如何绘制标记？就像使用画布的Google地图中的标记

我需要使用画布绘制自定义标记，到目前为止，我绘制了逆三角形形状。您对如何绘制标记形状有任何想法吗？

class DrawTriangle extends CustomPainter {

      Paint _paint;

      DrawTriangle() {
        _paint = Paint()
          ..color = Colors.green
          ..style = PaintingStyle.fill;
      }

      @override
      void paint(Canvas canvas, Size size) {
        var path = Path();
        path.moveTo(size.width, size.height);
        path.lineTo(size.width + 100, size.height - 100);
        path.lineTo(size.width - 100, size.height - 100);
        path.close();
        canvas.drawPath(path, _paint);
      }

      @override
      bool shouldRepaint(CustomPainter oldDelegate) {
        return false;
      }
    }
    Future<Uint8List> getBytesFromCanvas(
          int width, int height, Color color) async {
        final PictureRecorder pictureRecorder = PictureRecorder();
        final Canvas canvas = Canvas(pictureRecorder);
        CustomPainter painter = DrawTriangle();
        painter.paint(canvas, Size(100.0,100.0));
        final img = await pictureRecorder.endRecording().toImage(width, height);
        final data = await img.toByteData(format: ImageByteFormat.png);
        return data.buffer.asUint8List();
      }

上面的方法创建逆三角形，我需要创建一个标记形状。 我该如何实现？