@layerchart/webgl: WebGL layer and 3D marks

.changeset/config.json

@@ -2,7 +2,7 @@
   "$schema": "https://unpkg.com/@changesets/config@2.3.1/schema.json",
   "changelog": ["@svitejs/changesets-changelog-github-compact", { "repo": "techniq/layerchart" }],
   "commit": false,
-  "fixed": [],
+  "fixed": [["layerchart", "@layerchart/webgl"]],
   "linked": [],
   "access": "public",
   "baseBranch": "main",

.changeset/drag-dblclick.md

@@ -0,0 +1,5 @@
+---
+'layerchart': patch
+---
+
+fix(TransformContext): Don't zoom in on the double click two quick drags make

.changeset/highlight-domain-motion.md

@@ -0,0 +1,5 @@
+---
+'layerchart': patch
+---
+
+fix(Highlight): Move with a chart's `domain` pan or zoom rather than springing after it (`motion` now defaults to none on a `domain` transform)

.changeset/isometric-axis-tick-spacing.md

@@ -0,0 +1,5 @@
+---
+'layerchart': patch
+---
+
+fix(Axis): Space ticks the same along every axis of a chart with a `view` (ex. `isometric`), rather than wider along `x`, so a square floor's axes get as many ticks each

.changeset/isometric-pivot.md

@@ -0,0 +1,5 @@
+---
+'layerchart': patch
+---
+
+fix(Chart): Dragging to turn a panned `isometric` view turns it about what's in the middle, rather than the floor's center

.changeset/layerchart-webgl.md

@@ -0,0 +1,5 @@
+---
+'@layerchart/webgl': minor
+---
+
+feat: New `@layerchart/webgl` package for rendering with WebGL including support for data dense 2d charts and unique 3d features such as perspective, lights/shadows, and 3D surfaces.

.changeset/mark-z-extent.md

@@ -0,0 +1,5 @@
+---
+'layerchart': minor
+---
+
+feat(Chart): Add `MarkInfo.zExtent` to let a mark widen an automatic `zDomain` with heights from its own values

.changeset/quadtree-domain-settle.md

@@ -0,0 +1,5 @@
+---
+'layerchart': patch
+---
+
+fix(TooltipContext): Build a `quadtree` tooltip's tree once a `domain` pan or zoom rests, rather than at every step of it

.changeset/shared-exports.md

@@ -0,0 +1,5 @@
+---
+'layerchart': minor
+---
+
+feat: Export `binCells`, `binGrid`, and `isScaleLinear()` for drawing marks in other ways (ex. `@layerchart/webgl`)

.changeset/shift-scroll-zoom.md

@@ -0,0 +1,5 @@
+---
+'layerchart': patch
+---
+
+fix(TransformContext): Zoom on a `shift` scroll that's a little off straight (ex. a trackpad swipe), rather than panning a `domain` far sideways

.changeset/tooltip-reappear.md

@@ -0,0 +1,5 @@
+---
+'layerchart': patch
+---
+
+fix(Tooltip): Appear where the pointer is when shown again (ex. after a drag), rather than gliding over from where it was last seen

.changeset/transform-rotation-extent.md

@@ -0,0 +1,5 @@
+---
+'layerchart': minor
+---
+
+feat(TransformContext): Add `rotationExtent` (or `rotateExtent` / `tiltExtent`) to limit how far a drag turns a chart's `view` or a globe projection, and pass a view's turned `rotation` to `constrain`

.gitignore

@@ -20,7 +20,7 @@ bench-results/
 .live-code/
 
 # Generated API documentation
-**/generated/api/*.json
+**/generated/api/**/*.json
 
 # Generated StackBlitz files
 **/static/stackblitz-files.json

docs/.gitignore

@@ -27,7 +27,7 @@ vite.config.ts.timestamp-*
 .content-collections
 
 # Generated API documentation
-generated/api/*.json
+generated/api/**/*.json
 
 # Generated StackBlitz files
 static/stackblitz-files.json

docs/package.json

@@ -17,9 +17,9 @@
 		"test": "pnpm test:unit -- --run",
 		"test:visual": "node scripts/visual-snapshot.mjs capture snapshots/current.json --repeat 1 && node scripts/visual-snapshot.mjs compare snapshots/baseline.json snapshots/current.json",
 		"test:visual:update": "node scripts/visual-snapshot.mjs capture snapshots/baseline.json --repeat 3",
-		"generate:api": "layerstack-docs generate-api ../packages/layerchart/src/lib/components generated/api",
+		"generate:api": "layerstack-docs generate-api ../packages/layerchart/src/lib/components generated/api && layerstack-docs generate-api ../packages/webgl/src/lib/components generated/api/webgl",
 		"generate:screenshots": "layerstack-docs generate-screenshots src/examples/components static/screenshots",
-		"generate:catalog": "layerstack-docs generate-catalog ../packages/layerchart/src/lib/components src/examples/components src/examples/catalog",
+		"generate:catalog": "layerstack-docs generate-catalog ../packages/layerchart/src/lib/components src/examples/components src/examples/catalog && layerstack-docs generate-catalog ../packages/webgl/src/lib/components src/examples/components/webgl src/examples/catalog/webgl",
 		"generate:stackblitz": "layerstack-docs generate-stackblitz src static/stackblitz-files.json static/remote-sources.json --source src/lib/utils/data.ts=lib/utils/data.ts --remote data.remote.ts=lib/data.remote.ts --remote geo.remote.ts=lib/geo.remote.ts --remote graph.remote.ts=lib/graph.remote.ts",
 		"generate:releases": "layerstack-docs generate-releases techniq/layerchart generated/releases",
 		"generate:all": "pnpm generate:api && pnpm generate:screenshots && pnpm generate:catalog && pnpm generate:stackblitz && pnpm generate:releases"
@@ -33,6 +33,7 @@
 		"@iconify-json/lucide": "^1.2.111",
 		"@iconify-json/simple-icons": "^1.2.85",
 		"@iconify-json/vscode-icons": "^1.2.53",
+		"@layerchart/webgl": "workspace:*",
 		"@layerstack/docs": "1.0.0-next.6",
 		"@layerstack/svelte-actions": "1.0.1-next.20",
 		"@layerstack/svelte-state": "0.1.0-next.25",
@@ -44,6 +45,7 @@
 		"@sveltejs/kit": "^2.62.0",
 		"@sveltejs/vite-plugin-svelte": "^7.1.2",
 		"@tailwindcss/vite": "^4.3.0",
+		"@threlte/core": "^8.6.1",
 		"@types/d3-array": "^3.2.2",
 		"@types/d3-color": "^3.1.3",
 		"@types/d3-dsv": "^3.0.7",
@@ -59,6 +61,7 @@
 		"@types/d3-time": "^3.0.4",
 		"@types/node": "^25.9.1",
 		"@types/shapefile": "^0.6.4",
+		"@types/three": "^0.187.0",
 		"@types/topojson-client": "^3.1.5",
 		"@types/topojson-server": "^3.0.4",
 		"@types/topojson-simplify": "^3.0.3",
@@ -98,6 +101,7 @@
 		"svelte-check": "^4.5.0",
 		"svelte-ux": "2.0.0-next.22",
 		"tailwindcss": "^4.3.0",
+		"three": "^0.187.0",
 		"topojson-client": "^3.1.0",
 		"topojson-server": "^3.0.1",
 		"topojson-simplify": "^3.0.3",

docs/scripts/kontur-population.mjs

@@ -0,0 +1,151 @@
+/**
+ * Builds the people in each state for the `WebGL/state-population` example from Kontur Population
+ * (November 2023, CC BY 4.0): 400m H3 hexagons, which for the whole US is a 300MB download and an
+ * 840MB GeoPackage — too much to commit or fetch on every build.
+ *
+ *   node scripts/kontur-population.mjs <kontur_population_US_20231101.gpkg>
+ *
+ * Download and unzip it first:
+ * https://geodata-eu-central-1-kontur-public.s3.amazonaws.com/kontur_datasets/kontur_population_US_20231101.gpkg.gz
+ *
+ * Each hexagon's people go to the 0.01° cell its center is in, and each state's cells (clipped to
+ * us-atlas' 1:10m outlines) are summed again into about `COLUMNS` cells across the state.  Its
+ * largest places, from Natural Earth's populated places (public domain), are kept to label.
+ * Writes `static/data/examples/geo/kontur-population/<state>.json`: the cells as whole steps from
+ * the state's southwest corner, and the places as `[name, longitude, latitude]`,
+ * `{ origin, step, cells: [i, j, people, ...], cities }`.
+ */
+import { mkdirSync, writeFileSync } from 'node:fs';
+import { join } from 'node:path';
+import { DatabaseSync } from 'node:sqlite';
+import { geoBounds, geoContains, geoDistance } from 'd3-geo';
+import { feature } from 'topojson-client';
+
+/** us-atlas' territories, which Kontur's US population leaves out */
+const TERRITORIES = [
+	'American Samoa',
+	'Commonwealth of the Northern Mariana Islands',
+	'Guam',
+	'Puerto Rico',
+	'United States Virgin Islands'
+];
+/** How many places to label in each state, and how far apart, as a share of its size */
+const CITIES = 6;
+const CITY_SPACING = 0.12;
+/** About how many cells across each state, so its hexagons have a few each */
+const COLUMNS = 160;
+/** The cells hexagons are first summed into, in degrees */
+const FINE = 0.01;
+const ATLAS_URL = 'https://cdn.jsdelivr.net/npm/us-atlas@3/states-10m.json';
+const PLACES_URL =
+	'https://raw.githubusercontent.com/nvkelso/natural-earth-vector/v5.1.2/geojson/ne_10m_populated_places_simple.geojson';
+const OUT = 'static/data/examples/geo/kontur-population';
+
+const [source] = process.argv.slice(2);
+if (!source) {
+	console.error('Usage: node scripts/kontur-population.mjs <kontur_population_US.gpkg>');
+	process.exit(1);
+}
+
+const topology = await fetch(ATLAS_URL).then((r) => r.json());
+const states = feature(topology, topology.objects.states).features.filter(
+	(f) => !TERRITORIES.includes(f.properties.name)
+);
+const places = (await fetch(PLACES_URL).then((r) => r.json())).features
+	.map((f) => f.properties)
+	.filter((p) => p.adm0_a3 === 'USA');
+
+// Web Mercator (the GeoPackage's EPSG:3857) to and from longitude / latitude
+const R = 20037508.342789244;
+const toLonLat = (x, y) => [
+	(x / R) * 180,
+	(2 * Math.atan(Math.exp((y / R) * Math.PI)) - Math.PI / 2) * (180 / Math.PI)
+];
+
+/** People in each fine cell, by `i,j` */
+const fine = new Map();
+const db = new DatabaseSync(source, { readOnly: true });
+for (const { population, geom } of db
+	.prepare('select population, geom from population')
+	.iterate()) {
+	// A GeoPackage geometry's header: "GP", version, flags, SRS id, then (as its flags say) its
+	// envelope — here `[minx, maxx, miny, maxy]`, whose middle is the hexagon's center
+	const flags = geom[3];
+	if (((flags >> 1) & 7) === 0) continue;
+	const view = new DataView(geom.buffer, geom.byteOffset + 8, 32);
+	const little = (flags & 1) === 1;
+	const [minx, maxx, miny, maxy] = [0, 8, 16, 24].map((o) => view.getFloat64(o, little));
+	const [lon, lat] = toLonLat((minx + maxx) / 2, (miny + maxy) / 2);
+	const key = `${Math.round(lon / FINE)},${Math.round(lat / FINE)}`;
+	fine.set(key, (fine.get(key) ?? 0) + population);
+}
+const rows = Array.from(fine, ([key, people]) => {
+	const [i, j] = key.split(',').map(Number);
+	return [+(i * FINE).toFixed(2), +(j * FINE).toFixed(2), Math.round(people)];
+});
+
+mkdirSync(OUT, { recursive: true });
+for (const state of states) {
+	const [[w, s], [e, n]] = geoBounds(state);
+	// Alaska's Aleutians cross the antimeridian, so its west edge is east of its east edge
+	const wraps = w > e;
+	const width = wraps ? e - w + 360 : e - w;
+	const inside = (lon) => (wraps ? lon >= w || lon <= e : lon >= w && lon <= e);
+	const lat = (s + n) / 2;
+	// Cells about square on the ground: a degree of longitude is shorter than one of latitude
+	const across = Math.cos((lat * Math.PI) / 180);
+	const step = +(Math.max(width * across, n - s) / COLUMNS).toPrecision(2);
+	const stepLon = +(step / across).toPrecision(2);
+
+	const cells = new Map();
+	let people = 0;
+	for (const [lon, la, count] of rows) {
+		if (!inside(lon) || la < s || la > n || !geoContains(state, [lon, la])) continue;
+		const key = `${Math.round(lon / stepLon)},${Math.round(la / step)}`;
+		cells.set(key, (cells.get(key) ?? 0) + count);
+		people += count;
+	}
+	const entries = Array.from(cells, ([key, count]) => [
+		...key.split(',').map(Number),
+		Math.round(count)
+	]).filter((d) => d[2] > 0);
+	const i0 = Math.min(...entries.map((d) => d[0]));
+	const j0 = Math.min(...entries.map((d) => d[1]));
+	const data = {
+		origin: [+(i0 * stepLon).toFixed(4), +(j0 * step).toFixed(4)],
+		step: [stepLon, step],
+		cells: entries.flatMap(([i, j, count]) => [i - i0, j - j0, count])
+	};
+	// The largest places, each a little way from those already kept
+	const spacing = geoDistance([w, s], [w + width, n]) * CITY_SPACING;
+	const cities = [];
+	const candidates = places
+		.filter((p) => p.adm1name === state.properties.name)
+		.sort((a, b) => b.pop_max - a.pop_max);
+	for (const p of candidates) {
+		if (cities.length >= CITIES) break;
+		const at = [p.longitude, p.latitude];
+		if (cities.some(([, lon, la]) => geoDistance(at, [lon, la]) < spacing)) continue;
+		cities.push([p.name, +p.longitude.toFixed(3), +p.latitude.toFixed(3)]);
+	}
+	data.cities = cities;
+
+	const slug = state.properties.name.toLowerCase().replace(/ /g, '-');
+	writeFileSync(join(OUT, `${slug}.json`), JSON.stringify(data));
+	console.log(
+		`${slug}: ${entries.length} cells, ${Math.round(people).toLocaleString()} people, ${cities.map((c) => c[0]).join(', ')}`
+	);
+}
+
+// Every state there's a file for, by its file and name, for the example's list (and prerendering)
+writeFileSync(
+	join(OUT, 'states.json'),
+	JSON.stringify(
+		states
+			.map((state) => ({
+				value: state.properties.name.toLowerCase().replace(/ /g, '-'),
+				label: state.properties.name
+			}))
+			.sort((a, b) => a.label.localeCompare(b.label))
+	)
+);

docs/src/content/components/webgl/Arc.md

@@ -0,0 +1,21 @@
+---
+description: 'Primitive component which draws a curved segment on a chart to represent portions of a whole or highlight specific data ranges. In a WebGL layer, it stands up by its z.'
+category: WebGL marks
+related: [Arc, guides/webgl]
+components:
+  - { name: webgl/Arc, label: Arc }
+---
+
+::tip
+Part of [`@layerchart/webgl`](/docs/guides/webgl), drawn in a `WebGL` layer. See the [WebGL guide](/docs/guides/webgl) to get started.
+::
+
+## Usage
+
+An arc with LayerChart's [Arc](/docs/components/Arc) props: from `startAngle` to `endAngle` (ex. a slice from `d3.pie()`), or to a `value` through its `domain` and `range`, over a `track`. Radii are pixels, fractions of the chart's radius, or offsets from it, as LayerChart's are, and `class` styles it as on any LayerChart mark. It's centered in the plot (where LayerChart's draws inside a centered `Layer` or `Group`); `x` / `y` move it. `z` stands it up, as on an `isometric` chart; without one it lies flat.
+
+:example{ name="pie" }
+
+LayerChart's concentric gauges, unchanged but for `z`:
+
+:example{ name="concentric" }

docs/src/content/components/webgl/Area.md

@@ -0,0 +1,19 @@
+---
+description: 'Marking component which shades the space under a line on a chart to emphasize the magnitude and trend of data over a range. In a WebGL layer, it lies on the floor, or rises as a curtain with a z.'
+category: WebGL marks
+related: [Area, guides/webgl]
+components:
+  - { name: webgl/Area, label: Area }
+---
+
+::tip
+Part of [`@layerchart/webgl`](/docs/guides/webgl), drawn in a `WebGL` layer. See the [WebGL guide](/docs/guides/webgl) to get started.
+::
+
+## Usage
+
+A curtain from the floor (or `z0`) up to `z` along the rows, one per group.
+
+:example{ name="areas" }
+
+:example{ name="ridgeline" }

docs/src/content/components/webgl/Axis.md

@@ -0,0 +1,35 @@
+---
+description: "Commonly used component displays the scale and reference lines on a chart, providing context for interpreting data values. In a WebGL layer, it runs along the plot box's edges: bottom for x, left for y, and back for z."
+category: WebGL
+related: [Axis, guides/webgl]
+components:
+  - { name: webgl/Axis, label: Axis }
+---
+
+::tip
+Part of [`@layerchart/webgl`](/docs/guides/webgl), drawn in a `WebGL` layer. See the [WebGL guide](/docs/guides/webgl) to get started.
+::
+
+## Usage
+
+Tick labels along an edge: `bottom` for `x`, `left` for `y`, and `back` for `z` (up the corner behind the plot). They keep to the edges in front as the view turns.
+
+Labels are drawn on the plot box, turning with it: the floor's (`bottom`, `left`) lie on it, as on an [isometric](/docs/guides/isometric#text) chart, and the height axis' (`back`) stand on the back wall beside its edge. `tickLabelProps={{ viewport: true }}` and `labelProps={{ viewport: true }}` draw them facing the viewer instead, over the scene, upright and crisp however the view turns.
+
+```svelte
+<WebGL>
+	<Axis placement="bottom" label="x" />
+	<Axis
+		placement="left"
+		label="y"
+		tickLabelProps={{ viewport: true }}
+		labelProps={{ viewport: true }}
+	/>
+	<Axis placement="back" label="z" />
+	<Points />
+</WebGL>
+```
+
+:example{ component="webgl/Points" name="scatter-3d" }
+
+:example{ component="webgl/Spline" name="temperatures" }