feat(landing): topic search (#134)

* feat(landing): topic search

* fix: node click

web/components/routes/public/force-graph-client-lazy.tsx

@@ -0,0 +1,366 @@
+"use client"
+
+import * as react from "react"
+import * as fg from "@nothing-but/force-graph"
+import { ease, trig, raf } from "@nothing-but/utils"
+
+import * as schedule from "@/lib/utils/schedule"
+import * as canvas from "@/lib/utils/canvas"
+
+export type RawGraphNode = {
+	name: string
+	prettyName: string
+	connectedTopics: string[]
+}
+
+type HSL = [hue: number, saturation: number, lightness: number]
+
+const COLORS: readonly HSL[] = [
+	[3, 86, 64],
+	[31, 90, 69],
+	[15, 87, 66]
+]
+
+/* use a plain object instead of Map for faster lookups */
+type ColorMap = {[key: string]: string}
+type HSLMap   = Map<fg.graph.Node, HSL>
+
+const MAX_COLOR_ITERATIONS = 10
+
+/**
+ * Add a color to a node and all its connected nodes.
+ */
+function visitColorNode(
+	g:         fg.graph.Graph,
+	prev:      fg.graph.Node,
+	node:      fg.graph.Node,
+	hsl_map:   HSLMap,
+	add:       HSL,
+	iteration: number = 1
+): void {
+	if (iteration > MAX_COLOR_ITERATIONS) return
+
+	const color = hsl_map.get(node)
+
+	if (!color) {
+		hsl_map.set(node, [...add])
+	} else {
+		const add_strength = MAX_COLOR_ITERATIONS / iteration
+		color[0] = (color[0] + add[0] * add_strength) / (1 + add_strength)
+		color[1] = (color[1] + add[1] * add_strength) / (1 + add_strength)
+		color[2] = (color[2] + add[2] * add_strength) / (1 + add_strength)
+	}
+
+	for (let edge of g.edges) {
+		let b: fg.graph.Node
+		if      (edge.a === node) b = edge.b
+		else if (edge.b === node) b = edge.a
+		else continue
+		if (b !== prev) {
+			visitColorNode(g, node, b, hsl_map, add, iteration + 1)
+		}
+	}
+}
+
+function generateColorMap(g: fg.graph.Graph, nodes: readonly fg.graph.Node[]): ColorMap {
+	const hls_map: HSLMap = new Map()
+
+	for (let i = 0; i < nodes.length; i++) {
+		const node = nodes[i]!
+		const color = COLORS[i % COLORS.length]!
+		visitColorNode(g, node, node, hls_map, color)
+	}
+
+	const color_map: ColorMap = {}
+	for (const [node, [hue, saturation, lightness]] of hls_map.entries()) {
+		color_map[node.key as string] = `${hue} ${saturation}% ${lightness}%`
+	}
+
+	return color_map
+}
+
+function generateNodesFromRawData(g: fg.graph.Graph, raw_data: RawGraphNode[]): void {
+	const nodes_map = new Map<string, fg.graph.Node>()
+
+	/* create nodes */
+	for (const raw of raw_data) {
+		const node = fg.graph.make_node()
+		node.key = raw.name
+		node.label = raw.prettyName
+
+		fg.graph.add_node(g, node)
+		nodes_map.set(raw.name, node)
+	}
+
+	/* connections */
+	for (const raw of raw_data) {
+		const node_a = nodes_map.get(raw.name)!
+
+		for (const name_b of raw.connectedTopics) {
+			const node_b = nodes_map.get(name_b)!
+			fg.graph.connect(g, node_a, node_b)
+		}
+	}
+
+	/* calc mass from number of connections */
+	for (const node of g.nodes) {
+		let edges = fg.graph.get_node_edges(g, node)
+		node.mass = fg.graph.node_mass_from_edges(edges.length)
+	}
+
+	fg.graph.randomize_positions(g)
+}
+
+function filterNodes(
+	s: State,
+	filter: string
+): void {
+	fg.graph.clear_nodes(s.graph)
+
+	if (filter === "") {
+		fg.graph.add_nodes(s.graph, s.nodes)
+		fg.graph.add_edges(s.graph, s.edges)
+	} else {
+		// regex matching all letters of the filter (out of order)
+		const regex = new RegExp(filter.split("").join(".*"), "i")
+	
+		fg.graph.add_nodes(s.graph, s.nodes.filter(node => regex.test(node.label)))
+		fg.graph.add_edges(s.graph, s.edges.filter(edge => regex.test(edge.a.label) && regex.test(edge.b.label)))
+	}
+}
+
+const GRAPH_OPTIONS: fg.graph.Options = {
+	min_move: 0.001,
+	inertia_strength: 0.3,
+	origin_strength: 0.01,
+	repel_distance: 40,
+	repel_strength: 2,
+	link_strength: 0.015,
+	grid_size: 500
+}
+
+const TITLE_SIZE_PX = 400
+
+const simulateGraph = (
+	alpha: number,
+	graph: fg.graph.Graph,
+	canvas: fg.canvas.CanvasState,
+	vw: number,
+	vh: number
+): void => {
+	alpha = alpha / 10 // slow things down a bit
+
+	fg.graph.simulate(graph, alpha)
+
+	/*
+		Push nodes away from the center (the title)
+	*/
+	let grid_radius = graph.options.grid_size / 2
+	let origin_x = grid_radius + canvas.translate.x
+	let origin_y = grid_radius + canvas.translate.y
+	let vmax = Math.max(vw, vh)
+	let push_radius =
+		(Math.min(TITLE_SIZE_PX, vw / 2, vh / 2) / vmax) * (graph.options.grid_size / canvas.scale) +
+		80 /* additional margin for when scrolled in */
+
+	for (let node of graph.nodes) {
+
+		let dist_x = node.pos.x - origin_x
+		let dist_y = (node.pos.y - origin_y) * 2
+		let dist = Math.sqrt(dist_x * dist_x + dist_y * dist_y)
+		if (dist > push_radius) continue
+
+		let strength = ease.in_expo((push_radius - dist) / push_radius)
+
+		node.vel.x += strength * (node.pos.x - origin_x) * 10 * alpha
+		node.vel.y += strength * (node.pos.y - origin_y) * 10 * alpha
+	}
+}
+
+const drawGraph = (c: fg.canvas.CanvasState, color_map: ColorMap): void => {
+	fg.canvas.resetFrame(c)
+	fg.canvas.drawEdges(c)
+
+	/*
+		Draw text nodes
+	*/
+	let grid_size = c.graph.options.grid_size
+	let max_size  = Math.max(c.ctx.canvas.width, c.ctx.canvas.height)
+
+	let clip_rect = fg.canvas.get_ctx_clip_rect(c.ctx, {x: 100, y: 20})
+
+	c.ctx.textAlign = "center"
+	c.ctx.textBaseline = "middle"
+
+	for (let node of c.graph.nodes) {
+
+		let x = node.pos.x / grid_size * max_size
+		let y = node.pos.y / grid_size * max_size
+
+		if (fg.canvas.in_rect_xy(clip_rect, x, y)) {
+			
+			let base_size       = max_size / 220
+			let mass_boost_size = max_size / 140
+			let mass_boost      = (node.mass - 1) / 8 / c.scale
+
+			c.ctx.font = `${base_size + mass_boost * mass_boost_size}px sans-serif`
+	
+			let opacity = 0.6 + ((node.mass - 1) / 50) * 4
+
+			c.ctx.fillStyle = node.anchor || c.hovered_node === node
+				? `rgba(129, 140, 248, ${opacity})`
+				: `hsl(${color_map[node.key as string]} / ${opacity})`
+	
+			c.ctx.fillText(node.label, x, y)
+		}
+	}
+}
+
+class State {
+	ctx: CanvasRenderingContext2D | null = null
+
+	/* copy of all nodes to filter them */
+	nodes: fg.graph.Node[] = []
+	edges: fg.graph.Edge[] = []
+
+	graph: fg.graph.Graph = fg.graph.make_graph(GRAPH_OPTIONS)
+	gestures: fg.canvas.CanvasGestures | null = null
+
+	raf_id: number = 0
+	bump_end = 0
+	alpha = 0
+	frame_iter_limit = raf.frameIterationsLimit(60)
+	schedule_filter = schedule.scheduleIdle(filterNodes)
+	ro: ResizeObserver = new ResizeObserver(() => {})
+}
+
+function init(
+	s: State,
+	props: {
+		onNodeClick: (name: string) => void
+		raw_nodes: RawGraphNode[]
+		canvas_el: HTMLCanvasElement | null
+	}
+) {
+	let {canvas_el, raw_nodes} = props
+
+	if (canvas_el == null) return
+
+	s.ctx = canvas_el.getContext("2d")
+	if (s.ctx == null) return
+
+	generateNodesFromRawData(s.graph, raw_nodes)
+	s.nodes = s.graph.nodes.slice()
+	s.edges = s.graph.edges.slice()
+
+	let color_map = generateColorMap(s.graph, s.nodes)
+
+	let canvas_state = fg.canvas.canvasState({
+		ctx: s.ctx,
+		graph: s.graph,
+		max_scale: 3,
+		init_scale: 1.7,
+		init_grid_pos: trig.ZERO
+	})
+
+	s.ro = new ResizeObserver(() => {
+		if (canvas.resizeCanvasToDisplaySize(canvas_el)) {
+			fg.canvas.updateTranslate(canvas_state, canvas_state.translate.x, canvas_state.translate.y)
+		}
+	})
+	s.ro.observe(canvas_el)
+
+	function loop(time: number) {
+		let is_active = gestures.mode.type === fg.canvas.Mode.DraggingNode
+		let iterations = Math.min(2, raf.calcIterations(s.frame_iter_limit, time))
+
+		for (let i = iterations; i > 0; i--) {
+			s.alpha = raf.updateAlpha(s.alpha, is_active || time < s.bump_end)
+			simulateGraph(s.alpha, s.graph, canvas_state, window.innerWidth, window.innerHeight)
+		}
+		
+		if (iterations > 0) {
+			drawGraph(canvas_state, color_map)
+		}
+
+		s.raf_id = requestAnimationFrame(loop)
+	}
+	s.raf_id = requestAnimationFrame(loop)
+
+	let gestures = (s.gestures = fg.canvas.canvasGestures({
+		canvas: canvas_state,
+		onGesture: e => {
+			switch (e.type) {
+			case fg.canvas.GestureEventType.Translate:
+				s.bump_end = raf.bump(s.bump_end)
+				break
+			case fg.canvas.GestureEventType.NodeClick:
+				props.onNodeClick(e.node.key as string)
+				break
+			case fg.canvas.GestureEventType.NodeDrag:
+				fg.graph.set_position(canvas_state.graph, e.node, e.pos)
+				break
+			}
+		}
+	}))
+}
+
+function updateQuery(s: State, filter_query: string) {
+	s.schedule_filter.trigger(s, filter_query)
+	s.bump_end = raf.bump(s.bump_end)
+}
+
+function cleanup(s: State) {
+	cancelAnimationFrame(s.raf_id)
+	s.gestures && fg.canvas.cleanupCanvasGestures(s.gestures)
+	s.schedule_filter.clear()
+	s.ro.disconnect()
+}
+
+export type ForceGraphProps = {
+	onNodeClick: (name: string) => void
+	/**
+	 * Filter the displayed nodes by name.
+	 *
+	 * `""` means no filter
+	 */
+	filter_query: string
+	raw_nodes: RawGraphNode[]
+}
+
+export default function ForceGraphClient(props: ForceGraphProps): react.JSX.Element {
+	const [canvas_el, setCanvasEl] = react.useState<HTMLCanvasElement | null>(null)
+
+	const state = react.useRef(new State())
+
+	react.useEffect(() => {
+		init(state.current, {
+			canvas_el: canvas_el,
+			onNodeClick: props.onNodeClick,
+			raw_nodes: props.raw_nodes
+		})
+	}, [canvas_el])
+
+	react.useEffect(() => {
+		updateQuery(state.current, props.filter_query)
+	}, [props.filter_query])
+
+	react.useEffect(() => {
+		return () => cleanup(state.current)
+	}, [])
+
+	return (
+		<div className="absolute inset-0 overflow-hidden">
+			<canvas
+				ref={setCanvasEl}
+				style={{
+					position: "absolute",
+					top: "-10%",
+					left: "-10%",
+					width: "120%",
+					height: "120%"
+				}}
+			/>
+		</div>
+	)
+}