NoiseEngine/CubicNoise/Extensions.cs

using System;
using System.Collections.Generic;
using System.Text;
using CubicNoise.Noisers;

namespace CubicNoise
{
    public static class Extensions
    {
        // Source: https://andrewlock.net/why-is-string-gethashcode-different-each-time-i-run-my-program-in-net-core/
        public static int GetDeterministicHashCode(this string str)
        {
            unchecked
            {
                var hash1 = (5381 << 16) + 5381;
                var hash2 = hash1;

                for (var i = 0; i < str.Length; i += 2)
                {
                    hash1 = ((hash1 << 5) + hash1) ^ str[i];
                    if (i == str.Length - 1)
                        break;

                    hash2 = ((hash2 << 5) + hash2) ^ str[i + 1];
                }

                return hash1 + (hash2 * 1566083941);
            }
        }
    }
}