radius = 14,
tilt = 16,
turn = -14,
roll = 0,
perspective = 1200,
depth = 120,
scale = 1.18, // upstream hardcodes 1.18; the About page passes 1 below 900px so the plane fits its column
speed = 42,
direction = "up",
variance = 0.45,
parallax = 0.6,
pauseOnHover = false,
lift = 64,
fade = 0.6,
dim = 0.55,
grayscale = false,
overlayColor = "var(--bg)",
onSelect,
className = "",
style,
}) => {
const { useRef, useEffect, useLayoutEffect, useMemo, useState, useCallback } = React;
const containerRef = useRef(null);
const planeRef = useRef(null);
const trackRefs = useRef([]);
const rafRef = useRef(0);
const offsetsRef = useRef([]);
const velocitiesRef = useRef([]);
const hoveredColRef = useRef(-1);
const wallHoveredRef = useRef(false);
const pointerRef = useRef({ x: 0, y: 0 });
const dampedRef = useRef({ x: 0, y: 0 });
const lastTsRef = useRef(null);
const activeIdRef = useRef(null);
const hitRafRef = useRef(0);
const [containerHeight, setContainerHeight] = useState(600);
const [activeId, setActiveId] = useState(null);
const reduced = DW_reduced();
const columnItems = useMemo(() => {
const cols = Array.from({ length: columns }, () => []);
items.forEach((item, i) => cols[i % columns].push(item));
return cols.map((col) => (col.length ? col : items.slice(0, 1)));
}, [items, columns]);
// A tile is as tall as its own certificate. `ratio` is width/height of the source image.
const heightOf = useCallback(
(item) => (item && item.ratio ? Math.round(tileWidth / item.ratio) : tileHeight),
[tileWidth, tileHeight]);
const columnMeta = useMemo(() => columnItems.map((col) => {
// Summed, not `count * unit`: with mixed portrait and landscape tiles a fixed unit puts
// the wrap point out of step with the real column and the loop jumps every cycle.
const copyHeight = Math.max(1, col.reduce((sum, it) => sum + heightOf(it) + gap, 0));
// Upstream sizes the track against `containerHeight * 1.6`, which is not enough here for
// two reasons: the plane is scaled 1.18 and pitched, so it covers far more than the
// container, and the plane is centred on its *tallest* column — a short column therefore
// ran out and left visible emptiness where the queue should continue. The track has to
// cover the plane's extent plus a whole copy, because the drift translates it by up to
// `copyHeight` before wrapping.
const needed = containerHeight * DW_COVER + copyHeight;
return { copyHeight, copies: Math.max(3, Math.ceil(needed / copyHeight)) };
}), [columnItems, heightOf, gap, containerHeight]);
useLayoutEffect(() => {
const el = containerRef.current;
if (!el) return;
const ro = new ResizeObserver(([entry]) => setContainerHeight(entry.contentRect.height || 600));
ro.observe(el);
return () => ro.disconnect();
}, []);
const baseVelocities = useMemo(() => {
const dirSign = direction === "up" ? 1 : -1;
return columnItems.map((_, c) =>
speed * dwColumnFactor(c, variance) * dirSign * (c % 2 === 0 ? 1 : -1));
}, [columnItems, speed, direction, variance]);
useEffect(() => {
offsetsRef.current = columnMeta.map((m, c) => m.copyHeight * ((c * 0.37) % 1));
velocitiesRef.current = columnItems.map(() => 0);
}, [columnMeta, columnItems]);
// `translate(-50%, -50%)` centres the plane's *untransformed* box, which is not the same as
// centring what you see: under perspective, `rotateY` brings one edge toward the viewer and
// pushes the other away, so the near edge is magnified outward and the far edge shrinks
// inward. At turn -12deg that left the wall visibly right of centre. This measures the
// projected bounding box once and carries the difference as a screen-space nudge, so it
// stays correct if turn/tilt/depth/perspective are ever retuned rather than being a magic
// number that silently goes stale.
const shiftRef = useRef(0);
const applyPlane = useCallback((px, py) => {
const plane = planeRef.current;
if (!plane) return;
plane.style.transform =
`translate(-50%, -50%) translateX(${shiftRef.current}px) scale(${scale}) ` +
`rotateX(${tilt + py}deg) rotateY(${turn + px}deg) rotateZ(${roll}deg) ` +
`translateZ(${-depth}px)`;
}, [tilt, turn, roll, depth]);
// The nudge itself. Two things this has to get right, both learned the hard way:
//
// * **Measure the tiles actually on screen, not the plane's box.** The plane is ~2700px
// tall and mostly clipped, and under `rotateX` its far rows project to a different
// horizontal span than the rows you can see — so its bounding box is not what "looks
// centred" means. Only tiles overlapping the host's vertical band are counted.
// * **Iterate.** Perspective is not a linear map: shifting the plane changes its own
// projection, so a single measure-and-correct overshoots. This converges instead, and
// bails after a few passes rather than looping on a degenerate layout.
//
// Measured with the pointer lean at rest, or the reading bakes in whatever parallax happened
// to be applied at that instant.
const recentre = useCallback(() => {
const plane = planeRef.current, host = containerRef.current;
if (!plane || !host) return;
const h = host.getBoundingClientRect();
if (!h.width) return;
const hostCentre = h.left + h.width / 2;
shiftRef.current = 0;
for (let pass = 0; pass < 5; pass++) {
applyPlane(0, 0);
let left = Infinity, right = -Infinity;
const tiles = plane.querySelectorAll(".drift-wall__tile");
for (let i = 0; i < tiles.length; i++) {
const r = tiles[i].getBoundingClientRect();
if (!r.width || r.bottom < h.top || r.top > h.bottom) continue; // off the visible band
if (r.left < left) left = r.left;
if (r.right > right) right = r.right;
}
if (left === Infinity) return;
const delta = hostCentre - (left + right) / 2;
shiftRef.current += delta;
if (Math.abs(delta) < 0.5) break;
}
shiftRef.current = Math.round(shiftRef.current);
applyPlane(0, 0);
}, [applyPlane]);
useLayoutEffect(() => {
recentre();
// Tile heights settle after the scans decode, which changes the plane's box.
if (document.fonts && document.fonts.ready) document.fonts.ready.then(recentre);
window.addEventListener("resize", recentre);
return () => window.removeEventListener("resize", recentre);
}, [recentre, columnMeta, containerHeight]);
useEffect(() => {
// Reduced motion: place the plane and the columns once, then never run a loop.
if (reduced) {
applyPlane(0, 0);
trackRefs.current.forEach((el, c) => {
if (el) el.style.transform = `translate3d(0, ${-(offsetsRef.current[c] ?? 0)}px, 0)`;
});
return;
}
const el = containerRef.current;
if (!el) return;
let running = false;
const frame = (ts) => {
if (lastTsRef.current === null) lastTsRef.current = ts;
const dt = Math.min(0.05, Math.max(0, ts - lastTsRef.current) / 1000);
lastTsRef.current = ts;
const maxTilt = parallax * 8;
const damp = 1 - Math.exp(-dt / 0.12);
dampedRef.current.x += (pointerRef.current.x * maxTilt - dampedRef.current.x) * damp;
dampedRef.current.y += (-pointerRef.current.y * maxTilt - dampedRef.current.y) * damp;
applyPlane(dampedRef.current.x, dampedRef.current.y);
for (let c = 0; c < trackRefs.current.length; c++) {
const meta = columnMeta[c];
if (!meta) continue;
const paused = wallHoveredRef.current && pauseOnHover;
const target = baseVelocities[c] * (paused || hoveredColRef.current === c ? 0 : 1);
const ease = 1 - Math.exp(-dt / (target === 0 ? 0.16 : 0.28));
velocitiesRef.current[c] += (target - velocitiesRef.current[c]) * ease;
let next = (offsetsRef.current[c] ?? 0) + velocitiesRef.current[c] * dt;
next = ((next % meta.copyHeight) + meta.copyHeight) % meta.copyHeight;
offsetsRef.current[c] = next;
const t = trackRefs.current[c];
if (t) t.style.transform = `translate3d(0, ${-next}px, 0)`;
}
rafRef.current = requestAnimationFrame(frame);
};
const start = () => {
if (running) return;
running = true;
lastTsRef.current = null;
rafRef.current = requestAnimationFrame(frame);
};
const stop = () => {
running = false;
if (rafRef.current) cancelAnimationFrame(rafRef.current);
rafRef.current = 0;
lastTsRef.current = null;
};
const io = typeof IntersectionObserver === "function"
? new IntersectionObserver((es) => (es.some((e) => e.isIntersecting) ? start() : stop()),
{ rootMargin: "120px" })
: null;
if (io) io.observe(el); else start();
const onVis = () => (document.hidden ? stop() : start());
document.addEventListener("visibilitychange", onVis);
return () => {
stop();
if (io) io.disconnect();
document.removeEventListener("visibilitychange", onVis);
if (hitRafRef.current) cancelAnimationFrame(hitRafRef.current);
};
}, [reduced, baseVelocities, columnMeta, pauseOnHover, parallax, applyPlane]);
const release = useCallback(() => {
activeIdRef.current = null;
hoveredColRef.current = -1;
setActiveId(null);
}, []);
// Clicking a drifting tile does not work with `onClick`: a browser only fires `click` when
// mousedown and mouseup land on the *same* element, and by mouseup the tile has moved out
// from under the cursor — so the click is silently swallowed. The tile is captured on
// pointerdown instead and opened on pointerup, which also lets a touch drag scroll the page
// without opening anything: past ~10px of travel it is a scroll, not a tap.
const pressRef = useRef(null);
const itemFromTileId = useCallback((id) => {
if (!id) return null;
const [c, , i] = id.split("-").map(Number);
const col = columnItems[c];
return col ? col[i] : null;
}, [columnItems]);
// Hit-testing 3D-transformed quads is not watertight: about half of all points over the
// wall resolve to the track/column/plane rather than to a tile, so `closest` alone loses
// roughly every other press and the card reads as dead. When it misses, fall back to the
// tile whose projected box contains the point — nearest centre wins where they overlap.
const tileAt = useCallback((e) => {
const direct = e.target && e.target.closest ? e.target.closest("[data-tile-id]") : null;
if (direct) return direct;
const root = containerRef.current;
if (!root) return null;
const tiles = root.querySelectorAll("[data-tile-id]");
let best = null, bestDist = Infinity;
for (let i = 0; i < tiles.length; i++) {
const r = tiles[i].getBoundingClientRect();
if (!r.width || e.clientX < r.left || e.clientX > r.right
|| e.clientY < r.top || e.clientY > r.bottom) continue;
const d = Math.hypot(e.clientX - (r.left + r.width / 2), e.clientY - (r.top + r.height / 2));
if (d < bestDist) { bestDist = d; best = tiles[i]; }
}
return best;
}, []);
const onPointerDown = useCallback((e) => {
const tile = tileAt(e);
pressRef.current = tile
? { id: tile.dataset.tileId, x: e.clientX, y: e.clientY, t: Date.now() }
: null;
}, [tileAt]);
const onPointerUp = useCallback((e) => {
const press = pressRef.current;
pressRef.current = null;
if (!press || typeof onSelect !== "function") return;
if (Math.hypot(e.clientX - press.x, e.clientY - press.y) > 10) return; // a drag, not a tap
if (Date.now() - press.t > 700) return; // a long press
const item = itemFromTileId(press.id);
if (item) onSelect(item);
}, [onSelect, itemFromTileId]);
const onPointerMove = useCallback((e) => {
const rect = containerRef.current && containerRef.current.getBoundingClientRect();
if (!rect) return;
if (parallax > 0 && !reduced) {
pointerRef.current = {
x: (e.clientX - rect.left) / rect.width - 0.5,
y: (e.clientY - rect.top) / rect.height - 0.5,
};
}
// The hit test is the expensive part, and the answer cannot change more than once a frame.
const cx = e.clientX, cy = e.clientY;
if (hitRafRef.current) return;
hitRafRef.current = requestAnimationFrame(() => {
hitRafRef.current = 0;
const hit = document.elementFromPoint(cx, cy);
const tile = tileAt({ target: hit, clientX: cx, clientY: cy });
if (!tile) return;
const id = tile.dataset.tileId || null;
if (id === activeIdRef.current) return;
activeIdRef.current = id;
hoveredColRef.current = Number(tile.dataset.col);
setActiveId(id);
});
}, [parallax, reduced, tileAt]);
const cssVars = Object.assign({
"--dw-tile-w": `${tileWidth}px`,
"--dw-tile-h": `${tileHeight}px`,
"--dw-gap": `${gap}px`,
"--dw-radius": `${radius}px`,
"--dw-perspective": `${perspective}px`,
"--dw-lift": `${lift}px`,
"--dw-dim": dim,
"--dw-gray": grayscale ? 1 : 0,
"--dw-overlay": overlayColor,
"--dw-edge": `${Math.max(0, (1 - fade) * 100)}%`,
}, style);
const renderTile = (item, id, colIndex) => (