Ryujinx/Ryujinx.Graphics.Texture/Astc/AstcDecoder.cs

1403 lines
48 KiB
C#

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
namespace Ryujinx.Graphics.Texture.Astc
{
// 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 bool TryDecodeToRgba8(
Span<byte> data,
int blockWidth,
int blockHeight,
int blockDepth,
int width,
int height,
int depth,
int levels,
out Span<byte> decoded)
{
bool success = true;
using (MemoryStream inputStream = new MemoryStream(data.ToArray()))
{
BinaryReader binReader = new BinaryReader(inputStream);
if (blockWidth > 12 || blockHeight > 12)
{
throw new AstcDecoderException("Invalid block size.");
}
if (blockDepth != 1 || depth != 1)
{
// TODO: Support 3D textures.
throw new NotImplementedException("3D compressed textures are not unsupported.");
}
using (MemoryStream outputStream = new MemoryStream())
{
int blockIndex = 0;
int mipOffset = 0;
for (int l = 0; l < levels; l++)
{
for (int j = 0; j < height; j += blockHeight)
for (int i = 0; i < width; i += blockWidth)
{
int[] decompressedData = new int[144];
try
{
DecompressBlock(binReader.ReadBytes(0x10), decompressedData, blockWidth, blockHeight);
}
catch (Exception)
{
success = false;
}
int decompressedWidth = Math.Min(blockWidth, width - i);
int decompressedHeight = Math.Min(blockHeight, height - j);
int baseOffset = mipOffset + (j * width + i) * 4;
for (int jj = 0; jj < decompressedHeight; jj++)
{
outputStream.Seek(baseOffset + jj * width * 4, SeekOrigin.Begin);
byte[] outputBuffer = new byte[decompressedData.Length * sizeof(int)];
Buffer.BlockCopy(decompressedData, 0, outputBuffer, 0, outputBuffer.Length);
outputStream.Write(outputBuffer, jj * blockWidth * 4, decompressedWidth * 4);
}
blockIndex++;
}
mipOffset += width * height * 4;
width = Math.Max(1, width >> 1);
height = Math.Max(1, height >> 1);
}
decoded = outputStream.ToArray();
}
}
return success;
}
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 not supported.");
}
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;
}
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<IntegerEncoded> 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 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 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<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 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;
}
}
}