VitalApp/lib/pages/facial_recognition/widgets/face_bounding_box.dart

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:google_mlkit_face_detection/google_mlkit_face_detection.dart';
import '../index.dart';

class FaceBoundingBox extends GetView<FacialRecognitionController> {
  const FaceBoundingBox({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Obx(() {
      if (!controller.state.isShowFaceRecognitionResult) {
        return Container();
      }
      return Container(
        padding: const EdgeInsets.all(10),
        child: GetBuilder<FacialRecognitionController>(
            id: 'face_bounding_box',
            builder: (context) {
              return CustomPaint(
                size: Size.infinite,
                painter: _FaceBoundingBoxPainter(
                  faces: controller.kFrameFacesResult,
                  sourceImageSize: controller.kFrameImageSize,
                  isMirror: true,
                ),
              );
            }),
      );
    });
  }
}

class _FaceBoundingBoxPainter extends CustomPainter {
  final List<Face> faces;

  /// 是否镜像
  final bool isMirror;

  /// 原始图片大小
  final Size sourceImageSize;

  _FaceBoundingBoxPainter(
      {required this.faces,
      required this.isMirror,
      required this.sourceImageSize});

  @override
  void paint(Canvas canvas, Size size) {
    // 根据原始图片大小和当前画布大小，计算缩放比例
    final scaleX = size.width / sourceImageSize.width;
    final scaleY = size.height / sourceImageSize.height;
    if (isMirror) {
      canvas.scale(-scaleX, scaleY);
      canvas.translate(-sourceImageSize.width, 0);
    } else {
      canvas.scale(scaleX, scaleY);
      canvas.translate(0, 0);
    }

    for (final face in faces) {
      /// 绘制关键点
      // for (final FaceContour? contour in face.contours.values) {
      //   if (contour == null) continue;
      //   if (contour.points.isEmpty) continue;
      //   if (contour.type == FaceContourType.face) {
      //     // _drawContourPointsPath(canvas, size, contour.points);
      //   } else {
      //     // _drawContourPoints(canvas, size, contour.points);
      //   }
      // }

      /// 绘制人脸框
      _drawFaceRect(canvas, size, face.boundingBox);
    }

    /// 全屏画绿色
    // final paint2 = Paint()
    //   ..color = const Color.fromARGB(255, 36, 255, 36)
    //   ..strokeWidth = 5
    //   ..style = PaintingStyle.stroke;

    // canvas.drawRect(
    //   Rect.fromLTWH(0, 0, sourceImageSize.width, sourceImageSize.height),
    //   paint2,
    // );
  }

  /// 绘制contour连线
  void _drawContourPointsPath(
      Canvas canvas, Size size, List<Point<int>> points) {
    final paint = Paint()
      ..color = Colors.green
      ..strokeWidth = 4
      ..style = PaintingStyle.stroke;

    final path = Path();
    for (int i = 0; i < points.length; i++) {
      final point = points[i];
      if (i == 0) {
        path.moveTo(
          point.x.toDouble(),
          point.y.toDouble(),
        );
        continue;
      }
      path.lineTo(
        point.x.toDouble(),
        point.y.toDouble(),
      );
    }
    path.close();
    canvas.drawPath(path, paint);
  }

  /// 绘制contour点集
  void _drawContourPoints(Canvas canvas, Size size, List<Point<int>> points) {
    final paint = Paint()
      ..color = Colors.red
      ..strokeWidth = 2
      ..style = PaintingStyle.fill;

    for (final point in points) {
      canvas.drawCircle(
        Offset(
          point.x.toDouble(),
          point.y.toDouble(),
        ),
        2,
        paint,
      );
    }
  }

  /// 绘制人脸框
  void _drawFaceRect(Canvas canvas, Size size, Rect rect) {
    final paint = Paint()
      ..color = Colors.green
      ..strokeWidth = 3
      ..style = PaintingStyle.stroke;

    canvas.drawRect(rect, paint);
  }

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