// Copyright 2016 The University of North Carolina at Chapel Hill
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Please send all BUG REPORTS to <pavel@cs.unc.edu>.
// <http://gamma.cs.unc.edu/FasTC/>
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <cstring>
#include <vector>
#include "video_core/textures/astc.h"
class BitStream {
public:
explicit BitStream(unsigned char* ptr, int nBits = 0, int start_offset = 0)
: m_NumBits(nBits), m_CurByte(ptr), m_NextBit(start_offset % 8) {}
~BitStream() = default;
int GetBitsWritten() const {
return m_BitsWritten;
}
void WriteBitsR(unsigned int val, unsigned int nBits) {
for (unsigned int i = 0; i < nBits; i++) {
WriteBit((val >> (nBits - i - 1)) & 1);
}
}
void WriteBits(unsigned int val, unsigned int nBits) {
for (unsigned int i = 0; i < nBits; i++) {
WriteBit((val >> i) & 1);
}
}
int GetBitsRead() const {
return m_BitsRead;
}
int ReadBit() {
int bit = *m_CurByte >> m_NextBit++;
while (m_NextBit >= 8) {
m_NextBit -= 8;
m_CurByte++;
}
m_BitsRead++;
return bit & 1;
}
unsigned int ReadBits(unsigned int nBits) {
unsigned int ret = 0;
for (unsigned int i = 0; i < nBits; i++) {
ret |= (ReadBit() & 1) << i;
}
return ret;
}
private:
void WriteBit(int b) {
if (done)
return;
const unsigned int mask = 1 << m_NextBit++;
// clear the bit
*m_CurByte &= ~mask;
// Write the bit, if necessary
if (b)
*m_CurByte |= mask;
// Next byte?
if (m_NextBit >= 8) {
m_CurByte += 1;
m_NextBit = 0;
}
done = done || ++m_BitsWritten >= m_NumBits;
}
int m_BitsWritten = 0;
const int m_NumBits;
unsigned char* m_CurByte;
int m_NextBit = 0;
int m_BitsRead = 0;
bool done = false;
};
template <typename IntType>
class Bits {
private:
const IntType& m_Bits;
// Don't copy
Bits() {}
Bits(const Bits&) {}
Bits& operator=(const Bits&) {}
public:
explicit Bits(IntType& v) : m_Bits(v) {}
uint8_t operator[](uint32_t bitPos) {
return static_cast<uint8_t>((m_Bits >> bitPos) & 1);
}
IntType operator()(uint32_t start, uint32_t end) {
if (start == end) {
return (*this)[start];
} else if (start > end) {
uint32_t t = start;
start = end;
end = t;
}
uint64_t mask = (1 << (end - start + 1)) - 1;
return (m_Bits >> start) & mask;
}
};
enum EIntegerEncoding { eIntegerEncoding_JustBits, eIntegerEncoding_Quint, eIntegerEncoding_Trit };
class IntegerEncodedValue {
private:
const EIntegerEncoding m_Encoding;
const uint32_t m_NumBits;
uint32_t m_BitValue;
union {
uint32_t m_QuintValue;
uint32_t m_TritValue;
};
public:
// Jank, but we're not doing any heavy lifting in this class, so it's
// probably OK. It allows us to use these in std::vectors...
IntegerEncodedValue& operator=(const IntegerEncodedValue& other) {
new (this) IntegerEncodedValue(other);
return *this;
}
IntegerEncodedValue(EIntegerEncoding encoding, uint32_t numBits)
: m_Encoding(encoding), m_NumBits(numBits) {}
EIntegerEncoding GetEncoding() const {
return m_Encoding;
}
uint32_t BaseBitLength() const {
return m_NumBits;
}
uint32_t GetBitValue() const {
return m_BitValue;
}
void SetBitValue(uint32_t val) {
m_BitValue = val;
}
uint32_t GetTritValue() const {
return m_TritValue;
}
void SetTritValue(uint32_t val) {
m_TritValue = val;
}
uint32_t GetQuintValue() const {
return m_QuintValue;
}
void SetQuintValue(uint32_t val) {
m_QuintValue = val;
}
bool MatchesEncoding(const IntegerEncodedValue& other) {
return m_Encoding == other.m_Encoding && m_NumBits == other.m_NumBits;
}
// Returns the number of bits required to encode nVals values.
uint32_t GetBitLength(uint32_t nVals) {
uint32_t totalBits = m_NumBits * nVals;
if (m_Encoding == eIntegerEncoding_Trit) {
totalBits += (nVals * 8 + 4) / 5;
} else if (m_Encoding == eIntegerEncoding_Quint) {
totalBits += (nVals * 7 + 2) / 3;
}
return totalBits;
}
// Count the number of bits set in a number.
static inline uint32_t Popcnt(uint32_t n) {
uint32_t c;
for (c = 0; n; c++) {
n &= n - 1;
}
return c;
}
// Returns a new instance of this struct that corresponds to the
// can take no more than maxval values
static IntegerEncodedValue CreateEncoding(uint32_t maxVal) {
while (maxVal > 0) {
uint32_t check = maxVal + 1;
// Is maxVal a power of two?
if (!(check & (check - 1))) {
return IntegerEncodedValue(eIntegerEncoding_JustBits, Popcnt(maxVal));
}
// Is maxVal of the type 3*2^n - 1?
if ((check % 3 == 0) && !((check / 3) & ((check / 3) - 1))) {
return IntegerEncodedValue(eIntegerEncoding_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(eIntegerEncoding_Quint, Popcnt(check / 5 - 1));
}
// Apparently it can't be represented with a bounded integer sequence...
// just iterate.
maxVal--;
}
return IntegerEncodedValue(eIntegerEncoding_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, BitStream& bits,
uint32_t maxRange, uint32_t nValues) {
// Determine encoding parameters
IntegerEncodedValue val = IntegerEncodedValue::CreateEncoding(maxRange);
// Start decoding
uint32_t nValsDecoded = 0;
while (nValsDecoded < nValues) {
switch (val.GetEncoding()) {
case eIntegerEncoding_Quint:
DecodeQuintBlock(bits, result, val.BaseBitLength());
nValsDecoded += 3;
break;
case eIntegerEncoding_Trit:
DecodeTritBlock(bits, result, val.BaseBitLength());
nValsDecoded += 5;
break;
case eIntegerEncoding_JustBits:
val.SetBitValue(bits.ReadBits(val.BaseBitLength()));
result.push_back(val);
nValsDecoded++;
break;
}
}
}
private:
static void DecodeTritBlock(BitStream& bits, std::vector<IntegerEncodedValue>& result,
uint32_t nBitsPerValue) {
// Implement the algorithm in section C.2.12
uint32_t m[5];
uint32_t t[5];
uint32_t T;
// Read the trit encoded block according to
// table C.2.14
m[0] = bits.ReadBits(nBitsPerValue);
T = bits.ReadBits(2);
m[1] = bits.ReadBits(nBitsPerValue);
T |= bits.ReadBits(2) << 2;
m[2] = bits.ReadBits(nBitsPerValue);
T |= bits.ReadBit() << 4;
m[3] = bits.ReadBits(nBitsPerValue);
T |= bits.ReadBits(2) << 5;
m[4] = bits.ReadBits(nBitsPerValue);
T |= bits.ReadBit() << 7;
uint32_t C = 0;
Bits<uint32_t> Tb(T);
if (Tb(2, 4) == 7) {
C = (Tb(5, 7) << 2) | Tb(0, 1);
t[4] = t[3] = 2;
} else {
C = Tb(0, 4);
if (Tb(5, 6) == 3) {
t[4] = 2;
t[3] = Tb[7];
} else {
t[4] = Tb[7];
t[3] = Tb(5, 6);
}
}
Bits<uint32_t> Cb(C);
if (Cb(0, 1) == 3) {
t[2] = 2;
t[1] = Cb[4];
t[0] = (Cb[3] << 1) | (Cb[2] & ~Cb[3]);
} else if (Cb(2, 3) == 3) {
t[2] = 2;
t[1] = 2;
t[0] = Cb(0, 1);
} else {
t[2] = Cb[4];
t[1] = Cb(2, 3);
t[0] = (Cb[1] << 1) | (Cb[0] & ~Cb[1]);
}
for (uint32_t i = 0; i < 5; i++) {
IntegerEncodedValue val(eIntegerEncoding_Trit, nBitsPerValue);
val.SetBitValue(m[i]);
val.SetTritValue(t[i]);
result.push_back(val);
}
}
static void DecodeQuintBlock(BitStream& bits, std::vector<IntegerEncodedValue>& result,
uint32_t nBitsPerValue) {
// Implement the algorithm in section C.2.12
uint32_t m[3];
uint32_t q[3];
uint32_t Q;
// Read the trit encoded block according to
// table C.2.15
m[0] = bits.ReadBits(nBitsPerValue);
Q = bits.ReadBits(3);
m[1] = bits.ReadBits(nBitsPerValue);
Q |= bits.ReadBits(2) << 3;
m[2] = bits.ReadBits(nBitsPerValue);
Q |= bits.ReadBits(2) << 5;
Bits<uint32_t> Qb(Q);
if (Qb(1, 2) == 3 && Qb(5, 6) == 0) {
q[0] = q[1] = 4;
q[2] = (Qb[0] << 2) | ((Qb[4] & ~Qb[0]) << 1) | (Qb[3] & ~Qb[0]);
} else {
uint32_t C = 0;
if (Qb(1, 2) == 3) {
q[2] = 4;
C = (Qb(3, 4) << 3) | ((~Qb(5, 6) & 3) << 1) | Qb[0];
} else {
q[2] = Qb(5, 6);
C = Qb(0, 4);
}
Bits<uint32_t> Cb(C);
if (Cb(0, 2) == 5) {
q[1] = 4;
q[0] = Cb(3, 4);
} else {
q[1] = Cb(3, 4);
q[0] = Cb(0, 2);
}
}
for (uint32_t i = 0; i < 3; i++) {
IntegerEncodedValue val(eIntegerEncoding_Quint, nBitsPerValue);
val.m_BitValue = m[i];
val.m_QuintValue = q[i];
result.push_back(val);
}
}
};
namespace ASTCC {
struct TexelWeightParams {
uint32_t m_Width = 0;
uint32_t m_Height = 0;
bool m_bDualPlane = false;
uint32_t m_MaxWeight = 0;
bool m_bError = false;
bool m_bVoidExtentLDR = false;
bool m_bVoidExtentHDR = false;
uint32_t GetPackedBitSize() {
// How many indices do we have?
uint32_t nIdxs = m_Height * m_Width;
if (m_bDualPlane) {
nIdxs *= 2;
}
return IntegerEncodedValue::CreateEncoding(m_MaxWeight).GetBitLength(nIdxs);
}
uint32_t GetNumWeightValues() const {
uint32_t ret = m_Width * m_Height;
if (m_bDualPlane) {
ret *= 2;
}
return ret;
}
};
TexelWeightParams DecodeBlockInfo(BitStream& strm) {
TexelWeightParams params;
// Read the entire block mode all at once
uint16_t modeBits = strm.ReadBits(11);
// Does this match the void extent block mode?
if ((modeBits & 0x01FF) == 0x1FC) {
if (modeBits & 0x200) {
params.m_bVoidExtentHDR = true;
} else {
params.m_bVoidExtentLDR = true;
}
// Next two bits must be one.
if (!(modeBits & 0x400) || !strm.ReadBit()) {
params.m_bError = true;
}
return params;
}
// First check if the last four bits are zero
if ((modeBits & 0xF) == 0) {
params.m_bError = true;
return params;
}
// 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) {
params.m_bError = true;
return params;
}
// 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.
uint32_t layout = 0;
if ((modeBits & 0x1) || (modeBits & 0x2)) {
// layout is in [0-4]
if (modeBits & 0x8) {
// layout is in [2-4]
if (modeBits & 0x4) {
// layout is in [3-4]
if (modeBits & 0x100) {
layout = 4;
} else {
layout = 3;
}
} else {
layout = 2;
}
} else {
// layout is in [0-1]
if (modeBits & 0x4) {
layout = 1;
} else {
layout = 0;
}
}
} else {
// layout is in [5-9]
if (modeBits & 0x100) {
// layout is in [7-9]
if (modeBits & 0x80) {
// layout is in [7-8]
assert((modeBits & 0x40) == 0U);
if (modeBits & 0x20) {
layout = 8;
} else {
layout = 7;
}
} else {
layout = 9;
}
} else {
// layout is in [5-6]
if (modeBits & 0x80) {
layout = 6;
} else {
layout = 5;
}
}
}
assert(layout < 10);
// Determine R
uint32_t R = !!(modeBits & 0x10);
if (layout < 5) {
R |= (modeBits & 0x3) << 1;
} else {
R |= (modeBits & 0xC) >> 1;
}
assert(2 <= R && R <= 7);
// Determine width & height
switch (layout) {
case 0: {
uint32_t A = (modeBits >> 5) & 0x3;
uint32_t B = (modeBits >> 7) & 0x3;
params.m_Width = B + 4;
params.m_Height = A + 2;
break;
}
case 1: {
uint32_t A = (modeBits >> 5) & 0x3;
uint32_t B = (modeBits >> 7) & 0x3;
params.m_Width = B + 8;
params.m_Height = A + 2;
break;
}
case 2: {
uint32_t A = (modeBits >> 5) & 0x3;
uint32_t B = (modeBits >> 7) & 0x3;
params.m_Width = A + 2;
params.m_Height = B + 8;
break;
}
case 3: {
uint32_t A = (modeBits >> 5) & 0x3;
uint32_t B = (modeBits >> 7) & 0x1;
params.m_Width = A + 2;
params.m_Height = B + 6;
break;
}
case 4: {
uint32_t A = (modeBits >> 5) & 0x3;
uint32_t B = (modeBits >> 7) & 0x1;
params.m_Width = B + 2;
params.m_Height = A + 2;
break;
}
case 5: {
uint32_t A = (modeBits >> 5) & 0x3;
params.m_Width = 12;
params.m_Height = A + 2;
break;
}
case 6: {
uint32_t A = (modeBits >> 5) & 0x3;
params.m_Width = A + 2;
params.m_Height = 12;
break;
}
case 7: {
params.m_Width = 6;
params.m_Height = 10;
break;
}
case 8: {
params.m_Width = 10;
params.m_Height = 6;
break;
}
case 9: {
uint32_t A = (modeBits >> 5) & 0x3;
uint32_t B = (modeBits >> 9) & 0x3;
params.m_Width = A + 6;
params.m_Height = B + 6;
break;
}
default:
assert(!"Don't know this layout...");
params.m_bError = true;
break;
}
// Determine whether or not we're using dual planes
// and/or high precision layouts.
bool D = (layout != 9) && (modeBits & 0x400);
bool H = (layout != 9) && (modeBits & 0x200);
if (H) {
const uint32_t maxWeights[6] = {9, 11, 15, 19, 23, 31};
params.m_MaxWeight = maxWeights[R - 2];
} else {
const uint32_t maxWeights[6] = {1, 2, 3, 4, 5, 7};
params.m_MaxWeight = maxWeights[R - 2];
}
params.m_bDualPlane = D;
return params;
}
void FillVoidExtentLDR(BitStream& strm, uint32_t* const outBuf, uint32_t blockWidth,
uint32_t blockHeight) {
// Don't actually care about the void extent, just read the bits...
for (int i = 0; i < 4; ++i) {
strm.ReadBits(13);
}
// Decode the RGBA components and renormalize them to the range [0, 255]
uint16_t r = strm.ReadBits(16);
uint16_t g = strm.ReadBits(16);
uint16_t b = strm.ReadBits(16);
uint16_t a = strm.ReadBits(16);
uint32_t rgba = (r >> 8) | (g & 0xFF00) | (static_cast<uint32_t>(b) & 0xFF00) << 8 |
(static_cast<uint32_t>(a) & 0xFF00) << 16;
for (uint32_t j = 0; j < blockHeight; j++)
for (uint32_t i = 0; i < blockWidth; i++) {
outBuf[j * blockWidth + i] = rgba;
}
}
void FillError(uint32_t* outBuf, uint32_t blockWidth, uint32_t blockHeight) {
for (uint32_t j = 0; j < blockHeight; j++)
for (uint32_t i = 0; i < blockWidth; i++) {
outBuf[j * blockWidth + i] = 0xFFFF00FF;
}
}
// Replicates low numBits such that [(toBit - 1):(toBit - 1 - fromBit)]
// is the same as [(numBits - 1):0] and repeats all the way down.
template <typename IntType>
IntType Replicate(const IntType& val, uint32_t numBits, uint32_t toBit) {
if (numBits == 0)
return 0;
if (toBit == 0)
return 0;
IntType v = val & ((1 << numBits) - 1);
IntType res = v;
uint32_t reslen = numBits;
while (reslen < toBit) {
uint32_t comp = 0;
if (numBits > toBit - reslen) {
uint32_t newshift = toBit - reslen;
comp = numBits - newshift;
numBits = newshift;
}
res <<= numBits;
res |= v >> comp;
reslen += numBits;
}
return res;
}
class Pixel {
protected:
using ChannelType = int16_t;
uint8_t m_BitDepth[4] = {8, 8, 8, 8};
int16_t color[4] = {};
public:
Pixel() = default;
Pixel(ChannelType a, ChannelType r, ChannelType g, ChannelType b, unsigned bitDepth = 8)
: m_BitDepth{uint8_t(bitDepth), uint8_t(bitDepth), uint8_t(bitDepth), uint8_t(bitDepth)},
color{a, r, g, b} {}
// Changes the depth of each pixel. This scales the values to
// the appropriate bit depth by either truncating the least
// significant bits when going from larger to smaller bit depth
// or by repeating the most significant bits when going from
// smaller to larger bit depths.
void ChangeBitDepth(const uint8_t (&depth)[4]) {
for (uint32_t i = 0; i < 4; i++) {
Component(i) = ChangeBitDepth(Component(i), m_BitDepth[i], depth[i]);
m_BitDepth[i] = depth[i];
}
}
template <typename IntType>
static float ConvertChannelToFloat(IntType channel, uint8_t bitDepth) {
float denominator = static_cast<float>((1 << bitDepth) - 1);
return static_cast<float>(channel) / denominator;
}
// Changes the bit depth of a single component. See the comment
// above for how we do this.
static ChannelType ChangeBitDepth(Pixel::ChannelType val, uint8_t oldDepth, uint8_t newDepth) {
assert(newDepth <= 8);
assert(oldDepth <= 8);
if (oldDepth == newDepth) {
// Do nothing
return val;
} else if (oldDepth == 0 && newDepth != 0) {
return (1 << newDepth) - 1;
} else if (newDepth > oldDepth) {
return Replicate(val, oldDepth, newDepth);
} else {
// oldDepth > newDepth
if (newDepth == 0) {
return 0xFF;
} else {
uint8_t bitsWasted = oldDepth - newDepth;
uint16_t v = static_cast<uint16_t>(val);
v = (v + (1 << (bitsWasted - 1))) >> bitsWasted;
v = ::std::min<uint16_t>(::std::max<uint16_t>(0, v), (1 << newDepth) - 1);
return static_cast<uint8_t>(v);
}
}
assert(!"We shouldn't get here.");
return 0;
}
const ChannelType& A() const {
return color[0];
}
ChannelType& A() {
return color[0];
}
const ChannelType& R() const {
return color[1];
}
ChannelType& R() {
return color[1];
}
const ChannelType& G() const {
return color[2];
}
ChannelType& G() {
return color[2];
}
const ChannelType& B() const {
return color[3];
}
ChannelType& B() {
return color[3];
}
const ChannelType& Component(uint32_t idx) const {
return color[idx];
}
ChannelType& Component(uint32_t idx) {
return color[idx];
}
void GetBitDepth(uint8_t (&outDepth)[4]) const {
for (int i = 0; i < 4; i++) {
outDepth[i] = m_BitDepth[i];
}
}
// Take all of the components, transform them to their 8-bit variants,
// and then pack each channel into an R8G8B8A8 32-bit integer. We assume
// that the architecture is little-endian, so the alpha channel will end
// up in the most-significant byte.
uint32_t Pack() const {
Pixel eightBit(*this);
const uint8_t eightBitDepth[4] = {8, 8, 8, 8};
eightBit.ChangeBitDepth(eightBitDepth);
uint32_t r = 0;
r |= eightBit.A();
r <<= 8;
r |= eightBit.B();
r <<= 8;
r |= eightBit.G();
r <<= 8;
r |= eightBit.R();
return r;
}
// Clamps the pixel to the range [0,255]
void ClampByte() {
for (uint32_t i = 0; i < 4; i++) {
color[i] = (color[i] < 0) ? 0 : ((color[i] > 255) ? 255 : color[i]);
}
}
void MakeOpaque() {
A() = 255;
}
};
void DecodeColorValues(uint32_t* out, uint8_t* data, uint32_t* modes, const uint32_t nPartitions,
const uint32_t nBitsForColorData) {
// First figure out how many color values we have
uint32_t nValues = 0;
for (uint32_t i = 0; i < nPartitions; i++) {
nValues += ((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...
uint32_t range = 256;
while (--range > 0) {
IntegerEncodedValue val = IntegerEncodedValue::CreateEncoding(range);
uint32_t 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);
if (!newval.MatchesEncoding(val)) {
break;
}
}
// Return to last matching range.
range++;
break;
}
}
// We now have enough to decode our integer sequence.
std::vector<IntegerEncodedValue> decodedColorValues;
BitStream colorStream(data);
IntegerEncodedValue::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
uint32_t outIdx = 0;
std::vector<IntegerEncodedValue>::const_iterator itr;
for (itr = decodedColorValues.begin(); itr != decodedColorValues.end(); itr++) {
// Have we already decoded all that we need?
if (outIdx >= nValues) {
break;
}
const IntegerEncodedValue& val = *itr;
uint32_t bitlen = val.BaseBitLength();
uint32_t bitval = val.GetBitValue();
assert(bitlen >= 1);
uint32_t A = 0, B = 0, C = 0, D = 0;
// A is just the lsb replicated 9 times.
A = Replicate(bitval & 1, 1, 9);
switch (val.GetEncoding()) {
// Replicate bits
case eIntegerEncoding_JustBits:
out[outIdx++] = Replicate(bitval, bitlen, 8);
break;
// Use algorithm in C.2.13
case eIntegerEncoding_Trit: {
D = val.GetTritValue();
switch (bitlen) {
case 1: {
C = 204;
} break;
case 2: {
C = 93;
// B = b000b0bb0
uint32_t b = (bitval >> 1) & 1;
B = (b << 8) | (b << 4) | (b << 2) | (b << 1);
} break;
case 3: {
C = 44;
// B = cb000cbcb
uint32_t cb = (bitval >> 1) & 3;
B = (cb << 7) | (cb << 2) | cb;
} break;
case 4: {
C = 22;
// B = dcb000dcb
uint32_t dcb = (bitval >> 1) & 7;
B = (dcb << 6) | dcb;
} break;
case 5: {
C = 11;
// B = edcb000ed
uint32_t edcb = (bitval >> 1) & 0xF;
B = (edcb << 5) | (edcb >> 2);
} break;
case 6: {
C = 5;
// B = fedcb000f
uint32_t fedcb = (bitval >> 1) & 0x1F;
B = (fedcb << 4) | (fedcb >> 4);
} break;
default:
assert(!"Unsupported trit encoding for color values!");
break;
} // switch(bitlen)
} // case eIntegerEncoding_Trit
break;
case eIntegerEncoding_Quint: {
D = val.GetQuintValue();
switch (bitlen) {
case 1: {
C = 113;
} break;
case 2: {
C = 54;
// B = b0000bb00
uint32_t b = (bitval >> 1) & 1;
B = (b << 8) | (b << 3) | (b << 2);
} break;
case 3: {
C = 26;
// B = cb0000cbc
uint32_t cb = (bitval >> 1) & 3;
B = (cb << 7) | (cb << 1) | (cb >> 1);
} break;
case 4: {
C = 13;
// B = dcb0000dc
uint32_t dcb = (bitval >> 1) & 7;
B = (dcb << 6) | (dcb >> 1);
} break;
case 5: {
C = 6;
// B = edcb0000e
uint32_t edcb = (bitval >> 1) & 0xF;
B = (edcb << 5) | (edcb >> 3);
} break;
default:
assert(!"Unsupported quint encoding for color values!");
break;
} // switch(bitlen)
} // case eIntegerEncoding_Quint
break;
} // switch(val.GetEncoding())
if (val.GetEncoding() != eIntegerEncoding_JustBits) {
uint32_t T = D * C + B;
T ^= A;
T = (A & 0x80) | (T >> 2);
out[outIdx++] = T;
}
}
// Make sure that each of our values is in the proper range...
for (uint32_t i = 0; i < nValues; i++) {
assert(out[i] <= 255);
}
}
uint32_t UnquantizeTexelWeight(const IntegerEncodedValue& val) {
uint32_t bitval = val.GetBitValue();
uint32_t bitlen = val.BaseBitLength();
uint32_t A = Replicate(bitval & 1, 1, 7);
uint32_t B = 0, C = 0, D = 0;
uint32_t result = 0;
switch (val.GetEncoding()) {
case eIntegerEncoding_JustBits:
result = Replicate(bitval, bitlen, 6);
break;
case eIntegerEncoding_Trit: {
D = val.GetTritValue();
assert(D < 3);
switch (bitlen) {
case 0: {
uint32_t results[3] = {0, 32, 63};
result = results[D];
} break;
case 1: {
C = 50;
} break;
case 2: {
C = 23;
uint32_t b = (bitval >> 1) & 1;
B = (b << 6) | (b << 2) | b;
} break;
case 3: {
C = 11;
uint32_t cb = (bitval >> 1) & 3;
B = (cb << 5) | cb;
} break;
default:
assert(!"Invalid trit encoding for texel weight");
break;
}
} break;
case eIntegerEncoding_Quint: {
D = val.GetQuintValue();
assert(D < 5);
switch (bitlen) {
case 0: {
uint32_t results[5] = {0, 16, 32, 47, 63};
result = results[D];
} break;
case 1: {
C = 28;
} break;
case 2: {
C = 13;
uint32_t b = (bitval >> 1) & 1;
B = (b << 6) | (b << 1);
} break;
default:
assert(!"Invalid quint encoding for texel weight");
break;
}
} break;
}
if (val.GetEncoding() != eIntegerEncoding_JustBits && bitlen > 0) {
// Decode the value...
result = D * C + B;
result ^= A;
result = (A & 0x20) | (result >> 2);
}
assert(result < 64);
// Change from [0,63] to [0,64]
if (result > 32) {
result += 1;
}
return result;
}
void UnquantizeTexelWeights(uint32_t out[2][144], std::vector<IntegerEncodedValue>& weights,
const TexelWeightParams& params, const uint32_t blockWidth,
const uint32_t blockHeight) {
uint32_t weightIdx = 0;
uint32_t unquantized[2][144];
std::vector<IntegerEncodedValue>::const_iterator itr;
for (itr = weights.begin(); itr != weights.end(); itr++) {
unquantized[0][weightIdx] = UnquantizeTexelWeight(*itr);
if (params.m_bDualPlane) {
itr++;
unquantized[1][weightIdx] = UnquantizeTexelWeight(*itr);
if (itr == weights.end()) {
break;
}
}
if (++weightIdx >= (params.m_Width * params.m_Height))
break;
}
// Do infill if necessary (Section C.2.18) ...
uint32_t Ds = (1024 + (blockWidth / 2)) / (blockWidth - 1);
uint32_t Dt = (1024 + (blockHeight / 2)) / (blockHeight - 1);
const uint32_t kPlaneScale = params.m_bDualPlane ? 2U : 1U;
for (uint32_t plane = 0; plane < kPlaneScale; plane++)
for (uint32_t t = 0; t < blockHeight; t++)
for (uint32_t s = 0; s < blockWidth; s++) {
uint32_t cs = Ds * s;
uint32_t ct = Dt * t;
uint32_t gs = (cs * (params.m_Width - 1) + 32) >> 6;
uint32_t gt = (ct * (params.m_Height - 1) + 32) >> 6;
uint32_t js = gs >> 4;
uint32_t fs = gs & 0xF;
uint32_t jt = gt >> 4;
uint32_t ft = gt & 0x0F;
uint32_t w11 = (fs * ft + 8) >> 4;
uint32_t w10 = ft - w11;
uint32_t w01 = fs - w11;
uint32_t w00 = 16 - fs - ft + w11;
uint32_t v0 = js + jt * params.m_Width;
#define FIND_TEXEL(tidx, bidx) \
uint32_t p##bidx = 0; \
do { \
if ((tidx) < (params.m_Width * params.m_Height)) { \
p##bidx = unquantized[plane][(tidx)]; \
} \
} while (0)
FIND_TEXEL(v0, 00);
FIND_TEXEL(v0 + 1, 01);
FIND_TEXEL(v0 + params.m_Width, 10);
FIND_TEXEL(v0 + params.m_Width + 1, 11);
#undef FIND_TEXEL
out[plane][t * blockWidth + s] =
(p00 * w00 + p01 * w01 + p10 * w10 + p11 * w11 + 8) >> 4;
}
}
// Transfers a bit as described in C.2.14
static inline void BitTransferSigned(int32_t& a, int32_t& b) {
b >>= 1;
b |= a & 0x80;
a >>= 1;
a &= 0x3F;
if (a & 0x20)
a -= 0x40;
}
// Adds more precision to the blue channel as described
// in C.2.14
static inline Pixel BlueContract(int32_t a, int32_t r, int32_t g, int32_t b) {
return Pixel(static_cast<int16_t>(a), static_cast<int16_t>((r + b) >> 1),
static_cast<int16_t>((g + b) >> 1), static_cast<int16_t>(b));
}
// Partition selection functions as specified in
// C.2.21
static inline uint32_t hash52(uint32_t p) {
p ^= p >> 15;
p -= p << 17;
p += p << 7;
p += p << 4;
p ^= p >> 5;
p += p << 16;
p ^= p >> 7;
p ^= p >> 3;
p ^= p << 6;
p ^= p >> 17;
return p;
}
static uint32_t SelectPartition(int32_t seed, int32_t x, int32_t y, int32_t z,
int32_t partitionCount, int32_t smallBlock) {
if (1 == partitionCount)
return 0;
if (smallBlock) {
x <<= 1;
y <<= 1;
z <<= 1;
}
seed += (partitionCount - 1) * 1024;
uint32_t rnum = hash52(static_cast<uint32_t>(seed));
uint8_t seed1 = static_cast<uint8_t>(rnum & 0xF);
uint8_t seed2 = static_cast<uint8_t>((rnum >> 4) & 0xF);
uint8_t seed3 = static_cast<uint8_t>((rnum >> 8) & 0xF);
uint8_t seed4 = static_cast<uint8_t>((rnum >> 12) & 0xF);
uint8_t seed5 = static_cast<uint8_t>((rnum >> 16) & 0xF);
uint8_t seed6 = static_cast<uint8_t>((rnum >> 20) & 0xF);
uint8_t seed7 = static_cast<uint8_t>((rnum >> 24) & 0xF);
uint8_t seed8 = static_cast<uint8_t>((rnum >> 28) & 0xF);
uint8_t seed9 = static_cast<uint8_t>((rnum >> 18) & 0xF);
uint8_t seed10 = static_cast<uint8_t>((rnum >> 22) & 0xF);
uint8_t seed11 = static_cast<uint8_t>((rnum >> 26) & 0xF);
uint8_t seed12 = static_cast<uint8_t>(((rnum >> 30) | (rnum << 2)) & 0xF);
seed1 *= seed1;
seed2 *= seed2;
seed3 *= seed3;
seed4 *= seed4;
seed5 *= seed5;
seed6 *= seed6;
seed7 *= seed7;
seed8 *= seed8;
seed9 *= seed9;
seed10 *= seed10;
seed11 *= seed11;
seed12 *= seed12;
int32_t sh1, sh2, sh3;
if (seed & 1) {
sh1 = (seed & 2) ? 4 : 5;
sh2 = (partitionCount == 3) ? 6 : 5;
} else {
sh1 = (partitionCount == 3) ? 6 : 5;
sh2 = (seed & 2) ? 4 : 5;
}
sh3 = (seed & 0x10) ? sh1 : sh2;
seed1 >>= sh1;
seed2 >>= sh2;
seed3 >>= sh1;
seed4 >>= sh2;
seed5 >>= sh1;
seed6 >>= sh2;
seed7 >>= sh1;
seed8 >>= sh2;
seed9 >>= sh3;
seed10 >>= sh3;
seed11 >>= sh3;
seed12 >>= sh3;
int32_t a = seed1 * x + seed2 * y + seed11 * z + (rnum >> 14);
int32_t b = seed3 * x + seed4 * y + seed12 * z + (rnum >> 10);
int32_t c = seed5 * x + seed6 * y + seed9 * z + (rnum >> 6);
int32_t d = seed7 * x + seed8 * y + seed10 * z + (rnum >> 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 inline uint32_t Select2DPartition(int32_t seed, int32_t x, int32_t y, int32_t partitionCount,
int32_t smallBlock) {
return SelectPartition(seed, x, y, 0, partitionCount, smallBlock);
}
// Section C.2.14
void ComputeEndpoints(Pixel& ep1, Pixel& ep2, const uint32_t*& colorValues,
uint32_t colorEndpointMode) {
#define READ_UINT_VALUES(N) \
uint32_t v[N]; \
for (uint32_t i = 0; i < N; i++) { \
v[i] = *(colorValues++); \
}
#define READ_INT_VALUES(N) \
int32_t v[N]; \
for (uint32_t i = 0; i < N; i++) { \
v[i] = static_cast<int32_t>(*(colorValues++)); \
}
switch (colorEndpointMode) {
case 0: {
READ_UINT_VALUES(2)
ep1 = Pixel(0xFF, v[0], v[0], v[0]);
ep2 = Pixel(0xFF, v[1], v[1], v[1]);
} break;
case 1: {
READ_UINT_VALUES(2)
uint32_t L0 = (v[0] >> 2) | (v[1] & 0xC0);
uint32_t L1 = std::max(L0 + (v[1] & 0x3F), 0xFFU);
ep1 = Pixel(0xFF, L0, L0, L0);
ep2 = Pixel(0xFF, L1, L1, L1);
} break;
case 4: {
READ_UINT_VALUES(4)
ep1 = Pixel(v[2], v[0], v[0], v[0]);
ep2 = Pixel(v[3], v[1], v[1], v[1]);
} break;
case 5: {
READ_INT_VALUES(4)
BitTransferSigned(v[1], v[0]);
BitTransferSigned(v[3], v[2]);
ep1 = Pixel(v[2], v[0], v[0], v[0]);
ep2 = Pixel(v[2] + v[3], v[0] + v[1], v[0] + v[1], v[0] + v[1]);
ep1.ClampByte();
ep2.ClampByte();
} break;
case 6: {
READ_UINT_VALUES(4)
ep1 = Pixel(0xFF, v[0] * v[3] >> 8, v[1] * v[3] >> 8, v[2] * v[3] >> 8);
ep2 = Pixel(0xFF, v[0], v[1], v[2]);
} break;
case 8: {
READ_UINT_VALUES(6)
if (v[1] + v[3] + v[5] >= v[0] + v[2] + v[4]) {
ep1 = Pixel(0xFF, v[0], v[2], v[4]);
ep2 = Pixel(0xFF, v[1], v[3], v[5]);
} else {
ep1 = BlueContract(0xFF, v[1], v[3], v[5]);
ep2 = BlueContract(0xFF, v[0], v[2], v[4]);
}
} break;
case 9: {
READ_INT_VALUES(6)
BitTransferSigned(v[1], v[0]);
BitTransferSigned(v[3], v[2]);
BitTransferSigned(v[5], v[4]);
if (v[1] + v[3] + v[5] >= 0) {
ep1 = Pixel(0xFF, v[0], v[2], v[4]);
ep2 = Pixel(0xFF, v[0] + v[1], v[2] + v[3], v[4] + v[5]);
} else {
ep1 = BlueContract(0xFF, v[0] + v[1], v[2] + v[3], v[4] + v[5]);
ep2 = BlueContract(0xFF, v[0], v[2], v[4]);
}
ep1.ClampByte();
ep2.ClampByte();
} break;
case 10: {
READ_UINT_VALUES(6)
ep1 = Pixel(v[4], v[0] * v[3] >> 8, v[1] * v[3] >> 8, v[2] * v[3] >> 8);
ep2 = Pixel(v[5], v[0], v[1], v[2]);
} break;
case 12: {
READ_UINT_VALUES(8)
if (v[1] + v[3] + v[5] >= v[0] + v[2] + v[4]) {
ep1 = Pixel(v[6], v[0], v[2], v[4]);
ep2 = Pixel(v[7], v[1], v[3], v[5]);
} else {
ep1 = BlueContract(v[7], v[1], v[3], v[5]);
ep2 = BlueContract(v[6], v[0], v[2], v[4]);
}
} break;
case 13: {
READ_INT_VALUES(8)
BitTransferSigned(v[1], v[0]);
BitTransferSigned(v[3], v[2]);
BitTransferSigned(v[5], v[4]);
BitTransferSigned(v[7], v[6]);
if (v[1] + v[3] + v[5] >= 0) {
ep1 = Pixel(v[6], v[0], v[2], v[4]);
ep2 = Pixel(v[7] + v[6], v[0] + v[1], v[2] + v[3], v[4] + v[5]);
} else {
ep1 = BlueContract(v[6] + v[7], v[0] + v[1], v[2] + v[3], v[4] + v[5]);
ep2 = BlueContract(v[6], v[0], v[2], v[4]);
}
ep1.ClampByte();
ep2.ClampByte();
} break;
default:
assert(!"Unsupported color endpoint mode (is it HDR?)");
break;
}
#undef READ_UINT_VALUES
#undef READ_INT_VALUES
}
void DecompressBlock(uint8_t inBuf[16], const uint32_t blockWidth, const uint32_t blockHeight,
uint32_t* outBuf) {
BitStream strm(inBuf);
TexelWeightParams weightParams = DecodeBlockInfo(strm);
// Was there an error?
if (weightParams.m_bError) {
assert(!"Invalid block mode");
FillError(outBuf, blockWidth, blockHeight);
return;
}
if (weightParams.m_bVoidExtentLDR) {
FillVoidExtentLDR(strm, outBuf, blockWidth, blockHeight);
return;
}
if (weightParams.m_bVoidExtentHDR) {
assert(!"HDR void extent blocks are unsupported!");
FillError(outBuf, blockWidth, blockHeight);
return;
}
if (weightParams.m_Width > blockWidth) {
assert(!"Texel weight grid width should be smaller than block width");
FillError(outBuf, blockWidth, blockHeight);
return;
}
if (weightParams.m_Height > blockHeight) {
assert(!"Texel weight grid height should be smaller than block height");
FillError(outBuf, blockWidth, blockHeight);
return;
}
// Read num partitions
uint32_t nPartitions = strm.ReadBits(2) + 1;
assert(nPartitions <= 4);
if (nPartitions == 4 && weightParams.m_bDualPlane) {
assert(!"Dual plane mode is incompatible with four partition blocks");
FillError(outBuf, blockWidth, blockHeight);
return;
}
// Based on the number of partitions, read the color endpoint mode for
// each partition.
// Determine partitions, partition index, and color endpoint modes
int32_t planeIdx = -1;
uint32_t partitionIndex;
uint32_t colorEndpointMode[4] = {0, 0, 0, 0};
// Define color data.
uint8_t colorEndpointData[16];
memset(colorEndpointData, 0, sizeof(colorEndpointData));
BitStream colorEndpointStream(colorEndpointData, 16 * 8, 0);
// Read extra config data...
uint32_t baseCEM = 0;
if (nPartitions == 1) {
colorEndpointMode[0] = strm.ReadBits(4);
partitionIndex = 0;
} else {
partitionIndex = strm.ReadBits(10);
baseCEM = strm.ReadBits(6);
}
uint32_t baseMode = (baseCEM & 3);
// Remaining bits are color endpoint data...
uint32_t nWeightBits = weightParams.GetPackedBitSize();
int32_t remainingBits = 128 - nWeightBits - strm.GetBitsRead();
// Consider extra bits prior to texel data...
uint32_t extraCEMbits = 0;
if (baseMode) {
switch (nPartitions) {
case 2:
extraCEMbits += 2;
break;
case 3:
extraCEMbits += 5;
break;
case 4:
extraCEMbits += 8;
break;
default:
assert(false);
break;
}
}
remainingBits -= extraCEMbits;
// Do we have a dual plane situation?
uint32_t planeSelectorBits = 0;
if (weightParams.m_bDualPlane) {
planeSelectorBits = 2;
}
remainingBits -= planeSelectorBits;
// Read color data...
uint32_t colorDataBits = remainingBits;
while (remainingBits > 0) {
uint32_t nb = std::min(remainingBits, 8);
uint32_t b = strm.ReadBits(nb);
colorEndpointStream.WriteBits(b, nb);
remainingBits -= 8;
}
// Read the plane selection bits
planeIdx = strm.ReadBits(planeSelectorBits);
// Read the rest of the CEM
if (baseMode) {
uint32_t extraCEM = strm.ReadBits(extraCEMbits);
uint32_t CEM = (extraCEM << 6) | baseCEM;
CEM >>= 2;
bool C[4] = {0};
for (uint32_t i = 0; i < nPartitions; i++) {
C[i] = CEM & 1;
CEM >>= 1;
}
uint8_t M[4] = {0};
for (uint32_t i = 0; i < nPartitions; i++) {
M[i] = CEM & 3;
CEM >>= 2;
assert(M[i] <= 3);
}
for (uint32_t i = 0; i < nPartitions; i++) {
colorEndpointMode[i] = baseMode;
if (!(C[i]))
colorEndpointMode[i] -= 1;
colorEndpointMode[i] <<= 2;
colorEndpointMode[i] |= M[i];
}
} else if (nPartitions > 1) {
uint32_t CEM = baseCEM >> 2;
for (uint32_t i = 0; i < nPartitions; i++) {
colorEndpointMode[i] = CEM;
}
}
// Make sure everything up till here is sane.
for (uint32_t i = 0; i < nPartitions; i++) {
assert(colorEndpointMode[i] < 16);
}
assert(strm.GetBitsRead() + weightParams.GetPackedBitSize() == 128);
// Decode both color data and texel weight data
uint32_t colorValues[32]; // Four values, two endpoints, four maximum paritions
DecodeColorValues(colorValues, colorEndpointData, colorEndpointMode, nPartitions,
colorDataBits);
Pixel endpoints[4][2];
const uint32_t* colorValuesPtr = colorValues;
for (uint32_t i = 0; i < nPartitions; i++) {
ComputeEndpoints(endpoints[i][0], endpoints[i][1], colorValuesPtr, colorEndpointMode[i]);
}
// Read the texel weight data..
uint8_t texelWeightData[16];
memcpy(texelWeightData, inBuf, sizeof(texelWeightData));
// Reverse everything
for (uint32_t i = 0; i < 8; i++) {
// Taken from http://graphics.stanford.edu/~seander/bithacks.html#ReverseByteWith64Bits
#define REVERSE_BYTE(b) (((b)*0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32
unsigned char a = static_cast<unsigned char>(REVERSE_BYTE(texelWeightData[i]));
unsigned char b = static_cast<unsigned char>(REVERSE_BYTE(texelWeightData[15 - i]));
#undef REVERSE_BYTE
texelWeightData[i] = b;
texelWeightData[15 - i] = a;
}
// Make sure that higher non-texel bits are set to zero
const uint32_t clearByteStart = (weightParams.GetPackedBitSize() >> 3) + 1;
texelWeightData[clearByteStart - 1] &= (1 << (weightParams.GetPackedBitSize() % 8)) - 1;
memset(texelWeightData + clearByteStart, 0, 16 - clearByteStart);
std::vector<IntegerEncodedValue> texelWeightValues;
BitStream weightStream(texelWeightData);
IntegerEncodedValue::DecodeIntegerSequence(texelWeightValues, weightStream,
weightParams.m_MaxWeight,
weightParams.GetNumWeightValues());
// Blocks can be at most 12x12, so we can have as many as 144 weights
uint32_t weights[2][144];
UnquantizeTexelWeights(weights, texelWeightValues, weightParams, blockWidth, blockHeight);
// Now that we have endpoints and weights, we can interpolate and generate
// the proper decoding...
for (uint32_t j = 0; j < blockHeight; j++)
for (uint32_t i = 0; i < blockWidth; i++) {
uint32_t partition = Select2DPartition(partitionIndex, i, j, nPartitions,
(blockHeight * blockWidth) < 32);
assert(partition < nPartitions);
Pixel p;
for (uint32_t c = 0; c < 4; c++) {
uint32_t C0 = endpoints[partition][0].Component(c);
C0 = Replicate(C0, 8, 16);
uint32_t C1 = endpoints[partition][1].Component(c);
C1 = Replicate(C1, 8, 16);
uint32_t plane = 0;
if (weightParams.m_bDualPlane && (((planeIdx + 1) & 3) == c)) {
plane = 1;
}
uint32_t weight = weights[plane][j * blockWidth + i];
uint32_t C = (C0 * (64 - weight) + C1 * weight + 32) / 64;
if (C == 65535) {
p.Component(c) = 255;
} else {
double Cf = static_cast<double>(C);
p.Component(c) = static_cast<uint16_t>(255.0 * (Cf / 65536.0) + 0.5);
}
}
outBuf[j * blockWidth + i] = p.Pack();
}
}
} // namespace ASTCC
namespace Tegra::Texture::ASTC {
std::vector<uint8_t> Decompress(std::vector<uint8_t>& data, uint32_t width, uint32_t height,
uint32_t block_width, uint32_t block_height) {
uint32_t blockIdx = 0;
std::vector<uint8_t> outData;
outData.resize(height * width * 4);
for (uint32_t j = 0; j < height; j += block_height) {
for (uint32_t i = 0; i < width; i += block_width) {
uint8_t* blockPtr = data.data() + blockIdx * 16;
// Blocks can be at most 12x12
uint32_t uncompData[144];
ASTCC::DecompressBlock(blockPtr, block_width, block_height, uncompData);
uint32_t decompWidth = std::min(block_width, width - i);
uint32_t decompHeight = std::min(block_height, height - j);
uint8_t* outRow = outData.data() + (j * width + i) * 4;
for (uint32_t jj = 0; jj < decompHeight; jj++) {
memcpy(outRow + jj * width * 4, uncompData + jj * block_width, decompWidth * 4);
}
blockIdx++;
}
}
return outData;
}
} // namespace Tegra::Texture::ASTC
