gnssview/lib/sky/sky_plot.dart

import 'dart:math';
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import 'package:gnss/gnss.dart';

import '../Controller/gnss_controller.dart';

const signalNameList = <String>["GPS", "GLO", "GAL", "BDS", "QZS"];
const Map<String, String> signalPrefixList = {
  "GPS": "G",
  "GLO": "N",
  "GAL": "E",
  "BDS": "B",
  "QZS": "Q"
};
const Map<String, Color> signalColorMap = {
  "GPS": Color.fromARGB(255, 255, 0, 0),
  "GLO": Color.fromARGB(255, 0, 255, 0),
  "GAL": Color.fromARGB(255, 0, 0, 255),
  "BDS": Color.fromARGB(255, 146, 73, 206),
  "QZS": Color.fromARGB(255, 13, 179, 179),
};

class SkyPlotPage extends StatelessWidget {
  late final GnssController controller;
  // Map<String, ui.Image> imageList = {};
  @override
  SkyPlotPage({super.key}) {
    controller = Get.find<GnssController>();
  }
  Future<ui.Image> loadImage(String path) async {
    ByteData data = await rootBundle.load(path);
    ui.Codec codec = await ui.instantiateImageCodec(data.buffer.asUint8List());
    ui.FrameInfo fi = await codec.getNextFrame();
    return fi.image;
  }

  @override
  Widget build(BuildContext context) {
    bool isDarkMode = Theme.of(context).brightness == Brightness.dark;
    final size = MediaQuery.of(context).size;
    return Obx(() {
      controller.signalUpdate.value;
      return SizedBox(
        width: size.width,
        height: size.height,
        child: CustomPaint(
          painter:
              SkyPlotPainter(controller.signalData, controller.selectedSignal),
        ),
      );
    });
  }
}

class SkyPlotPainter extends CustomPainter {
  final SignalData? signalData;
  final Map<String, bool> selectedSignal;
  final satelliteRadius = 12.0;
  SkyPlotPainter(this.signalData, this.selectedSignal);

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = const ui.Color.fromARGB(255, 0, 0, 0)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 2.0; // 设置线条的粗细，这里设置为2.0

    final double radius = min(size.width / 2.4, size.height / 2);
    final Offset center = Offset(size.width / 2, size.height / 2 - 5);

    // Draw concentric circles for different elevation angles
    for (int i = 0; i <= 90; i += 30) {
      double r = radius * (90 - i) / 90;
      canvas.drawCircle(center, r, paint);
    }

    // Draw lines for different azimuth angles
    for (int i = 0; i < 360; i += 30) {
      double radians = i * pi / 180;
      double x = center.dx + radius * cos(radians);
      double y = center.dy + radius * sin(radians);
      canvas.drawLine(center, Offset(x, y), paint);

      String text;
      if (i == 0) {
        text = ' N';
      } else if (i == 180) {
        text = 'S';
      } else {
        text = '${(i + 90) % 360}';
      }
      TextPainter textPainter = TextPainter(
        text: TextSpan(
            text: text,
            style: const TextStyle(color: Colors.black, fontSize: 15)),
        textDirection: TextDirection.ltr,
      );
      textPainter.layout(); // 布局文本
      // 计算文本的位置并绘制
      double textX = x + 14 * cos(radians); // 向外偏移
      double textY = y + 14 * sin(radians); // 向外偏移
      textPainter.paint(canvas, Offset(textX - 12, textY - 8));
    }
    if (signalData == null) {
      return;
    }
    // Draw satellite positions
    final satellitePaint = Paint()..style = PaintingStyle.fill;
    signalData!.forEach((key, value) {
      if (selectedSignal[key] == true) {
        satellitePaint.color = signalColorMap[key] ?? Colors.yellow;
        drawGnssSignal(canvas, center, radius, value, satellitePaint, key);
      }
    });
  }

  void drawGnssSignal(
    Canvas canvas,
    Offset center,
    double radius,
    List<SignalGNSS> signals,
    Paint paint,
    String neme,
  ) {
    for (final signal in signals) {
      final int el = signal.elevation;

      final double az = (360 - signal.azimuth + 90) * pi / 180;

      final double r = radius * (90 - el) / 90;
      final double x = center.dx + r * cos(az);
      final double y = center.dy + r * sin(az);

      canvas.drawCircle(Offset(x, y), satelliteRadius, paint);
      TextPainter(
        text: TextSpan(
          text: signalPrefixList[neme]! + signal.prn.toString().padLeft(2, '0'),
          style: const TextStyle(color: Colors.white, fontSize: 12),
        ),
        textDirection: TextDirection.ltr,
      )
        ..layout()
        ..paint(canvas, Offset(x - 9, y - 7));
    }
  }

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