idle-survivors/Assets/Scripts/Attribute.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Attribute : ScriptableObject
{
    public long Base { get; set; }
    public long BaseBonus { get; set; }
    public long PermyriadBonus { get; set; }
    public long FlatBonus { get; set; }

    public long Value => Calc(Base, BaseBonus, PermyriadBonus, FlatBonus);

    /// <summary>
    /// Calculates the stat value with accumulated buff and debuff modifiers.
    /// </summary>
    /// <param name="baseValue">Base value.</param>
    /// <param name="baseBonus">Additive bonus applied before multiplicative scaling.</param>
    /// <param name="permyriadBonus">Multiplicative scaling in hundredths of a percent. E.g., 625 permyriad corresponds to 6.25%.</param>
    /// <param name="flatBonus">Additive bonus applied after multiplicative scaling.</param>
    /// <returns>(base + baseBonus) * (100% + permyriadBonus) + flatBonus, bounded below by 0.</returns>
    public static long Calc(long baseValue, long baseBonus, long permyriadBonus, long flatBonus)
    {
        var r = baseValue + baseBonus;
        var m = permyriadBonus + 10000;
        r = r * (m / 10000) + (r / 10000) * (m % 10000) + flatBonus;
        if (r <= 0)
        {
            return 0;
        }
        return r;
    }
}