using System; using System.Collections; using System.Collections.Generic; using System.Diagnostics; using System.IO; namespace Ryujinx.Graphics.Gal.Texture { public class ASTCDecoderException : Exception { public ASTCDecoderException(string ExMsg) : base(ExMsg) { } } //https://github.com/GammaUNC/FasTC/blob/master/ASTCEncoder/src/Decompressor.cpp public static class ASTCDecoder { struct TexelWeightParams { public int Width; public int Height; public bool DualPlane; public int MaxWeight; public bool Error; public bool VoidExtentLDR; public bool VoidExtentHDR; public int GetPackedBitSize() { // How many indices do we have? int Indices = Height * Width; if (DualPlane) { Indices *= 2; } IntegerEncoded IntEncoded = IntegerEncoded.CreateEncoding(MaxWeight); return IntEncoded.GetBitLength(Indices); } public int GetNumWeightValues() { int Ret = Width * Height; if (DualPlane) { Ret *= 2; } return Ret; } } public static byte[] DecodeToRGBA8888( byte[] InputBuffer, int BlockX, int BlockY, int BlockZ, int X, int Y, int Z) { using (MemoryStream InputStream = new MemoryStream(InputBuffer)) { BinaryReader BinReader = new BinaryReader(InputStream); if (BlockX > 12 || BlockY > 12) { throw new ASTCDecoderException("Block size unsupported!"); } if (BlockZ != 1 || Z != 1) { throw new ASTCDecoderException("3D compressed textures unsupported!"); } using (MemoryStream OutputStream = new MemoryStream()) { int BlockIndex = 0; for (int j = 0; j < Y; j += BlockY) { for (int i = 0; i < X; i += BlockX) { int[] DecompressedData = new int[144]; DecompressBlock(BinReader.ReadBytes(0x10), DecompressedData, BlockX, BlockY); int DecompressedWidth = Math.Min(BlockX, X - i); int DecompressedHeight = Math.Min(BlockY, Y - j); int BaseOffsets = (j * X + i) * 4; for (int jj = 0; jj < DecompressedHeight; jj++) { OutputStream.Seek(BaseOffsets + jj * X * 4, SeekOrigin.Begin); byte[] OutputBuffer = new byte[DecompressedData.Length * sizeof(int)]; Buffer.BlockCopy(DecompressedData, 0, OutputBuffer, 0, OutputBuffer.Length); OutputStream.Write(OutputBuffer, jj * BlockX * 4, DecompressedWidth * 4); } BlockIndex++; } } return OutputStream.ToArray(); } } } public static bool DecompressBlock( byte[] InputBuffer, int[] OutputBuffer, int BlockWidth, int BlockHeight) { BitArrayStream BitStream = new BitArrayStream(new BitArray(InputBuffer)); TexelWeightParams TexelParams = DecodeBlockInfo(BitStream); if (TexelParams.Error) { throw new ASTCDecoderException("Invalid block mode"); } if (TexelParams.VoidExtentLDR) { FillVoidExtentLDR(BitStream, OutputBuffer, BlockWidth, BlockHeight); return true; } if (TexelParams.VoidExtentHDR) { throw new ASTCDecoderException("HDR void extent blocks are unsupported!"); } if (TexelParams.Width > BlockWidth) { throw new ASTCDecoderException("Texel weight grid width should be smaller than block width"); } if (TexelParams.Height > BlockHeight) { throw new ASTCDecoderException("Texel weight grid height should be smaller than block height"); } // Read num partitions int NumberPartitions = BitStream.ReadBits(2) + 1; Debug.Assert(NumberPartitions <= 4); if (NumberPartitions == 4 && TexelParams.DualPlane) { throw new ASTCDecoderException("Dual plane mode is incompatible with four partition blocks"); } // Based on the number of partitions, read the color endpoint mode for // each partition. // Determine partitions, partition index, and color endpoint modes int PlaneIndices = -1; int PartitionIndex; uint[] ColorEndpointMode = { 0, 0, 0, 0 }; BitArrayStream ColorEndpointStream = new BitArrayStream(new BitArray(16 * 8)); // Read extra config data... uint BaseColorEndpointMode = 0; if (NumberPartitions == 1) { ColorEndpointMode[0] = (uint)BitStream.ReadBits(4); PartitionIndex = 0; } else { PartitionIndex = BitStream.ReadBits(10); BaseColorEndpointMode = (uint)BitStream.ReadBits(6); } uint BaseMode = (BaseColorEndpointMode & 3); // Remaining bits are color endpoint data... int NumberWeightBits = TexelParams.GetPackedBitSize(); int RemainingBits = 128 - NumberWeightBits - BitStream.Position; // Consider extra bits prior to texel data... uint ExtraColorEndpointModeBits = 0; if (BaseMode != 0) { switch (NumberPartitions) { case 2: ExtraColorEndpointModeBits += 2; break; case 3: ExtraColorEndpointModeBits += 5; break; case 4: ExtraColorEndpointModeBits += 8; break; default: Debug.Assert(false); break; } } RemainingBits -= (int)ExtraColorEndpointModeBits; // Do we have a dual plane situation? int PlaneSelectorBits = 0; if (TexelParams.DualPlane) { PlaneSelectorBits = 2; } RemainingBits -= PlaneSelectorBits; // Read color data... int ColorDataBits = RemainingBits; while (RemainingBits > 0) { int NumberBits = Math.Min(RemainingBits, 8); int Bits = BitStream.ReadBits(NumberBits); ColorEndpointStream.WriteBits(Bits, NumberBits); RemainingBits -= 8; } // Read the plane selection bits PlaneIndices = BitStream.ReadBits(PlaneSelectorBits); // Read the rest of the CEM if (BaseMode != 0) { uint ExtraColorEndpointMode = (uint)BitStream.ReadBits((int)ExtraColorEndpointModeBits); uint TempColorEndpointMode = (ExtraColorEndpointMode << 6) | BaseColorEndpointMode; TempColorEndpointMode >>= 2; bool[] C = new bool[4]; for (int i = 0; i < NumberPartitions; i++) { C[i] = (TempColorEndpointMode & 1) != 0; TempColorEndpointMode >>= 1; } byte[] M = new byte[4]; for (int i = 0; i < NumberPartitions; i++) { M[i] = (byte)(TempColorEndpointMode & 3); TempColorEndpointMode >>= 2; Debug.Assert(M[i] <= 3); } for (int i = 0; i < NumberPartitions; i++) { ColorEndpointMode[i] = BaseMode; if (!(C[i])) ColorEndpointMode[i] -= 1; ColorEndpointMode[i] <<= 2; ColorEndpointMode[i] |= M[i]; } } else if (NumberPartitions > 1) { uint TempColorEndpointMode = BaseColorEndpointMode >> 2; for (uint i = 0; i < NumberPartitions; i++) { ColorEndpointMode[i] = TempColorEndpointMode; } } // Make sure everything up till here is sane. for (int i = 0; i < NumberPartitions; i++) { Debug.Assert(ColorEndpointMode[i] < 16); } Debug.Assert(BitStream.Position + TexelParams.GetPackedBitSize() == 128); // Decode both color data and texel weight data int[] ColorValues = new int[32]; // Four values * two endpoints * four maximum partitions DecodeColorValues(ColorValues, ColorEndpointStream.ToByteArray(), ColorEndpointMode, NumberPartitions, ColorDataBits); ASTCPixel[][] EndPoints = new ASTCPixel[4][]; EndPoints[0] = new ASTCPixel[2]; EndPoints[1] = new ASTCPixel[2]; EndPoints[2] = new ASTCPixel[2]; EndPoints[3] = new ASTCPixel[2]; int ColorValuesPosition = 0; for (int i = 0; i < NumberPartitions; i++) { ComputeEndpoints(EndPoints[i], ColorValues, ColorEndpointMode[i], ref ColorValuesPosition); } // Read the texel weight data. byte[] TexelWeightData = (byte[])InputBuffer.Clone(); // Reverse everything for (int i = 0; i < 8; i++) { byte a = ReverseByte(TexelWeightData[i]); byte b = ReverseByte(TexelWeightData[15 - i]); TexelWeightData[i] = b; TexelWeightData[15 - i] = a; } // Make sure that higher non-texel bits are set to zero int ClearByteStart = (TexelParams.GetPackedBitSize() >> 3) + 1; TexelWeightData[ClearByteStart - 1] &= (byte)((1 << (TexelParams.GetPackedBitSize() % 8)) - 1); int cLen = 16 - ClearByteStart; for (int i = ClearByteStart; i < ClearByteStart + cLen; i++) TexelWeightData[i] = 0; List TexelWeightValues = new List(); BitArrayStream WeightBitStream = new BitArrayStream(new BitArray(TexelWeightData)); IntegerEncoded.DecodeIntegerSequence(TexelWeightValues, WeightBitStream, TexelParams.MaxWeight, TexelParams.GetNumWeightValues()); // Blocks can be at most 12x12, so we can have as many as 144 weights int[][] Weights = new int[2][]; Weights[0] = new int[144]; Weights[1] = new int[144]; UnquantizeTexelWeights(Weights, TexelWeightValues, TexelParams, BlockWidth, BlockHeight); // Now that we have endpoints and weights, we can interpolate and generate // the proper decoding... for (int j = 0; j < BlockHeight; j++) { for (int i = 0; i < BlockWidth; i++) { int Partition = Select2DPartition(PartitionIndex, i, j, NumberPartitions, ((BlockHeight * BlockWidth) < 32)); Debug.Assert(Partition < NumberPartitions); ASTCPixel Pixel = new ASTCPixel(0, 0, 0, 0); for (int Component = 0; Component < 4; Component++) { int Component0 = EndPoints[Partition][0].GetComponent(Component); Component0 = BitArrayStream.Replicate(Component0, 8, 16); int Component1 = EndPoints[Partition][1].GetComponent(Component); Component1 = BitArrayStream.Replicate(Component1, 8, 16); int Plane = 0; if (TexelParams.DualPlane && (((PlaneIndices + 1) & 3) == Component)) { Plane = 1; } int Weight = Weights[Plane][j * BlockWidth + i]; int FinalComponent = (Component0 * (64 - Weight) + Component1 * Weight + 32) / 64; if (FinalComponent == 65535) { Pixel.SetComponent(Component, 255); } else { double FinalComponentFloat = FinalComponent; Pixel.SetComponent(Component, (int)(255.0 * (FinalComponentFloat / 65536.0) + 0.5)); } } OutputBuffer[j * BlockWidth + i] = Pixel.Pack(); } } return true; } private static int Select2DPartition(int Seed, int X, int Y, int PartitionCount, bool IsSmallBlock) { return SelectPartition(Seed, X, Y, 0, PartitionCount, IsSmallBlock); } private static int SelectPartition(int Seed, int X, int Y, int Z, int PartitionCount, bool IsSmallBlock) { if (PartitionCount == 1) { return 0; } if (IsSmallBlock) { X <<= 1; Y <<= 1; Z <<= 1; } Seed += (PartitionCount - 1) * 1024; int RightNum = Hash52((uint)Seed); byte Seed01 = (byte)(RightNum & 0xF); byte Seed02 = (byte)((RightNum >> 4) & 0xF); byte Seed03 = (byte)((RightNum >> 8) & 0xF); byte Seed04 = (byte)((RightNum >> 12) & 0xF); byte Seed05 = (byte)((RightNum >> 16) & 0xF); byte Seed06 = (byte)((RightNum >> 20) & 0xF); byte Seed07 = (byte)((RightNum >> 24) & 0xF); byte Seed08 = (byte)((RightNum >> 28) & 0xF); byte Seed09 = (byte)((RightNum >> 18) & 0xF); byte Seed10 = (byte)((RightNum >> 22) & 0xF); byte Seed11 = (byte)((RightNum >> 26) & 0xF); byte Seed12 = (byte)(((RightNum >> 30) | (RightNum << 2)) & 0xF); Seed01 *= Seed01; Seed02 *= Seed02; Seed03 *= Seed03; Seed04 *= Seed04; Seed05 *= Seed05; Seed06 *= Seed06; Seed07 *= Seed07; Seed08 *= Seed08; Seed09 *= Seed09; Seed10 *= Seed10; Seed11 *= Seed11; Seed12 *= Seed12; int SeedHash1, SeedHash2, SeedHash3; if ((Seed & 1) != 0) { SeedHash1 = (Seed & 2) != 0 ? 4 : 5; SeedHash2 = (PartitionCount == 3) ? 6 : 5; } else { SeedHash1 = (PartitionCount == 3) ? 6 : 5; SeedHash2 = (Seed & 2) != 0 ? 4 : 5; } SeedHash3 = (Seed & 0x10) != 0 ? SeedHash1 : SeedHash2; Seed01 >>= SeedHash1; Seed02 >>= SeedHash2; Seed03 >>= SeedHash1; Seed04 >>= SeedHash2; Seed05 >>= SeedHash1; Seed06 >>= SeedHash2; Seed07 >>= SeedHash1; Seed08 >>= SeedHash2; Seed09 >>= SeedHash3; Seed10 >>= SeedHash3; Seed11 >>= SeedHash3; Seed12 >>= SeedHash3; int a = Seed01 * X + Seed02 * Y + Seed11 * Z + (RightNum >> 14); int b = Seed03 * X + Seed04 * Y + Seed12 * Z + (RightNum >> 10); int c = Seed05 * X + Seed06 * Y + Seed09 * Z + (RightNum >> 6); int d = Seed07 * X + Seed08 * Y + Seed10 * Z + (RightNum >> 2); a &= 0x3F; b &= 0x3F; c &= 0x3F; d &= 0x3F; if (PartitionCount < 4) d = 0; if (PartitionCount < 3) c = 0; if (a >= b && a >= c && a >= d) return 0; else if (b >= c && b >= d) return 1; else if (c >= d) return 2; return 3; } static int Hash52(uint Val) { Val ^= Val >> 15; Val -= Val << 17; Val += Val << 7; Val += Val << 4; Val ^= Val >> 5; Val += Val << 16; Val ^= Val >> 7; Val ^= Val >> 3; Val ^= Val << 6; Val ^= Val >> 17; return (int)Val; } static void UnquantizeTexelWeights( int[][] OutputBuffer, List Weights, TexelWeightParams TexelParams, int BlockWidth, int BlockHeight) { int WeightIndices = 0; int[][] Unquantized = new int[2][]; Unquantized[0] = new int[144]; Unquantized[1] = new int[144]; for (int i = 0; i < Weights.Count; i++) { Unquantized[0][WeightIndices] = UnquantizeTexelWeight(Weights[i]); if (TexelParams.DualPlane) { i++; Unquantized[1][WeightIndices] = UnquantizeTexelWeight(Weights[i]); if (i == Weights.Count) { break; } } if (++WeightIndices >= (TexelParams.Width * TexelParams.Height)) break; } // Do infill if necessary (Section C.2.18) ... int Ds = (1024 + (BlockWidth / 2)) / (BlockWidth - 1); int Dt = (1024 + (BlockHeight / 2)) / (BlockHeight - 1); int PlaneScale = TexelParams.DualPlane ? 2 : 1; for (int Plane = 0; Plane < PlaneScale; Plane++) { for (int t = 0; t < BlockHeight; t++) { for (int s = 0; s < BlockWidth; s++) { int cs = Ds * s; int ct = Dt * t; int gs = (cs * (TexelParams.Width - 1) + 32) >> 6; int gt = (ct * (TexelParams.Height - 1) + 32) >> 6; int js = gs >> 4; int fs = gs & 0xF; int jt = gt >> 4; int ft = gt & 0x0F; int w11 = (fs * ft + 8) >> 4; int w10 = ft - w11; int w01 = fs - w11; int w00 = 16 - fs - ft + w11; int v0 = js + jt * TexelParams.Width; int p00 = 0; int p01 = 0; int p10 = 0; int p11 = 0; if (v0 < (TexelParams.Width * TexelParams.Height)) { p00 = Unquantized[Plane][v0]; } if (v0 + 1 < (TexelParams.Width * TexelParams.Height)) { p01 = Unquantized[Plane][v0 + 1]; } if (v0 + TexelParams.Width < (TexelParams.Width * TexelParams.Height)) { p10 = Unquantized[Plane][v0 + TexelParams.Width]; } if (v0 + TexelParams.Width + 1 < (TexelParams.Width * TexelParams.Height)) { p11 = Unquantized[Plane][v0 + TexelParams.Width + 1]; } OutputBuffer[Plane][t * BlockWidth + s] = (p00 * w00 + p01 * w01 + p10 * w10 + p11 * w11 + 8) >> 4; } } } } static int UnquantizeTexelWeight(IntegerEncoded IntEncoded) { int BitValue = IntEncoded.BitValue; int BitLength = IntEncoded.NumberBits; int A = BitArrayStream.Replicate(BitValue & 1, 1, 7); int B = 0, C = 0, D = 0; int Result = 0; switch (IntEncoded.GetEncoding()) { case IntegerEncoded.EIntegerEncoding.JustBits: Result = BitArrayStream.Replicate(BitValue, BitLength, 6); break; case IntegerEncoded.EIntegerEncoding.Trit: { D = IntEncoded.TritValue; Debug.Assert(D < 3); switch (BitLength) { case 0: { int[] Results = { 0, 32, 63 }; Result = Results[D]; break; } case 1: { C = 50; break; } case 2: { C = 23; int b = (BitValue >> 1) & 1; B = (b << 6) | (b << 2) | b; break; } case 3: { C = 11; int cb = (BitValue >> 1) & 3; B = (cb << 5) | cb; break; } default: throw new ASTCDecoderException("Invalid trit encoding for texel weight"); } break; } case IntegerEncoded.EIntegerEncoding.Quint: { D = IntEncoded.QuintValue; Debug.Assert(D < 5); switch (BitLength) { case 0: { int[] Results = { 0, 16, 32, 47, 63 }; Result = Results[D]; break; } case 1: { C = 28; break; } case 2: { C = 13; int b = (BitValue >> 1) & 1; B = (b << 6) | (b << 1); break; } default: throw new ASTCDecoderException("Invalid quint encoding for texel weight"); } break; } } if (IntEncoded.GetEncoding() != IntegerEncoded.EIntegerEncoding.JustBits && BitLength > 0) { // Decode the value... Result = D * C + B; Result ^= A; Result = (A & 0x20) | (Result >> 2); } Debug.Assert(Result < 64); // Change from [0,63] to [0,64] if (Result > 32) { Result += 1; } return Result; } static byte ReverseByte(byte b) { // Taken from http://graphics.stanford.edu/~seander/bithacks.html#ReverseByteWith64Bits return (byte)((((b) * 0x80200802L) & 0x0884422110L) * 0x0101010101L >> 32); } static uint[] ReadUintColorValues(int Number, int[] ColorValues, ref int ColorValuesPosition) { uint[] Ret = new uint[Number]; for (int i = 0; i < Number; i++) { Ret[i] = (uint)ColorValues[ColorValuesPosition++]; } return Ret; } static int[] ReadIntColorValues(int Number, int[] ColorValues, ref int ColorValuesPosition) { int[] Ret = new int[Number]; for (int i = 0; i < Number; i++) { Ret[i] = ColorValues[ColorValuesPosition++]; } return Ret; } static void ComputeEndpoints( ASTCPixel[] EndPoints, int[] ColorValues, uint ColorEndpointMode, ref int ColorValuesPosition) { switch (ColorEndpointMode) { case 0: { uint[] Val = ReadUintColorValues(2, ColorValues, ref ColorValuesPosition); EndPoints[0] = new ASTCPixel(0xFF, (short)Val[0], (short)Val[0], (short)Val[0]); EndPoints[1] = new ASTCPixel(0xFF, (short)Val[1], (short)Val[1], (short)Val[1]); break; } case 1: { uint[] Val = ReadUintColorValues(2, ColorValues, ref ColorValuesPosition); int L0 = (int)((Val[0] >> 2) | (Val[1] & 0xC0)); int L1 = (int)Math.Max(L0 + (Val[1] & 0x3F), 0xFFU); EndPoints[0] = new ASTCPixel(0xFF, (short)L0, (short)L0, (short)L0); EndPoints[1] = new ASTCPixel(0xFF, (short)L1, (short)L1, (short)L1); break; } case 4: { uint[] Val = ReadUintColorValues(4, ColorValues, ref ColorValuesPosition); EndPoints[0] = new ASTCPixel((short)Val[2], (short)Val[0], (short)Val[0], (short)Val[0]); EndPoints[1] = new ASTCPixel((short)Val[3], (short)Val[1], (short)Val[1], (short)Val[1]); break; } case 5: { int[] Val = ReadIntColorValues(4, ColorValues, ref ColorValuesPosition); BitArrayStream.BitTransferSigned(ref Val[1], ref Val[0]); BitArrayStream.BitTransferSigned(ref Val[3], ref Val[2]); EndPoints[0] = new ASTCPixel((short)Val[2], (short)Val[0], (short)Val[0], (short)Val[0]); EndPoints[1] = new ASTCPixel((short)(Val[2] + Val[3]), (short)(Val[0] + Val[1]), (short)(Val[0] + Val[1]), (short)(Val[0] + Val[1])); EndPoints[0].ClampByte(); EndPoints[1].ClampByte(); break; } case 6: { uint[] Val = ReadUintColorValues(4, ColorValues, ref ColorValuesPosition); EndPoints[0] = new ASTCPixel(0xFF, (short)(Val[0] * Val[3] >> 8), (short)(Val[1] * Val[3] >> 8), (short)(Val[2] * Val[3] >> 8)); EndPoints[1] = new ASTCPixel(0xFF, (short)Val[0], (short)Val[1], (short)Val[2]); break; } case 8: { uint[] Val = ReadUintColorValues(6, ColorValues, ref ColorValuesPosition); if (Val[1] + Val[3] + Val[5] >= Val[0] + Val[2] + Val[4]) { EndPoints[0] = new ASTCPixel(0xFF, (short)Val[0], (short)Val[2], (short)Val[4]); EndPoints[1] = new ASTCPixel(0xFF, (short)Val[1], (short)Val[3], (short)Val[5]); } else { EndPoints[0] = ASTCPixel.BlueContract(0xFF, (short)Val[1], (short)Val[3], (short)Val[5]); EndPoints[1] = ASTCPixel.BlueContract(0xFF, (short)Val[0], (short)Val[2], (short)Val[4]); } break; } case 9: { int[] Val = ReadIntColorValues(6, ColorValues, ref ColorValuesPosition); BitArrayStream.BitTransferSigned(ref Val[1], ref Val[0]); BitArrayStream.BitTransferSigned(ref Val[3], ref Val[2]); BitArrayStream.BitTransferSigned(ref Val[5], ref Val[4]); if (Val[1] + Val[3] + Val[5] >= 0) { EndPoints[0] = new ASTCPixel(0xFF, (short)Val[0], (short)Val[2], (short)Val[4]); EndPoints[1] = new ASTCPixel(0xFF, (short)(Val[0] + Val[1]), (short)(Val[2] + Val[3]), (short)(Val[4] + Val[5])); } else { EndPoints[0] = ASTCPixel.BlueContract(0xFF, Val[0] + Val[1], Val[2] + Val[3], Val[4] + Val[5]); EndPoints[1] = ASTCPixel.BlueContract(0xFF, Val[0], Val[2], Val[4]); } EndPoints[0].ClampByte(); EndPoints[1].ClampByte(); break; } case 10: { uint[] Val = ReadUintColorValues(6, ColorValues, ref ColorValuesPosition); EndPoints[0] = new ASTCPixel((short)Val[4], (short)(Val[0] * Val[3] >> 8), (short)(Val[1] * Val[3] >> 8), (short)(Val[2] * Val[3] >> 8)); EndPoints[1] = new ASTCPixel((short)Val[5], (short)Val[0], (short)Val[1], (short)Val[2]); break; } case 12: { uint[] Val = ReadUintColorValues(8, ColorValues, ref ColorValuesPosition); if (Val[1] + Val[3] + Val[5] >= Val[0] + Val[2] + Val[4]) { EndPoints[0] = new ASTCPixel((short)Val[6], (short)Val[0], (short)Val[2], (short)Val[4]); EndPoints[1] = new ASTCPixel((short)Val[7], (short)Val[1], (short)Val[3], (short)Val[5]); } else { EndPoints[0] = ASTCPixel.BlueContract((short)Val[7], (short)Val[1], (short)Val[3], (short)Val[5]); EndPoints[1] = ASTCPixel.BlueContract((short)Val[6], (short)Val[0], (short)Val[2], (short)Val[4]); } break; } case 13: { int[] Val = ReadIntColorValues(8, ColorValues, ref ColorValuesPosition); BitArrayStream.BitTransferSigned(ref Val[1], ref Val[0]); BitArrayStream.BitTransferSigned(ref Val[3], ref Val[2]); BitArrayStream.BitTransferSigned(ref Val[5], ref Val[4]); BitArrayStream.BitTransferSigned(ref Val[7], ref Val[6]); if (Val[1] + Val[3] + Val[5] >= 0) { EndPoints[0] = new ASTCPixel((short)Val[6], (short)Val[0], (short)Val[2], (short)Val[4]); EndPoints[1] = new ASTCPixel((short)(Val[7] + Val[6]), (short)(Val[0] + Val[1]), (short)(Val[2] + Val[3]), (short)(Val[4] + Val[5])); } else { EndPoints[0] = ASTCPixel.BlueContract(Val[6] + Val[7], Val[0] + Val[1], Val[2] + Val[3], Val[4] + Val[5]); EndPoints[1] = ASTCPixel.BlueContract(Val[6], Val[0], Val[2], Val[4]); } EndPoints[0].ClampByte(); EndPoints[1].ClampByte(); break; } default: throw new ASTCDecoderException("Unsupported color endpoint mode (is it HDR?)"); } } static void DecodeColorValues( int[] OutputValues, byte[] InputData, uint[] Modes, int NumberPartitions, int NumberBitsForColorData) { // First figure out how many color values we have int NumberValues = 0; for (int i = 0; i < NumberPartitions; i++) { NumberValues += (int)((Modes[i] >> 2) + 1) << 1; } // Then based on the number of values and the remaining number of bits, // figure out the max value for each of them... int Range = 256; while (--Range > 0) { IntegerEncoded IntEncoded = IntegerEncoded.CreateEncoding(Range); int BitLength = IntEncoded.GetBitLength(NumberValues); if (BitLength <= NumberBitsForColorData) { // Find the smallest possible range that matches the given encoding while (--Range > 0) { IntegerEncoded NewIntEncoded = IntegerEncoded.CreateEncoding(Range); if (!NewIntEncoded.MatchesEncoding(IntEncoded)) { break; } } // Return to last matching range. Range++; break; } } // We now have enough to decode our integer sequence. List IntegerEncodedSequence = new List(); BitArrayStream ColorBitStream = new BitArrayStream(new BitArray(InputData)); IntegerEncoded.DecodeIntegerSequence(IntegerEncodedSequence, ColorBitStream, Range, NumberValues); // Once we have the decoded values, we need to dequantize them to the 0-255 range // This procedure is outlined in ASTC spec C.2.13 int OutputIndices = 0; foreach (IntegerEncoded IntEncoded in IntegerEncodedSequence) { int BitLength = IntEncoded.NumberBits; int BitValue = IntEncoded.BitValue; Debug.Assert(BitLength >= 1); int A = 0, B = 0, C = 0, D = 0; // A is just the lsb replicated 9 times. A = BitArrayStream.Replicate(BitValue & 1, 1, 9); switch (IntEncoded.GetEncoding()) { case IntegerEncoded.EIntegerEncoding.JustBits: { OutputValues[OutputIndices++] = BitArrayStream.Replicate(BitValue, BitLength, 8); break; } case IntegerEncoded.EIntegerEncoding.Trit: { D = IntEncoded.TritValue; switch (BitLength) { case 1: { C = 204; break; } case 2: { C = 93; // B = b000b0bb0 int b = (BitValue >> 1) & 1; B = (b << 8) | (b << 4) | (b << 2) | (b << 1); break; } case 3: { C = 44; // B = cb000cbcb int cb = (BitValue >> 1) & 3; B = (cb << 7) | (cb << 2) | cb; break; } case 4: { C = 22; // B = dcb000dcb int dcb = (BitValue >> 1) & 7; B = (dcb << 6) | dcb; break; } case 5: { C = 11; // B = edcb000ed int edcb = (BitValue >> 1) & 0xF; B = (edcb << 5) | (edcb >> 2); break; } case 6: { C = 5; // B = fedcb000f int fedcb = (BitValue >> 1) & 0x1F; B = (fedcb << 4) | (fedcb >> 4); break; } default: throw new ASTCDecoderException("Unsupported trit encoding for color values!"); } break; } case IntegerEncoded.EIntegerEncoding.Quint: { D = IntEncoded.QuintValue; switch (BitLength) { case 1: { C = 113; break; } case 2: { C = 54; // B = b0000bb00 int b = (BitValue >> 1) & 1; B = (b << 8) | (b << 3) | (b << 2); break; } case 3: { C = 26; // B = cb0000cbc int cb = (BitValue >> 1) & 3; B = (cb << 7) | (cb << 1) | (cb >> 1); break; } case 4: { C = 13; // B = dcb0000dc int dcb = (BitValue >> 1) & 7; B = (dcb << 6) | (dcb >> 1); break; } case 5: { C = 6; // B = edcb0000e int edcb = (BitValue >> 1) & 0xF; B = (edcb << 5) | (edcb >> 3); break; } default: throw new ASTCDecoderException("Unsupported quint encoding for color values!"); } break; } } if (IntEncoded.GetEncoding() != IntegerEncoded.EIntegerEncoding.JustBits) { int T = D * C + B; T ^= A; T = (A & 0x80) | (T >> 2); OutputValues[OutputIndices++] = T; } } // Make sure that each of our values is in the proper range... for (int i = 0; i < NumberValues; i++) { Debug.Assert(OutputValues[i] <= 255); } } static void FillVoidExtentLDR(BitArrayStream BitStream, int[] OutputBuffer, int BlockWidth, int BlockHeight) { // Don't actually care about the void extent, just read the bits... for (int i = 0; i < 4; ++i) { BitStream.ReadBits(13); } // Decode the RGBA components and renormalize them to the range [0, 255] ushort R = (ushort)BitStream.ReadBits(16); ushort G = (ushort)BitStream.ReadBits(16); ushort B = (ushort)BitStream.ReadBits(16); ushort A = (ushort)BitStream.ReadBits(16); int RGBA = (R >> 8) | (G & 0xFF00) | ((B) & 0xFF00) << 8 | ((A) & 0xFF00) << 16; for (int j = 0; j < BlockHeight; j++) { for (int i = 0; i < BlockWidth; i++) { OutputBuffer[j * BlockWidth + i] = RGBA; } } } static TexelWeightParams DecodeBlockInfo(BitArrayStream BitStream) { TexelWeightParams TexelParams = new TexelWeightParams(); // Read the entire block mode all at once ushort ModeBits = (ushort)BitStream.ReadBits(11); // Does this match the void extent block mode? if ((ModeBits & 0x01FF) == 0x1FC) { if ((ModeBits & 0x200) != 0) { TexelParams.VoidExtentHDR = true; } else { TexelParams.VoidExtentLDR = true; } // Next two bits must be one. if ((ModeBits & 0x400) == 0 || BitStream.ReadBits(1) == 0) { TexelParams.Error = true; } return TexelParams; } // First check if the last four bits are zero if ((ModeBits & 0xF) == 0) { TexelParams.Error = true; return TexelParams; } // If the last two bits are zero, then if bits // [6-8] are all ones, this is also reserved. if ((ModeBits & 0x3) == 0 && (ModeBits & 0x1C0) == 0x1C0) { TexelParams.Error = true; return TexelParams; } // Otherwise, there is no error... Figure out the layout // of the block mode. Layout is determined by a number // between 0 and 9 corresponding to table C.2.8 of the // ASTC spec. int Layout = 0; if ((ModeBits & 0x1) != 0 || (ModeBits & 0x2) != 0) { // layout is in [0-4] if ((ModeBits & 0x8) != 0) { // layout is in [2-4] if ((ModeBits & 0x4) != 0) { // layout is in [3-4] if ((ModeBits & 0x100) != 0) { Layout = 4; } else { Layout = 3; } } else { Layout = 2; } } else { // layout is in [0-1] if ((ModeBits & 0x4) != 0) { Layout = 1; } else { Layout = 0; } } } else { // layout is in [5-9] if ((ModeBits & 0x100) != 0) { // layout is in [7-9] if ((ModeBits & 0x80) != 0) { // layout is in [7-8] Debug.Assert((ModeBits & 0x40) == 0); if ((ModeBits & 0x20) != 0) { Layout = 8; } else { Layout = 7; } } else { Layout = 9; } } else { // layout is in [5-6] if ((ModeBits & 0x80) != 0) { Layout = 6; } else { Layout = 5; } } } Debug.Assert(Layout < 10); // Determine R int R = (ModeBits >> 4) & 1; if (Layout < 5) { R |= (ModeBits & 0x3) << 1; } else { R |= (ModeBits & 0xC) >> 1; } Debug.Assert(2 <= R && R <= 7); // Determine width & height switch (Layout) { case 0: { int A = (ModeBits >> 5) & 0x3; int B = (ModeBits >> 7) & 0x3; TexelParams.Width = B + 4; TexelParams.Height = A + 2; break; } case 1: { int A = (ModeBits >> 5) & 0x3; int B = (ModeBits >> 7) & 0x3; TexelParams.Width = B + 8; TexelParams.Height = A + 2; break; } case 2: { int A = (ModeBits >> 5) & 0x3; int B = (ModeBits >> 7) & 0x3; TexelParams.Width = A + 2; TexelParams.Height = B + 8; break; } case 3: { int A = (ModeBits >> 5) & 0x3; int B = (ModeBits >> 7) & 0x1; TexelParams.Width = A + 2; TexelParams.Height = B + 6; break; } case 4: { int A = (ModeBits >> 5) & 0x3; int B = (ModeBits >> 7) & 0x1; TexelParams.Width = B + 2; TexelParams.Height = A + 2; break; } case 5: { int A = (ModeBits >> 5) & 0x3; TexelParams.Width = 12; TexelParams.Height = A + 2; break; } case 6: { int A = (ModeBits >> 5) & 0x3; TexelParams.Width = A + 2; TexelParams.Height = 12; break; } case 7: { TexelParams.Width = 6; TexelParams.Height = 10; break; } case 8: { TexelParams.Width = 10; TexelParams.Height = 6; break; } case 9: { int A = (ModeBits >> 5) & 0x3; int B = (ModeBits >> 9) & 0x3; TexelParams.Width = A + 6; TexelParams.Height = B + 6; break; } default: //Don't know this layout... TexelParams.Error = true; break; } // Determine whether or not we're using dual planes // and/or high precision layouts. bool D = ((Layout != 9) && ((ModeBits & 0x400) != 0)); bool H = (Layout != 9) && ((ModeBits & 0x200) != 0); if (H) { int[] MaxWeights = { 9, 11, 15, 19, 23, 31 }; TexelParams.MaxWeight = MaxWeights[R - 2]; } else { int[] MaxWeights = { 1, 2, 3, 4, 5, 7 }; TexelParams.MaxWeight = MaxWeights[R - 2]; } TexelParams.DualPlane = D; return TexelParams; } } }