Particle blendmode

main.dart

import 'package:flutter/material.dart';
import 'package:simple_animations/simple_animations.dart';

/*
environment:
  sdk: '>=2.12.0 <3.0.0'

dependencies:
  flutter:
    sdk: flutter
  simple_animations: ^3.0.0-nullsafety.4
*/

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: SafeArea(
          child: LoopAnimation( // Loop to see FPS
              duration: Duration(seconds: 1),
              tween: ConstantTween(1),
              builder: (context, _, value) {
                return Container(
                  child: CustomPaint(
                    painter: MyPainter(),
                  ),
                );
              }),
        ),
      ),
    );
  }
}

class MyPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    var paint = Paint()
      ..color = Colors.red
      ..maskFilter = MaskFilter.blur(BlurStyle.normal, 100)
      ..blendMode = BlendMode.darken;

    for (var i = 0; i < 100; i++) {
      canvas.drawRect(Rect.fromLTWH(5.0 * i % 100, 5.0 * i, 100, 100), paint);
    }
  }

  @override
  bool shouldRepaint(covariant MyPainter oldDelegate) {
    return true;
  }
}