public static T Enum <T>(this ZergRandom random)
{
// f**k c#
var vals = System.Enum.GetValues(typeof(T));
return((T)vals.GetValue(random.Range(0, vals.Length)));
}
public static int Range(this ZergRandom rand, int min, int max)
{
if (max <= min)
{
return(min);
}
return(min + rand.Next() % (max - min));
}
public static T RandomElement <T>(this ICollection <T> list, ZergRandom random)
{
if (list.Count < 1)
{
return(default(T));
}
return(list.ElementAt(random.Next(0, list.Count)));
}
public static List <T> RandomOrder <T>(this IReadOnlyList <T> list, ZergRandom random)
{
var indexes = RandomNonoverlappedIndices(list.Count, list.Count, random);
var result = new List <T>(list.Count);
for (int i = 0; i < list.Count; i++)
{
result.Add(default(T));
}
for (var i = 0; i < indexes.Length; i++)
{
var index = indexes[i];
result[i] = list[index];
}
return(result);
}
// max is exclusive index max, count is number of random indexes returned
public static int[] RandomNonoverlappedIndices(int max, int count, ZergRandom random)
{
if (max < count)
{
int[] r = new int[max];
for (int i = 0; i < max; i++)
{
r[i] = i;
}
return(r);
}
int[] result = new int[count];
var range = Enumerable.Range(0, max).ToList();
for (int i = 0; i < count; ++i)
{
int randIndex = random.Next(0, max - i);
int rand = range[randIndex];
result[i] = rand;
range[randIndex] = range[max - i - 1];
}
return(result);
}
public static bool ChancePercent(this ZergRandom rand, int percent)
{
return(rand.NextDouble() * 100 < percent);
}
public static T RandomElement <T>(this IEnumerable <T> list, ZergRandom random)
{
return(list.ToList().RandomElement(random));
}
public static List <T> Shuffle <T>(this IReadOnlyList <T> list, ZergRandom random) => list.RandomOrder(random);
public static IEnumerable <T> RandomElements <T>(this List <T> list, ZergRandom random, int count)
{
return(RandomNonoverlappedIndices(list.Count, count, random).Select(i => list[i]));
}
public static float Range(this ZergRandom rand, float min, float max)
{
return((float)rand.NextDouble() * (max - min) + min);
}
public static bool Chance(this ZergRandom rand, float chance)
{
return(rand.NextDouble() * 100 < chance);
}
