Function calculatePositions

apps/sim/lib/workflows/autolayout/core.ts:278–378

(
  layers: Map<number, GraphNode[]>,
  edges: Edge[],
  options: LayoutOptions = {}
)

 * Target handles are also calculated per-block to ensure precise alignment.
 */
export function calculatePositions(
  layers: Map<number, GraphNode[]>,
  edges: Edge[],
  options: LayoutOptions = {}
): void {
  const horizontalSpacing = options.horizontalSpacing ?? DEFAULT_LAYOUT_OPTIONS.horizontalSpacing
  const verticalSpacing = options.verticalSpacing ?? DEFAULT_LAYOUT_OPTIONS.verticalSpacing
  const padding = options.padding ?? DEFAULT_LAYOUT_OPTIONS.padding

  const layerNumbers = Array.from(layers.keys()).sort((a, b) => a - b)

  const layerWidths = new Map<number, number>()
  for (const layerNum of layerNumbers) {
    const nodesInLayer = layers.get(layerNum)!
    const maxWidth = Math.max(...nodesInLayer.map((n) => n.metrics.width))
    layerWidths.set(layerNum, maxWidth)
  }

  const layerXPositions = new Map<number, number>()
  let cumulativeX = padding.x

  for (const layerNum of layerNumbers) {
    layerXPositions.set(layerNum, cumulativeX)
    cumulativeX += layerWidths.get(layerNum)! + horizontalSpacing
  }

  const allNodes = new Map<string, GraphNode>()
  for (const nodesInLayer of layers.values()) {
    for (const node of nodesInLayer) {
      allNodes.set(node.id, node)
    }
  }

  const incomingEdgesMap = new Map<string, Edge[]>()
  for (const edge of edges) {
    if (!incomingEdgesMap.has(edge.target)) {
      incomingEdgesMap.set(edge.target, [])
    }
    incomingEdgesMap.get(edge.target)!.push(edge)
  }

  for (const layerNum of layerNumbers) {
    const nodesInLayer = layers.get(layerNum)!
    const xPosition = layerXPositions.get(layerNum)!

    const containersInLayer = nodesInLayer.filter(isContainerBlock)
    const nonContainersInLayer = nodesInLayer.filter((n) => !isContainerBlock(n))

    if (layerNum === 0) {
      let yOffset = padding.y

      containersInLayer.sort((a, b) => b.metrics.height - a.metrics.height)

      for (const node of containersInLayer) {
        node.position = { x: xPosition, y: yOffset }
        yOffset += node.metrics.height + verticalSpacing
      }