obfuz/Editor/Utils/RandomWithKey.cs

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// Copyright 2025 Code Philosophy
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
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namespace Obfuz.Utils
{
public class RandomWithKey : IRandom
{
private const long a = 1664525;
private const long c = 1013904223;
private const long m = 4294967296; // 2^32
private readonly int[] _key;
private int _nextIndex;
private int _seed;
public RandomWithKey(int[] key, int seed)
{
_key = key;
_seed = seed;
}
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public int[] Key => _key;
public int NextInt(int min, int max)
{
return min + NextInt(max - min);
}
public int NextInt(int max)
{
return (int)((uint)NextInt() % (uint)max);
}
private int GetNextSalt()
{
if (_nextIndex >= _key.Length)
{
_nextIndex = 0;
}
return _key[_nextIndex++];
}
public int NextInt()
{
_seed = (int)((a * _seed + c) % m);
return _seed ^ GetNextSalt();
}
public long NextLong()
{
return ((long)NextInt() << 32) | (uint)NextInt();
}
public float NextFloat()
{
return (float)((double)(uint)NextInt() / uint.MaxValue);
}
public bool NextInPercentage(float percentage)
{
return NextFloat() < percentage;
}
}
}