public static IntegerEncoded CreateEncoding(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, BitArrayStream.PopCnt(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, BitArrayStream.PopCnt(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, BitArrayStream.PopCnt(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 DecodeIntegerSequence( List <IntegerEncoded> decodeIntegerSequence, BitArrayStream 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(bitStream, decodeIntegerSequence, intEncoded.NumberBits); numberValuesDecoded += 3; break; } case EIntegerEncoding.Trit: { DecodeTritBlock(bitStream, decodeIntegerSequence, intEncoded.NumberBits); numberValuesDecoded += 5; break; } case EIntegerEncoding.JustBits: { intEncoded.BitValue = bitStream.ReadBits(intEncoded.NumberBits); decodeIntegerSequence.Add(intEncoded); numberValuesDecoded++; break; } } } }
public static void DecodeIntegerSequence( List <IntegerEncoded> DecodeIntegerSequence, BitArrayStream 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(BitStream, DecodeIntegerSequence, IntEncoded.NumberBits); NumberValuesDecoded += 3; break; } case EIntegerEncoding.Trit: { DecodeTritBlock(BitStream, DecodeIntegerSequence, IntEncoded.NumberBits); NumberValuesDecoded += 5; break; } case EIntegerEncoding.JustBits: { IntEncoded.BitValue = BitStream.ReadBits(IntEncoded.NumberBits); DecodeIntegerSequence.Add(IntEncoded); NumberValuesDecoded++; break; } } } }
short ChangeBitDepth(short value, byte oldDepth, byte newDepth) { Debug.Assert(newDepth <= 8); Debug.Assert(oldDepth <= 8); if (oldDepth == newDepth) { // Do nothing return(value); } else if (oldDepth == 0 && newDepth != 0) { return((short)((1 << newDepth) - 1)); } else if (newDepth > oldDepth) { return((short)BitArrayStream.Replicate(value, oldDepth, newDepth)); } else { // oldDepth > newDepth if (newDepth == 0) { return(0xFF); } else { byte bitsWasted = (byte)(oldDepth - newDepth); short tempValue = value; tempValue = (short)((tempValue + (1 << (bitsWasted - 1))) >> bitsWasted); tempValue = Math.Min(Math.Max((short)0, tempValue), (short)((1 << newDepth) - 1)); return((byte)(tempValue)); } } }
short ChangeBitDepth(short Value, byte OldDepth, byte NewDepth) { Debug.Assert(NewDepth <= 8); Debug.Assert(OldDepth <= 8); if (OldDepth == NewDepth) { // Do nothing return(Value); } else if (OldDepth == 0 && NewDepth != 0) { return((short)((1 << NewDepth) - 1)); } else if (NewDepth > OldDepth) { return((short)BitArrayStream.Replicate(Value, OldDepth, NewDepth)); } else { // oldDepth > newDepth if (NewDepth == 0) { return(0xFF); } else { byte BitsWasted = (byte)(OldDepth - NewDepth); short TempValue = Value; TempValue = (short)((TempValue + (1 << (BitsWasted - 1))) >> BitsWasted); TempValue = Math.Min(Math.Max((short)0, TempValue), (short)((1 << NewDepth) - 1)); return((byte)(TempValue)); } } }
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 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; } } }
public static void DecodeTritBlock( BitArrayStream BitStream, List <IntegerEncoded> ListIntegerEncoded, int NumberBitsPerValue) { // Implement the algorithm in section C.2.12 int[] m = new int[5]; int[] t = new int[5]; int T; // Read the trit encoded block according to // table C.2.14 m[0] = BitStream.ReadBits(NumberBitsPerValue); T = BitStream.ReadBits(2); m[1] = BitStream.ReadBits(NumberBitsPerValue); T |= BitStream.ReadBits(2) << 2; m[2] = BitStream.ReadBits(NumberBitsPerValue); T |= BitStream.ReadBits(1) << 4; m[3] = BitStream.ReadBits(NumberBitsPerValue); T |= BitStream.ReadBits(2) << 5; m[4] = BitStream.ReadBits(NumberBitsPerValue); T |= BitStream.ReadBits(1) << 7; int C = 0; BitArrayStream Tb = new BitArrayStream(new BitArray(new int[] { T })); if (Tb.ReadBits(2, 4) == 7) { C = (Tb.ReadBits(5, 7) << 2) | Tb.ReadBits(0, 1); t[4] = t[3] = 2; } else { C = Tb.ReadBits(0, 4); if (Tb.ReadBits(5, 6) == 3) { t[4] = 2; t[3] = Tb.ReadBit(7); } else { t[4] = Tb.ReadBit(7); t[3] = Tb.ReadBits(5, 6); } } BitArrayStream Cb = new BitArrayStream(new BitArray(new int[] { C })); if (Cb.ReadBits(0, 1) == 3) { t[2] = 2; t[1] = Cb.ReadBit(4); t[0] = (Cb.ReadBit(3) << 1) | (Cb.ReadBit(2) & ~Cb.ReadBit(3)); } else if (Cb.ReadBits(2, 3) == 3) { t[2] = 2; t[1] = 2; t[0] = Cb.ReadBits(0, 1); } else { t[2] = Cb.ReadBit(4); t[1] = Cb.ReadBits(2, 3); t[0] = (Cb.ReadBit(1) << 1) | (Cb.ReadBit(0) & ~Cb.ReadBit(1)); } for (int i = 0; i < 5; i++) { IntegerEncoded IntEncoded = new IntegerEncoded(EIntegerEncoding.Trit, NumberBitsPerValue) { BitValue = m[i], TritValue = t[i] }; ListIntegerEncoded.Add(IntEncoded); } }
public static void DecodeTritBlock( BitArrayStream bitStream, List <IntegerEncoded> listIntegerEncoded, int numberBitsPerValue) { // Implement the algorithm in section C.2.12 int[] m = new int[5]; int[] t = new int[5]; int T; // Read the trit encoded block according to // table C.2.14 m[0] = bitStream.ReadBits(numberBitsPerValue); T = bitStream.ReadBits(2); m[1] = bitStream.ReadBits(numberBitsPerValue); T |= bitStream.ReadBits(2) << 2; m[2] = bitStream.ReadBits(numberBitsPerValue); T |= bitStream.ReadBits(1) << 4; m[3] = bitStream.ReadBits(numberBitsPerValue); T |= bitStream.ReadBits(2) << 5; m[4] = bitStream.ReadBits(numberBitsPerValue); T |= bitStream.ReadBits(1) << 7; int c = 0; BitArrayStream tb = new BitArrayStream(new BitArray(new int[] { T })); if (tb.ReadBits(2, 4) == 7) { c = (tb.ReadBits(5, 7) << 2) | tb.ReadBits(0, 1); t[4] = t[3] = 2; } else { c = tb.ReadBits(0, 4); if (tb.ReadBits(5, 6) == 3) { t[4] = 2; t[3] = tb.ReadBit(7); } else { t[4] = tb.ReadBit(7); t[3] = tb.ReadBits(5, 6); } } BitArrayStream cb = new BitArrayStream(new BitArray(new int[] { c })); if (cb.ReadBits(0, 1) == 3) { t[2] = 2; t[1] = cb.ReadBit(4); t[0] = (cb.ReadBit(3) << 1) | (cb.ReadBit(2) & ~cb.ReadBit(3)); } else if (cb.ReadBits(2, 3) == 3) { t[2] = 2; t[1] = 2; t[0] = cb.ReadBits(0, 1); } else { t[2] = cb.ReadBit(4); t[1] = cb.ReadBits(2, 3); t[0] = (cb.ReadBit(1) << 1) | (cb.ReadBit(0) & ~cb.ReadBit(1)); } for (int i = 0; i < 5; i++) { IntegerEncoded intEncoded = new IntegerEncoded(EIntegerEncoding.Trit, numberBitsPerValue) { BitValue = m[i], TritValue = t[i] }; listIntegerEncoded.Add(intEncoded); } }
public static void DecodeQuintBlock( BitArrayStream bitStream, List <IntegerEncoded> listIntegerEncoded, int numberBitsPerValue) { // Implement the algorithm in section C.2.12 int[] m = new int[3]; int[] qa = new int[3]; int q; // Read the trit encoded block according to // table C.2.15 m[0] = bitStream.ReadBits(numberBitsPerValue); q = bitStream.ReadBits(3); m[1] = bitStream.ReadBits(numberBitsPerValue); q |= bitStream.ReadBits(2) << 3; m[2] = bitStream.ReadBits(numberBitsPerValue); q |= bitStream.ReadBits(2) << 5; BitArrayStream qb = new BitArrayStream(new BitArray(new int[] { q })); if (qb.ReadBits(1, 2) == 3 && qb.ReadBits(5, 6) == 0) { qa[0] = qa[1] = 4; qa[2] = (qb.ReadBit(0) << 2) | ((qb.ReadBit(4) & ~qb.ReadBit(0)) << 1) | (qb.ReadBit(3) & ~qb.ReadBit(0)); } else { int c = 0; if (qb.ReadBits(1, 2) == 3) { qa[2] = 4; c = (qb.ReadBits(3, 4) << 3) | ((~qb.ReadBits(5, 6) & 3) << 1) | qb.ReadBit(0); } else { qa[2] = qb.ReadBits(5, 6); c = qb.ReadBits(0, 4); } BitArrayStream cb = new BitArrayStream(new BitArray(new int[] { c })); if (cb.ReadBits(0, 2) == 5) { qa[1] = 4; qa[0] = cb.ReadBits(3, 4); } else { qa[1] = cb.ReadBits(3, 4); qa[0] = cb.ReadBits(0, 2); } } for (int i = 0; i < 3; i++) { IntegerEncoded intEncoded = new IntegerEncoded(EIntegerEncoding.Quint, numberBitsPerValue) { BitValue = m[i], QuintValue = qa[i] }; listIntegerEncoded.Add(intEncoded); } }
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 <IntegerEncoded> texelWeightValues = new List <IntegerEncoded>(); 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); }
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 <IntegerEncoded> IntegerEncodedSequence = new List <IntegerEncoded>(); 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 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); }
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); }
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 <IntegerEncoded> TexelWeightValues = new List <IntegerEncoded>(); 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); }
public static void DecodeQuintBlock( BitArrayStream BitStream, List <IntegerEncoded> ListIntegerEncoded, int NumberBitsPerValue) { // Implement the algorithm in section C.2.12 int[] m = new int[3]; int[] q = new int[3]; int Q; // Read the trit encoded block according to // table C.2.15 m[0] = BitStream.ReadBits(NumberBitsPerValue); Q = BitStream.ReadBits(3); m[1] = BitStream.ReadBits(NumberBitsPerValue); Q |= BitStream.ReadBits(2) << 3; m[2] = BitStream.ReadBits(NumberBitsPerValue); Q |= BitStream.ReadBits(2) << 5; BitArrayStream Qb = new BitArrayStream(new BitArray(new int[] { Q })); if (Qb.ReadBits(1, 2) == 3 && Qb.ReadBits(5, 6) == 0) { q[0] = q[1] = 4; q[2] = (Qb.ReadBit(0) << 2) | ((Qb.ReadBit(4) & ~Qb.ReadBit(0)) << 1) | (Qb.ReadBit(3) & ~Qb.ReadBit(0)); } else { int C = 0; if (Qb.ReadBits(1, 2) == 3) { q[2] = 4; C = (Qb.ReadBits(3, 4) << 3) | ((~Qb.ReadBits(5, 6) & 3) << 1) | Qb.ReadBit(0); } else { q[2] = Qb.ReadBits(5, 6); C = Qb.ReadBits(0, 4); } BitArrayStream Cb = new BitArrayStream(new BitArray(new int[] { C })); if (Cb.ReadBits(0, 2) == 5) { q[1] = 4; q[0] = Cb.ReadBits(3, 4); } else { q[1] = Cb.ReadBits(3, 4); q[0] = Cb.ReadBits(0, 2); } } for (int i = 0; i < 3; i++) { IntegerEncoded IntEncoded = new IntegerEncoded(EIntegerEncoding.Quint, NumberBitsPerValue) { BitValue = m[i], QuintValue = q[i] }; ListIntegerEncoded.Add(IntEncoded); } }
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 b2 = (bitValue >> 1) & 1; b = (b2 << 6) | (b2 << 2) | b2; 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 b2 = (bitValue >> 1) & 1; b = (b2 << 6) | (b2 << 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 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 <IntegerEncoded> integerEncodedSequence = new List <IntegerEncoded>(); 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 b2 = (bitValue >> 1) & 1; b = (b2 << 8) | (b2 << 4) | (b2 << 2) | (b2 << 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 b2 = (bitValue >> 1) & 1; b = (b2 << 8) | (b2 << 3) | (b2 << 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 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?)"); } }