pose_detection_tflite 1.2.2

Pose & landmark detection using on-device TFLite models.

example/lib/main.dart

import 'dart:io';
import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:pose_detection_tflite/pose_detection_tflite.dart';
import 'package:camera_macos/camera_macos_controller.dart';
import 'package:camera_macos/camera_macos_view.dart';
import 'package:camera_macos/camera_macos_arguments.dart';
import 'package:opencv_dart/opencv_dart.dart' as cv;

void main() {
  runApp(const PoseDetectionApp());
}

class PoseDetectionApp extends StatelessWidget {
  const PoseDetectionApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Pose Detection Demo',
      theme: ThemeData(
        colorSchemeSeed: Colors.blue,
        useMaterial3: true,
      ),
      home: const HomeScreen(),
    );
  }
}

class HomeScreen extends StatelessWidget {
  const HomeScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Pose Detection Demo'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.accessibility_new, size: 100, color: Colors.blue[300]),
            const SizedBox(height: 48),
            Text(
              'Choose Detection Mode',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
            const SizedBox(height: 48),
            _buildModeCard(
              context,
              icon: Icons.image,
              title: 'Still Image',
              description: 'Detect poses in photos from gallery or camera',
              onTap: () {
                Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => const StillImageScreen(),
                  ),
                );
              },
            ),
            const SizedBox(height: 24),
            _buildModeCard(
              context,
              icon: Icons.videocam,
              title: 'Live Camera',
              description: 'Real-time pose detection from camera feed',
              onTap: () {
                Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => const CameraScreen(),
                  ),
                );
              },
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildModeCard(
    BuildContext context, {
    required IconData icon,
    required String title,
    required String description,
    required VoidCallback onTap,
  }) {
    return SizedBox(
      width: 400,
      child: Card(
        elevation: 4,
        child: InkWell(
          onTap: onTap,
          borderRadius: BorderRadius.circular(12),
          child: Padding(
            padding: const EdgeInsets.all(24),
            child: Row(
              children: [
                Icon(icon, size: 64, color: Colors.blue),
                const SizedBox(width: 24),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        title,
                        style: Theme.of(context).textTheme.titleLarge,
                      ),
                      const SizedBox(height: 8),
                      Text(
                        description,
                        style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                              color: Colors.grey[600],
                            ),
                      ),
                    ],
                  ),
                ),
                const Icon(Icons.arrow_forward_ios),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class StillImageScreen extends StatefulWidget {
  const StillImageScreen({super.key});

  @override
  State<StillImageScreen> createState() => _StillImageScreenState();
}

class _StillImageScreenState extends State<StillImageScreen> {
  final PoseDetector _poseDetector = PoseDetector(
    mode: PoseMode.boxesAndLandmarks,
    landmarkModel: PoseLandmarkModel.heavy,
    detectorConf: 0.6,
    detectorIou: 0.4,
    maxDetections: 10,
    minLandmarkScore: 0.5,
    performanceConfig:
        const PerformanceConfig.xnnpack(), // Enable XNNPACK for 2-5x speedup
  );
  final ImagePicker _picker = ImagePicker();

  bool _isInitialized = false;
  bool _isProcessing = false;
  File? _imageFile;
  List<Pose> _results = [];
  String? _errorMessage;

  @override
  void initState() {
    super.initState();
    _initializeDetectors();
  }

  Future<void> _initializeDetectors() async {
    setState(() {
      _isProcessing = true;
      _errorMessage = null;
    });

    try {
      await _poseDetector.initialize();
      setState(() {
        _isInitialized = true;
        _isProcessing = false;
      });
    } catch (e) {
      setState(() {
        _isProcessing = false;
        _errorMessage = 'Failed to initialize: $e';
      });
    }
  }

  Future<void> _pickImage(ImageSource source) async {
    try {
      final XFile? pickedFile = await _picker.pickImage(source: source);
      if (pickedFile == null) return;

      setState(() {
        _imageFile = File(pickedFile.path);
        _results = [];
        _isProcessing = true;
        _errorMessage = null;
      });

      final Uint8List bytes = await _imageFile!.readAsBytes();
      final List<Pose> results = await _poseDetector.detect(bytes);

      setState(() {
        _results = results;
        _isProcessing = false;
        if (results.isEmpty) _errorMessage = 'No people detected in image';
      });
    } catch (e) {
      setState(() {
        _isProcessing = false;
        _errorMessage = 'Error: $e';
      });
    }
  }

  void _showImageSourceDialog() {
    showDialog(
      context: context,
      builder: (context) {
        return AlertDialog(
          title: const Text('Select Image Source'),
          content: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              ListTile(
                leading: const Icon(Icons.photo_library),
                title: const Text('Gallery'),
                onTap: () {
                  Navigator.pop(context);
                  _pickImage(ImageSource.gallery);
                },
              ),
              ListTile(
                leading: const Icon(Icons.camera_alt),
                title: const Text('Camera'),
                onTap: () {
                  Navigator.pop(context);
                  _pickImage(ImageSource.camera);
                },
              ),
            ],
          ),
        );
      },
    );
  }

  @override
  void dispose() {
    _poseDetector.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Pose Detection Demo'),
        actions: [
          if (_isInitialized && _imageFile != null)
            IconButton(
              icon: const Icon(Icons.info_outline),
              onPressed: _showPoseInfo,
            ),
        ],
      ),
      body: _buildBody(),
      floatingActionButton: _isInitialized && !_isProcessing
          ? FloatingActionButton.extended(
              onPressed: _showImageSourceDialog,
              icon: const Icon(Icons.add_photo_alternate),
              label: const Text('Select Image'),
            )
          : null,
    );
  }

  Widget _buildBody() {
    if (!_isInitialized && _isProcessing) {
      return const Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            CircularProgressIndicator(),
            SizedBox(height: 16),
            Text('Initializing pose detector...'),
          ],
        ),
      );
    }

    if (_errorMessage != null && _imageFile == null) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Icon(Icons.error_outline, size: 64, color: Colors.red),
            const SizedBox(height: 16),
            Text(
              _errorMessage!,
              textAlign: TextAlign.center,
              style: const TextStyle(color: Colors.red),
            ),
            const SizedBox(height: 16),
            ElevatedButton(
              onPressed: _initializeDetectors,
              child: const Text('Retry'),
            ),
          ],
        ),
      );
    }

    if (_imageFile == null) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.person_outline, size: 100, color: Colors.grey[400]),
            const SizedBox(height: 24),
            Text('Select an image to detect pose',
                style: TextStyle(fontSize: 18, color: Colors.grey[600])),
            const SizedBox(height: 16),
            ElevatedButton.icon(
              onPressed: _showImageSourceDialog,
              icon: const Icon(Icons.add_photo_alternate),
              label: const Text('Select Image'),
            ),
          ],
        ),
      );
    }

    return SingleChildScrollView(
      child: Column(
        children: [
          PoseVisualizerWidget(
            imageFile: _imageFile!,
            results: _results,
          ),
          if (_isProcessing)
            const Padding(
              padding: EdgeInsets.all(16),
              child: Column(
                children: [
                  CircularProgressIndicator(),
                  SizedBox(height: 8),
                  Text('Detecting pose...'),
                ],
              ),
            ),
          if (_errorMessage != null && !_isProcessing)
            Padding(
              padding: const EdgeInsets.all(16),
              child: Card(
                color: Colors.red[50],
                child: Padding(
                  padding: const EdgeInsets.all(16),
                  child: Row(
                    children: [
                      const Icon(Icons.error_outline, color: Colors.red),
                      const SizedBox(width: 8),
                      Expanded(child: Text(_errorMessage!)),
                    ],
                  ),
                ),
              ),
            ),
          if (_results.isNotEmpty)
            Padding(
              padding: const EdgeInsets.all(16),
              child: Card(
                child: Padding(
                  padding: const EdgeInsets.all(16),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text('Detections: ${_results.length} ✓',
                          style: Theme.of(context)
                              .textTheme
                              .titleLarge
                              ?.copyWith(
                                  color: Colors.green,
                                  fontWeight: FontWeight.bold)),
                    ],
                  ),
                ),
              ),
            ),
        ],
      ),
    );
  }

  void _showPoseInfo() {
    if (_results.isEmpty) return;
    final Pose first = _results.first;

    showModalBottomSheet(
      context: context,
      builder: (context) => DraggableScrollableSheet(
        initialChildSize: 0.7,
        minChildSize: 0.5,
        maxChildSize: 0.95,
        expand: false,
        builder: (context, scrollController) => ListView(
          controller: scrollController,
          padding: const EdgeInsets.all(16),
          children: [
            Text('Landmark Details (first pose)',
                style: Theme.of(context).textTheme.headlineSmall),
            const SizedBox(height: 16),
            ..._buildLandmarkListFor(first),
          ],
        ),
      ),
    );
  }

  List<Widget> _buildLandmarkListFor(Pose result) {
    final List<PoseLandmark> lm = result.landmarks;
    return lm.map((landmark) {
      final Point pixel =
          landmark.toPixel(result.imageWidth, result.imageHeight);
      return Card(
        margin: const EdgeInsets.only(bottom: 8),
        child: ListTile(
          leading: CircleAvatar(
            backgroundColor:
                landmark.visibility > 0.5 ? Colors.green : Colors.orange,
            child: Text(landmark.type.index.toString(),
                style: const TextStyle(fontSize: 12)),
          ),
          title: Text(_landmarkName(landmark.type),
              style: const TextStyle(fontWeight: FontWeight.w500)),
          subtitle: Text(''
              'Position: (${pixel.x}, ${pixel.y})\n'
              'Visibility: ${(landmark.visibility * 100).toStringAsFixed(0)}%'),
          isThreeLine: true,
        ),
      );
    }).toList();
  }

  String _landmarkName(PoseLandmarkType type) {
    return type
        .toString()
        .split('.')
        .last
        .replaceAllMapped(
          RegExp(r'[A-Z]'),
          (match) => ' ${match.group(0)}',
        )
        .trim();
  }
}

class PoseVisualizerWidget extends StatelessWidget {
  final File imageFile;
  final List<Pose> results;

  const PoseVisualizerWidget(
      {super.key, required this.imageFile, required this.results});

  @override
  Widget build(BuildContext context) {
    return LayoutBuilder(builder: (context, constraints) {
      return Stack(
        children: [
          Image.file(imageFile, fit: BoxFit.contain),
          Positioned.fill(
              child:
                  CustomPaint(painter: MultiOverlayPainter(results: results))),
        ],
      );
    });
  }
}

class MultiOverlayPainter extends CustomPainter {
  final List<Pose> results;

  MultiOverlayPainter({required this.results});

  @override
  void paint(Canvas canvas, Size size) {
    if (results.isEmpty) return;

    final int iw = results.first.imageWidth;
    final int ih = results.first.imageHeight;

    final double imageAspect = iw / ih;
    final double canvasAspect = size.width / size.height;
    double scaleX, scaleY;
    double offsetX = 0, offsetY = 0;

    if (canvasAspect > imageAspect) {
      scaleY = size.height / ih;
      scaleX = scaleY;
      offsetX = (size.width - iw * scaleX) / 2;
    } else {
      scaleX = size.width / iw;
      scaleY = scaleX;
      offsetY = (size.height - ih * scaleY) / 2;
    }

    for (final r in results) {
      _drawBbox(canvas, r, scaleX, scaleY, offsetX, offsetY);
      if (r.hasLandmarks) {
        _drawConnections(canvas, r, scaleX, scaleY, offsetX, offsetY);
        _drawLandmarks(canvas, r, scaleX, scaleY, offsetX, offsetY);
      }
    }
  }

  void _drawConnections(Canvas canvas, Pose result, double scaleX,
      double scaleY, double offsetX, double offsetY) {
    final Paint paint = Paint()
      ..color = Colors.green.withValues(alpha: 0.8)
      ..strokeWidth = 3
      ..strokeCap = StrokeCap.round;

    // Use the predefined skeleton connections from the package
    for (final List<PoseLandmarkType> c in poseLandmarkConnections) {
      final PoseLandmark? start = result.getLandmark(c[0]);
      final PoseLandmark? end = result.getLandmark(c[1]);
      if (start != null &&
          end != null &&
          start.visibility > 0.5 &&
          end.visibility > 0.5) {
        canvas.drawLine(
          Offset(start.x * scaleX + offsetX, start.y * scaleY + offsetY),
          Offset(end.x * scaleX + offsetX, end.y * scaleY + offsetY),
          paint,
        );
      }
    }
  }

  void _drawLandmarks(Canvas canvas, Pose result, double scaleX, double scaleY,
      double offsetX, double offsetY) {
    for (final PoseLandmark l in result.landmarks) {
      if (l.visibility > 0.5) {
        final Offset center =
            Offset(l.x * scaleX + offsetX, l.y * scaleY + offsetY);
        final Paint glow = Paint()..color = Colors.blue.withValues(alpha: 0.3);
        final Paint point = Paint()..color = Colors.red;
        final Paint centerDot = Paint()..color = Colors.white;
        canvas.drawCircle(center, 8, glow);
        canvas.drawCircle(center, 5, point);
        canvas.drawCircle(center, 2, centerDot);
      }
    }
  }

  void _drawBbox(Canvas canvas, Pose r, double scaleX, double scaleY,
      double offsetX, double offsetY) {
    final Paint boxPaint = Paint()
      ..color = Colors.orangeAccent.withValues(alpha: 0.9)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 3;

    final Paint fillPaint = Paint()
      ..color = Colors.orangeAccent.withValues(alpha: 0.08)
      ..style = PaintingStyle.fill;

    final double x1 = r.boundingBox.left * scaleX + offsetX;
    final double y1 = r.boundingBox.top * scaleY + offsetY;
    final double x2 = r.boundingBox.right * scaleX + offsetX;
    final double y2 = r.boundingBox.bottom * scaleY + offsetY;
    final Rect rect = Rect.fromLTRB(x1, y1, x2, y2);
    canvas.drawRect(rect, fillPaint);
    canvas.drawRect(rect, boxPaint);
  }

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

class CameraScreen extends StatefulWidget {
  const CameraScreen({super.key});

  @override
  State<CameraScreen> createState() => _CameraScreenState();
}

class _CameraScreenState extends State<CameraScreen> {
  CameraMacOSController? _cameraController;
  final PoseDetector _poseDetector = PoseDetector(
    mode: PoseMode.boxesAndLandmarks,
    landmarkModel:
        PoseLandmarkModel.lite, // Use lite for better real-time performance
    detectorConf: 0.7,
    detectorIou: 0.4,
    maxDetections: 5,
    minLandmarkScore: 0.5,
    performanceConfig: const PerformanceConfig
        .xnnpack(), // Enable XNNPACK for real-time performance
  );

  bool _isInitialized = false;
  bool _isProcessing = false;
  bool _isDisposed = false;
  String? _errorMessage;
  Size? _cameraSize;

  // Performance: Use ValueNotifier for efficient pose overlay updates
  // This avoids full widget rebuilds - only the CustomPaint repaints
  final ValueNotifier<List<Pose>> _poseNotifier = ValueNotifier<List<Pose>>([]);

  // Performance: Dynamic frame throttling based on processing time
  int _lastProcessedTime = 0;
  static const int _minProcessingIntervalMs = 50; // Max ~20 detection FPS

  // Performance metrics (debug)
  int _detectionCount = 0;
  double _avgProcessingTimeMs = 0;

  @override
  void initState() {
    super.initState();
    _initializePoseDetector();
  }

  Future<void> _initializePoseDetector() async {
    try {
      if (_isDisposed) return;

      await _poseDetector.initialize();

      if (_isDisposed) return;

      setState(() {
        _isInitialized = true;
      });
    } catch (e) {
      if (!_isDisposed && mounted) {
        setState(() {
          _errorMessage = 'Failed to initialize pose detector: $e';
        });
      }
    }
  }

  void _onCameraInitialized(CameraMacOSController controller) {
    if (_isDisposed) {
      controller.destroy();
      return;
    }

    setState(() {
      _cameraController = controller;
    });

    controller.startImageStream((CameraImageData? imageData) {
      if (imageData != null && !_isDisposed) {
        _processCameraImage(imageData);
      }
    });
  }

  /// Converts ARGB camera bytes directly to BGR cv.Mat without PNG encoding.
  ///
  /// This is 10-50x faster than the PNG encode/decode path because:
  /// - No PNG compression (saves 100-200ms per frame)
  /// - No PNG decompression (saves 50-100ms per frame)
  /// - Single buffer copy instead of 3-4 copies
  cv.Mat _convertARGBtoBGRMat(CameraImageData imageData) {
    final int w = imageData.width;
    final int h = imageData.height;
    final Uint8List argb = imageData.bytes;

    // Pre-allocate BGR buffer (3 bytes per pixel instead of 4)
    final Uint8List bgr = Uint8List(w * h * 3);

    // ARGB to BGR conversion in a single pass
    // ARGB layout: [A, R, G, B, A, R, G, B, ...]
    // BGR layout:  [B, G, R, B, G, R, ...]
    int srcIdx = 0;
    int dstIdx = 0;
    final int pixelCount = w * h;
    for (int i = 0; i < pixelCount; i++) {
      // Skip Alpha (srcIdx + 0), read RGB
      bgr[dstIdx] = argb[srcIdx + 3]; // B
      bgr[dstIdx + 1] = argb[srcIdx + 2]; // G
      bgr[dstIdx + 2] = argb[srcIdx + 1]; // R
      srcIdx += 4;
      dstIdx += 3;
    }

    return cv.Mat.fromList(h, w, cv.MatType.CV_8UC3, bgr);
  }

  Future<void> _processCameraImage(CameraImageData imageData) async {
    if (_isDisposed || !_isInitialized || _isProcessing) return;

    // Dynamic throttling: Skip if not enough time has passed
    final int now = DateTime.now().millisecondsSinceEpoch;
    if (now - _lastProcessedTime < _minProcessingIntervalMs) {
      return;
    }

    _isProcessing = true;
    final int startTime = now;

    try {
      // Set camera size once (for overlay coordinate mapping)
      if (_cameraSize == null && mounted && !_isDisposed) {
        setState(() {
          _cameraSize =
              Size(imageData.width.toDouble(), imageData.height.toDouble());
        });
      }

      // PERFORMANCE FIX: Convert ARGB directly to BGR Mat
      // This bypasses PNG encoding entirely (saves 150-300ms per frame)
      final cv.Mat mat = _convertARGBtoBGRMat(imageData);

      if (_isDisposed) {
        mat.dispose();
        return;
      }

      // Use the new detectOnMat method - no image decoding needed
      final List<Pose> poses = await _poseDetector.detectOnMat(
        mat,
        imageWidth: imageData.width,
        imageHeight: imageData.height,
      );

      // Clean up native Mat resource
      mat.dispose();

      // PERFORMANCE FIX: Update via ValueNotifier instead of setState
      // This only repaints the CustomPaint, not the entire widget tree
      if (!_isDisposed) {
        _poseNotifier.value = poses;
      }

      // Update performance metrics
      _lastProcessedTime = DateTime.now().millisecondsSinceEpoch;
      final int processingTime = _lastProcessedTime - startTime;
      _detectionCount++;
      _avgProcessingTimeMs =
          (_avgProcessingTimeMs * (_detectionCount - 1) + processingTime) /
              _detectionCount;
    } catch (e) {
      // Silently ignore errors to maintain camera feed
    } finally {
      _isProcessing = false;
    }
  }

  @override
  void dispose() {
    _isDisposed = true;
    _poseNotifier.dispose();

    if (_cameraController != null) {
      try {
        _cameraController!.stopImageStream();
      } catch (_) {}
      _cameraController!.destroy();
    }

    _poseDetector.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Live Pose Detection'),
        actions: [
          if (_isInitialized && _cameraController != null)
            Padding(
              padding: const EdgeInsets.all(8.0),
              child: Center(
                // Use ValueListenableBuilder for pose count too
                child: ValueListenableBuilder<List<Pose>>(
                  valueListenable: _poseNotifier,
                  builder: (context, poses, _) => Text(
                    '${poses.length} pose(s)',
                    style: const TextStyle(fontSize: 16),
                  ),
                ),
              ),
            ),
        ],
      ),
      body: _buildBody(),
    );
  }

  Widget _buildBody() {
    if (_errorMessage != null && !_isInitialized) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Icon(Icons.error_outline, size: 64, color: Colors.red),
            const SizedBox(height: 16),
            Text(
              _errorMessage!,
              textAlign: TextAlign.center,
              style: const TextStyle(color: Colors.red),
            ),
            const SizedBox(height: 16),
            ElevatedButton(
              onPressed: () {
                setState(() {
                  _errorMessage = null;
                });
                _initializePoseDetector();
              },
              child: const Text('Retry'),
            ),
          ],
        ),
      );
    }

    if (!_isInitialized) {
      return const Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            CircularProgressIndicator(),
            SizedBox(height: 16),
            Text('Initializing pose detector...'),
          ],
        ),
      );
    }

    return Stack(
      fit: StackFit.expand,
      children: [
        // Camera preview and overlay wrapped in matching AspectRatio widgets
        // This ensures the overlay coordinates match exactly where the camera renders
        if (_cameraSize != null)
          Center(
            child: AspectRatio(
              aspectRatio: _cameraSize!.width / _cameraSize!.height,
              child: Stack(
                fit: StackFit.expand,
                children: [
                  // Camera preview
                  CameraMacOSView(
                    onCameraInizialized: _onCameraInitialized,
                    cameraMode: CameraMacOSMode.photo,
                    enableAudio: false,
                  ),
                  // Pose overlay - now guaranteed to match camera preview bounds
                  ValueListenableBuilder<List<Pose>>(
                    valueListenable: _poseNotifier,
                    builder: (context, poses, _) {
                      if (poses.isEmpty) return const SizedBox.shrink();
                      return CustomPaint(
                        painter: CameraPoseOverlayPainter(
                          poses: poses,
                          cameraSize: _cameraSize!,
                        ),
                      );
                    },
                  ),
                ],
              ),
            ),
          )
        else
          // Show camera without overlay until we know the size
          CameraMacOSView(
            onCameraInizialized: _onCameraInitialized,
            cameraMode: CameraMacOSMode.photo,
            enableAudio: false,
          ),

        // Status indicator with performance metrics
        Positioned(
          bottom: 16,
          left: 0,
          right: 0,
          child: Center(
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
              decoration: BoxDecoration(
                color: Colors.black54,
                borderRadius: BorderRadius.circular(20),
              ),
              child: Text(
                _isProcessing
                    ? 'Processing...'
                    : 'Ready (${_avgProcessingTimeMs.toStringAsFixed(0)}ms avg)',
                style: const TextStyle(color: Colors.white),
              ),
            ),
          ),
        ),
      ],
    );
  }
}

class CameraPoseOverlayPainter extends CustomPainter {
  final List<Pose> poses;
  final Size cameraSize;

  CameraPoseOverlayPainter({
    required this.poses,
    required this.cameraSize,
  });

  @override
  void paint(Canvas canvas, Size size) {
    if (poses.isEmpty) return;

    // Get image dimensions from first pose
    final int imageWidth = poses.first.imageWidth;
    final int imageHeight = poses.first.imageHeight;

    // Direct scaling: overlay is now wrapped in AspectRatio matching camera preview,
    // so canvas size has the same aspect ratio as the image. No letterbox offsets needed.
    final double scaleX = size.width / imageWidth;
    final double scaleY = size.height / imageHeight;

    for (final pose in poses) {
      _drawBbox(canvas, pose, scaleX, scaleY, 0, 0);
      if (pose.hasLandmarks) {
        _drawConnections(canvas, pose, scaleX, scaleY, 0, 0);
        _drawLandmarks(canvas, pose, scaleX, scaleY, 0, 0);
      }
    }
  }

  void _drawConnections(Canvas canvas, Pose pose, double scaleX, double scaleY,
      double offsetX, double offsetY) {
    final Paint paint = Paint()
      ..color = Colors.green.withValues(alpha: 0.8)
      ..strokeWidth = 3
      ..strokeCap = StrokeCap.round;

    // Use the predefined skeleton connections from the package
    for (final List<PoseLandmarkType> c in poseLandmarkConnections) {
      final PoseLandmark? start = pose.getLandmark(c[0]);
      final PoseLandmark? end = pose.getLandmark(c[1]);
      if (start != null &&
          end != null &&
          start.visibility > 0.5 &&
          end.visibility > 0.5) {
        canvas.drawLine(
          Offset(start.x * scaleX + offsetX, start.y * scaleY + offsetY),
          Offset(end.x * scaleX + offsetX, end.y * scaleY + offsetY),
          paint,
        );
      }
    }
  }

  void _drawLandmarks(Canvas canvas, Pose pose, double scaleX, double scaleY,
      double offsetX, double offsetY) {
    for (final PoseLandmark l in pose.landmarks) {
      if (l.visibility > 0.5) {
        final Offset center =
            Offset(l.x * scaleX + offsetX, l.y * scaleY + offsetY);
        final Paint glow = Paint()..color = Colors.blue.withValues(alpha: 0.3);
        final Paint point = Paint()..color = Colors.red;
        final Paint centerDot = Paint()..color = Colors.white;
        canvas.drawCircle(center, 8, glow);
        canvas.drawCircle(center, 5, point);
        canvas.drawCircle(center, 2, centerDot);
      }
    }
  }

  void _drawBbox(Canvas canvas, Pose pose, double scaleX, double scaleY,
      double offsetX, double offsetY) {
    final Paint boxPaint = Paint()
      ..color = Colors.orangeAccent.withValues(alpha: 0.9)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 3;

    final Paint fillPaint = Paint()
      ..color = Colors.orangeAccent.withValues(alpha: 0.08)
      ..style = PaintingStyle.fill;

    final double x1 = pose.boundingBox.left * scaleX + offsetX;
    final double y1 = pose.boundingBox.top * scaleY + offsetY;
    final double x2 = pose.boundingBox.right * scaleX + offsetX;
    final double y2 = pose.boundingBox.bottom * scaleY + offsetY;
    final Rect rect = Rect.fromLTRB(x1, y1, x2, y2);
    canvas.drawRect(rect, fillPaint);
    canvas.drawRect(rect, boxPaint);
  }

  @override
  bool shouldRepaint(CameraPoseOverlayPainter oldDelegate) {
    // Only repaint if poses actually changed
    if (poses.length != oldDelegate.poses.length) return true;
    if (poses.isEmpty) return false;

    // Quick check: compare first pose bounding box
    final Pose current = poses.first;
    final Pose old = oldDelegate.poses.first;
    return current.boundingBox.left != old.boundingBox.left ||
        current.boundingBox.top != old.boundingBox.top ||
        current.boundingBox.right != old.boundingBox.right ||
        current.boundingBox.bottom != old.boundingBox.bottom;
  }
}