Polygon Widget

polygon_widget.dart

class ClipPolygon extends StatelessWidget {
  final Widget child;
  final int sides;

  ClipPolygon({
    @required this.child,
    @required this.sides,
  });

  @override
  Widget build(BuildContext context) {
    return new AspectRatio(
        aspectRatio: 1.0,
        child: new ClipPath(
          clipper: new Polygon(sides: sides),
          child: child,
        ));
  }
}

class Polygon extends CustomClipper<Path> {
  final int sides;

  Polygon({@required this.sides});

  Path draw(double width) {
    final anglePerSide = 360 / sides;
    final radius = width / 2;

    Path path = new Path();

    for (var i = 0; i <= sides; i++) {
      double currentAngle = anglePerSide * i;
      bool isFirst = i == 0;

      _drawLine(path, currentAngle, radius, isFirst);
    }

    return path;
  }

  double _angleToRadian(double angle) {
    return angle * (pi / 180);
  }

  Offset _getOffset(double angle, double radius) {
    //final rotationAwareAngle = angle - 90;
    final radian = _angleToRadian(angle);
    print(angle);
    final x = cos(radian) * radius + radius;
    final y = sin(radian) * radius + radius;
    print(x);
    print(y);
    return new Offset(x, y);
  }

  _drawLine(Path path, double currentAngle, double radius, bool move) {
    Offset current = _getOffset(currentAngle, radius);

    if (move)
      path.moveTo(current.dx, current.dy);
    else
      path.lineTo(current.dx, current.dy);
  }

  @override
  Path getClip(Size size) {
    return draw(size.width);
  }

  @override
  bool shouldReclip(CustomClipper<Path> oldClipper) {
    return true;
  }
}