Reuse canvas scenes across viewport and interaction metadata changes

2026-11-09 21:46:58 +08:00
parent bb5bc9d8e9
commit 732c15f7bf
5 changed files with 69 additions and 5 deletions
@@ -0,0 +1,27 @@
+import {fault} from '../canvas-core/values.ts';
+import type {Document,Registry} from '../canvas-core/types.ts';
+import type {SessionSnapshot,ViewState} from '../canvas-core/gestures.ts';
+import type {DocumentQueries} from '../canvas-core/queries.ts';
+import {createGeometryProjectionCache} from './geometry-cache.ts';
+import {projectCanvas} from './projection.ts';
+import type {RendererCatalog} from './renderers.ts';
+
+/** One view's derived scene. Viewport/tool/mode and task status do not change scene inputs. */
+export function createSceneProjection(){
+ let geometry=createGeometryProjectionCache();
+ type Inputs={owner:object;document:Document;registry:Registry;catalog:RendererCatalog;canvasId:ViewState['canvasId'];selection:ViewState['selection'];preview:NonNullable<SessionSnapshot['gesture']>['preview']|undefined;edgeId:string|undefined;path:NonNullable<SessionSnapshot['connectionGesture']>['path']|undefined};
+ let previous:Inputs|undefined,value:ReturnType<typeof projectCanvas>|undefined;
+ return Object.freeze({
+  project(owner:object,document:Document,view:ViewState,sessions:SessionSnapshot,registry:Registry,catalog:RendererCatalog,queries?:DocumentQueries){
+   if(queries&&queries.document!==document)throw fault('stale_query_snapshot');
+   if(queries&&queries.registry!==registry)throw fault('query_registry_changed');
+   const preview=sessions.gesture?.preview,connection=sessions.connectionGesture;
+   const next:Inputs={owner,document,registry,catalog,canvasId:view.canvasId,selection:view.selection,preview:preview?.size?preview:undefined,edgeId:connection?.target.id,path:connection?.path};
+   if(previous&&Object.keys(next).every(key=>Object.is(next[key as keyof Inputs],previous![key as keyof Inputs])))return value!;
+   // Read the captured session, not a newer live gesture during an older React render.
+   const result=projectCanvas(document,view.canvasId,registry,view.selection,id=>next.preview?.get(id),connection,catalog,{queries,geometry,owner});
+   previous=next;value=result;return result;
+  },
+  clear(){previous=undefined;value=undefined;geometry=createGeometryProjectionCache();},
+ });
+}