/// <summary>
/// Gets a random <see cref="System.Double"/> number within a specific range.
/// </summary>
/// <param name="rnd">A <see cref="System.Random"/> instance.</param>
/// <param name="minValue">The inclusive lower bound of the random number returned.</param>
/// <param name="maxValue">The inclusive upper bound of the random number returned.</param>
/// <returns>A random <see cref="System.Double"/> number.</returns>
/// <exception cref="System.ArgumentOutOfRangeException">Occurs when <paramref name="min"/> is greater than <paramref name="max"/>.</exception>
public static double NextDouble(this Random rnd, double minValue, double maxValue)
{
ExceptionHelper.MinMaxArgumentCheck(minValue, maxValue);
if (minValue == maxValue)
{
return(minValue);
}
else
{
return(rnd.NextDouble() * (maxValue - minValue) + minValue);
}
}
/// <summary>
/// Gets a random 64-bit integer within a specific range.
/// </summary>
/// <param name="rnd">A <see cref="System.Random" /> instance.</param>
/// <param name="minValue">The inclusive lower bound of the random number returned.</param>
/// <param name="maxValue">The exclusive upper bound of the random number returned.
/// <paramref name="maxValue" /> must be greater than or equal to <paramref name="minValue" />.
/// <para>Whether this bound is inclusive is determined by the third argument <paramref name="maxValueInclusive" />.</para></param>
/// <returns>
/// A random 64-bit integer.
/// </returns>
/// <exception cref="System.ArgumentOutOfRangeException">Occurs when <paramref name="minValue" /> is greater than <paramref name="maxValue" />.</exception>
public unsafe static long Next(this Random rnd, long minValue, long maxValue)
{
ExceptionHelper.MinMaxArgumentCheck(minValue, maxValue);
if (minValue == maxValue)
{
return(minValue);
}
else
{
var buffer = new byte[8];
rnd.NextBytes(buffer);
fixed(byte *bufferPtr = buffer)
{
var randomValue = *((ulong *)bufferPtr);
return((long)(randomValue % (ulong)(maxValue - minValue)) + minValue);
}
}
}
/// <summary>
/// Gets a random integer within a specific range.
/// </summary>
/// <param name="rnd">A <see cref="System.Random" /> instance.</param>
/// <param name="minValue">The inclusive lower bound of the random number returned.</param>
/// <param name="maxValue">The upper bound of the random number returned.
/// <paramref name="maxValue" /> must be greater than or equal to <paramref name="minValue" />.
/// <para>Whether this bound is inclusive is determined by the third argument <paramref name="maxValueInclusive" />.</para></param>
/// <param name="maxValueInclusive">Specifies whether <paramref name="maxValue" /> can be returned.</param>
/// <returns>
/// A random integer.
/// </returns>
/// <exception cref="System.ArgumentOutOfRangeException">Occurs when <paramref name="minValue"/> is greater than <paramref name="maxValue"/>.</exception>
public unsafe static int Next(this Random rnd, int minValue, int maxValue, bool maxValueInclusive)
{
ExceptionHelper.MinMaxArgumentCheck(minValue, maxValue);
if (minValue == maxValue)
{
return(minValue);
}
else
{
var buffer = new byte[4];
rnd.NextBytes(buffer);
fixed(byte *bufferPtr = buffer)
{
var randomValue = *((uint *)bufferPtr);
return((int)(randomValue % (uint)(maxValue - minValue + (maxValueInclusive ? 1 : 0))) + minValue);
}
}
}
