import 'dart:typed_data';
import 'dart:math' as math;
import 'dart:ui' as ui;

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class MobilePoint {
  static math.Random generator = math.Random();

  MobilePoint.random(this.size) {
    x = generator.nextDouble() * size.width;
    y = generator.nextDouble() * size.height;
    dx = (generator.nextDouble() - 0.5) * size.width / 100;
    dy = (generator.nextDouble() - 0.5) * size.height / 100;
  }

  void bump() {
    x += dx;
    if (x > size.width) {
      x = size.width * 2 - x;
      dx = -dx;
    } else if (x < 0) {
      x = -x;
      dx = -dx;
    }
    y += dy;
    if (y > size.height) {
      y = size.height * 2 - y;
      dy = -dy;
    } else if (y < 0) {
      y = -y;
      dy = -dy;
    }
  }

  Size size;
  double x = 0, y = 0;
  double dx = 0, dy = 0;
}

class _MyHomePageState extends State<MyHomePage> with SingleTickerProviderStateMixin {
  static Size pointFieldSize = Size(200, 200);
  List<MobilePoint> points = List<MobilePoint>.generate(100, (index) => MobilePoint.random(pointFieldSize));
  late AnimationController controller;

  @override
  void initState() {
    super.initState();
    controller = AnimationController(vsync: this);
    controller.repeat(period: Duration(seconds: 10));
  }

  @override
  void dispose() {
    controller.stop();
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: AnimatedBuilder(
          animation: controller,
          builder: (context, child) {
            final Float32List pointList = Float32List(points.length * 2);
            for (int i = 0; i < points.length; i++) {
              points[i].bump();
              pointList[i * 2] = points[i].x;
              pointList[i * 2 + 1] = points[i].y;
            }
            return Column(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              crossAxisAlignment: CrossAxisAlignment.center,
              children: <Widget>[
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: <Widget>[
                    CustomPaint(
                      size: pointFieldSize,
                      painter: PointPainter(pointList, ui.PointMode.points),
                    ),
                    CustomPaint(
                      size: pointFieldSize,
                      painter: PointPainter(pointList, ui.PointMode.lines),
                    ),
                  ],
                ),
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: <Widget>[
                    CustomPaint(
                      size: pointFieldSize,
                      painter: PointPainter(pointList, ui.PointMode.polygon),
                    ),
                    CustomPaint(
                      size: pointFieldSize,
                      painter: PathPainter(points),
                    ),
                  ],
                ),
              ],
            );
          },
        ),
      ),
    );
  }
}

class PointPainter extends CustomPainter {
  PointPainter(this.list, this.mode);

  final ui.PointMode mode;
  final Float32List list;

  @override
  void paint(Canvas canvas, Size size) {
    Paint paint = Paint()
      ..color = Colors.blue.withAlpha(64)
      ..strokeWidth = 4.0
      ..strokeJoin = StrokeJoin.miter
      ..strokeCap = StrokeCap.square;
    canvas.drawRawPoints(mode, list, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) => true;
}

class PathPainter extends CustomPainter {
  PathPainter(this.list);

  final List<MobilePoint> list;

  @override
  void paint(Canvas canvas, Size size) {
    Paint paint = Paint()
      ..color = Colors.blue.withAlpha(64)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 4.0
      ..strokeJoin = StrokeJoin.miter
      ..strokeCap = StrokeCap.square;
    Path path = Path();
    path.moveTo(list[0].x, list[1].y);
    for (int i = 1; i < list.length; i++) {
      path.lineTo(list[i].x, list[i].y);
    }
    canvas.drawPath(path, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) => true;
}