Implement object selection

TODO.md

@@ -87,9 +87,9 @@ A step-by-step checklist for porting MatterControl's design features to a Vue +
 
 ### Object Picking
 - [x] Add Raycaster for mouse picking
-- [ ] Implement click-to-select single object
-- [ ] Implement click-on-empty to deselect
-- [ ] Add `selectedObjects` array to Pinia store
+- [x] Implement click-to-select single object
+- [x] Implement click-on-empty to deselect
+- [x] Add `selectedObjects` array to Pinia store
 - [ ] Implement Shift+click for multi-select
 - [ ] Implement Ctrl+click to toggle selection
 - [ ] Add "Select All" (Ctrl+A) shortcut

src/App.vue

@@ -1,11 +1,22 @@
 <script setup lang="ts">
 import AppLayout from './components/AppLayout.vue'
 import Viewport from './components/Viewport.vue'
+import { useSceneStore, type SceneObject } from './stores/scene'
+
+const sceneStore = useSceneStore()
+
+function handlePick(object: SceneObject | null) {
+  if (object) {
+    sceneStore.select(object.id)
+  } else {
+    sceneStore.clearSelection()
+  }
+}
 </script>
 
 <template>
   <AppLayout>
-    <Viewport />
+    <Viewport @pick="handlePick" />
   </AppLayout>
 </template>
 

src/stores/scene.spec.ts

@@ -193,4 +193,60 @@ describe('useSceneStore', () => {
       expect(list[1]?.name).toBe('B')
     })
   })
+
+  describe('selection', () => {
+    it('select() selects a single object', () => {
+      const obj = store.addObject(createTestMesh(), 'Test')
+
+      store.select(obj.id)
+
+      expect(store.selectedObjects).toHaveLength(1)
+      expect(store.selectedObjects[0]?.id).toBe(obj.id)
+    })
+
+    it('select() replaces previous selection', () => {
+      const obj1 = store.addObject(createTestMesh(), 'A')
+      const obj2 = store.addObject(createTestMesh(), 'B')
+
+      store.select(obj1.id)
+      store.select(obj2.id)
+
+      expect(store.selectedObjects).toHaveLength(1)
+      expect(store.selectedObjects[0]?.id).toBe(obj2.id)
+    })
+
+    it('select() ignores locked objects', () => {
+      const obj = store.addObject(createTestMesh(), 'Test')
+      store.setObjectLocked(obj.id, true)
+
+      store.select(obj.id)
+
+      expect(store.selectedObjects).toHaveLength(0)
+    })
+
+    it('select() ignores non-existent ids', () => {
+      store.select('nonexistent')
+
+      expect(store.selectedObjects).toHaveLength(0)
+    })
+
+    it('clearSelection() deselects all objects', () => {
+      const obj = store.addObject(createTestMesh(), 'Test')
+      store.select(obj.id)
+
+      store.clearSelection()
+
+      expect(store.selectedObjects).toHaveLength(0)
+    })
+
+    it('selectedObjects returns SceneObjects for selected ids', () => {
+      const obj1 = store.addObject(createTestMesh(), 'A')
+      store.addObject(createTestMesh(), 'B')
+
+      store.select(obj1.id)
+
+      expect(store.selectedObjects).toHaveLength(1)
+      expect(store.selectedObjects[0]?.name).toBe('A')
+    })
+  })
 })

src/stores/scene.ts

@@ -13,6 +13,7 @@ export interface SceneObject {
 export const useSceneStore = defineStore('scene', () => {
   // Use shallowRef to avoid Vue making THREE.Mesh objects deeply reactive
   const objects = shallowRef<SceneObject[]>([])
+  const selectedIds = shallowRef<Set<string>>(new Set())
   let threeScene: THREE.Scene | null = null
   let nextId = 1
 
@@ -108,15 +109,30 @@ export const useSceneStore = defineStore('scene', () => {
     )
   }
 
+  function select(id: string): void {
+    const obj = objects.value.find((o) => o.id === id)
+    if (!obj || obj.locked) return
+    selectedIds.value = new Set([id])
+  }
+
+  function clearSelection(): void {
+    selectedIds.value = new Set()
+  }
+
   const objectList = computed(() => objects.value)
   const objectCount = computed(() => objects.value.length)
+  const selectedObjects = computed(() =>
+    objects.value.filter((o) => selectedIds.value.has(o.id))
+  )
 
   return {
     // State
     objects,
+    selectedIds,
     // Getters
     objectList,
     objectCount,
+    selectedObjects,
     // Actions
     setScene,
     addObject,
@@ -126,5 +142,7 @@ export const useSceneStore = defineStore('scene', () => {
     setObjectVisible,
     setObjectLocked,
     renameObject,
+    select,
+    clearSelection,
   }
 })