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Diffstat (limited to 'Ryujinx.Audio/Renderer/Utils/BitArray.cs')
-rw-r--r-- | Ryujinx.Audio/Renderer/Utils/BitArray.cs | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/Ryujinx.Audio/Renderer/Utils/BitArray.cs b/Ryujinx.Audio/Renderer/Utils/BitArray.cs new file mode 100644 index 00000000..6109dd01 --- /dev/null +++ b/Ryujinx.Audio/Renderer/Utils/BitArray.cs @@ -0,0 +1,120 @@ +// +// Copyright (c) 2019-2021 Ryujinx +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with this program. If not, see <https://www.gnu.org/licenses/>. +// + +using System; +using System.Runtime.CompilerServices; + +namespace Ryujinx.Audio.Renderer.Utils +{ + /// <summary> + /// A simple bit array implementation backed by a <see cref="Memory{T}"/>. + /// </summary> + public class BitArray + { + /// <summary> + /// The backing storage of the <see cref="BitArray"/>. + /// </summary> + private Memory<byte> _storage; + + /// <summary> + /// Create a new <see cref="BitArray"/> from <see cref="Memory{T}"/>. + /// </summary> + /// <param name="storage">The backing storage of the <see cref="BitArray"/>.</param> + public BitArray(Memory<byte> storage) + { + _storage = storage; + } + + /// <summary> + /// Get the byte position of a given bit index. + /// </summary> + /// <param name="index">A bit index.</param> + /// <returns>The byte position of a given bit index.</returns> + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private static int ToPosition(int index) => index / 8; + + /// <summary> + /// Get the bit position of a given bit index inside a byte. + /// </summary> + /// <param name="index">A bit index.</param> + /// <returns>The bit position of a given bit index inside a byte.</returns> + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private static int ToBitPosition(int index) => index % 8; + + /// <summary> + /// Test if the bit at the given index is set. + /// </summary> + /// <param name="index">A bit index.</param> + /// <returns>Return true if the bit at the given index is set</returns> + [MethodImpl(MethodImplOptions.AggressiveInlining)] + public bool Test(int index) + { + ulong mask = 1ul << ToBitPosition(index); + + return (_storage.Span[ToPosition(index)] & mask) == mask; + } + + /// <summary> + /// Set the bit at the given index. + /// </summary> + /// <param name="index">A bit index.</param> + [MethodImpl(MethodImplOptions.AggressiveInlining)] + public void Set(int index) + { + Set(index, true); + } + + /// <summary> + /// Reset the bit at the given index. + /// </summary> + /// <param name="index">A bit index.</param> + [MethodImpl(MethodImplOptions.AggressiveInlining)] + public void Reset(int index) + { + Set(index, false); + } + + /// <summary> + /// Set a bit value at the given index. + /// </summary> + /// <param name="index">A bit index.</param> + /// <param name="value">The new bit value.</param> + [MethodImpl(MethodImplOptions.AggressiveInlining)] + private void Set(int index, bool value) + { + byte mask = (byte)(1 << ToBitPosition(index)); + + if (value) + { + _storage.Span[ToPosition(index)] |= mask; + } + else + { + _storage.Span[ToPosition(index)] &= (byte)~mask; + } + } + + /// <summary> + /// Reset all bits in the storage. + /// </summary> + [MethodImpl(MethodImplOptions.AggressiveInlining)] + public void Reset() + { + _storage.Span.Fill(0); + } + } +} |