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//
// Copyright 2013 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// loadimage_etc.cpp: Decodes ETC and EAC encoded textures.
#include "image_util/loadimage.h"
#include <type_traits>
#include "common/mathutil.h"
#include "image_util/imageformats.h"
namespace angle
{
namespace
{
using IntensityModifier = const int[4];
// Table 3.17.2 sorted according to table 3.17.3
// clang-format off
static IntensityModifier intensityModifierDefault[] =
{
{ 2, 8, -2, -8 },
{ 5, 17, -5, -17 },
{ 9, 29, -9, -29 },
{ 13, 42, -13, -42 },
{ 18, 60, -18, -60 },
{ 24, 80, -24, -80 },
{ 33, 106, -33, -106 },
{ 47, 183, -47, -183 },
};
// clang-format on
// Table C.12, intensity modifier for non opaque punchthrough alpha
// clang-format off
static IntensityModifier intensityModifierNonOpaque[] =
{
{ 0, 8, 0, -8 },
{ 0, 17, 0, -17 },
{ 0, 29, 0, -29 },
{ 0, 42, 0, -42 },
{ 0, 60, 0, -60 },
{ 0, 80, 0, -80 },
{ 0, 106, 0, -106 },
{ 0, 183, 0, -183 },
};
// clang-format on
static const int kNumPixelsInBlock = 16;
struct ETC2Block
{
// Decodes unsigned single or dual channel ETC2 block to 8-bit color
void decodeAsSingleETC2Channel(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destPixelStride,
size_t destRowPitch,
bool isSigned) const
{
for (size_t j = 0; j < 4 && (y + j) < h; j++)
{
uint8_t *row = dest + (j * destRowPitch);
for (size_t i = 0; i < 4 && (x + i) < w; i++)
{
uint8_t *pixel = row + (i * destPixelStride);
if (isSigned)
{
*pixel = clampSByte(getSingleETC2Channel(i, j, isSigned));
}
else
{
*pixel = clampByte(getSingleETC2Channel(i, j, isSigned));
}
}
}
}
// Decodes unsigned single or dual channel EAC block to 16-bit color
void decodeAsSingleEACChannel(uint16_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destPixelStride,
size_t destRowPitch,
bool isSigned,
bool isFloat) const
{
for (size_t j = 0; j < 4 && (y + j) < h; j++)
{
uint16_t *row = reinterpret_cast<uint16_t *>(reinterpret_cast<uint8_t *>(dest) +
(j * destRowPitch));
for (size_t i = 0; i < 4 && (x + i) < w; i++)
{
uint16_t *pixel = row + (i * destPixelStride);
if (isSigned)
{
int16_t tempPixel =
renormalizeEAC<int16_t>(getSingleEACChannel(i, j, isSigned));
*pixel =
isFloat ? gl::float32ToFloat16(float(gl::normalize(tempPixel))) : tempPixel;
}
else
{
uint16_t tempPixel =
renormalizeEAC<uint16_t>(getSingleEACChannel(i, j, isSigned));
*pixel =
isFloat ? gl::float32ToFloat16(float(gl::normalize(tempPixel))) : tempPixel;
}
}
}
}
// Decodes RGB block to rgba8
void decodeAsRGB(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destRowPitch,
const uint8_t alphaValues[4][4],
bool punchThroughAlpha) const
{
bool opaqueBit = u.idht.mode.idm.diffbit;
bool nonOpaquePunchThroughAlpha = punchThroughAlpha && !opaqueBit;
// Select mode
if (u.idht.mode.idm.diffbit || punchThroughAlpha)
{
const auto &block = u.idht.mode.idm.colors.diff;
int r = (block.R + block.dR);
int g = (block.G + block.dG);
int b = (block.B + block.dB);
if (r < 0 || r > 31)
{
decodeTBlock(dest, x, y, w, h, destRowPitch, alphaValues,
nonOpaquePunchThroughAlpha);
}
else if (g < 0 || g > 31)
{
decodeHBlock(dest, x, y, w, h, destRowPitch, alphaValues,
nonOpaquePunchThroughAlpha);
}
else if (b < 0 || b > 31)
{
decodePlanarBlock(dest, x, y, w, h, destRowPitch, alphaValues);
}
else
{
decodeDifferentialBlock(dest, x, y, w, h, destRowPitch, alphaValues,
nonOpaquePunchThroughAlpha);
}
}
else
{
decodeIndividualBlock(dest, x, y, w, h, destRowPitch, alphaValues,
nonOpaquePunchThroughAlpha);
}
}
// Transcodes RGB block to BC1
void transcodeAsBC1(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
const uint8_t alphaValues[4][4],
bool punchThroughAlpha) const
{
bool opaqueBit = u.idht.mode.idm.diffbit;
bool nonOpaquePunchThroughAlpha = punchThroughAlpha && !opaqueBit;
// Select mode
if (u.idht.mode.idm.diffbit || punchThroughAlpha)
{
const auto &block = u.idht.mode.idm.colors.diff;
int r = (block.R + block.dR);
int g = (block.G + block.dG);
int b = (block.B + block.dB);
if (r < 0 || r > 31)
{
transcodeTBlockToBC1(dest, x, y, w, h, alphaValues, nonOpaquePunchThroughAlpha);
}
else if (g < 0 || g > 31)
{
transcodeHBlockToBC1(dest, x, y, w, h, alphaValues, nonOpaquePunchThroughAlpha);
}
else if (b < 0 || b > 31)
{
transcodePlanarBlockToBC1(dest, x, y, w, h, alphaValues);
}
else
{
transcodeDifferentialBlockToBC1(dest, x, y, w, h, alphaValues,
nonOpaquePunchThroughAlpha);
}
}
else
{
transcodeIndividualBlockToBC1(dest, x, y, w, h, alphaValues,
nonOpaquePunchThroughAlpha);
}
}
private:
union
{
// Individual, differential, H and T modes
struct
{
union
{
// Individual and differential modes
struct
{
union
{
struct // Individual colors
{
unsigned char R2 : 4;
unsigned char R1 : 4;
unsigned char G2 : 4;
unsigned char G1 : 4;
unsigned char B2 : 4;
unsigned char B1 : 4;
} indiv;
struct // Differential colors
{
signed char dR : 3;
unsigned char R : 5;
signed char dG : 3;
unsigned char G : 5;
signed char dB : 3;
unsigned char B : 5;
} diff;
} colors;
bool flipbit : 1;
bool diffbit : 1;
unsigned char cw2 : 3;
unsigned char cw1 : 3;
} idm;
// T mode
struct
{
// Byte 1
unsigned char TR1b : 2;
unsigned char TdummyB : 1;
unsigned char TR1a : 2;
unsigned char TdummyA : 3;
// Byte 2
unsigned char TB1 : 4;
unsigned char TG1 : 4;
// Byte 3
unsigned char TG2 : 4;
unsigned char TR2 : 4;
// Byte 4
unsigned char Tdb : 1;
bool Tflipbit : 1;
unsigned char Tda : 2;
unsigned char TB2 : 4;
} tm;
// H mode
struct
{
// Byte 1
unsigned char HG1a : 3;
unsigned char HR1 : 4;
unsigned char HdummyA : 1;
// Byte 2
unsigned char HB1b : 2;
unsigned char HdummyC : 1;
unsigned char HB1a : 1;
unsigned char HG1b : 1;
unsigned char HdummyB : 3;
// Byte 3
unsigned char HG2a : 3;
unsigned char HR2 : 4;
unsigned char HB1c : 1;
// Byte 4
unsigned char Hdb : 1;
bool Hflipbit : 1;
unsigned char Hda : 1;
unsigned char HB2 : 4;
unsigned char HG2b : 1;
} hm;
} mode;
unsigned char pixelIndexMSB[2];
unsigned char pixelIndexLSB[2];
} idht;
// planar mode
struct
{
// Byte 1
unsigned char GO1 : 1;
unsigned char RO : 6;
unsigned char PdummyA : 1;
// Byte 2
unsigned char BO1 : 1;
unsigned char GO2 : 6;
unsigned char PdummyB : 1;
// Byte 3
unsigned char BO3a : 2;
unsigned char PdummyD : 1;
unsigned char BO2 : 2;
unsigned char PdummyC : 3;
// Byte 4
unsigned char RH2 : 1;
bool Pflipbit : 1;
unsigned char RH1 : 5;
unsigned char BO3b : 1;
// Byte 5
unsigned char BHa : 1;
unsigned char GH : 7;
// Byte 6
unsigned char RVa : 3;
unsigned char BHb : 5;
// Byte 7
unsigned char GVa : 5;
unsigned char RVb : 3;
// Byte 8
unsigned char BV : 6;
unsigned char GVb : 2;
} pblk;
// Single channel block
struct
{
union
{
unsigned char us;
signed char s;
} base_codeword;
unsigned char table_index : 4;
unsigned char multiplier : 4;
unsigned char mc1 : 2;
unsigned char mb : 3;
unsigned char ma : 3;
unsigned char mf1 : 1;
unsigned char me : 3;
unsigned char md : 3;
unsigned char mc2 : 1;
unsigned char mh : 3;
unsigned char mg : 3;
unsigned char mf2 : 2;
unsigned char mk1 : 2;
unsigned char mj : 3;
unsigned char mi : 3;
unsigned char mn1 : 1;
unsigned char mm : 3;
unsigned char ml : 3;
unsigned char mk2 : 1;
unsigned char mp : 3;
unsigned char mo : 3;
unsigned char mn2 : 2;
} scblk;
} u;
static unsigned char clampByte(int value)
{
return static_cast<unsigned char>(gl::clamp(value, 0, 255));
}
static signed char clampSByte(int value)
{
return static_cast<signed char>(gl::clamp(value, -128, 127));
}
template <typename T>
static T renormalizeEAC(int value)
{
int upper = 0;
int lower = 0;
int shift = 0;
if (std::is_same<T, int16_t>::value)
{
// The spec states that -1024 invalid and should be clamped to -1023
upper = 1023;
lower = -1023;
shift = 5;
}
else if (std::is_same<T, uint16_t>::value)
{
upper = 2047;
lower = 0;
shift = 5;
}
else
{
// We currently only support renormalizing int16_t or uint16_t
UNREACHABLE();
}
return static_cast<T>(gl::clamp(value, lower, upper)) << shift;
}
static R8G8B8A8 createRGBA(int red, int green, int blue, int alpha)
{
R8G8B8A8 rgba;
rgba.R = clampByte(red);
rgba.G = clampByte(green);
rgba.B = clampByte(blue);
rgba.A = clampByte(alpha);
return rgba;
}
static R8G8B8A8 createRGBA(int red, int green, int blue)
{
return createRGBA(red, green, blue, 255);
}
static int extend_4to8bits(int x) { return (x << 4) | x; }
static int extend_5to8bits(int x) { return (x << 3) | (x >> 2); }
static int extend_6to8bits(int x) { return (x << 2) | (x >> 4); }
static int extend_7to8bits(int x) { return (x << 1) | (x >> 6); }
void decodeIndividualBlock(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destRowPitch,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
const auto &block = u.idht.mode.idm.colors.indiv;
int r1 = extend_4to8bits(block.R1);
int g1 = extend_4to8bits(block.G1);
int b1 = extend_4to8bits(block.B1);
int r2 = extend_4to8bits(block.R2);
int g2 = extend_4to8bits(block.G2);
int b2 = extend_4to8bits(block.B2);
decodeIndividualOrDifferentialBlock(dest, x, y, w, h, destRowPitch, r1, g1, b1, r2, g2, b2,
alphaValues, nonOpaquePunchThroughAlpha);
}
void decodeDifferentialBlock(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destRowPitch,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
const auto &block = u.idht.mode.idm.colors.diff;
int b1 = extend_5to8bits(block.B);
int g1 = extend_5to8bits(block.G);
int r1 = extend_5to8bits(block.R);
int r2 = extend_5to8bits(block.R + block.dR);
int g2 = extend_5to8bits(block.G + block.dG);
int b2 = extend_5to8bits(block.B + block.dB);
decodeIndividualOrDifferentialBlock(dest, x, y, w, h, destRowPitch, r1, g1, b1, r2, g2, b2,
alphaValues, nonOpaquePunchThroughAlpha);
}
void decodeIndividualOrDifferentialBlock(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destRowPitch,
int r1,
int g1,
int b1,
int r2,
int g2,
int b2,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
const IntensityModifier *intensityModifier =
nonOpaquePunchThroughAlpha ? intensityModifierNonOpaque : intensityModifierDefault;
R8G8B8A8 subblockColors0[4];
R8G8B8A8 subblockColors1[4];
for (size_t modifierIdx = 0; modifierIdx < 4; modifierIdx++)
{
const int i1 = intensityModifier[u.idht.mode.idm.cw1][modifierIdx];
subblockColors0[modifierIdx] = createRGBA(r1 + i1, g1 + i1, b1 + i1);
const int i2 = intensityModifier[u.idht.mode.idm.cw2][modifierIdx];
subblockColors1[modifierIdx] = createRGBA(r2 + i2, g2 + i2, b2 + i2);
}
if (u.idht.mode.idm.flipbit)
{
uint8_t *curPixel = dest;
for (size_t j = 0; j < 2 && (y + j) < h; j++)
{
R8G8B8A8 *row = reinterpret_cast<R8G8B8A8 *>(curPixel);
for (size_t i = 0; i < 4 && (x + i) < w; i++)
{
row[i] = subblockColors0[getIndex(i, j)];
row[i].A = alphaValues[j][i];
}
curPixel += destRowPitch;
}
for (size_t j = 2; j < 4 && (y + j) < h; j++)
{
R8G8B8A8 *row = reinterpret_cast<R8G8B8A8 *>(curPixel);
for (size_t i = 0; i < 4 && (x + i) < w; i++)
{
row[i] = subblockColors1[getIndex(i, j)];
row[i].A = alphaValues[j][i];
}
curPixel += destRowPitch;
}
}
else
{
uint8_t *curPixel = dest;
for (size_t j = 0; j < 4 && (y + j) < h; j++)
{
R8G8B8A8 *row = reinterpret_cast<R8G8B8A8 *>(curPixel);
for (size_t i = 0; i < 2 && (x + i) < w; i++)
{
row[i] = subblockColors0[getIndex(i, j)];
row[i].A = alphaValues[j][i];
}
for (size_t i = 2; i < 4 && (x + i) < w; i++)
{
row[i] = subblockColors1[getIndex(i, j)];
row[i].A = alphaValues[j][i];
}
curPixel += destRowPitch;
}
}
if (nonOpaquePunchThroughAlpha)
{
decodePunchThroughAlphaBlock(dest, x, y, w, h, destRowPitch);
}
}
void decodeTBlock(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destRowPitch,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
// Table C.8, distance index for T and H modes
const auto &block = u.idht.mode.tm;
int r1 = extend_4to8bits(block.TR1a << 2 | block.TR1b);
int g1 = extend_4to8bits(block.TG1);
int b1 = extend_4to8bits(block.TB1);
int r2 = extend_4to8bits(block.TR2);
int g2 = extend_4to8bits(block.TG2);
int b2 = extend_4to8bits(block.TB2);
static int distance[8] = {3, 6, 11, 16, 23, 32, 41, 64};
const int d = distance[block.Tda << 1 | block.Tdb];
const R8G8B8A8 paintColors[4] = {
createRGBA(r1, g1, b1),
createRGBA(r2 + d, g2 + d, b2 + d),
createRGBA(r2, g2, b2),
createRGBA(r2 - d, g2 - d, b2 - d),
};
uint8_t *curPixel = dest;
for (size_t j = 0; j < 4 && (y + j) < h; j++)
{
R8G8B8A8 *row = reinterpret_cast<R8G8B8A8 *>(curPixel);
for (size_t i = 0; i < 4 && (x + i) < w; i++)
{
row[i] = paintColors[getIndex(i, j)];
row[i].A = alphaValues[j][i];
}
curPixel += destRowPitch;
}
if (nonOpaquePunchThroughAlpha)
{
decodePunchThroughAlphaBlock(dest, x, y, w, h, destRowPitch);
}
}
void decodeHBlock(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destRowPitch,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
// Table C.8, distance index for T and H modes
const auto &block = u.idht.mode.hm;
int r1 = extend_4to8bits(block.HR1);
int g1 = extend_4to8bits(block.HG1a << 1 | block.HG1b);
int b1 = extend_4to8bits(block.HB1a << 3 | block.HB1b << 1 | block.HB1c);
int r2 = extend_4to8bits(block.HR2);
int g2 = extend_4to8bits(block.HG2a << 1 | block.HG2b);
int b2 = extend_4to8bits(block.HB2);
static const int distance[8] = {3, 6, 11, 16, 23, 32, 41, 64};
const int orderingTrickBit =
((r1 << 16 | g1 << 8 | b1) >= (r2 << 16 | g2 << 8 | b2) ? 1 : 0);
const int d = distance[(block.Hda << 2) | (block.Hdb << 1) | orderingTrickBit];
const R8G8B8A8 paintColors[4] = {
createRGBA(r1 + d, g1 + d, b1 + d),
createRGBA(r1 - d, g1 - d, b1 - d),
createRGBA(r2 + d, g2 + d, b2 + d),
createRGBA(r2 - d, g2 - d, b2 - d),
};
uint8_t *curPixel = dest;
for (size_t j = 0; j < 4 && (y + j) < h; j++)
{
R8G8B8A8 *row = reinterpret_cast<R8G8B8A8 *>(curPixel);
for (size_t i = 0; i < 4 && (x + i) < w; i++)
{
row[i] = paintColors[getIndex(i, j)];
row[i].A = alphaValues[j][i];
}
curPixel += destRowPitch;
}
if (nonOpaquePunchThroughAlpha)
{
decodePunchThroughAlphaBlock(dest, x, y, w, h, destRowPitch);
}
}
void decodePlanarBlock(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t pitch,
const uint8_t alphaValues[4][4]) const
{
int ro = extend_6to8bits(u.pblk.RO);
int go = extend_7to8bits(u.pblk.GO1 << 6 | u.pblk.GO2);
int bo =
extend_6to8bits(u.pblk.BO1 << 5 | u.pblk.BO2 << 3 | u.pblk.BO3a << 1 | u.pblk.BO3b);
int rh = extend_6to8bits(u.pblk.RH1 << 1 | u.pblk.RH2);
int gh = extend_7to8bits(u.pblk.GH);
int bh = extend_6to8bits(u.pblk.BHa << 5 | u.pblk.BHb);
int rv = extend_6to8bits(u.pblk.RVa << 3 | u.pblk.RVb);
int gv = extend_7to8bits(u.pblk.GVa << 2 | u.pblk.GVb);
int bv = extend_6to8bits(u.pblk.BV);
uint8_t *curPixel = dest;
for (size_t j = 0; j < 4 && (y + j) < h; j++)
{
R8G8B8A8 *row = reinterpret_cast<R8G8B8A8 *>(curPixel);
int ry = static_cast<int>(j) * (rv - ro) + 2;
int gy = static_cast<int>(j) * (gv - go) + 2;
int by = static_cast<int>(j) * (bv - bo) + 2;
for (size_t i = 0; i < 4 && (x + i) < w; i++)
{
row[i] = createRGBA(((static_cast<int>(i) * (rh - ro) + ry) >> 2) + ro,
((static_cast<int>(i) * (gh - go) + gy) >> 2) + go,
((static_cast<int>(i) * (bh - bo) + by) >> 2) + bo,
alphaValues[j][i]);
}
curPixel += pitch;
}
}
// Index for individual, differential, H and T modes
size_t getIndex(size_t x, size_t y) const
{
size_t bitIndex = x * 4 + y;
size_t bitOffset = bitIndex & 7;
size_t lsb = (u.idht.pixelIndexLSB[1 - (bitIndex >> 3)] >> bitOffset) & 1;
size_t msb = (u.idht.pixelIndexMSB[1 - (bitIndex >> 3)] >> bitOffset) & 1;
return (msb << 1) | lsb;
}
void decodePunchThroughAlphaBlock(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
size_t destRowPitch) const
{
uint8_t *curPixel = dest;
for (size_t j = 0; j < 4 && (y + j) < h; j++)
{
R8G8B8A8 *row = reinterpret_cast<R8G8B8A8 *>(curPixel);
for (size_t i = 0; i < 4 && (x + i) < w; i++)
{
if (getIndex(i, j) == 2) // msb == 1 && lsb == 0
{
row[i] = createRGBA(0, 0, 0, 0);
}
}
curPixel += destRowPitch;
}
}
uint16_t RGB8ToRGB565(const R8G8B8A8 &rgba) const
{
return (static_cast<uint16_t>(rgba.R >> 3) << 11) |
(static_cast<uint16_t>(rgba.G >> 2) << 5) |
(static_cast<uint16_t>(rgba.B >> 3) << 0);
}
uint32_t matchBC1Bits(const int *pixelIndices,
const int *pixelIndexCounts,
const R8G8B8A8 *subblockColors,
size_t numColors,
const R8G8B8A8 &minColor,
const R8G8B8A8 &maxColor,
bool nonOpaquePunchThroughAlpha) const
{
// Project each pixel on the (maxColor, minColor) line to decide which
// BC1 code to assign to it.
uint8_t decodedColors[2][3] = {{maxColor.R, maxColor.G, maxColor.B},
{minColor.R, minColor.G, minColor.B}};
int direction[3];
for (int ch = 0; ch < 3; ch++)
{
direction[ch] = decodedColors[0][ch] - decodedColors[1][ch];
}
int stops[2];
for (int i = 0; i < 2; i++)
{
stops[i] = decodedColors[i][0] * direction[0] + decodedColors[i][1] * direction[1] +
decodedColors[i][2] * direction[2];
}
ASSERT(numColors <= kNumPixelsInBlock);
int encodedColors[kNumPixelsInBlock];
if (nonOpaquePunchThroughAlpha)
{
for (size_t i = 0; i < numColors; i++)
{
const int count = pixelIndexCounts[i];
if (count > 0)
{
// In non-opaque mode, 3 is for tranparent pixels.
if (0 == subblockColors[i].A)
{
encodedColors[i] = 3;
}
else
{
const R8G8B8A8 &pixel = subblockColors[i];
const int dot = pixel.R * direction[0] + pixel.G * direction[1] +
pixel.B * direction[2];
const int factor = gl::clamp(
static_cast<int>(
(static_cast<float>(dot - stops[1]) / (stops[0] - stops[1])) * 2 +
0.5f),
0, 2);
switch (factor)
{
case 0:
encodedColors[i] = 0;
break;
case 1:
encodedColors[i] = 2;
break;
case 2:
default:
encodedColors[i] = 1;
break;
}
}
}
}
}
else
{
for (size_t i = 0; i < numColors; i++)
{
const int count = pixelIndexCounts[i];
if (count > 0)
{
// In opaque mode, the code is from 0 to 3.
const R8G8B8A8 &pixel = subblockColors[i];
const int dot =
pixel.R * direction[0] + pixel.G * direction[1] + pixel.B * direction[2];
const int factor = gl::clamp(
static_cast<int>(
(static_cast<float>(dot - stops[1]) / (stops[0] - stops[1])) * 3 +
0.5f),
0, 3);
switch (factor)
{
case 0:
encodedColors[i] = 1;
break;
case 1:
encodedColors[i] = 3;
break;
case 2:
encodedColors[i] = 2;
break;
case 3:
default:
encodedColors[i] = 0;
break;
}
}
}
}
uint32_t bits = 0;
for (int i = kNumPixelsInBlock - 1; i >= 0; i--)
{
bits <<= 2;
bits |= encodedColors[pixelIndices[i]];
}
return bits;
}
void packBC1(void *bc1,
const int *pixelIndices,
const int *pixelIndexCounts,
const R8G8B8A8 *subblockColors,
size_t numColors,
int minColorIndex,
int maxColorIndex,
bool nonOpaquePunchThroughAlpha) const
{
const R8G8B8A8 &minColor = subblockColors[minColorIndex];
const R8G8B8A8 &maxColor = subblockColors[maxColorIndex];
uint32_t bits;
uint16_t max16 = RGB8ToRGB565(maxColor);
uint16_t min16 = RGB8ToRGB565(minColor);
if (max16 != min16)
{
// Find the best BC1 code for each pixel
bits = matchBC1Bits(pixelIndices, pixelIndexCounts, subblockColors, numColors, minColor,
maxColor, nonOpaquePunchThroughAlpha);
}
else
{
// Same colors, BC1 index 0 is the color in both opaque and transparent mode
bits = 0;
// BC1 index 3 is transparent
if (nonOpaquePunchThroughAlpha)
{
for (int i = 0; i < kNumPixelsInBlock; i++)
{
if (0 == subblockColors[pixelIndices[i]].A)
{
bits |= (3 << (i * 2));
}
}
}
}
if (max16 < min16)
{
std::swap(max16, min16);
uint32_t xorMask = 0;
if (nonOpaquePunchThroughAlpha)
{
// In transparent mode switching the colors is doing the
// following code swap: 0 <-> 1. 0xA selects the second bit of
// each code, bits >> 1 selects the first bit of the code when
// the seconds bit is set (case 2 and 3). We invert all the
// non-selected bits, that is the first bit when the code is
// 0 or 1.
xorMask = ~((bits >> 1) | 0xAAAAAAAA);
}
else
{
// In opaque mode switching the two colors is doing the
// following code swaps: 0 <-> 1 and 2 <-> 3. This is
// equivalent to flipping the first bit of each code
// (5 = 0b0101)
xorMask = 0x55555555;
}
bits ^= xorMask;
}
struct BC1Block
{
uint16_t color0;
uint16_t color1;
uint32_t bits;
};
// Encode the opaqueness in the order of the two BC1 colors
BC1Block *dest = reinterpret_cast<BC1Block *>(bc1);
if (nonOpaquePunchThroughAlpha)
{
dest->color0 = min16;
dest->color1 = max16;
}
else
{
dest->color0 = max16;
dest->color1 = min16;
}
dest->bits = bits;
}
void transcodeIndividualBlockToBC1(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
const auto &block = u.idht.mode.idm.colors.indiv;
int r1 = extend_4to8bits(block.R1);
int g1 = extend_4to8bits(block.G1);
int b1 = extend_4to8bits(block.B1);
int r2 = extend_4to8bits(block.R2);
int g2 = extend_4to8bits(block.G2);
int b2 = extend_4to8bits(block.B2);
transcodeIndividualOrDifferentialBlockToBC1(dest, x, y, w, h, r1, g1, b1, r2, g2, b2,
alphaValues, nonOpaquePunchThroughAlpha);
}
void transcodeDifferentialBlockToBC1(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
const auto &block = u.idht.mode.idm.colors.diff;
int b1 = extend_5to8bits(block.B);
int g1 = extend_5to8bits(block.G);
int r1 = extend_5to8bits(block.R);
int r2 = extend_5to8bits(block.R + block.dR);
int g2 = extend_5to8bits(block.G + block.dG);
int b2 = extend_5to8bits(block.B + block.dB);
transcodeIndividualOrDifferentialBlockToBC1(dest, x, y, w, h, r1, g1, b1, r2, g2, b2,
alphaValues, nonOpaquePunchThroughAlpha);
}
void extractPixelIndices(int *pixelIndices,
int *pixelIndicesCounts,
size_t x,
size_t y,
size_t w,
size_t h,
bool flipbit,
size_t subblockIdx) const
{
size_t dxBegin = 0;
size_t dxEnd = 4;
size_t dyBegin = subblockIdx * 2;
size_t dyEnd = dyBegin + 2;
if (!flipbit)
{
std::swap(dxBegin, dyBegin);
std::swap(dxEnd, dyEnd);
}
for (size_t j = dyBegin; j < dyEnd; j++)
{
int *row = &pixelIndices[j * 4];
for (size_t i = dxBegin; i < dxEnd; i++)
{
const size_t pixelIndex = subblockIdx * 4 + getIndex(i, j);
row[i] = static_cast<int>(pixelIndex);
pixelIndicesCounts[pixelIndex]++;
}
}
}
void selectEndPointPCA(const int *pixelIndexCounts,
const R8G8B8A8 *subblockColors,
size_t numColors,
int *minColorIndex,
int *maxColorIndex) const
{
// determine color distribution
int mu[3], min[3], max[3];
for (int ch = 0; ch < 3; ch++)
{
int muv = 0;
int minv = 255;
int maxv = 0;
for (size_t i = 0; i < numColors; i++)
{
const int count = pixelIndexCounts[i];
if (count > 0)
{
const auto &pixel = subblockColors[i];
if (pixel.A > 0)
{
// Non-transparent pixels
muv += (&pixel.R)[ch] * count;
minv = std::min<int>(minv, (&pixel.R)[ch]);
maxv = std::max<int>(maxv, (&pixel.R)[ch]);
}
}
}
mu[ch] = (muv + kNumPixelsInBlock / 2) / kNumPixelsInBlock;
min[ch] = minv;
max[ch] = maxv;
}
// determine covariance matrix
int cov[6] = {0, 0, 0, 0, 0, 0};
for (size_t i = 0; i < numColors; i++)
{
const int count = pixelIndexCounts[i];
if (count > 0)
{
const auto &pixel = subblockColors[i];
if (pixel.A > 0)
{
int r = pixel.R - mu[0];
int g = pixel.G - mu[1];
int b = pixel.B - mu[2];
cov[0] += r * r * count;
cov[1] += r * g * count;
cov[2] += r * b * count;
cov[3] += g * g * count;
cov[4] += g * b * count;
cov[5] += b * b * count;
}
}
}
// Power iteration algorithm to get the eigenvalues and eigenvector
// Starts with diagonal vector
float vfr = static_cast<float>(max[0] - min[0]);
float vfg = static_cast<float>(max[1] - min[1]);
float vfb = static_cast<float>(max[2] - min[2]);
float eigenvalue = 0.0f;
constexpr size_t kPowerIterations = 4;
for (size_t i = 0; i < kPowerIterations; i++)
{
float r = vfr * cov[0] + vfg * cov[1] + vfb * cov[2];
float g = vfr * cov[1] + vfg * cov[3] + vfb * cov[4];
float b = vfr * cov[2] + vfg * cov[4] + vfb * cov[5];
vfr = r;
vfg = g;
vfb = b;
eigenvalue = sqrt(r * r + g * g + b * b);
if (eigenvalue > 0)
{
float invNorm = 1.0f / eigenvalue;
vfr *= invNorm;
vfg *= invNorm;
vfb *= invNorm;
}
}
int vr, vg, vb;
static const float kDefaultLuminanceThreshold = 4.0f * 255;
static const float kQuantizeRange = 512.0f;
if (eigenvalue < kDefaultLuminanceThreshold) // too small, default to luminance
{
// Luminance weights defined by ITU-R Recommendation BT.601, scaled by 1000
vr = 299;
vg = 587;
vb = 114;
}
else
{
// From the eigenvalue and eigenvector, choose the axis to project
// colors on. When projecting colors we want to do integer computations
// for speed, so we normalize the eigenvector to the [0, 512] range.
float magn = std::max(std::max(std::abs(vfr), std::abs(vfg)), std::abs(vfb));
magn = kQuantizeRange / magn;
vr = static_cast<int>(vfr * magn);
vg = static_cast<int>(vfg * magn);
vb = static_cast<int>(vfb * magn);
}
// Pick colors at extreme points
int minD = INT_MAX;
int maxD = 0;
size_t minIndex = 0;
size_t maxIndex = 0;
for (size_t i = 0; i < numColors; i++)
{
const int count = pixelIndexCounts[i];
if (count > 0)
{
const auto &pixel = subblockColors[i];
if (pixel.A > 0)
{
int dot = pixel.R * vr + pixel.G * vg + pixel.B * vb;
if (dot < minD)
{
minD = dot;
minIndex = i;
}
if (dot > maxD)
{
maxD = dot;
maxIndex = i;
}
}
}
}
*minColorIndex = static_cast<int>(minIndex);
*maxColorIndex = static_cast<int>(maxIndex);
}
void transcodeIndividualOrDifferentialBlockToBC1(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
int r1,
int g1,
int b1,
int r2,
int g2,
int b2,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
// A BC1 block has 2 endpoints, pixels is encoded as linear
// interpolations of them. A ETC1/ETC2 individual or differential block
// has 2 subblocks. Each subblock has one color and a modifier. We
// select axis by principal component analysis (PCA) to use as
// our two BC1 endpoints and then map pixels to BC1 by projecting on the
// line between the two endpoints and choosing the right fraction.
// The goal of this algorithm is make it faster than decode ETC to RGBs
// and then encode to BC. To achieve this, we only extract subblock
// colors, pixel indices, and counts of each pixel indices from ETC.
// With those information, we can only encode used subblock colors
// to BC1, and copy the bits to the right pixels.
// Fully decode and encode need to process 16 RGBA pixels. With this
// algorithm, it's 8 pixels at maximum for a individual or
// differential block. Saves us bandwidth and computations.
static const size_t kNumColors = 8;
const IntensityModifier *intensityModifier =
nonOpaquePunchThroughAlpha ? intensityModifierNonOpaque : intensityModifierDefault;
// Compute the colors that pixels can have in each subblock both for
// the decoding of the RGBA data and BC1 encoding
R8G8B8A8 subblockColors[kNumColors];
for (size_t modifierIdx = 0; modifierIdx < 4; modifierIdx++)
{
if (nonOpaquePunchThroughAlpha && (modifierIdx == 2))
{
// In ETC opaque punch through formats, individual and
// differential blocks take index 2 as transparent pixel.
// Thus we don't need to compute its color, just assign it
// as black.
subblockColors[modifierIdx] = createRGBA(0, 0, 0, 0);
subblockColors[4 + modifierIdx] = createRGBA(0, 0, 0, 0);
}
else
{
const int i1 = intensityModifier[u.idht.mode.idm.cw1][modifierIdx];
subblockColors[modifierIdx] = createRGBA(r1 + i1, g1 + i1, b1 + i1);
const int i2 = intensityModifier[u.idht.mode.idm.cw2][modifierIdx];
subblockColors[4 + modifierIdx] = createRGBA(r2 + i2, g2 + i2, b2 + i2);
}
}
int pixelIndices[kNumPixelsInBlock];
int pixelIndexCounts[kNumColors] = {0};
// Extract pixel indices from a ETC block.
for (size_t blockIdx = 0; blockIdx < 2; blockIdx++)
{
extractPixelIndices(pixelIndices, pixelIndexCounts, x, y, w, h, u.idht.mode.idm.flipbit,
blockIdx);
}
int minColorIndex, maxColorIndex;
selectEndPointPCA(pixelIndexCounts, subblockColors, kNumColors, &minColorIndex,
&maxColorIndex);
packBC1(dest, pixelIndices, pixelIndexCounts, subblockColors, kNumColors, minColorIndex,
maxColorIndex, nonOpaquePunchThroughAlpha);
}
void transcodeTBlockToBC1(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
static const size_t kNumColors = 4;
// Table C.8, distance index for T and H modes
const auto &block = u.idht.mode.tm;
int r1 = extend_4to8bits(block.TR1a << 2 | block.TR1b);
int g1 = extend_4to8bits(block.TG1);
int b1 = extend_4to8bits(block.TB1);
int r2 = extend_4to8bits(block.TR2);
int g2 = extend_4to8bits(block.TG2);
int b2 = extend_4to8bits(block.TB2);
static int distance[8] = {3, 6, 11, 16, 23, 32, 41, 64};
const int d = distance[block.Tda << 1 | block.Tdb];
// In ETC opaque punch through formats, index == 2 means transparent pixel.
// Thus we don't need to compute its color, just assign it as black.
const R8G8B8A8 paintColors[kNumColors] = {
createRGBA(r1, g1, b1),
createRGBA(r2 + d, g2 + d, b2 + d),
nonOpaquePunchThroughAlpha ? createRGBA(0, 0, 0, 0) : createRGBA(r2, g2, b2),
createRGBA(r2 - d, g2 - d, b2 - d),
};
int pixelIndices[kNumPixelsInBlock];
int pixelIndexCounts[kNumColors] = {0};
for (size_t j = 0; j < 4; j++)
{
int *row = &pixelIndices[j * 4];
for (size_t i = 0; i < 4; i++)
{
const size_t pixelIndex = getIndex(i, j);
row[i] = static_cast<int>(pixelIndex);
pixelIndexCounts[pixelIndex]++;
}
}
int minColorIndex, maxColorIndex;
selectEndPointPCA(pixelIndexCounts, paintColors, kNumColors, &minColorIndex,
&maxColorIndex);
packBC1(dest, pixelIndices, pixelIndexCounts, paintColors, kNumColors, minColorIndex,
maxColorIndex, nonOpaquePunchThroughAlpha);
}
void transcodeHBlockToBC1(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
const uint8_t alphaValues[4][4],
bool nonOpaquePunchThroughAlpha) const
{
static const size_t kNumColors = 4;
// Table C.8, distance index for T and H modes
const auto &block = u.idht.mode.hm;
int r1 = extend_4to8bits(block.HR1);
int g1 = extend_4to8bits(block.HG1a << 1 | block.HG1b);
int b1 = extend_4to8bits(block.HB1a << 3 | block.HB1b << 1 | block.HB1c);
int r2 = extend_4to8bits(block.HR2);
int g2 = extend_4to8bits(block.HG2a << 1 | block.HG2b);
int b2 = extend_4to8bits(block.HB2);
static const int distance[8] = {3, 6, 11, 16, 23, 32, 41, 64};
const int orderingTrickBit =
((r1 << 16 | g1 << 8 | b1) >= (r2 << 16 | g2 << 8 | b2) ? 1 : 0);
const int d = distance[(block.Hda << 2) | (block.Hdb << 1) | orderingTrickBit];
// In ETC opaque punch through formats, index == 2 means transparent pixel.
// Thus we don't need to compute its color, just assign it as black.
const R8G8B8A8 paintColors[kNumColors] = {
createRGBA(r1 + d, g1 + d, b1 + d),
createRGBA(r1 - d, g1 - d, b1 - d),
nonOpaquePunchThroughAlpha ? createRGBA(0, 0, 0, 0)
: createRGBA(r2 + d, g2 + d, b2 + d),
createRGBA(r2 - d, g2 - d, b2 - d),
};
int pixelIndices[kNumPixelsInBlock];
int pixelIndexCounts[kNumColors] = {0};
for (size_t j = 0; j < 4; j++)
{
int *row = &pixelIndices[j * 4];
for (size_t i = 0; i < 4; i++)
{
const size_t pixelIndex = getIndex(i, j);
row[i] = static_cast<int>(pixelIndex);
pixelIndexCounts[pixelIndex]++;
}
}
int minColorIndex, maxColorIndex;
selectEndPointPCA(pixelIndexCounts, paintColors, kNumColors, &minColorIndex,
&maxColorIndex);
packBC1(dest, pixelIndices, pixelIndexCounts, paintColors, kNumColors, minColorIndex,
maxColorIndex, nonOpaquePunchThroughAlpha);
}
void transcodePlanarBlockToBC1(uint8_t *dest,
size_t x,
size_t y,
size_t w,
size_t h,
const uint8_t alphaValues[4][4]) const
{
static const size_t kNumColors = kNumPixelsInBlock;
R8G8B8A8 rgbaBlock[kNumColors];
decodePlanarBlock(reinterpret_cast<uint8_t *>(rgbaBlock), x, y, w, h, sizeof(R8G8B8A8) * 4,
alphaValues);
// Planar block doesn't have a color table, fill indices as full
int pixelIndices[kNumPixelsInBlock] = {0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15};
int pixelIndexCounts[kNumColors] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
int minColorIndex, maxColorIndex;
selectEndPointPCA(pixelIndexCounts, rgbaBlock, kNumColors, &minColorIndex, &maxColorIndex);
packBC1(dest, pixelIndices, pixelIndexCounts, rgbaBlock, kNumColors, minColorIndex,
maxColorIndex, false);
}
// Single channel utility functions
int getSingleEACChannel(size_t x, size_t y, bool isSigned) const
{
int codeword = isSigned ? u.scblk.base_codeword.s : u.scblk.base_codeword.us;
int multiplier = (u.scblk.multiplier == 0) ? 1 : u.scblk.multiplier * 8;
return codeword * 8 + 4 + getSingleChannelModifier(x, y) * multiplier;
}
int getSingleETC2Channel(size_t x, size_t y, bool isSigned) const
{
int codeword = isSigned ? u.scblk.base_codeword.s : u.scblk.base_codeword.us;
return codeword + getSingleChannelModifier(x, y) * u.scblk.multiplier;
}
int getSingleChannelIndex(size_t x, size_t y) const
{
ASSERT(x < 4 && y < 4);
// clang-format off
switch (x * 4 + y)
{
case 0: return u.scblk.ma;
case 1: return u.scblk.mb;
case 2: return u.scblk.mc1 << 1 | u.scblk.mc2;
case 3: return u.scblk.md;
case 4: return u.scblk.me;
case 5: return u.scblk.mf1 << 2 | u.scblk.mf2;
case 6: return u.scblk.mg;
case 7: return u.scblk.mh;
case 8: return u.scblk.mi;
case 9: return u.scblk.mj;
case 10: return u.scblk.mk1 << 1 | u.scblk.mk2;
case 11: return u.scblk.ml;
case 12: return u.scblk.mm;
case 13: return u.scblk.mn1 << 2 | u.scblk.mn2;
case 14: return u.scblk.mo;
case 15: return u.scblk.mp;
default: UNREACHABLE(); return 0;
}
// clang-format on
}
int getSingleChannelModifier(size_t x, size_t y) const
{
// clang-format off
static const int modifierTable[16][8] =
{
{ -3, -6, -9, -15, 2, 5, 8, 14 },
{ -3, -7, -10, -13, 2, 6, 9, 12 },
{ -2, -5, -8, -13, 1, 4, 7, 12 },
{ -2, -4, -6, -13, 1, 3, 5, 12 },
{ -3, -6, -8, -12, 2, 5, 7, 11 },
{ -3, -7, -9, -11, 2, 6, 8, 10 },
{ -4, -7, -8, -11, 3, 6, 7, 10 },
{ -3, -5, -8, -11, 2, 4, 7, 10 },
{ -2, -6, -8, -10, 1, 5, 7, 9 },
{ -2, -5, -8, -10, 1, 4, 7, 9 },
{ -2, -4, -8, -10, 1, 3, 7, 9 },
{ -2, -5, -7, -10, 1, 4, 6, 9 },
{ -3, -4, -7, -10, 2, 3, 6, 9 },
{ -1, -2, -3, -10, 0, 1, 2, 9 },
{ -4, -6, -8, -9, 3, 5, 7, 8 },
{ -3, -5, -7, -9, 2, 4, 6, 8 }
};
// clang-format on
return modifierTable[u.scblk.table_index][getSingleChannelIndex(x, y)];
}
};
// clang-format off
static const uint8_t DefaultETCAlphaValues[4][4] =
{
{ 255, 255, 255, 255 },
{ 255, 255, 255, 255 },
{ 255, 255, 255, 255 },
{ 255, 255, 255, 255 },
};
// clang-format on
void LoadR11EACToR8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch,
bool isSigned)
{
for (size_t z = 0; z < depth; z++)
{
for (size_t y = 0; y < height; y += 4)
{
const ETC2Block *sourceRow =
priv::OffsetDataPointer<ETC2Block>(input, y / 4, z, inputRowPitch, inputDepthPitch);
uint8_t *destRow =
priv::OffsetDataPointer<uint8_t>(output, y, z, outputRowPitch, outputDepthPitch);
for (size_t x = 0; x < width; x += 4)
{
const ETC2Block *sourceBlock = sourceRow + (x / 4);
uint8_t *destPixels = destRow + x;
sourceBlock->decodeAsSingleETC2Channel(destPixels, x, y, width, height, 1,
outputRowPitch, isSigned);
}
}
}
}
void LoadRG11EACToRG8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch,
bool isSigned)
{
for (size_t z = 0; z < depth; z++)
{
for (size_t y = 0; y < height; y += 4)
{
const ETC2Block *sourceRow =
priv::OffsetDataPointer<ETC2Block>(input, y / 4, z, inputRowPitch, inputDepthPitch);
uint8_t *destRow =
priv::OffsetDataPointer<uint8_t>(output, y, z, outputRowPitch, outputDepthPitch);
for (size_t x = 0; x < width; x += 4)
{
uint8_t *destPixelsRed = destRow + (x * 2);
const ETC2Block *sourceBlockRed = sourceRow + (x / 2);
sourceBlockRed->decodeAsSingleETC2Channel(destPixelsRed, x, y, width, height, 2,
outputRowPitch, isSigned);
uint8_t *destPixelsGreen = destPixelsRed + 1;
const ETC2Block *sourceBlockGreen = sourceBlockRed + 1;
sourceBlockGreen->decodeAsSingleETC2Channel(destPixelsGreen, x, y, width, height, 2,
outputRowPitch, isSigned);
}
}
}
}
void LoadR11EACToR16(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch,
bool isSigned,
bool isFloat)
{
for (size_t z = 0; z < depth; z++)
{
for (size_t y = 0; y < height; y += 4)
{
const ETC2Block *sourceRow =
priv::OffsetDataPointer<ETC2Block>(input, y / 4, z, inputRowPitch, inputDepthPitch);
uint16_t *destRow =
priv::OffsetDataPointer<uint16_t>(output, y, z, outputRowPitch, outputDepthPitch);
for (size_t x = 0; x < width; x += 4)
{
const ETC2Block *sourceBlock = sourceRow + (x / 4);
uint16_t *destPixels = destRow + x;
sourceBlock->decodeAsSingleEACChannel(destPixels, x, y, width, height, 1,
outputRowPitch, isSigned, isFloat);
}
}
}
}
void LoadRG11EACToRG16(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch,
bool isSigned,
bool isFloat)
{
for (size_t z = 0; z < depth; z++)
{
for (size_t y = 0; y < height; y += 4)
{
const ETC2Block *sourceRow =
priv::OffsetDataPointer<ETC2Block>(input, y / 4, z, inputRowPitch, inputDepthPitch);
uint16_t *destRow =
priv::OffsetDataPointer<uint16_t>(output, y, z, outputRowPitch, outputDepthPitch);
for (size_t x = 0; x < width; x += 4)
{
uint16_t *destPixelsRed = destRow + (x * 2);
const ETC2Block *sourceBlockRed = sourceRow + (x / 2);
sourceBlockRed->decodeAsSingleEACChannel(destPixelsRed, x, y, width, height, 2,
outputRowPitch, isSigned, isFloat);
uint16_t *destPixelsGreen = destPixelsRed + 1;
const ETC2Block *sourceBlockGreen = sourceBlockRed + 1;
sourceBlockGreen->decodeAsSingleEACChannel(destPixelsGreen, x, y, width, height, 2,
outputRowPitch, isSigned, isFloat);
}
}
}
}
void LoadETC2RGB8ToRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch,
bool punchthroughAlpha)
{
for (size_t z = 0; z < depth; z++)
{
for (size_t y = 0; y < height; y += 4)
{
const ETC2Block *sourceRow =
priv::OffsetDataPointer<ETC2Block>(input, y / 4, z, inputRowPitch, inputDepthPitch);
uint8_t *destRow =
priv::OffsetDataPointer<uint8_t>(output, y, z, outputRowPitch, outputDepthPitch);
for (size_t x = 0; x < width; x += 4)
{
const ETC2Block *sourceBlock = sourceRow + (x / 4);
uint8_t *destPixels = destRow + (x * 4);
sourceBlock->decodeAsRGB(destPixels, x, y, width, height, outputRowPitch,
DefaultETCAlphaValues, punchthroughAlpha);
}
}
}
}
void LoadETC2RGB8ToBC1(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch,
bool punchthroughAlpha)
{
for (size_t z = 0; z < depth; z++)
{
for (size_t y = 0; y < height; y += 4)
{
const ETC2Block *sourceRow =
priv::OffsetDataPointer<ETC2Block>(input, y / 4, z, inputRowPitch, inputDepthPitch);
uint8_t *destRow = priv::OffsetDataPointer<uint8_t>(output, y / 4, z, outputRowPitch,
outputDepthPitch);
for (size_t x = 0; x < width; x += 4)
{
const ETC2Block *sourceBlock = sourceRow + (x / 4);
uint8_t *destPixels = destRow + (x * 2);
sourceBlock->transcodeAsBC1(destPixels, x, y, width, height, DefaultETCAlphaValues,
punchthroughAlpha);
}
}
}
}
void LoadETC2RGBA8ToRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch,
bool srgb)
{
uint8_t decodedAlphaValues[4][4];
for (size_t z = 0; z < depth; z++)
{
for (size_t y = 0; y < height; y += 4)
{
const ETC2Block *sourceRow =
priv::OffsetDataPointer<ETC2Block>(input, y / 4, z, inputRowPitch, inputDepthPitch);
uint8_t *destRow =
priv::OffsetDataPointer<uint8_t>(output, y, z, outputRowPitch, outputDepthPitch);
for (size_t x = 0; x < width; x += 4)
{
const ETC2Block *sourceBlockAlpha = sourceRow + (x / 2);
sourceBlockAlpha->decodeAsSingleETC2Channel(
reinterpret_cast<uint8_t *>(decodedAlphaValues), x, y, width, height, 1, 4,
false);
uint8_t *destPixels = destRow + (x * 4);
const ETC2Block *sourceBlockRGB = sourceBlockAlpha + 1;
sourceBlockRGB->decodeAsRGB(destPixels, x, y, width, height, outputRowPitch,
decodedAlphaValues, false);
}
}
}
}
} // anonymous namespace
void LoadETC1RGB8ToRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToRGBA8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadETC1RGB8ToBC1(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToBC1(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadEACR11ToR8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadR11EACToR8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadEACR11SToR8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadR11EACToR8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true);
}
void LoadEACRG11ToRG8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadRG11EACToRG8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadEACRG11SToRG8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadRG11EACToRG8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true);
}
void LoadEACR11ToR16(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadR11EACToR16(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false, false);
}
void LoadEACR11SToR16(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadR11EACToR16(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true, false);
}
void LoadEACRG11ToRG16(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadRG11EACToRG16(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false, false);
}
void LoadEACRG11SToRG16(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadRG11EACToRG16(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true, false);
}
void LoadEACR11ToR16F(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadR11EACToR16(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false, true);
}
void LoadEACR11SToR16F(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadR11EACToR16(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true, true);
}
void LoadEACRG11ToRG16F(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadRG11EACToRG16(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false, true);
}
void LoadEACRG11SToRG16F(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadRG11EACToRG16(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true, true);
}
void LoadETC2RGB8ToRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToRGBA8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadETC2RGB8ToBC1(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToBC1(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadETC2SRGB8ToRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToRGBA8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadETC2SRGB8ToBC1(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToBC1(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadETC2RGB8A1ToRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToRGBA8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true);
}
void LoadETC2RGB8A1ToBC1(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToBC1(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true);
}
void LoadETC2SRGB8A1ToRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToRGBA8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true);
}
void LoadETC2SRGB8A1ToBC1(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGB8ToBC1(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true);
}
void LoadETC2RGBA8ToRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGBA8ToRGBA8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, false);
}
void LoadETC2SRGBA8ToSRGBA8(size_t width,
size_t height,
size_t depth,
const uint8_t *input,
size_t inputRowPitch,
size_t inputDepthPitch,
uint8_t *output,
size_t outputRowPitch,
size_t outputDepthPitch)
{
LoadETC2RGBA8ToRGBA8(width, height, depth, input, inputRowPitch, inputDepthPitch, output,
outputRowPitch, outputDepthPitch, true);
}
} // namespace angle