fix: prevent initial text position jump

src/core/Autosizer.ts

@@ -44,8 +44,10 @@ const getFilteredChildren = (
   const filtered: CoreNode[] = [];
   while (children.length > 0) {
     const id = children.pop()!;
-    const child = childMap.get(id)!;
-    filtered.push(child);
+    const child = childMap.get(id);
+    if (child !== undefined) {
+      filtered.push(child);
+    }
   }
   return filtered;
 };

src/core/CoreTextNode.ts

@@ -77,6 +77,28 @@ export class CoreTextNode extends CoreNode implements CoreTextNodeProps {
 
   private _type: 'sdf' | 'canvas' = 'sdf'; // Default to SDF renderer
 
+  /**
+   * Only texts whose parent transform/layout depends on measured dimensions
+   * need eager layout to avoid an initial position jump.
+   */
+  private requiresLayoutForInitialTransform(props: CoreTextNodeProps): boolean {
+    const parent = props.parent;
+    if (parent === null) {
+      return false;
+    }
+
+    if (
+      parent.mountX !== 0 ||
+      parent.mountY !== 0 ||
+      parent.pivotX !== 0.5 ||
+      parent.pivotY !== 0.5
+    ) {
+      return true;
+    }
+
+    return parent.autosizer !== null || parent.parentAutosizer !== null;
+  }
+
   constructor(
     stage: Stage,
     props: CoreTextNodeProps,
@@ -92,6 +114,16 @@ export class CoreTextNode extends CoreNode implements CoreTextNodeProps {
     this.textProps = props;
     this._containType = TextConstraint[props.contain];
 
+    if (
+      (props.forceLoad === true || props.parent !== null) &&
+      this.requiresLayoutForInitialTransform(props) === true &&
+      this.fontHandler.isFontLoaded(this.textProps.fontFamily) === true
+    ) {
+      const resp = this.textRenderer.renderText(this.textProps);
+      this.handleRenderResult(resp);
+      this._layoutGenerated = true;
+    }
+
     this.setUpdateType(UpdateType.All);
   }