50 lines
1.5 KiB
C#
50 lines
1.5 KiB
C#
using System.Runtime.CompilerServices;
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namespace LibAtrac9.Utilities
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{
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internal static class Helpers
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{
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static short Clamp16(int value)
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{
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if (value > short.MaxValue)
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return short.MaxValue;
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if (value < short.MinValue)
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return short.MinValue;
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return (short)value;
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}
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public static int GetNextMultiple(int value, int multiple)
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{
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if (multiple <= 0)
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return value;
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if (value % multiple == 0)
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return value;
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return value + multiple - value % multiple;
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}
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/// <summary>
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/// Returns the floor of the base 2 logarithm of a specified number.
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/// </summary>
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/// <param name="value">The number whose logarithm is to be found.</param>
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/// <returns>The floor of the base 2 logarithm of <paramref name="value"/>.</returns>
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public static int Log2(int value)
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{
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value |= value >> 1;
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value |= value >> 2;
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value |= value >> 4;
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value |= value >> 8;
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value |= value >> 16;
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return MultiplyDeBruijnBitPosition[(uint)(value * 0x07C4ACDDU) >> 27];
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}
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private static readonly int[] MultiplyDeBruijnBitPosition =
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{
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0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30,
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8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31
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};
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}
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}
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