testdartpad

main.dart

import 'package:flutter/material.dart';
import 'dart:math';
import 'dart:ui';

final Color darkBlue = Color.fromARGB(255, 18, 32, 47);

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child:CustomPaint(
            painter: RosePainter(2, 4, 300, 300, 200, 0.1),
            child: Container(),
            ),
        ),
      ),
    );
  }
}

class RosePainter extends CustomPainter {
  double d, r, n, c;
  double k, transformx, transformy;
  List<Offset> points = [];
  RosePainter(
      this.d, this.n, this.transformx, this.transformy, this.r, this.c) {
    k = n / d;
  }

  @override
  void paint(Canvas canvas, Size size) {
    var paint = Paint();
    paint.color = Colors.red;
    paint.strokeWidth = 2;
    for (double i = 0; i < 2 * d * pi; i += 0.01) {
      points.add(
          Offset(r * (cos(k * i) + c) * cos(i), r * (cos(k * i) + c) * sin(i))
              .translate(transformx, transformy));
    }
    canvas.drawPoints(PointMode.polygon, points, paint);
  }

  @override
  bool shouldRepaint(RosePainter oldDelegate) => true;

  @override
  bool shouldRebuildSemantics(RosePainter oldDelegate) => false;
}