/
ProportionalValue.cs
45 lines (40 loc) · 1.09 KB
/
ProportionalValue.cs
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using UnityEngine;
using System;
using System.Collections;
using System.Collections.Generic;
public class ProportionValue<T>
{
public double Proportion { get; set; }
public T Value { get; set; }
}
public static class ProportionValue
{
public static ProportionValue<T> Create<T>(double proportion, T value)
{
return new ProportionValue<T> { Proportion = proportion, Value = value };
}
public static T ChooseByRandom<T>(this IEnumerable<ProportionValue<T>> collection)
{
double rnd = UnityEngine.Random.Range(0.0f, 0.99f);
foreach (var item in collection)
{
if (rnd < item.Proportion)
return item.Value;
rnd -= item.Proportion;
}
throw new InvalidOperationException(
"The proportions in the collection do not add up to 1.");
}
}
/* -----
* Usage
* -----
var list = new[] {
ProportionValue.Create(0.7, "a"),
ProportionValue.Create(0.2, "b"),
ProportionValue.Create(0.1, "c")
};
// Outputs "a" with probability 0.7, etc.
Console.WriteLine(list.ChooseByRandom());
*
*/