fis_lib_business_components/lib/components/white_board/utils.dart

import 'dart:convert';
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:crypto/crypto.dart';

class ColorUtil {
  static Color generateColor(String uuid) {
    final hash = sha256.convert(utf8.encode(uuid)).toString();
    final intHash = int.parse(hash.substring(hash.length - 10), radix: 16);
    final Random random = Random(intHash);
    final double r = random.nextInt(256).toDouble();
    final double g = random.nextInt(256).toDouble();
    final double b = random.nextInt(256).toDouble();

    List<double> hsl = rgbToHsl(r, g, b);
    List<int> rgb = hslToRgb(hsl[0], hsl[1], hsl[2]);
    return Color.fromRGBO(
      rgb[0],
      rgb[1],
      rgb[2],
      1,
    );
  }

  static List<double> rgbToHsl(double r, double g, double b) {
    r /= 255;
    g /= 255;
    b /= 255;

    double max1 = max(max(r, g), b);
    double min1 = min(min(r, g), b);
    double h = 0;

    if (max1 == min1) {
      h = 0; // achromatic
    } else {
      double d = max1 - min1;
      if (max1 == r) {
        h = (g - b) / d + (g < b ? 6 : 0);
      } else if (max1 == g) {
        h = (b - r) / d + 2;
      } else if (max1 == b) {
        h = (r - g) / d + 4;
      }
      h /= 6;
    }

    return [h, 0.8, 0.5];
  }

  static List<int> hslToRgb(double h, double s, double l) {
    double r, g, b;

    if (s == 0) {
      r = g = b = l; // achromatic
    } else {
      double q = l < 0.5 ? l * (1 + s) : l + s - l * s;
      double p = 2 * l - q;
      r = hue2rgb(p, q, h + 1 / 3);
      g = hue2rgb(p, q, h);
      b = hue2rgb(p, q, h - 1 / 3);
    }

    return [r * 255, g * 255, b * 255].map((value) => value.round()).toList();
  }

  static double hue2rgb(double p, double q, double t) {
    if (t < 0) t += 1;
    if (t > 1) t -= 1;
    if (t < 1 / 6) return p + (q - p) * 6 * t;
    if (t < 1 / 2) return q;
    if (t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
    return p;
  }
}

class PointsUtil {
  static String compressPointsList(List<List<double>> points) {
    // print(points);
    String result = '';
    for (List<double> point in points) {
      result +=
          point[0].toStringAsFixed(4).replaceAll('0.', '').padRight(4, '0') +
              point[1].toStringAsFixed(4).replaceAll('0.', '').padRight(4, '0');
    }
    return result;
  }

  static List<List<double>> decompressPointsList(String compressed) {
    List<List<double>> result = [];
    for (int i = 0; i < compressed.length; i += 8) {
      String xString = compressed.substring(i, i + 4);
      String yString = compressed.substring(i + 4, i + 8);
      double x = double.parse(xString) / 10000;
      double y = double.parse(yString) / 10000;
      result.add([x, y]);
    }
    print(result);
    return result;
  }
}