level height

packages/viewer/src/systems/level/level-system.tsx

@@ -1,27 +1,88 @@
-import { type LevelNode, sceneRegistry, useScene } from '@pascal-app/core'
+import { type CeilingNode, type LevelNode, sceneRegistry, useScene, type WallNode } from '@pascal-app/core'
 import { useFrame } from '@react-three/fiber'
 import { lerp } from 'three/src/math/MathUtils.js'
 import useViewer from '../../store/use-viewer'
 
-const LEVEL_HEIGHT = 2.5
+const DEFAULT_LEVEL_HEIGHT = 2.5
 const EXPLODED_GAP = 5
 
+// Cache: levelId → computed height. Invalidated by nodes reference change.
+// Zustand produces a new `nodes` object on every mutation, so reference equality
+// is a zero-cost way to detect stale data without any subscription overhead.
+const heightCache = new Map<string, number>()
+let lastNodesRef: object | null = null
+
+function getLevelHeight(
+  levelId: string,
+  nodes: ReturnType<typeof useScene.getState>['nodes'],
+): number {
+  if (heightCache.has(levelId)) return heightCache.get(levelId)!
+
+  const level = nodes[levelId as LevelNode['id']] as LevelNode | undefined
+  if (!level) return DEFAULT_LEVEL_HEIGHT
+
+  let maxTop = 0
+
+  for (const childId of level.children) {
+    const child = nodes[childId as keyof typeof nodes]
+    if (!child) continue
+    if (child.type === 'ceiling') {
+      // ceiling.height is the interior face Y in level-local space
+      const ch = (child as CeilingNode).height ?? DEFAULT_LEVEL_HEIGHT
+      if (ch > maxTop) maxTop = ch
+    } else if (child.type === 'wall') {
+      // Wall mesh is pushed up to slabElevation by WallSystem.
+      // mesh.position.y + wall.height gives the actual top Y in level-local space.
+      const meshY = sceneRegistry.nodes.get(childId as any)?.position.y ?? 0
+      const top = meshY + ((child as WallNode).height ?? DEFAULT_LEVEL_HEIGHT)
+      if (top > maxTop) maxTop = top
+    }
+  }
+
+  const height = maxTop > 0 ? maxTop : DEFAULT_LEVEL_HEIGHT
+  heightCache.set(levelId, height)
+  return height
+}
+
 export const LevelSystem = () => {
   useFrame((_, delta) => {
+    const nodes = useScene.getState().nodes
+
+    // Clear cache when nodes reference changes (any node was mutated)
+    if (nodes !== lastNodesRef) {
+      heightCache.clear()
+      lastNodesRef = nodes
+    }
+
     const levelMode = useViewer.getState().levelMode
     const selectedLevel = useViewer.getState().selection.levelId
+
+    // Collect and sort levels by floor index so we can compute cumulative offsets.
+    // Level 0 → Y=0, Level 1 → Y=height(0), Level 2 → Y=height(0)+height(1), etc.
+    type LevelEntry = { levelId: string; index: number; obj: NonNullable<ReturnType<typeof sceneRegistry.nodes.get>> }
+    const entries: LevelEntry[] = []
     sceneRegistry.byType.level.forEach((levelId) => {
       const obj = sceneRegistry.nodes.get(levelId)
-      if (obj) {
-        const level = useScene.getState().nodes[levelId as LevelNode['id']]
-        const targetY =
-          ((level as any).level || 0) *
-          (LEVEL_HEIGHT + (levelMode === 'exploded' ?  EXPLODED_GAP: 0))
-        obj.position.y = lerp(obj.position.y, targetY, delta * 3)
-
-        obj.visible = levelMode !== 'solo' || level?.id === selectedLevel || !selectedLevel
+      const level = nodes[levelId as LevelNode['id']]
+      if (obj && level) {
+        entries.push({ levelId, index: (level as any).level ?? 0, obj })
       }
     })
+    entries.sort((a, b) => a.index - b.index)
+
+    // Walk sorted levels, accumulating base Y offsets
+    let cumulativeY = 0
+    for (const { levelId, index, obj } of entries) {
+      const level = nodes[levelId as LevelNode['id']]
+      const baseY = cumulativeY
+      const explodedExtra = levelMode === 'exploded' ? index * EXPLODED_GAP : 0
+      const targetY = baseY + explodedExtra
+
+      obj.position.y = lerp(obj.position.y, targetY, delta * 3)
+      obj.visible = levelMode !== 'solo' || level?.id === selectedLevel || !selectedLevel
+
+      cumulativeY += getLevelHeight(levelId, nodes)
+    }
   })
   return null
 }