Update viewer.js

viewer.js

@@ -7,6 +7,7 @@ export let app = null;
 let cameraEntity   = null;
 let modelEntity    = null;
 let viewerInitialized = false;
+let resizeObserver = null; // will hold our ResizeObserver
 
 let chosenCameraX, chosenCameraY, chosenCameraZ;
 let minZoom, maxZoom, minAngle, maxAngle, minAzimuth, maxAzimuth, minPivotY, minY;
@@ -137,7 +138,7 @@ export async function initializeViewer(config, instanceId) {
       pc.GSplatHandler
     ];
 
-    // ─── REPLACED: use pc.Application (instead of deprecated / removed AppBase) ──
+    // ─── REPLACED: use pc.Application ───────────────────────────────────────────
     app = new pc.Application(canvas, createOptions);
 
     // Configure application
@@ -307,6 +308,17 @@ export async function initializeViewer(config, instanceId) {
       // 9f. Resize canvas one last time to fit container
       app.resizeCanvas(viewerContainerElem.clientWidth, viewerContainerElem.clientHeight);
 
+      // ─── NEW: Attach ResizeObserver to keep canvas in sync ─────────────────
+      resizeObserver = new ResizeObserver(entries => {
+        for (let entry of entries) {
+          const { width, height } = entry.contentRect;
+          if (app) {
+            app.resizeCanvas(width, height);
+          }
+        }
+      });
+      resizeObserver.observe(viewerContainerElem);
+
       // ─── NEW: Load & initialize the tooltips module ──────────────────────
       try {
         const tooltipsModule = await import('./tooltips.js');
@@ -394,6 +406,7 @@ export function resetViewerCamera() {
  * cleanupViewer()
  *
  * Destroys the PlayCanvas `app` (if it exists) and clears references.  Called when the user clicks “X”.
+ * Also disconnects the ResizeObserver to prevent memory leaks.
  */
 export function cleanupViewer() {
   if (app) {
@@ -404,6 +417,10 @@ export function cleanupViewer() {
     }
     app = null;
   }
+  if (resizeObserver && viewerContainerElem) {
+    resizeObserver.disconnect();
+    resizeObserver = null;
+  }
   cameraEntity   = null;
   modelEntity    = null;
   viewerInitialized = false;