Function useGraphData

packages/memory-graph/src/hooks/use-graph-data.ts:458–630

(
	documents: GraphApiDocument[],
	draggingNodeId: string | null,
	canvasWidth: number,
	canvasHeight: number,
	colors: GraphThemeColors,
)

}

export function useGraphData(
	documents: GraphApiDocument[],
	draggingNodeId: string | null,
	canvasWidth: number,
	canvasHeight: number,
	colors: GraphThemeColors,
) {
	const nodeCache = useRef<Map<string, GraphNode>>(new Map())

	const graphData = useMemo<{
		nodes: GraphNode[]
		cache: Map<string, GraphNode>
	}>(() => {
		if (!documents || documents.length === 0) {
			return { nodes: [], cache: new Map<string, GraphNode>() }
		}

		const currentIds = new Set<string>()
		for (const doc of documents) {
			currentIds.add(doc.id)
			for (const mem of doc.memories) currentIds.add(mem.id)
		}

		const previousCache = nodeCache.current
		const nextCache = new Map<string, GraphNode>()
		const appendPlacementNodes = Array.from(previousCache.values()).filter(
			(node) => currentIds.has(node.id),
		)
		const shouldAppendNewNodes = appendPlacementNodes.length > 0
		const appendBaseBounds = shouldAppendNewNodes
			? getNodeBounds(appendPlacementNodes)
			: null
		const appendSpatialGrid =
			shouldAppendNewNodes && appendBaseBounds
				? buildAppendSpatialGrid(appendPlacementNodes)
				: null
		let appendIndex = 0
		const clusterAssignments = computeClusterAssignments(documents)

		const result: GraphNode[] = []
		// Spiral layout: documents form a compact spiral core, memories orbit
		// around their parent documents. The force simulation then gently
		// pushes memories outward to create the constellation/starburst effect.
		const cx = canvasWidth / 2
		const cy = canvasHeight / 2
		const docCount = documents.length
		// Wide spiral so documents start well-separated. The simulation
		// refines positions but the initial spread prevents clustering.
		const spiralScale = Math.sqrt(docCount) * 60
		// Golden angle (~137.5 deg) produces optimal packing in a spiral
		const goldenAngle = Math.PI * (3 - Math.sqrt(5))

		for (let docIdx = 0; docIdx < docCount; docIdx++) {
			const doc = documents[docIdx]
			const docCluster = getDocumentClusterAssignment(doc, clusterAssignments)
			const angle = docIdx * goldenAngle
			const radius = spiralScale * Math.sqrt((docIdx + 1) / docCount)
			const initialX = cx + Math.cos(angle) * radius