feat(editor): preset-system primitives (#340)

packages/core/src/events/bus.ts

@@ -130,6 +130,13 @@ export interface ThumbnailGenerateEvent {
    * that should fire immediately from the current camera pose.
    */
   snapLevels?: boolean
+  /**
+   * When true, keep the rendered alpha channel — emits a transparent PNG
+   * without baking the scene background into the output. Used by the
+   * preset capture flow so saved preset thumbnails composite cleanly on
+   * any palette background.
+   */
+  transparent?: boolean
 }
 
 export interface CameraControlFitSceneEvent {

packages/core/src/registry/__bench__/relations-resolver.bench.ts

@@ -110,6 +110,8 @@ function makeScene(nodes: Record<string, AnyNode>): SceneApi {
     markDirty: () => {},
     pauseHistory: () => {},
     resumeHistory: () => {},
+    getSubtreeSnapshot: () => null,
+    materializeSubtree: () => null,
   }
 }
 

packages/core/src/registry/index.ts

@@ -1,6 +1,23 @@
+export type {
+  ArcResizeHandle,
+  Cursor,
+  EditorApi,
+  EndpointMoveHandle,
+  HandleAnchor,
+  HandleAxis,
+  HandleDescriptor,
+  HandleList,
+  HandlePlacement,
+  HandlePortal,
+  LinearResizeHandle,
+  RadialResizeHandle,
+  TapActionHandle,
+} from './handles'
 export {
   discoverPlugins,
   getSelectableKinds,
+  isPresettable,
+  isPresettableKind,
   isRegistryMovable,
   isRegistrySelectable,
   kindsWithFloorplanScope,
@@ -17,22 +34,14 @@ export {
   collectDescendants,
   type SpatialQuery,
 } from './relations-resolver'
-export type {
-  ArcResizeHandle,
-  Cursor,
-  EditorApi,
-  EndpointMoveHandle,
-  HandleAnchor,
-  HandleAxis,
-  HandleDescriptor,
-  HandleList,
-  HandlePlacement,
-  HandlePortal,
-  LinearResizeHandle,
-  RadialResizeHandle,
-  TapActionHandle,
-} from './handles'
 export { createSceneApi, type SceneStoreLike } from './scene-api'
+export {
+  buildSubtreeSnapshot,
+  type MaterializedSubtree,
+  materializeSubtree,
+  type NodeSubtree,
+  type SubtreeNode,
+} from './subtree'
 export type {
   Affordance,
   AnyNodeDefinition,

packages/core/src/registry/registry.test.ts

@@ -1,6 +1,12 @@
 import { beforeEach, describe, expect, test } from 'bun:test'
 import { z } from 'zod'
-import { loadPlugin, nodeRegistry, registerNode } from './registry'
+import {
+  isPresettable,
+  isPresettableKind,
+  loadPlugin,
+  nodeRegistry,
+  registerNode,
+} from './registry'
 import type { AnyNodeDefinition, Plugin } from './types'
 
 function makeDefinition(
@@ -70,6 +76,41 @@ describe('nodeRegistry', () => {
   })
 })
 
+describe('isPresettable', () => {
+  beforeEach(() => {
+    nodeRegistry._reset()
+  })
+
+  test('explicit true wins', () => {
+    const def = makeDefinition('explicit-true', { capabilities: { presettable: true } })
+    expect(isPresettable(def)).toBe(true)
+  })
+
+  test('explicit false wins even with parametrics', () => {
+    const def = makeDefinition('explicit-false', {
+      capabilities: { presettable: false },
+      parametrics: { groups: [] } as any,
+    })
+    expect(isPresettable(def)).toBe(false)
+  })
+
+  test('defaults to true when parametrics exists', () => {
+    const def = makeDefinition('param', { parametrics: { groups: [] } as any })
+    expect(isPresettable(def)).toBe(true)
+  })
+
+  test('defaults to false without parametrics', () => {
+    const def = makeDefinition('no-param')
+    expect(isPresettable(def)).toBe(false)
+  })
+
+  test('isPresettableKind looks up the registry', () => {
+    registerNode(makeDefinition('shelfy', { parametrics: { groups: [] } as any }))
+    expect(isPresettableKind('shelfy')).toBe(true)
+    expect(isPresettableKind('unknown')).toBe(false)
+  })
+})
+
 describe('loadPlugin', () => {
   beforeEach(() => {
     nodeRegistry._reset()

packages/core/src/registry/registry.ts

@@ -146,6 +146,24 @@ export function isRegistryMovable(kind: string): boolean {
   return false
 }
 
+/**
+ * Whether the kind can be saved as a reusable preset. Default: an
+ * explicit `capabilities.presettable` boolean wins; otherwise the kind
+ * is presettable iff it declares `def.parametrics`. Read by host apps
+ * (community shell) to gate "save as preset" UI on a selection.
+ */
+export function isPresettable(def: AnyNodeDefinition): boolean {
+  if (typeof def.capabilities.presettable === 'boolean') {
+    return def.capabilities.presettable
+  }
+  return def.parametrics !== undefined
+}
+
+export function isPresettableKind(kind: string): boolean {
+  const def = nodeRegistry.get(kind)
+  return def ? isPresettable(def) : false
+}
+
 export async function loadPlugin(plugin: Plugin): Promise<void> {
   if (plugin.apiVersion !== HOST_API_VERSION) {
     throw new Error(

packages/core/src/registry/relations-resolver.test.ts

@@ -47,6 +47,8 @@ function makeFakeScene(nodes: Record<string, AnyNode>): SceneApi {
     markDirty: () => {},
     pauseHistory: () => {},
     resumeHistory: () => {},
+    getSubtreeSnapshot: () => null,
+    materializeSubtree: () => null,
   }
 }
 

packages/core/src/registry/scene-api.ts

@@ -1,5 +1,6 @@
 import type { AnyNode, AnyNodeId } from '../schema/types'
 import { pauseSceneHistory, resumeSceneHistory } from '../store/history-control'
+import { buildSubtreeSnapshot, materializeSubtree as runMaterializeSubtree } from './subtree'
 import type { SceneApi } from './types'
 
 /**
@@ -14,6 +15,7 @@ export type SceneStoreLike = {
     rootNodeIds: AnyNodeId[]
     dirtyNodes: Set<AnyNodeId>
     createNode: (node: AnyNode, parentId?: AnyNodeId) => void
+    createNodes?: (ops: { node: AnyNode; parentId?: AnyNodeId }[]) => void
     updateNode: (id: AnyNodeId, data: Partial<AnyNode>) => void
     deleteNode: (id: AnyNodeId) => void
     markDirty: (id: AnyNodeId) => void
@@ -104,5 +106,39 @@ export function createSceneApi(store: SceneStoreLike): SceneApi {
       resumeSceneHistory(store)
       snapshot = null
     },
+
+    getSubtreeSnapshot(rootId) {
+      return buildSubtreeSnapshot(store.getState().nodes, rootId)
+    },
+
+    materializeSubtree(subtree, position, parentId) {
+      const { rootId, nodes } = runMaterializeSubtree(subtree, position)
+      const state = store.getState()
+      // Prefer batched `createNodes` when the store exposes it — keeps
+      // children-array writes and dirty-marking in one tick, identical
+      // to how `applyNodeChanges` lands a multi-node paste. The
+      // minimal `SceneStoreLike` does not require it, so the test
+      // store can fall back to per-node `createNode` calls.
+      const root = nodes[0]
+      if (!root) return null
+      const ops: { node: AnyNode; parentId?: AnyNodeId }[] = []
+      for (let i = 0; i < nodes.length; i += 1) {
+        const node = nodes[i]!
+        if (i === 0) {
+          ops.push(parentId ? { node, parentId } : { node })
+        } else {
+          ops.push({ node })
+        }
+      }
+      const createNodes = state.createNodes
+      if (createNodes) {
+        createNodes(ops)
+      } else {
+        for (const op of ops) {
+          state.createNode(op.node, op.parentId)
+        }
+      }
+      return rootId
+    },
   }
 }

packages/core/src/registry/subtree.test.ts

@@ -0,0 +1,164 @@
+import { describe, expect, test } from 'bun:test'
+import type { AnyNode, AnyNodeId } from '../schema/types'
+import { buildSubtreeSnapshot, materializeSubtree } from './subtree'
+
+function makeNode(id: string, type: string, extra: Record<string, unknown> = {}): AnyNode {
+  return {
+    object: 'node',
+    id,
+    type,
+    parentId: null,
+    visible: true,
+    metadata: {},
+    ...extra,
+  } as unknown as AnyNode
+}
+
+describe('buildSubtreeSnapshot', () => {
+  test('returns null for missing root', () => {
+    expect(buildSubtreeSnapshot({}, 'missing' as AnyNodeId)).toBeNull()
+  })
+
+  test('strips id / parentId / position / wallId from the root', () => {
+    const nodes: Record<AnyNodeId, AnyNode> = {
+      ['door_1' as AnyNodeId]: makeNode('door_1', 'door', {
+        parentId: 'level_1',
+        position: [1, 2, 3],
+        wallId: 'wall_x',
+        wallT: 0.4,
+        width: 0.9,
+        height: 2.1,
+      }),
+    }
+    const snap = buildSubtreeSnapshot(nodes, 'door_1' as AnyNodeId)
+    expect(snap).not.toBeNull()
+    expect((snap?.root as any).id).toBeUndefined()
+    expect((snap?.root as any).parentId).toBeUndefined()
+    expect((snap?.root as any).position).toBeUndefined()
+    expect((snap?.root as any).wallId).toBeUndefined()
+    expect((snap?.root as any).wallT).toBeUndefined()
+    expect((snap?.root as any).width).toBe(0.9)
+    expect((snap?.root as any).height).toBe(2.1)
+    expect(snap?.rootKind).toBe('door')
+  })
+
+  test('captures descendants via the children array', () => {
+    const nodes: Record<AnyNodeId, AnyNode> = {
+      ['shelf_1' as AnyNodeId]: makeNode('shelf_1', 'shelf', {
+        position: [5, 0, 5],
+        children: ['item_a', 'item_b'],
+        width: 1,
+      }),
+      ['item_a' as AnyNodeId]: makeNode('item_a', 'item', {
+        parentId: 'shelf_1',
+        position: [0, 0, 0],
+      }),
+      ['item_b' as AnyNodeId]: makeNode('item_b', 'item', {
+        parentId: 'shelf_1',
+        position: [0.3, 0, 0],
+      }),
+    }
+    const snap = buildSubtreeSnapshot(nodes, 'shelf_1' as AnyNodeId)
+    expect(snap?.descendants).toHaveLength(2)
+    // Descendants keep their local positions.
+    expect((snap?.descendants[0] as any).position).toEqual([0, 0, 0])
+    expect((snap?.descendants[1] as any).position).toEqual([0.3, 0, 0])
+    // Internal child references rewritten to tokens, not original ids.
+    const childTokens = (snap?.root as any).children as string[]
+    expect(childTokens).toHaveLength(2)
+    for (const t of childTokens) {
+      expect(t.includes('::')).toBe(true)
+      expect(t.startsWith('item::')).toBe(true)
+    }
+  })
+})
+
+describe('materializeSubtree', () => {
+  test('round-trips a single-node snapshot at a new position with fresh ids', () => {
+    const original = makeNode('door_orig', 'door', {
+      position: [1, 2, 3],
+      wallId: 'wall_x',
+      width: 0.9,
+      height: 2.1,
+    })
+    const snap = buildSubtreeSnapshot(
+      { ['door_orig' as AnyNodeId]: original },
+      'door_orig' as AnyNodeId,
+    )
+    if (!snap) throw new Error('snap')
+
+    const { rootId, nodes } = materializeSubtree(snap, [10, 0, -4])
+    expect(nodes).toHaveLength(1)
+    const newRoot = nodes[0] as any
+    expect(newRoot.id).toBe(rootId)
+    expect(newRoot.id).not.toBe('door_orig')
+    expect(newRoot.id.startsWith('door_')).toBe(true)
+    expect(newRoot.parentId).toBeNull()
+    expect(newRoot.position).toEqual([10, 0, -4])
+    // Host ref was stripped at snapshot time; materialize doesn't re-add it.
+    expect(newRoot.wallId).toBeUndefined()
+    // Parametric fields preserved verbatim.
+    expect(newRoot.width).toBe(0.9)
+    expect(newRoot.height).toBe(2.1)
+  })
+
+  test('preserves a parent/child subtree with remapped ids and relative positions', () => {
+    const nodes: Record<AnyNodeId, AnyNode> = {
+      ['shelf_1' as AnyNodeId]: makeNode('shelf_1', 'shelf', {
+        position: [5, 0, 5],
+        children: ['item_a', 'item_b'],
+        width: 1,
+      }),
+      ['item_a' as AnyNodeId]: makeNode('item_a', 'item', {
+        parentId: 'shelf_1',
+        position: [0, 0, 0],
+      }),
+      ['item_b' as AnyNodeId]: makeNode('item_b', 'item', {
+        parentId: 'shelf_1',
+        position: [0.3, 0, 0],
+      }),
+    }
+    const snap = buildSubtreeSnapshot(nodes, 'shelf_1' as AnyNodeId)!
+    const { rootId, nodes: out } = materializeSubtree(snap, [99, 0, -99])
+    expect(out).toHaveLength(3)
+    const root = out[0] as any
+    expect(root.id).toBe(rootId)
+    expect(root.id).not.toBe('shelf_1')
+    expect(root.position).toEqual([99, 0, -99])
+    // Children point at fresh ids that exist in the output.
+    const ids = new Set(out.map((n) => (n as any).id))
+    expect(root.children).toHaveLength(2)
+    for (const cid of root.children) expect(ids.has(cid)).toBe(true)
+    // Descendant parentIds point at the new root id.
+    for (let i = 1; i < out.length; i += 1) {
+      const desc = out[i] as any
+      expect(desc.parentId).toBe(rootId)
+      // Position preserved.
+      expect(Array.isArray(desc.position)).toBe(true)
+    }
+    // Internal-token metadata is gone.
+    for (const node of out) {
+      const md = (node as any).metadata ?? {}
+      expect(md.__subtreeKey).toBeUndefined()
+    }
+  })
+
+  test('two materializations yield disjoint id sets', () => {
+    const nodes: Record<AnyNodeId, AnyNode> = {
+      ['shelf_1' as AnyNodeId]: makeNode('shelf_1', 'shelf', {
+        position: [0, 0, 0],
+        children: ['item_a'],
+      }),
+      ['item_a' as AnyNodeId]: makeNode('item_a', 'item', {
+        parentId: 'shelf_1',
+        position: [0, 0, 0],
+      }),
+    }
+    const snap = buildSubtreeSnapshot(nodes, 'shelf_1' as AnyNodeId)!
+    const first = materializeSubtree(snap, [0, 0, 0])
+    const second = materializeSubtree(snap, [1, 0, 0])
+    const idsA = new Set(first.nodes.map((n) => (n as any).id))
+    const idsB = new Set(second.nodes.map((n) => (n as any).id))
+    for (const id of idsA) expect(idsB.has(id)).toBe(false)
+  })
+})