Fix spawn floorplan move handle

packages/nodes/src/spawn/floorplan-move.ts

@@ -0,0 +1,39 @@
+import {
+  type AnyNodeId,
+  type FloorplanMoveTarget,
+  type FloorplanMoveTargetSession,
+  type SpawnNode,
+  snapScalar,
+  useScene,
+} from '@pascal-app/core'
+import { getSegmentGridStep } from '@pascal-app/editor'
+
+export const spawnFloorplanMoveTarget: FloorplanMoveTarget<SpawnNode> = ({ node }) => {
+  const spawnId = node.id as AnyNodeId
+  const startY = node.position[1]
+  const originalPosition: [number, number, number] = [...node.position]
+  let lastPosition: [number, number, number] | null = null
+
+  const session: FloorplanMoveTargetSession = {
+    affectedIds: [spawnId],
+    apply({ planPoint, modifiers }) {
+      const step = getSegmentGridStep()
+      const snap = (value: number) => (modifiers.shiftKey ? value : snapScalar(value, step))
+      const next: [number, number, number] = [snap(planPoint[0]), startY, snap(planPoint[1])]
+
+      if (lastPosition && lastPosition[0] === next[0] && lastPosition[2] === next[2]) return
+      lastPosition = next
+      useScene.getState().updateNodes([{ id: spawnId, data: { position: next } }])
+    },
+    canCommit() {
+      if (!lastPosition) return false
+      return lastPosition[0] !== originalPosition[0] || lastPosition[2] !== originalPosition[2]
+    },
+    commit() {
+      if (!lastPosition) return
+      useScene.getState().updateNodes([{ id: spawnId, data: { position: lastPosition } }])
+    },
+  }
+
+  return session
+}