astc: Make IntegerEncodedValue a trivial structure

This commit is contained in:
ReinUsesLisp 2020-03-13 22:49:28 -03:00
parent 70a31eda62
commit e183820956

View file

@ -160,124 +160,34 @@ private:
enum class IntegerEncoding { JustBits, Qus32, Trit };
class IntegerEncodedValue {
private:
IntegerEncoding m_Encoding{};
u32 m_NumBits = 0;
u32 m_BitValue = 0;
union {
u32 m_Qus32Value = 0;
u32 m_TritValue;
};
struct IntegerEncodedValue {
constexpr IntegerEncodedValue(IntegerEncoding encoding_, u32 num_bits_)
: encoding{encoding_}, num_bits{num_bits_} {}
public:
constexpr IntegerEncodedValue() = default;
constexpr IntegerEncodedValue(IntegerEncoding encoding, u32 numBits)
: m_Encoding(encoding), m_NumBits(numBits) {}
IntegerEncoding GetEncoding() const {
return m_Encoding;
}
u32 BaseBitLength() const {
return m_NumBits;
}
u32 GetBitValue() const {
return m_BitValue;
}
void SetBitValue(u32 val) {
m_BitValue = val;
}
u32 GetTritValue() const {
return m_TritValue;
}
void SetTritValue(u32 val) {
m_TritValue = val;
}
u32 GetQus32Value() const {
return m_Qus32Value;
}
void SetQus32Value(u32 val) {
m_Qus32Value = val;
}
bool MatchesEncoding(const IntegerEncodedValue& other) const {
return m_Encoding == other.m_Encoding && m_NumBits == other.m_NumBits;
constexpr bool MatchesEncoding(const IntegerEncodedValue& other) const {
return encoding == other.encoding && num_bits == other.num_bits;
}
// Returns the number of bits required to encode nVals values.
u32 GetBitLength(u32 nVals) const {
u32 totalBits = m_NumBits * nVals;
if (m_Encoding == IntegerEncoding::Trit) {
u32 totalBits = num_bits * nVals;
if (encoding == IntegerEncoding::Trit) {
totalBits += (nVals * 8 + 4) / 5;
} else if (m_Encoding == IntegerEncoding::Qus32) {
} else if (encoding == IntegerEncoding::Qus32) {
totalBits += (nVals * 7 + 2) / 3;
}
return totalBits;
}
// Returns a new instance of this struct that corresponds to the
// can take no more than maxval values
static IntegerEncodedValue CreateEncoding(u32 maxVal) {
while (maxVal > 0) {
u32 check = maxVal + 1;
IntegerEncoding encoding;
u32 num_bits;
u32 bit_value = 0;
union {
u32 qus32_value = 0;
u32 trit_value;
};
};
// Is maxVal a power of two?
if (!(check & (check - 1))) {
return IntegerEncodedValue(IntegerEncoding::JustBits, Popcnt(maxVal));
}
// Is maxVal of the type 3*2^n - 1?
if ((check % 3 == 0) && !((check / 3) & ((check / 3) - 1))) {
return IntegerEncodedValue(IntegerEncoding::Trit, Popcnt(check / 3 - 1));
}
// Is maxVal of the type 5*2^n - 1?
if ((check % 5 == 0) && !((check / 5) & ((check / 5) - 1))) {
return IntegerEncodedValue(IntegerEncoding::Qus32, Popcnt(check / 5 - 1));
}
// Apparently it can't be represented with a bounded s32eger sequence...
// just iterate.
maxVal--;
}
return IntegerEncodedValue(IntegerEncoding::JustBits, 0);
}
// Fills result with the values that are encoded in the given
// bitstream. We must know beforehand what the maximum possible
// value is, and how many values we're decoding.
static void DecodeIntegerSequence(std::vector<IntegerEncodedValue>& result,
InputBitStream& bits, u32 maxRange, u32 nValues) {
// Determine encoding parameters
IntegerEncodedValue val = IntegerEncodedValue::CreateEncoding(maxRange);
// Start decoding
u32 nValsDecoded = 0;
while (nValsDecoded < nValues) {
switch (val.GetEncoding()) {
case IntegerEncoding::Qus32:
DecodeQus32Block(bits, result, val.BaseBitLength());
nValsDecoded += 3;
break;
case IntegerEncoding::Trit:
DecodeTritBlock(bits, result, val.BaseBitLength());
nValsDecoded += 5;
break;
case IntegerEncoding::JustBits:
val.SetBitValue(bits.ReadBits(val.BaseBitLength()));
result.push_back(val);
nValsDecoded++;
break;
}
}
}
private:
static void DecodeTritBlock(InputBitStream& bits, std::vector<IntegerEncodedValue>& result,
u32 nBitsPerValue) {
// Implement the algorithm in section C.2.12
@ -330,11 +240,10 @@ private:
t[0] = (Cb[1] << 1) | (Cb[0] & ~Cb[1]);
}
for (u32 i = 0; i < 5; i++) {
IntegerEncodedValue val(IntegerEncoding::Trit, nBitsPerValue);
val.SetBitValue(m[i]);
val.SetTritValue(t[i]);
result.push_back(val);
for (std::size_t i = 0; i < 5; ++i) {
IntegerEncodedValue& val = result.emplace_back(IntegerEncoding::Trit, nBitsPerValue);
val.bit_value = m[i];
val.trit_value = t[i];
}
}
@ -378,14 +287,71 @@ private:
}
}
for (u32 i = 0; i < 3; i++) {
IntegerEncodedValue val(IntegerEncoding::Qus32, nBitsPerValue);
val.m_BitValue = m[i];
val.m_Qus32Value = q[i];
for (std::size_t i = 0; i < 3; ++i) {
IntegerEncodedValue& val = result.emplace_back(IntegerEncoding::Qus32, nBitsPerValue);
val.bit_value = m[i];
val.qus32_value = q[i];
}
}
// Returns a new instance of this struct that corresponds to the
// can take no more than maxval values
static IntegerEncodedValue CreateEncoding(u32 maxVal) {
while (maxVal > 0) {
u32 check = maxVal + 1;
// Is maxVal a power of two?
if (!(check & (check - 1))) {
return IntegerEncodedValue(IntegerEncoding::JustBits, Popcnt(maxVal));
}
// Is maxVal of the type 3*2^n - 1?
if ((check % 3 == 0) && !((check / 3) & ((check / 3) - 1))) {
return IntegerEncodedValue(IntegerEncoding::Trit, Popcnt(check / 3 - 1));
}
// Is maxVal of the type 5*2^n - 1?
if ((check % 5 == 0) && !((check / 5) & ((check / 5) - 1))) {
return IntegerEncodedValue(IntegerEncoding::Qus32, Popcnt(check / 5 - 1));
}
// Apparently it can't be represented with a bounded s32eger sequence...
// just iterate.
maxVal--;
}
return IntegerEncodedValue(IntegerEncoding::JustBits, 0);
}
// Fills result with the values that are encoded in the given
// bitstream. We must know beforehand what the maximum possible
// value is, and how many values we're decoding.
static void DecodeIntegerSequence(std::vector<IntegerEncodedValue>& result, InputBitStream& bits,
u32 maxRange, u32 nValues) {
// Determine encoding parameters
IntegerEncodedValue val = CreateEncoding(maxRange);
// Start decoding
u32 nValsDecoded = 0;
while (nValsDecoded < nValues) {
switch (val.encoding) {
case IntegerEncoding::Qus32:
DecodeQus32Block(bits, result, val.num_bits);
nValsDecoded += 3;
break;
case IntegerEncoding::Trit:
DecodeTritBlock(bits, result, val.num_bits);
nValsDecoded += 5;
break;
case IntegerEncoding::JustBits:
val.bit_value = bits.ReadBits(val.num_bits);
result.push_back(val);
nValsDecoded++;
break;
}
}
}
};
namespace ASTCC {
@ -405,7 +371,7 @@ struct TexelWeightParams {
nIdxs *= 2;
}
return IntegerEncodedValue::CreateEncoding(m_MaxWeight).GetBitLength(nIdxs);
return CreateEncoding(m_MaxWeight).GetBitLength(nIdxs);
}
u32 GetNumWeightValues() const {
@ -814,12 +780,12 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
// figure out the max value for each of them...
u32 range = 256;
while (--range > 0) {
IntegerEncodedValue val = IntegerEncodedValue::CreateEncoding(range);
IntegerEncodedValue val = CreateEncoding(range);
u32 bitLength = val.GetBitLength(nValues);
if (bitLength <= nBitsForColorData) {
// Find the smallest possible range that matches the given encoding
while (--range > 0) {
IntegerEncodedValue newval = IntegerEncodedValue::CreateEncoding(range);
IntegerEncodedValue newval = CreateEncoding(range);
if (!newval.MatchesEncoding(val)) {
break;
}
@ -834,7 +800,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
// We now have enough to decode our s32eger sequence.
std::vector<IntegerEncodedValue> decodedColorValues;
InputBitStream colorStream(data);
IntegerEncodedValue::DecodeIntegerSequence(decodedColorValues, colorStream, range, nValues);
DecodeIntegerSequence(decodedColorValues, colorStream, range, nValues);
// 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
@ -846,8 +812,8 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
}
const IntegerEncodedValue& val = *itr;
u32 bitlen = val.BaseBitLength();
u32 bitval = val.GetBitValue();
u32 bitlen = val.num_bits;
u32 bitval = val.bit_value;
assert(bitlen >= 1);
@ -855,7 +821,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
// A is just the lsb replicated 9 times.
A = Replicate(bitval & 1, 1, 9);
switch (val.GetEncoding()) {
switch (val.encoding) {
// Replicate bits
case IntegerEncoding::JustBits:
out[outIdx++] = Replicate(bitval, bitlen, 8);
@ -864,7 +830,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
// Use algorithm in C.2.13
case IntegerEncoding::Trit: {
D = val.GetTritValue();
D = val.trit_value;
switch (bitlen) {
case 1: {
@ -915,7 +881,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
case IntegerEncoding::Qus32: {
D = val.GetQus32Value();
D = val.qus32_value;
switch (bitlen) {
case 1: {
@ -956,9 +922,9 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
} // switch(bitlen)
} // case IntegerEncoding::Qus32
break;
} // switch(val.GetEncoding())
} // switch(val.encoding)
if (val.GetEncoding() != IntegerEncoding::JustBits) {
if (val.encoding != IntegerEncoding::JustBits) {
u32 T = D * C + B;
T ^= A;
T = (A & 0x80) | (T >> 2);
@ -973,20 +939,20 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
}
static u32 UnquantizeTexelWeight(const IntegerEncodedValue& val) {
u32 bitval = val.GetBitValue();
u32 bitlen = val.BaseBitLength();
u32 bitval = val.bit_value;
u32 bitlen = val.num_bits;
u32 A = Replicate(bitval & 1, 1, 7);
u32 B = 0, C = 0, D = 0;
u32 result = 0;
switch (val.GetEncoding()) {
switch (val.encoding) {
case IntegerEncoding::JustBits:
result = Replicate(bitval, bitlen, 6);
break;
case IntegerEncoding::Trit: {
D = val.GetTritValue();
D = val.trit_value;
assert(D < 3);
switch (bitlen) {
@ -1018,7 +984,7 @@ static u32 UnquantizeTexelWeight(const IntegerEncodedValue& val) {
} break;
case IntegerEncoding::Qus32: {
D = val.GetQus32Value();
D = val.qus32_value;
assert(D < 5);
switch (bitlen) {
@ -1044,7 +1010,7 @@ static u32 UnquantizeTexelWeight(const IntegerEncodedValue& val) {
} break;
}
if (val.GetEncoding() != IntegerEncoding::JustBits && bitlen > 0) {
if (val.encoding != IntegerEncoding::JustBits && bitlen > 0) {
// Decode the value...
result = D * C + B;
result ^= A;
@ -1562,8 +1528,7 @@ static void DecompressBlock(const u8 inBuf[16], const u32 blockWidth, const u32
std::vector<IntegerEncodedValue> texelWeightValues;
InputBitStream weightStream(texelWeightData);
IntegerEncodedValue::DecodeIntegerSequence(texelWeightValues, weightStream,
weightParams.m_MaxWeight,
DecodeIntegerSequence(texelWeightValues, weightStream, weightParams.m_MaxWeight,
weightParams.GetNumWeightValues());
// Blocks can be at most 12x12, so we can have as many as 144 weights