faster selection in editor

src/components/ObjectEditorView.tsx

@@ -13,24 +13,51 @@ type ObjectEditorViewProps = {
     object: Runtime<ObjectInstance>;
 }
 
-export const ObjectEditorView = observer(function ({ object }: ObjectEditorViewProps) {
-    const groupRef = useRef<Group>(null);
-
-    const objectType = state.world.getObjectTypeById(object.typeId);
+type SelectionOverlayProps = {
+    objectId: string;
+    groupRef: RefObject<Group | null>;
+    onTransformEnd: () => void;
+}
 
+// Separate observer so only the 2 affected instances (selected/deselected)
+// re-render on selection change, not all N objects in the scene.
+const SelectionOverlay = observer(function ({ objectId, groupRef, onTransformEnd }: SelectionOverlayProps) {
     const isSelected = state.worldEditor.isEnabled &&
-        state.worldEditor.selectedObjectId === object.id;
+        state.worldEditor.selectedObjectId === objectId;
     const selectionMode = isSelected ? state.worldEditor.selectedObjectMode : undefined;
 
     useHelper(isSelected ? groupRef : { current: null } as any, BoxHelper, 'white');
 
+    if (!isSelected || selectionMode === undefined || !groupRef.current)
+        return null;
+
+    return (
+        <TransformControls
+            object={groupRef as RefObject<Group>}
+            mode={selectionMode}
+            onMouseUp={onTransformEnd}
+        />
+    );
+});
+
+export const ObjectEditorView = observer(function ({ object }: ObjectEditorViewProps) {
+    const groupRef = useRef<Group>(null);
+
+    // Only observes world object types — not selection state — so won't
+    // re-render when a different object is selected.
+    const objectType = state.world.getObjectTypeById(object.typeId);
     if (!objectType)
         return null;
 
     function handleClick(e: ThreeEvent<MouseEvent>) {
         if (e.delta > 5) return;
         e.stopPropagation();
-        state.worldEditor.setSelectedObject(object.id, nextSelectionEditMode(selectionMode));
+        // Reading selection state inside an event handler: not tracked by observer.
+        const currentMode = state.worldEditor.isEnabled &&
+            state.worldEditor.selectedObjectId === object.id
+            ? state.worldEditor.selectedObjectMode
+            : undefined;
+        state.worldEditor.setSelectedObject(object.id, nextSelectionEditMode(currentMode));
     }
 
     function handleTransformEnd() {
@@ -45,13 +72,11 @@ export const ObjectEditorView = observer(function ({ object }: ObjectEditorViewP
     }
 
     return (<>
-        {(isSelected && selectionMode !== undefined && groupRef.current) &&
-            <TransformControls
-                object={groupRef as RefObject<Group>}
-                mode={selectionMode}
-                onMouseUp={handleTransformEnd}
+        <SelectionOverlay
+            objectId={object.id}
+            groupRef={groupRef}
+            onTransformEnd={handleTransformEnd}
         />
-        }
         <ObjectViewInternal
             ref={groupRef}
             object={object}

src/components/ObjectViewInternal.tsx

@@ -16,7 +16,7 @@ type ObjectViewInternalProps = {
     onClick?: (e: ThreeEvent<MouseEvent>) => void;
 }
 
-export const ObjectViewInternal = observer(forwardRef<Group, ObjectViewInternalProps>(
+export const ObjectViewInternal = observer(forwardRef<Group | null, ObjectViewInternalProps>(
     function ({ object, objectType, onClick }, ref) {
         const trimeshArgs = useMemo(
             () => buildObjectTrimesh(objectType, state.world.data.voxelTypes),