private IList <Color> DecodeSinglePartition(BitReader br, BlockMode blockMode)
{
var colorEndpointMode = DecodeColorEndpointModes(br, blockMode, 1)[0];
if (colorEndpointMode.EndpointValueCount > 18 || blockMode.IsHdr != colorEndpointMode.IsHdr)
{
return(ErrorColors);
}
var colorBits = ColorHelper.CalculateColorBits(1, blockMode.WeightBitCount, blockMode.IsDualPlane);
var quantizationLevel = ColorHelper.QuantizationModeTable[colorEndpointMode.EndpointValueCount >> 1][colorBits];
if (quantizationLevel < 4)
{
return(ErrorColors);
}
var colorValues = IntegerSequenceEncoding.Decode(br, quantizationLevel, colorEndpointMode.EndpointValueCount);
var colorEndpoints = ColorUnquantization.DecodeColorEndpoints(colorValues, colorEndpointMode.Format, quantizationLevel);
// Weights decoding
br.Position = 128 - blockMode.WeightBitCount;
var result = new Color[_x * _y * _z];
if (blockMode.IsDualPlane)
{
br.Position = 128 - blockMode.WeightBitCount - 2;
var plane2ColorComponent = br.ReadBits <int>(2);
var indices = IntegerSequenceEncoding.Decode(br, blockMode.QuantizationMode, blockMode.WeightCount);
for (var i = 0; i < blockMode.WeightCount; i++)
{
var plane1Weight = WeightUnquantization.WeightUnquantizationTable[blockMode.QuantizationMode][indices[i * 2]];
var plane2Weight = WeightUnquantization.WeightUnquantizationTable[blockMode.QuantizationMode][indices[i * 2 + 1]];
result[i] = ColorHelper.InterpolateColor(colorEndpoints, plane1Weight, plane2Weight, plane2ColorComponent);
}
}
else
{
var indices = IntegerSequenceEncoding.Decode(br, blockMode.QuantizationMode, blockMode.WeightCount);
for (var i = 0; i < blockMode.WeightCount; i++)
{
var weight = WeightUnquantization.WeightUnquantizationTable[blockMode.QuantizationMode][indices[i]];
result[i] = ColorHelper.InterpolateColor(colorEndpoints, weight, -1, -1);
}
}
return(result);
}
private IList <Color> DecodeMultiPartition(BitReader br, BlockMode blockMode, int partitions)
{
var colorEndpointModes = DecodeColorEndpointModes(br, blockMode, partitions);
var colorValueCount = colorEndpointModes.Sum(x => x.EndpointValueCount);
if (colorValueCount > 18 || colorEndpointModes.Any(x => x.IsHdr != blockMode.IsHdr))
{
return(ErrorColors);
}
var colorBits = ColorHelper.CalculateColorBits(partitions, blockMode.WeightBitCount, blockMode.IsDualPlane);
var quantizationLevel = ColorHelper.QuantizationModeTable[colorValueCount >> 1][colorBits];
if (quantizationLevel < 4)
{
return(ErrorColors);
}
br.Position = 19 + Constants.PartitionBits;
var colorValues = IntegerSequenceEncoding.Decode(br, quantizationLevel, colorValueCount);
var colorEndpoints = new UInt4[partitions][];
for (var i = 0; i < partitions; i++)
{
colorEndpoints[i] = ColorUnquantization.DecodeColorEndpoints(colorValues, colorEndpointModes[i].Format, quantizationLevel);
}
br.Position = 13;
var partitionIndex = br.ReadBits <uint>(10);
var elementsInBlock = _x * _y * _z;
var partitionIndices = new int[elementsInBlock];
for (int z = 0; z < _z; z++)
{
for (int y = 0; y < _y; y++)
{
for (int x = 0; x < _x; x++)
{
partitionIndices[x * y * z] =
PartitionSelection.SelectPartition(partitionIndex, x, y, z, partitions, elementsInBlock < 32);
}
}
}
var result = new Color[elementsInBlock];
if (blockMode.IsDualPlane)
{
// TODO: Should those 2 bits below the weights be here for multi partition due to encodedType high part?
br.Position = 128 - blockMode.WeightBitCount - 2;
var plane2ColorComponent = br.ReadBits <int>(2);
var indices = IntegerSequenceEncoding.Decode(br, blockMode.QuantizationMode, blockMode.WeightCount);
for (var i = 0; i < blockMode.WeightCount; i++)
{
var plane1Weight = WeightUnquantization.WeightUnquantizationTable[blockMode.QuantizationMode][indices[i * 2]];
var plane2Weight = WeightUnquantization.WeightUnquantizationTable[blockMode.QuantizationMode][indices[i * 2 + 1]];
result[i] = ColorHelper.InterpolateColor(colorEndpoints[partitionIndices[i]], plane1Weight, plane2Weight, plane2ColorComponent);
}
}
else
{
var indices = IntegerSequenceEncoding.Decode(br, blockMode.QuantizationMode, blockMode.WeightCount);
for (var i = 0; i < blockMode.WeightCount; i++)
{
var weight = WeightUnquantization.WeightUnquantizationTable[blockMode.QuantizationMode][indices[i]];
result[i] = ColorHelper.InterpolateColor(colorEndpoints[partitionIndices[i]], weight, -1, -1);
}
}
return(result);
}