async function drawGraph(url, baseUrl, pathColors, depth, enableDrag, enableLegend, enableZoom) { const { index, links, content } = await fetchData const curPage = url.replace(baseUrl, "") const parseIdsFromLinks = (links) => [...(new Set(links.flatMap(link => ([link.source, link.target]))))] const neighbours = new Set() const wl = [curPage || "/", "__SENTINEL"] if (depth >= 0) { while (depth >= 0 && wl.length > 0) { // compute neighbours const cur = wl.shift() if (cur === "__SENTINEL") { depth-- wl.push("__SENTINEL") } else { neighbours.add(cur) const outgoing = index.links[cur] || [] const incoming = index.backlinks[cur] || [] wl.push(...outgoing.map(l => l.target), ...incoming.map(l => l.source)) } } } else { parseIdsFromLinks(links).forEach(id => neighbours.add(id)) } const data = { nodes: [...neighbours].map(id => ({ id })), links: links.filter(l => neighbours.has(l.source) && neighbours.has(l.target)), } const color = (d) => { if (d.id === curPage || (d.id === "/" && curPage === "")) { return "var(--g-node-active)" } for (const pathColor of pathColors) { const path = Object.keys(pathColor)[0] const colour = pathColor[path] if (d.id.startsWith(path)) { return colour } } return "var(--g-node)" } const drag = simulation => { function dragstarted(event, d) { if (!event.active) simulation.alphaTarget(1).restart() d.fx = d.x d.fy = d.y } function dragged(event, d) { d.fx = event.x d.fy = event.y } function dragended(event, d) { if (!event.active) simulation.alphaTarget(0) d.fx = null d.fy = null } const noop = () => { } return d3.drag() .on("start", enableDrag ? dragstarted : noop) .on("drag", enableDrag ? dragged : noop) .on("end", enableDrag ? dragended : noop) } const height = Math.max(document.getElementById("graph-container").offsetHeight, 250) const width = document.getElementById("graph-container").offsetWidth const simulation = d3.forceSimulation(data.nodes) .force("charge", d3.forceManyBody().strength(-30)) .force("link", d3.forceLink(data.links).id(d => d.id).distance(40)) .force("center", d3.forceCenter()) const svg = d3.select('#graph-container') .append('svg') .attr('width', width) .attr('height', height) .attr("viewBox", [-width / 2, -height / 2, width, height]) if (enableLegend) { const legend = [ { "Current": "var(--g-node-active)" }, { "Note": "var(--g-node)" }, ...pathColors ] legend.forEach((legendEntry, i) => { const key = Object.keys(legendEntry)[0] const colour = legendEntry[key] svg.append("circle").attr("cx", -width / 2 + 20).attr("cy", height / 2 - 30 * (i + 1)).attr("r", 6).style("fill", colour) svg.append("text").attr("x", -width / 2 + 40).attr("y", height / 2 - 30 * (i + 1)).text(key).style("font-size", "15px").attr("alignment-baseline", "middle") }) } // draw links between nodes const link = svg.append("g") .selectAll("line") .data(data.links) .join("line") .attr("class", "link") .attr("stroke", "var(--g-link)") .attr("stroke-width", 2) .attr("data-source", d => d.source.id) .attr("data-target", d => d.target.id) // svg groups const graphNode = svg.append("g") .selectAll("g") .data(data.nodes) .enter().append("g") // calculate radius const nodeRadius = (d) => { const numOut = index.links[d.id]?.length || 0 const numIn = index.backlinks[d.id]?.length || 0 return 3 + (numOut + numIn) / 4 } // draw individual nodes const node = graphNode.append("circle") .attr("class", "node") .attr("id", (d) => d.id) .attr("r", nodeRadius) .attr("fill", color) .style("cursor", "pointer") .on("click", (_, d) => { window.location.href = `${baseUrl}/${decodeURI(d.id).replace(/\s+/g, '-')}/` }) .on("mouseover", function(_, d) { d3.selectAll(".node") .transition() .duration(100) .attr("fill", "var(--g-node-inactive)") const neighbours = parseIdsFromLinks([...(index.links[d.id] || []), ...(index.backlinks[d.id] || [])]) const neighbourNodes = d3.selectAll(".node").filter(d => neighbours.includes(d.id)) const currentId = d.id const linkNodes = d3.selectAll(".link").filter(d => d.source.id === currentId || d.target.id === currentId) // highlight neighbour nodes neighbourNodes .transition() .duration(200) .attr("fill", color) // highlight links linkNodes .transition() .duration(200) .attr("stroke", "var(--g-link-active)") // show text for self d3.select(this.parentNode) .raise() .select("text") .transition() .duration(200) .style("opacity", 1) .raise() }).on("mouseleave", function(_, d) { d3.selectAll(".node") .transition() .duration(200) .attr("fill", color) const currentId = d.id const linkNodes = d3.selectAll(".link").filter(d => d.source.id === currentId || d.target.id === currentId) linkNodes .transition() .duration(200) .attr("stroke", "var(--g-link)") d3.select(this.parentNode) .select("text") .transition() .duration(200) .style("opacity", 0) }) .call(drag(simulation)) // draw labels const labels = graphNode.append("text") .attr("dx", 0) .attr("dy", d => nodeRadius(d) + 8 + "px") .attr("text-anchor", "middle") .text((d) => content[d.id]?.title || d.id.replace("-", " ")) .style("opacity", 0) .style("pointer-events", "none") .style("font-size", "0.4em") .raise() .call(drag(simulation)) // set panning if (enableZoom) { svg.call(d3.zoom() .extent([[0, 0], [width, height]]) .scaleExtent([0.25, 4]) .on("zoom", ({ transform }) => { link.attr("transform", transform) node.attr("transform", transform) const scale = transform.k const scaledOpacity = Math.max((scale - 1) / 3.75, 0) labels .attr("transform", transform) .style("opacity", scaledOpacity) })) } // progress the simulation simulation.on("tick", () => { link .attr("x1", d => d.source.x) .attr("y1", d => d.source.y) .attr("x2", d => d.target.x) .attr("y2", d => d.target.y) node .attr("cx", d => d.x) .attr("cy", d => d.y) labels .attr("x", d => d.x) .attr("y", d => d.y) }) }