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using System.Collections;
using System.Collections.Generic;
namespace Ryujinx.Graphics.Texture
{
public struct IntegerEncoded
{
public enum EIntegerEncoding
{
JustBits,
Quint,
Trit
}
EIntegerEncoding _encoding;
public int NumberBits { get; private set; }
public int BitValue { get; private set; }
public int TritValue { get; private set; }
public int QuintValue { get; private set; }
public IntegerEncoded(EIntegerEncoding encoding, int numBits)
{
_encoding = encoding;
NumberBits = numBits;
BitValue = 0;
TritValue = 0;
QuintValue = 0;
}
public bool MatchesEncoding(IntegerEncoded other)
{
return _encoding == other._encoding && NumberBits == other.NumberBits;
}
public EIntegerEncoding GetEncoding()
{
return _encoding;
}
public int GetBitLength(int numberVals)
{
int totalBits = NumberBits * numberVals;
if (_encoding == EIntegerEncoding.Trit)
{
totalBits += (numberVals * 8 + 4) / 5;
}
else if (_encoding == EIntegerEncoding.Quint)
{
totalBits += (numberVals * 7 + 2) / 3;
}
return totalBits;
}
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 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 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;
}
}
}
}
}
}
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