using System; using System.Numerics; namespace Ryujinx.Graphics.Texture.Astc { internal struct IntegerEncoded { internal const int StructSize = 8; private static readonly IntegerEncoded[] Encodings; public enum EIntegerEncoding : byte { JustBits, Quint, Trit } EIntegerEncoding _encoding; public byte NumberBits { get; private set; } public byte TritValue { get; private set; } public byte QuintValue { get; private set; } public int BitValue { get; private set; } static IntegerEncoded() { Encodings = new IntegerEncoded[0x100]; for (int i = 0; i < Encodings.Length; i++) { Encodings[i] = CreateEncodingCalc(i); } } public IntegerEncoded(EIntegerEncoding encoding, int numBits) { _encoding = encoding; NumberBits = (byte)numBits; BitValue = 0; TritValue = 0; QuintValue = 0; } public bool MatchesEncoding(IntegerEncoded other) { return _encoding == other._encoding && NumberBits == other.NumberBits; } public EIntegerEncoding GetEncoding() { return _encoding; } public int GetBitLength(int numberVals) { int totalBits = NumberBits * numberVals; if (_encoding == EIntegerEncoding.Trit) { totalBits += (numberVals * 8 + 4) / 5; } else if (_encoding == EIntegerEncoding.Quint) { totalBits += (numberVals * 7 + 2) / 3; } return totalBits; } public static IntegerEncoded CreateEncoding(int maxVal) { return Encodings[maxVal]; } private static IntegerEncoded CreateEncodingCalc(int maxVal) { while (maxVal > 0) { int check = maxVal + 1; // Is maxVal a power of two? if ((check & (check - 1)) == 0) { return new IntegerEncoded(EIntegerEncoding.JustBits, BitOperations.PopCount((uint)maxVal)); } // Is maxVal of the type 3*2^n - 1? if ((check % 3 == 0) && ((check / 3) & ((check / 3) - 1)) == 0) { return new IntegerEncoded(EIntegerEncoding.Trit, BitOperations.PopCount((uint)(check / 3 - 1))); } // Is maxVal of the type 5*2^n - 1? if ((check % 5 == 0) && ((check / 5) & ((check / 5) - 1)) == 0) { return new IntegerEncoded(EIntegerEncoding.Quint, BitOperations.PopCount((uint)(check / 5 - 1))); } // Apparently it can't be represented with a bounded integer sequence... // just iterate. maxVal--; } return new IntegerEncoded(EIntegerEncoding.JustBits, 0); } public static void DecodeTritBlock( ref BitStream128 bitStream, ref IntegerSequence listIntegerEncoded, int numberBitsPerValue) { // Implement the algorithm in section C.2.12 Span<int> m = stackalloc int[5]; m[0] = bitStream.ReadBits(numberBitsPerValue); int encoded = bitStream.ReadBits(2); m[1] = bitStream.ReadBits(numberBitsPerValue); encoded |= bitStream.ReadBits(2) << 2; m[2] = bitStream.ReadBits(numberBitsPerValue); encoded |= bitStream.ReadBits(1) << 4; m[3] = bitStream.ReadBits(numberBitsPerValue); encoded |= bitStream.ReadBits(2) << 5; m[4] = bitStream.ReadBits(numberBitsPerValue); encoded |= bitStream.ReadBits(1) << 7; ReadOnlySpan<byte> encodings = GetTritEncoding(encoded); IntegerEncoded intEncoded = new IntegerEncoded(EIntegerEncoding.Trit, numberBitsPerValue); for (int i = 0; i < 5; i++) { intEncoded.BitValue = m[i]; intEncoded.TritValue = encodings[i]; listIntegerEncoded.Add(ref intEncoded); } } public static void DecodeQuintBlock( ref BitStream128 bitStream, ref IntegerSequence listIntegerEncoded, int numberBitsPerValue) { ReadOnlySpan<byte> interleavedBits = new byte[] { 3, 2, 2 }; // Implement the algorithm in section C.2.12 Span<int> m = stackalloc int[3]; ulong encoded = 0; int encodedBitsRead = 0; for (int i = 0; i < m.Length; i++) { m[i] = bitStream.ReadBits(numberBitsPerValue); uint encodedBits = (uint)bitStream.ReadBits(interleavedBits[i]); encoded |= encodedBits << encodedBitsRead; encodedBitsRead += interleavedBits[i]; } ReadOnlySpan<byte> encodings = GetQuintEncoding((int)encoded); for (int i = 0; i < 3; i++) { IntegerEncoded intEncoded = new IntegerEncoded(EIntegerEncoding.Quint, numberBitsPerValue) { BitValue = m[i], QuintValue = encodings[i] }; listIntegerEncoded.Add(ref intEncoded); } } public static void DecodeIntegerSequence( ref IntegerSequence decodeIntegerSequence, ref BitStream128 bitStream, int maxRange, int numberValues) { // Determine encoding parameters IntegerEncoded intEncoded = CreateEncoding(maxRange); // Start decoding int numberValuesDecoded = 0; while (numberValuesDecoded < numberValues) { switch (intEncoded.GetEncoding()) { case EIntegerEncoding.Quint: { DecodeQuintBlock(ref bitStream, ref decodeIntegerSequence, intEncoded.NumberBits); numberValuesDecoded += 3; break; } case EIntegerEncoding.Trit: { DecodeTritBlock(ref bitStream, ref decodeIntegerSequence, intEncoded.NumberBits); numberValuesDecoded += 5; break; } case EIntegerEncoding.JustBits: { intEncoded.BitValue = bitStream.ReadBits(intEncoded.NumberBits); decodeIntegerSequence.Add(ref intEncoded); numberValuesDecoded++; break; } } } } private static ReadOnlySpan<byte> GetTritEncoding(int index) { return TritEncodings.Slice(index * 5, 5); } private static ReadOnlySpan<byte> GetQuintEncoding(int index) { return QuintEncodings.Slice(index * 3, 3); } private static ReadOnlySpan<byte> TritEncodings => new byte[] { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 2, 1, 0, 0, 0, 1, 0, 2, 0, 0, 0, 2, 0, 0, 0, 1, 2, 0, 0, 0, 2, 2, 0, 0, 0, 2, 0, 2, 0, 0, 0, 2, 2, 0, 0, 1, 2, 2, 0, 0, 2, 2, 2, 0, 0, 2, 0, 2, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 2, 0, 1, 0, 0, 0, 1, 2, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 2, 1, 1, 0, 0, 1, 1, 2, 0, 0, 0, 2, 1, 0, 0, 1, 2, 1, 0, 0, 2, 2, 1, 0, 0, 2, 1, 2, 0, 0, 0, 0, 0, 2, 2, 1, 0, 0, 2, 2, 2, 0, 0, 2, 2, 0, 0, 2, 2, 2, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 2, 0, 0, 1, 0, 0, 0, 2, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 2, 1, 0, 1, 0, 1, 0, 2, 1, 0, 0, 2, 0, 1, 0, 1, 2, 0, 1, 0, 2, 2, 0, 1, 0, 2, 0, 2, 1, 0, 0, 2, 2, 1, 0, 1, 2, 2, 1, 0, 2, 2, 2, 1, 0, 2, 0, 2, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 2, 0, 1, 1, 0, 0, 1, 2, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 2, 1, 1, 1, 0, 1, 1, 2, 1, 0, 0, 2, 1, 1, 0, 1, 2, 1, 1, 0, 2, 2, 1, 1, 0, 2, 1, 2, 1, 0, 0, 1, 0, 2, 2, 1, 1, 0, 2, 2, 2, 1, 0, 2, 2, 1, 0, 2, 2, 2, 0, 0, 0, 2, 0, 1, 0, 0, 2, 0, 2, 0, 0, 2, 0, 0, 0, 2, 2, 0, 0, 1, 0, 2, 0, 1, 1, 0, 2, 0, 2, 1, 0, 2, 0, 1, 0, 2, 2, 0, 0, 2, 0, 2, 0, 1, 2, 0, 2, 0, 2, 2, 0, 2, 0, 2, 0, 2, 2, 0, 0, 2, 2, 2, 0, 1, 2, 2, 2, 0, 2, 2, 2, 2, 0, 2, 0, 2, 2, 0, 0, 0, 1, 2, 0, 1, 0, 1, 2, 0, 2, 0, 1, 2, 0, 0, 1, 2, 2, 0, 0, 1, 1, 2, 0, 1, 1, 1, 2, 0, 2, 1, 1, 2, 0, 1, 1, 2, 2, 0, 0, 2, 1, 2, 0, 1, 2, 1, 2, 0, 2, 2, 1, 2, 0, 2, 1, 2, 2, 0, 0, 2, 0, 2, 2, 1, 2, 0, 2, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 2, 0, 0, 0, 0, 2, 1, 0, 0, 0, 2, 2, 0, 0, 0, 2, 0, 0, 2, 0, 2, 0, 1, 0, 0, 2, 1, 1, 0, 0, 2, 2, 1, 0, 0, 2, 1, 0, 2, 0, 2, 0, 2, 0, 0, 2, 1, 2, 0, 0, 2, 2, 2, 0, 0, 2, 2, 0, 2, 0, 2, 0, 2, 2, 0, 2, 1, 2, 2, 0, 2, 2, 2, 2, 0, 2, 2, 0, 2, 0, 2, 0, 0, 1, 0, 2, 1, 0, 1, 0, 2, 2, 0, 1, 0, 2, 0, 1, 2, 0, 2, 0, 1, 1, 0, 2, 1, 1, 1, 0, 2, 2, 1, 1, 0, 2, 1, 1, 2, 0, 2, 0, 2, 1, 0, 2, 1, 2, 1, 0, 2, 2, 2, 1, 0, 2, 2, 1, 2, 0, 2, 0, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 2, 0, 0, 0, 1, 0, 0, 2, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 2, 1, 0, 0, 1, 1, 0, 2, 0, 1, 0, 2, 0, 0, 1, 1, 2, 0, 0, 1, 2, 2, 0, 0, 1, 2, 0, 2, 0, 1, 0, 2, 2, 0, 1, 1, 2, 2, 0, 1, 2, 2, 2, 0, 1, 2, 0, 2, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 2, 0, 1, 0, 1, 0, 1, 2, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 2, 1, 1, 0, 1, 1, 1, 2, 0, 1, 0, 2, 1, 0, 1, 1, 2, 1, 0, 1, 2, 2, 1, 0, 1, 2, 1, 2, 0, 1, 0, 0, 1, 2, 2, 1, 0, 1, 2, 2, 2, 0, 1, 2, 2, 0, 1, 2, 2, 2, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 2, 0, 0, 1, 1, 0, 0, 2, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 1, 2, 1, 0, 1, 1, 1, 0, 2, 1, 1, 0, 2, 0, 1, 1, 1, 2, 0, 1, 1, 2, 2, 0, 1, 1, 2, 0, 2, 1, 1, 0, 2, 2, 1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 1, 1, 2, 0, 2, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 2, 0, 1, 1, 1, 0, 1, 2, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 0, 2, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 2, 1, 1, 0, 1, 1, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 2, 0, 0, 0, 2, 1, 1, 0, 0, 2, 1, 2, 0, 0, 2, 1, 0, 0, 2, 2, 1, 0, 1, 0, 2, 1, 1, 1, 0, 2, 1, 2, 1, 0, 2, 1, 1, 0, 2, 2, 1, 0, 2, 0, 2, 1, 1, 2, 0, 2, 1, 2, 2, 0, 2, 1, 2, 0, 2, 2, 1, 0, 2, 2, 2, 1, 1, 2, 2, 2, 1, 2, 2, 2, 2, 1, 2, 0, 2, 2, 1, 0, 0, 1, 2, 1, 1, 0, 1, 2, 1, 2, 0, 1, 2, 1, 0, 1, 2, 2, 1, 0, 1, 1, 2, 1, 1, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 2, 2, 1, 0, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 2, 1, 2, 1, 2, 1, 2, 2, 1, 0, 2, 1, 2, 2, 1, 2, 1, 2, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 0, 0, 0, 1, 2, 1, 0, 0, 1, 2, 2, 0, 0, 1, 2, 0, 0, 2, 1, 2, 0, 1, 0, 1, 2, 1, 1, 0, 1, 2, 2, 1, 0, 1, 2, 1, 0, 2, 1, 2, 0, 2, 0, 1, 2, 1, 2, 0, 1, 2, 2, 2, 0, 1, 2, 2, 0, 2, 1, 2, 0, 2, 2, 1, 2, 1, 2, 2, 1, 2, 2, 2, 2, 1, 2, 2, 0, 2, 1, 2, 0, 0, 1, 1, 2, 1, 0, 1, 1, 2, 2, 0, 1, 1, 2, 0, 1, 2, 1, 2, 0, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 2, 1, 2, 0, 2, 1, 1, 2, 1, 2, 1, 1, 2, 2, 2, 1, 1, 2, 2, 1, 2, 1, 2, 0, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2 }; private static ReadOnlySpan<byte> QuintEncodings => new byte[] { 0, 0, 0, 1, 0, 0, 2, 0, 0, 3, 0, 0, 4, 0, 0, 0, 4, 0, 4, 4, 0, 4, 4, 4, 0, 1, 0, 1, 1, 0, 2, 1, 0, 3, 1, 0, 4, 1, 0, 1, 4, 0, 4, 4, 1, 4, 4, 4, 0, 2, 0, 1, 2, 0, 2, 2, 0, 3, 2, 0, 4, 2, 0, 2, 4, 0, 4, 4, 2, 4, 4, 4, 0, 3, 0, 1, 3, 0, 2, 3, 0, 3, 3, 0, 4, 3, 0, 3, 4, 0, 4, 4, 3, 4, 4, 4, 0, 0, 1, 1, 0, 1, 2, 0, 1, 3, 0, 1, 4, 0, 1, 0, 4, 1, 4, 0, 4, 0, 4, 4, 0, 1, 1, 1, 1, 1, 2, 1, 1, 3, 1, 1, 4, 1, 1, 1, 4, 1, 4, 1, 4, 1, 4, 4, 0, 2, 1, 1, 2, 1, 2, 2, 1, 3, 2, 1, 4, 2, 1, 2, 4, 1, 4, 2, 4, 2, 4, 4, 0, 3, 1, 1, 3, 1, 2, 3, 1, 3, 3, 1, 4, 3, 1, 3, 4, 1, 4, 3, 4, 3, 4, 4, 0, 0, 2, 1, 0, 2, 2, 0, 2, 3, 0, 2, 4, 0, 2, 0, 4, 2, 2, 0, 4, 3, 0, 4, 0, 1, 2, 1, 1, 2, 2, 1, 2, 3, 1, 2, 4, 1, 2, 1, 4, 2, 2, 1, 4, 3, 1, 4, 0, 2, 2, 1, 2, 2, 2, 2, 2, 3, 2, 2, 4, 2, 2, 2, 4, 2, 2, 2, 4, 3, 2, 4, 0, 3, 2, 1, 3, 2, 2, 3, 2, 3, 3, 2, 4, 3, 2, 3, 4, 2, 2, 3, 4, 3, 3, 4, 0, 0, 3, 1, 0, 3, 2, 0, 3, 3, 0, 3, 4, 0, 3, 0, 4, 3, 0, 0, 4, 1, 0, 4, 0, 1, 3, 1, 1, 3, 2, 1, 3, 3, 1, 3, 4, 1, 3, 1, 4, 3, 0, 1, 4, 1, 1, 4, 0, 2, 3, 1, 2, 3, 2, 2, 3, 3, 2, 3, 4, 2, 3, 2, 4, 3, 0, 2, 4, 1, 2, 4, 0, 3, 3, 1, 3, 3, 2, 3, 3, 3, 3, 3, 4, 3, 3, 3, 4, 3, 0, 3, 4, 1, 3, 4 }; } }