({ x: target ?? 0, v: 0 });
const [moving, setMoving] = React.useState(false);
const shown = React.useRef(target);
/* before the new value paints, the dot is put back where it was, so the spring carries it from there */
useIsomorphicLayoutEffect(() => {
if (target == null || shown.current === target) return;
const from = shown.current;
shown.current = target;
if (less || from == null) {
spring.current = { x: target, v: 0 };
return;
}
if (dot.current) dot.current.style.left = `${spring.current.x}%`;
queueMicrotask(() => setMoving(true));
}, [target, less]);
useFrame((dt) => {
if (target == null) return;
const s = (spring.current = springStep(spring.current, target, 170, 0.62, dt));
if (dot.current) dot.current.style.left = `${s.x}%`;
if (Math.abs(s.x - target) < 0.02 && Math.abs(s.v) < 0.2) {
spring.current = { x: target, v: 0 };
if (dot.current) dot.current.style.left = `${target}%`;
setMoving(false);
}
}, moving && !less);
const bandFrom = range.low == null ? 0 : pct(range.low);
const bandTo = range.high == null ? 100 : pct(range.high);
const row = size === "row";
const trackH = row ? "h-[6px]" : "h-[10px]";
const bar = (
{optimal && (
)}
{!row &&
[range.low, range.high].map((l, i) =>
l == null ? null : ,
)}
{previous && value != null && (
<>
)}
{target != null && (
{/* on a record's bar the value is written over its dot, so the scale reads at a glance */}
{size === "full" && value != null && (
{format(value)}
)}
)}
);
if (row) return {bar}
;
const limits = (
{[range.low, range.high].map((l, i) => {
if (l == null) return null;
const at = pct(l);
return (
80 ? { right: `${100 - at}%`, transform: "translateX(50%)" } : { left: `${at}%`, transform: "translateX(-50%)" }}>
{format(l)}
);
})}
);
if (size === "card")
return (
{value == null && No result yet · {rangeName(range.kind)} {rangeText(range, format)}{unitText}}
{bar}
{limits}
);
return (
{value == null ? (
--
) : (
)}
{unit}
{value != null && (
{word}
)}
{children != null &&
{children}
}
{optimal &&
(() => {
/* the optimal band's name sits over its start, or over its end when the value's own label is there; with
the value at both, it is left to the list below, so two labels never sit on each other */
const from = Math.min(70, optimal.low == null ? bandFrom : pct(optimal.low));
const to = optimal.high == null ? bandTo : pct(optimal.high);
const at = value == null || flag === "may-be-wrong" ? null : pct(value);
const clear = (a: number, b: number) => at == null || at < a - 4 || at > b + 4;
const style = clear(from, from + 22) ? { left: `${from}%` } : clear(to - 22, to) ? { right: `${Math.max(0, 100 - to)}%` } : null;
return (
{style && (
Optimal {rangeText(optimal, format)}
)}
);
})()}
{bar}
{limits}
- {rangeName(range.kind)}
-
{rangeText(range, format)}
{unitText} · {range.source}
{optimal && (
<>
- Optimal
-
{rangeText(optimal, format)}
{unitText} · {optimal.source}
)}
{previous && (
<>
- Previous
-
{format(previous.value)}
{unitText} · {previous.label}
)}
{measured && (
<>
- Measured
- {measured}
)}
);
}
export { RangeBar, type RangeBarProps };
```
### lib/notchset/physics.ts
```tsx
// Notchset range-bar 2.0.0 · https://notchset.dev/changelog
"use client";
/*
* Physics: what every showcase piece moves by (SHOWCASE-RULES.md, "Real physics"), so a spring settles the same at 60
* and at 120 Hz and only one piece on a screen is ever running. Plain hooks and functions, no markup.
*
* - Time-based: a frame gets the seconds since the last one (capped, so a hidden tab never lands as one huge step),
* and simulations that collide take fixed steps of 1/120 s from an accumulator.
* - One running loop per viewport: the latest piece that asked and is on screen moves; every other one shows its
* still until it is the latest again.
* - Less motion, from the app (data-motion="reduced") or the device, which always wins: a piece shows its still.
* - Self-play hands over for good at the first pointer press, key or wheel inside the piece.
*/
import * as React from "react";
/** Less motion, asked by the device or by the app on the root. */
export function lessMotion(): boolean {
if (typeof document === "undefined") return true;
return document.documentElement.dataset.motion === "reduced" || (typeof matchMedia !== "undefined" && matchMedia("(prefers-reduced-motion: reduce)").matches);
}
/** Less motion, kept current as the device's setting or the root's data-motion changes. */
export function useLessMotion(): boolean {
/* read at once in the browser, so a piece never starts in its still and then jumps; true on a server */
const [less, setLess] = React.useState(() => lessMotion());
React.useEffect(() => {
const read = () => setLess(lessMotion());
read();
const q = typeof matchMedia !== "undefined" ? matchMedia("(prefers-reduced-motion: reduce)") : null;
q?.addEventListener("change", read);
const mo = typeof MutationObserver !== "undefined" ? new MutationObserver(read) : null;
mo?.observe(document.documentElement, { attributes: true, attributeFilter: ["data-motion"] });
return () => {
q?.removeEventListener("change", read);
mo?.disconnect();
};
}, []);
return less;
}
/** Whether the element is on screen (without an IntersectionObserver, as in a test, it counts as seen). */
export function useSeen(el: React.RefObject): boolean {
const [seen, setSeen] = React.useState(typeof IntersectionObserver === "undefined");
React.useEffect(() => {
const node = el.current;
if (!node || typeof IntersectionObserver === "undefined") return;
const io = new IntersectionObserver((es) => setSeen(es.some((e) => e.isIntersecting)), { threshold: 0.15 });
io.observe(node);
const vis = () => document.hidden && setSeen(false);
document.addEventListener("visibilitychange", vis);
return () => {
io.disconnect();
document.removeEventListener("visibilitychange", vis);
};
}, [el]);
return seen;
}
/* ---------- one running loop per viewport ---------- */
const askers: string[] = [];
const listeners = new Set<() => void>();
let ownerNow: string | null = null;
function publish() {
ownerNow = askers[askers.length - 1] ?? null;
for (const l of listeners) l();
}
function subscribe(l: () => void) {
listeners.add(l);
return () => listeners.delete(l);
}
/**
* Whether this piece may run its loop now: it asks while `wants` (on screen, motion allowed, something to play), and
* the latest that asked runs; when it stops asking, the one before it takes over.
*/
export function useLoopTurn(wants: boolean): boolean {
const id = React.useId();
React.useEffect(() => {
if (!wants) return;
askers.push(id);
publish();
return () => {
const i = askers.lastIndexOf(id);
if (i >= 0) askers.splice(i, 1);
publish();
};
}, [id, wants]);
const owner = React.useSyncExternalStore(subscribe, () => ownerNow, () => null);
return wants && owner === id;
}
/** Calls `frame(dt, now)` every animation frame while `on`, with dt in seconds (at most 1/20 s); paused in a hidden tab. */
export function useFrame(frame: (dt: number, now: number) => void, on: boolean): void {
const cb = React.useRef(frame);
React.useEffect(() => {
cb.current = frame;
});
React.useEffect(() => {
if (!on) return;
let raf = 0, last = performance.now();
const tick = (now: number) => {
const dt = Math.min(0.05, Math.max(0, (now - last) / 1000));
last = now;
if (!document.hidden) cb.current(dt, now);
raf = requestAnimationFrame(tick);
};
raf = requestAnimationFrame(tick);
return () => cancelAnimationFrame(raf);
}, [on]);
}
/** A damped spring's state: where it is and how fast it is going. */
export type SpringState = { x: number; v: number };
/**
* One step of a damped spring toward `target` (semi-implicit Euler, stable at a frame's dt): `stiffness` pulls, and
* `damping` is the share of critical damping (1 settles without overshoot, under 1 overshoots and rings).
*/
export function springStep(s: SpringState, target: number, stiffness: number, damping: number, dt: number): SpringState {
const c = 2 * Math.sqrt(stiffness) * damping;
const v = s.v + (stiffness * (target - s.x) - c * s.v) * dt;
return { x: s.x + v * dt, v };
}
/** Whether a spring has come to rest at its target. */
export function springAtRest(s: SpringState, target: number, eps = 0.0005): boolean {
return Math.abs(s.x - target) < eps && Math.abs(s.v) < eps * 10;
}
/** Runs `step(h)` in fixed steps of `h` seconds for the time that passed; returns the time left over for next frame. */
export function fixedSteps(carry: number, dt: number, step: (h: number) => void, h = 1 / 120, max = 12): number {
let acc = carry + dt, n = 0;
while (acc >= h && n < max) {
step(h);
acc -= h;
n++;
}
return n >= max ? 0 : acc;
}
/**
* Self-play until the first touch: `mine` turns true for good at the first pointer press, key or wheel inside the
* root, so every queued step can be dropped and the visitor holds it from there. Bind `handOver` to the root's events.
*/
export function useHandover(start = false): [boolean, () => void] {
const [mine, setMine] = React.useState(start);
const handOver = React.useCallback(() => setMine(true), []);
return [mine, handOver];
}
/** A ghost cursor's script: where it is (0–1 of the stage) at each moment (ms), and whether it presses. */
export type GhostKey = { t: number; x: number; y: number; down?: boolean | undefined };
/** Where the ghost is at `t` ms: eased between its keys (a hand's narration, not physics), pressing as its key says. */
export function ghostAt(script: GhostKey[], t: number): { x: number; y: number; down: boolean; done: boolean } {
const last = script[script.length - 1]!;
if (t >= last.t) return { x: last.x, y: last.y, down: !!last.down, done: true };
let i = 0;
while (i < script.length - 1 && script[i + 1]!.t <= t) i++;
const a = script[i]!, b = script[i + 1] ?? a;
const u = b.t === a.t ? 1 : (t - a.t) / (b.t - a.t);
const e = u < 0.5 ? 4 * u * u * u : 1 - Math.pow(-2 * u + 2, 3) / 2;
return { x: a.x + (b.x - a.x) * e, y: a.y + (b.y - a.y) * e, down: !!a.down, done: false };
}
/** A colour role read from the page (for a canvas, which can't read a CSS variable), as an [r, g, b, a] in 0–255. */
export function readColor(el: Element, role: string): [number, number, number, number] {
const probe = document.createElement("i");
probe.style.cssText = `position:absolute;visibility:hidden;color:var(${role})`;
el.appendChild(probe);
const c = getComputedStyle(probe).color;
probe.remove();
/* whatever space the browser serialises it in (rgb, color(srgb …), oklab …), a pixel says it in sRGB */
try {
const cv = document.createElement("canvas");
cv.width = cv.height = 1;
const g = cv.getContext("2d", { willReadFrequently: true });
if (g) {
g.clearRect(0, 0, 1, 1);
g.fillStyle = c;
g.fillRect(0, 0, 1, 1);
const d = g.getImageData(0, 0, 1, 1).data;
return [d[0]!, d[1]!, d[2]!, d[3]!];
}
} catch {}
const m = c.match(/[\d.]+/g)?.map(Number) ?? [0, 0, 0, 1];
return [m[0] ?? 0, m[1] ?? 0, m[2] ?? 0, (m[3] ?? 1) * 255];
}
/** Mixes two [r, g, b, a] colours by t (0–1). */
export function mixColor(a: readonly number[], b: readonly number[], t: number): string {
const k = Math.max(0, Math.min(1, t));
const ch = (i: number) => a[i]! + (b[i]! - a[i]!) * k;
return `rgba(${Math.round(ch(0))},${Math.round(ch(1))},${Math.round(ch(2))},${(ch(3) / 255).toFixed(3)})`;
}
/** The width an element is given, kept current (a callback ref, so a replaced element is followed). */
export function useWidth(fallback = 520): [React.RefCallback, number] {
const [el, setEl] = React.useState(null);
const [w, setW] = React.useState(fallback);
React.useEffect(() => {
if (!el) return;
const read = () => setW(Math.max(200, Math.round(el.clientWidth || fallback)));
read();
if (typeof ResizeObserver === "undefined") return;
const ro = new ResizeObserver(read);
ro.observe(el);
return () => ro.disconnect();
}, [el, fallback]);
return [setEl, w];
}
/**
* A copy of a simulation's state for drawing: the frame loop changes the live state (a ref) in place, and the piece
* draws from the copy it last painted, so rendering never reads a ref. Plain objects, arrays and typed arrays.
*/
export function snapshot(x: T): T {
if (Array.isArray(x)) return x.map(snapshot) as T;
if (ArrayBuffer.isView(x)) return (x as unknown as Float32Array).slice() as unknown as T;
if (x && typeof x === "object") {
const out: Record = {};
for (const [k, v] of Object.entries(x)) out[k] = snapshot(v);
return out as T;
}
return x;
}
```
### lib/notchset/standing.ts
```tsx
// Notchset range-bar 2.0.0 · https://notchset.dev/changelog
/*
* Standing: where a value sits against a named range, as one calculation every health piece reads (the range bar,
* the results strip, a result list, a metric card), so a value can never read "High" in one place and "In range" in
* another. A range always says whose it is: the lab's printed reference range, an optimal range with its source, or
* your own baseline from your last nights. Plain functions, no React.
*/
/** Whose range it is. Never a bare band: the source is always said. */
export type RangeKind = "lab" | "optimal" | "baseline";
/** A range, open at either end ("< 100" has no low). Values are in the unit the value is shown in. */
export type ValueRange = {
low?: number | undefined;
high?: number | undefined;
kind: RangeKind;
/** who set it: "Northside Lab", "Endocrine Society 2024", "Your last 14 nights" */
source: string;
};
/** Where a value stands: below, inside or above its range; unknown when there is no range or no value. */
export type Standing = "low" | "in" | "high" | "unknown";
/** A value's standing against a range: inclusive at both limits, as labs print them ("30–100" includes 30). */
export function standingOf(value: number | null | undefined, range: Pick | null | undefined): Standing {
if (value == null || !Number.isFinite(value) || !range) return "unknown";
if (range.low == null && range.high == null) return "unknown";
if (range.low != null && value < range.low) return "low";
if (range.high != null && value > range.high) return "high";
return "in";
}
/** The word for a standing. A baseline says "usual", never "range", because it is yours, not a reference. */
export function standingWord(s: Standing, kind: RangeKind = "lab"): string {
if (kind === "baseline") return s === "low" ? "Below your usual" : s === "high" ? "Above your usual" : s === "in" ? "Your usual" : "No baseline yet";
return s === "low" ? "Low" : s === "high" ? "High" : s === "in" ? "In range" : "No range";
}
/** A value's flag beyond its standing: the lab marked it critical, or it may have been read wrong. */
export type ValueFlag = "critical" | "may-be-wrong" | undefined;
/**
* The tone a standing is said in (LANGUAGE.md §9b): in range is good news (ok), out of range needs attention (warn;
* a high LDL isn't an error), and only the lab's critical flag or a value that may be wrong is bad. Your usual is
* plain ink: being normal for you is not news.
*/
export function standingTone(s: Standing, flag?: ValueFlag, kind: RangeKind = "lab"): "ok" | "warn" | "bad" | "neutral" {
if (flag) return "bad";
if (s === "unknown") return "neutral";
if (s === "in") return kind === "baseline" ? "neutral" : "ok";
return "warn";
}
/** The word a flag is said in, which replaces the standing's word: nothing is concluded from it. */
export function flagWord(flag: ValueFlag): string | null {
return flag === "critical" ? "Flagged by your lab" : flag === "may-be-wrong" ? "May be wrong" : null;
}
/** "30–100", "< 100", "> 40", in the value's own precision. */
export function rangeText(r: Pick, fmt: (n: number) => string = String): string {
if (r.low != null && r.high != null) return `${fmt(r.low)}–${fmt(r.high)}`;
if (r.high != null) return `< ${fmt(r.high)}`;
if (r.low != null) return `> ${fmt(r.low)}`;
return "";
}
/** Whose range, in words: "Lab range", "Optimal", "Your usual". */
export function rangeName(kind: RangeKind): string {
return kind === "lab" ? "Lab range" : kind === "optimal" ? "Optimal" : "Your usual";
}
/** A number in the precision its unit is read at: one decimal under 10, none above (5.4 %, 128 mg/dL). */
export function formatReading(n: number, decimals?: number): string {
const d = decimals ?? (Math.abs(n) < 10 && !Number.isInteger(n) ? 1 : 0);
return n.toLocaleString("en-US", { minimumFractionDigits: d, maximumFractionDigits: d });
}
/** What a change means: better, worse or the same, by the measure's better direction (LANGUAGE.md §9, delta chips). */
export type Better = "up" | "down" | "in-range";
/**
* A change between two readings, signed and toned by what's better for this measure, never by up or down. For a
* measure whose better direction is "in-range" (vitamin D, TSH), moving toward the range is better.
*/
export function changeTone(now: number, then: number, better: Better, range?: Pick): "ok" | "bad" | "neutral" {
if (now === then) return "neutral";
if (better === "up") return now > then ? "ok" : "bad";
if (better === "down") return now < then ? "ok" : "bad";
if (!range) return "neutral";
const dist = (v: number) => (range.low != null && v < range.low ? range.low - v : range.high != null && v > range.high ? v - range.high : 0);
const a = dist(now), b = dist(then);
return a === b ? "neutral" : a < b ? "ok" : "bad";
}
/** Plausible limits for a reading a person types (the log), per measure, so a slip ("310/80") is caught before it's kept. */
export const PLAUSIBLE = {
weight: { low: 25, high: 300, unit: "kg" },
systolic: { low: 60, high: 260, unit: "mmHg" },
diastolic: { low: 30, high: 160, unit: "mmHg" },
glucose: { low: 20, high: 600, unit: "mg/dL" },
heartRate: { low: 25, high: 230, unit: "bpm" },
} as const;
/** Whether a typed reading is plausible; when it isn't, the words that say what to check ("BP 310/80? Check the value"). */
export function plausible(kind: keyof typeof PLAUSIBLE, value: number): { ok: true } | { ok: false; reason: string } {
const p = PLAUSIBLE[kind];
if (!Number.isFinite(value)) return { ok: false, reason: "Type a number" };
if (value < p.low || value > p.high) return { ok: false, reason: `${formatReading(value)} ${p.unit}? Check the value: it's outside what a body reads (${p.low}–${p.high})` };
return { ok: true };
}
/**
* Where a value stands, in three (Superpower's and Whoop's model): Optimal (inside the optimal range), Normal (inside
* the lab's range, outside the optimal one) and Out of range (outside the lab's). Where no optimal range is named the
* lab's range is the optimal one, and the host says so. A flag (critical, may be wrong) is said instead, never a grade.
*/
export type Grade = "optimal" | "normal" | "out" | "unknown";
export function gradeOf(value: number | null | undefined, lab: Pick | null | undefined, optimal?: Pick | null): Grade {
const s = standingOf(value, lab);
if (s === "unknown") return "unknown";
if (s !== "in") return "out";
if (!optimal) return "optimal";
return standingOf(value, optimal) === "in" ? "optimal" : "normal";
}
export function gradeWord(g: Grade): string {
return g === "optimal" ? "Optimal" : g === "normal" ? "Normal" : g === "out" ? "Out of range" : "No range";
}
/**
* The tone a grade is said in, from the existing roles (no new hue): Optimal ok, Normal plain ink (inside the lab's
* range is not news), Out of range warn, and a flag (critical, may be wrong) bad. Always a dot and a word.
*/
export function gradeTone(g: Grade, flag?: ValueFlag): "ok" | "neutral" | "warn" | "bad" {
if (flag) return "bad";
return g === "optimal" ? "ok" : g === "out" ? "warn" : "neutral";
}
/** The dot's colour for a grade (the segmented bar, a row's dot). */
export function gradeColor(g: Grade, flag?: ValueFlag): string {
const t = gradeTone(g, flag);
return t === "ok" ? "var(--ns-standing-in)" : t === "warn" ? "var(--ns-standing-out)" : t === "bad" ? "var(--ns-standing-critical)" : "var(--ns-ink-3)";
}
/**
* The tone a reading against your own usual is said in, by which way is better for that measure: above your usual
* HRV is good news (ok), above your usual resting heart rate needs a look (warn), inside your usual is plain ink.
* For a measure that's best inside its band (skin temperature), outside it either way is warn.
*/
export function usualTone(s: Standing, better: Better): "ok" | "neutral" | "warn" {
if (s === "in" || s === "unknown") return "neutral";
if (better === "up") return s === "high" ? "ok" : "warn";
if (better === "down") return s === "low" ? "ok" : "warn";
return "warn";
}
```
The foundation (the tokens listed above, keyframes and motion levels) installs once with the first component; its CSS is public at https://notchset.dev/r/notchset-foundation.json.