[windows] bounded blurs don't render correctly #191611

import 'package:flutter/material.dart';

void main() => runApp(const BoundedBlurReproApp());

class BoundedBlurReproApp extends StatefulWidget {
  const BoundedBlurReproApp({super.key});

  @override
  State<BoundedBlurReproApp> createState() => _BoundedBlurReproAppState();
}

class _BoundedBlurReproAppState extends State<BoundedBlurReproApp> {
  bool _bounded = true;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Bounded Blur Scroll Bug'),
          actions: [
            Row(
              children: [
                Text(_bounded ? 'Bounded (Buggy)' : 'Unbounded (Works)'),
                Switch(
                  value: _bounded,
                  onChanged: (val) => setState(() => _bounded = val),
                ),
              ],
            ),
          ],
        ),
        body: Stack(
          children: [
            // 1. High-contrast colorful background
            Positioned.fill(
              child: Column(
                children: List.generate(
                  8,
                  (i) => Expanded(
                    child: Container(
                      color: Colors.primaries[i % Colors.primaries.length],
                      alignment: Alignment.center,
                      child: Text(
                        'Background Stripe $i',
                        style: const TextStyle(
                          fontSize: 24,
                          color: Colors.white70,
                        ),
                      ),
                    ),
                  ),
                ),
              ),
            ),

            // 2. Scrollable list of glass panels
            ListView.builder(
              itemCount: 20,
              padding: const EdgeInsets.all(16),
              itemBuilder: (context, index) {
                return Padding(
                  padding: const EdgeInsets.symmetric(vertical: 12),
                  child: ClipRRect(
                    borderRadius: BorderRadius.circular(16),
                    child: BackdropFilter(
                      filterConfig: ImageFilterConfig.blur(
                        sigmaX: 20,
                        sigmaY: 20,
                        bounded: _bounded,
                      ),
                      child: Container(
                        height: 140,
                        color: Colors.black.withValues(alpha: 0.2),
                        alignment: Alignment.center,
                        child: Text(
                          'Panel #$index (${_bounded ? "Bounded" : "Unbounded"})',
                          style: const TextStyle(
                            color: Colors.white,
                            fontSize: 18,
                            fontWeight: FontWeight.bold,
                          ),
                        ),
                      ),
                    ),
                  ),
                );
              },
            ),
          ],
        ),
      ),
    );
  }
}