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 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 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); }
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 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); }
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); }