fis_lib_measure/lib/view/vid_painter/vid_painter.dart

import 'package:flutter/material.dart';
import 'dart:ui' as ui;

class VidPainter extends CustomPainter {
  VidPainter(
      {required this.image,
      required this.frameIndex,
      this.colorFilterMatrix = const <double>[
        1, 0, 0, 0, 0, // red
        0, 1, 0, 0, 0, // green
        0, 0, 1, 0, 0, // blue
        0, 0, 0, 1, 0, // alpha
      ]});
  ui.Image image;
  int frameIndex;
  List<double> colorFilterMatrix;

  @override
  void paint(Canvas canvas, Size size) async {
    canvas.save();
    final double scaleX = size.width / image.width;
    final double scaleY = size.height / image.height;
    final double scale = scaleX < scaleY ? scaleX : scaleY;
    final double offsetX = (size.width - image.width * scale) / 2;
    final double offsetY = (size.height - image.height * scale) / 2;
    canvas.drawImageRect(
        image,
        Rect.fromLTWH(0, 0, image.width.toDouble(), image.height.toDouble()),
        Rect.fromLTWH(
            offsetX, offsetY, image.width * scale, image.height * scale),
        Paint()
          ..colorFilter = ColorFilter.matrix(colorFilterMatrix)
          ..filterQuality = FilterQuality.high);
    canvas.restore();
  }

  @override
  bool shouldRepaint(covariant VidPainter oldDelegate) {
    return oldDelegate.frameIndex != frameIndex ||
        oldDelegate.colorFilterMatrix != colorFilterMatrix;
  }
}