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- // SPDX-License-Identifier: MPL-2.0
- // Copyright © 2022 Skyline Team and Contributors (https://github.com/skyline-emu/)
- // Copyright 2019 The SwiftShader Authors. All Rights Reserved.
- // This BCn Decoder is directly derivative of Swiftshader's BCn Decoder found at: https://github.com/google/swiftshader/blob/d070309f7d154d6764cbd514b1a5c8bfcef61d06/src/Device/BC_Decoder.cpp
- // This file does not follow the Skyline code conventions but has certain Skyline specific code
- // There are a lot of implicit and narrowing conversions in this file due to this (Warnings are disabled as a result)
- #include <array>
- #include <assert.h>
- #include <stddef.h>
- #include <stdint.h>
- namespace {
- constexpr int BlockWidth = 4;
- constexpr int BlockHeight = 4;
- struct BC_color {
- void decode(uint8_t *dst, size_t x, size_t y, size_t dstW, size_t dstH, size_t dstPitch, size_t dstBpp, bool hasAlphaChannel, bool hasSeparateAlpha) const {
- Color c[4];
- c[0].extract565(c0);
- c[1].extract565(c1);
- if (hasSeparateAlpha || (c0 > c1)) {
- c[2] = ((c[0] * 2) + c[1]) / 3;
- c[3] = ((c[1] * 2) + c[0]) / 3;
- } else {
- c[2] = (c[0] + c[1]) >> 1;
- if (hasAlphaChannel) {
- c[3].clearAlpha();
- }
- }
- for (int j = 0; j < BlockHeight && (y + j) < dstH; j++) {
- size_t dstOffset = j * dstPitch;
- size_t idxOffset = j * BlockHeight;
- for (size_t i = 0; i < BlockWidth && (x + i) < dstW; i++, idxOffset++, dstOffset += dstBpp) {
- *reinterpret_cast<unsigned int *>(dst + dstOffset) = c[getIdx(idxOffset)].pack8888();
- }
- }
- }
- private:
- struct Color {
- Color() {
- c[0] = c[1] = c[2] = 0;
- c[3] = 0xFF000000;
- }
- void extract565(const unsigned int c565) {
- c[0] = ((c565 & 0x0000001F) << 3) | ((c565 & 0x0000001C) >> 2);
- c[1] = ((c565 & 0x000007E0) >> 3) | ((c565 & 0x00000600) >> 9);
- c[2] = ((c565 & 0x0000F800) >> 8) | ((c565 & 0x0000E000) >> 13);
- }
- unsigned int pack8888() const {
- return ((c[0] & 0xFF) << 16) | ((c[1] & 0xFF) << 8) | (c[2] & 0xFF) | c[3];
- }
- void clearAlpha() {
- c[3] = 0;
- }
- Color operator*(int factor) const {
- Color res;
- for (int i = 0; i < 4; ++i) {
- res.c[i] = c[i] * factor;
- }
- return res;
- }
- Color operator/(int factor) const {
- Color res;
- for (int i = 0; i < 4; ++i) {
- res.c[i] = c[i] / factor;
- }
- return res;
- }
- Color operator>>(int shift) const {
- Color res;
- for (int i = 0; i < 4; ++i) {
- res.c[i] = c[i] >> shift;
- }
- return res;
- }
- Color operator+(Color const &obj) const {
- Color res;
- for (int i = 0; i < 4; ++i) {
- res.c[i] = c[i] + obj.c[i];
- }
- return res;
- }
- private:
- int c[4];
- };
- size_t getIdx(int i) const {
- size_t offset = i << 1; // 2 bytes per index
- return (idx & (0x3 << offset)) >> offset;
- }
- unsigned short c0;
- unsigned short c1;
- unsigned int idx;
- };
- static_assert(sizeof(BC_color) == 8, "BC_color must be 8 bytes");
- struct BC_channel {
- void decode(uint8_t *dst, size_t x, size_t y, size_t dstW, size_t dstH, size_t dstPitch, size_t dstBpp, size_t channel, bool isSigned) const {
- int c[8] = {0};
- if (isSigned) {
- c[0] = static_cast<signed char>(data & 0xFF);
- c[1] = static_cast<signed char>((data & 0xFF00) >> 8);
- } else {
- c[0] = static_cast<uint8_t>(data & 0xFF);
- c[1] = static_cast<uint8_t>((data & 0xFF00) >> 8);
- }
- if (c[0] > c[1]) {
- for (int i = 2; i < 8; ++i) {
- c[i] = ((8 - i) * c[0] + (i - 1) * c[1]) / 7;
- }
- } else {
- for (int i = 2; i < 6; ++i) {
- c[i] = ((6 - i) * c[0] + (i - 1) * c[1]) / 5;
- }
- c[6] = isSigned ? -128 : 0;
- c[7] = isSigned ? 127 : 255;
- }
- for (size_t j = 0; j < BlockHeight && (y + j) < dstH; j++) {
- for (size_t i = 0; i < BlockWidth && (x + i) < dstW; i++) {
- dst[channel + (i * dstBpp) + (j * dstPitch)] = static_cast<uint8_t>(c[getIdx((j * BlockHeight) + i)]);
- }
- }
- }
- private:
- uint8_t getIdx(int i) const {
- int offset = i * 3 + 16;
- return static_cast<uint8_t>((data & (0x7ull << offset)) >> offset);
- }
- uint64_t data;
- };
- static_assert(sizeof(BC_channel) == 8, "BC_channel must be 8 bytes");
- struct BC_alpha {
- void decode(uint8_t *dst, size_t x, size_t y, size_t dstW, size_t dstH, size_t dstPitch, size_t dstBpp) const {
- dst += 3; // Write only to alpha (channel 3)
- for (size_t j = 0; j < BlockHeight && (y + j) < dstH; j++, dst += dstPitch) {
- uint8_t *dstRow = dst;
- for (size_t i = 0; i < BlockWidth && (x + i) < dstW; i++, dstRow += dstBpp) {
- *dstRow = getAlpha(j * BlockHeight + i);
- }
- }
- }
- private:
- uint8_t getAlpha(int i) const {
- int offset = i << 2;
- int alpha = (data & (0xFull << offset)) >> offset;
- return static_cast<uint8_t>(alpha | (alpha << 4));
- }
- uint64_t data;
- };
- static_assert(sizeof(BC_alpha) == 8, "BC_alpha must be 8 bytes");
- namespace BC6H {
- static constexpr int MaxPartitions = 64;
- // @fmt:off
- static constexpr uint8_t PartitionTable2[MaxPartitions][16] = {
- { 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1 },
- { 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1 },
- { 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1 },
- { 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1 },
- { 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1 },
- { 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1 },
- { 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1 },
- { 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1 },
- { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1 },
- { 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 },
- { 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1 },
- { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1 },
- { 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 },
- { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1 },
- { 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 },
- { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1 },
- { 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1 },
- { 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0 },
- { 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0 },
- { 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0 },
- { 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0 },
- { 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0 },
- { 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0 },
- { 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1 },
- { 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0 },
- { 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0 },
- { 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0 },
- { 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0 },
- { 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0 },
- { 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0 },
- { 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0 },
- { 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0 },
- { 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1 },
- { 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1 },
- { 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0 },
- { 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0 },
- { 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0 },
- { 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0 },
- { 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1 },
- { 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1 },
- { 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0 },
- { 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0 },
- { 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0 },
- { 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0 },
- { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 },
- { 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1 },
- { 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1 },
- { 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0 },
- { 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0 },
- { 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0 },
- { 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0 },
- { 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0 },
- { 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1 },
- { 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1 },
- { 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0 },
- { 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0 },
- { 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1 },
- { 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1 },
- { 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1 },
- { 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1 },
- { 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1 },
- { 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0 },
- { 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0 },
- { 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1 },
- };
- static constexpr uint8_t AnchorTable2[MaxPartitions] = {
- 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf,
- 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf,
- 0xf, 0x2, 0x8, 0x2, 0x2, 0x8, 0x8, 0xf,
- 0x2, 0x8, 0x2, 0x2, 0x8, 0x8, 0x2, 0x2,
- 0xf, 0xf, 0x6, 0x8, 0x2, 0x8, 0xf, 0xf,
- 0x2, 0x8, 0x2, 0x2, 0x2, 0xf, 0xf, 0x6,
- 0x6, 0x2, 0x6, 0x8, 0xf, 0xf, 0x2, 0x2,
- 0xf, 0xf, 0xf, 0xf, 0xf, 0x2, 0x2, 0xf,
- };
- // @fmt:on
- // 1.0f in half-precision floating point format
- static constexpr uint16_t halfFloat1 = 0x3C00;
- union Color {
- struct RGBA {
- uint16_t r = 0;
- uint16_t g = 0;
- uint16_t b = 0;
- uint16_t a = halfFloat1;
- RGBA(uint16_t r, uint16_t g, uint16_t b)
- : r(r), g(g), b(b) {
- }
- RGBA &operator=(const RGBA &other) {
- this->r = other.r;
- this->g = other.g;
- this->b = other.b;
- this->a = halfFloat1;
- return *this;
- }
- };
- Color(uint16_t r, uint16_t g, uint16_t b)
- : rgba(r, g, b) {
- }
- Color(int r, int g, int b)
- : rgba((uint16_t) r, (uint16_t) g, (uint16_t) b) {
- }
- Color() {}
- Color(const Color &other) {
- this->rgba = other.rgba;
- }
- Color &operator=(const Color &other) {
- this->rgba = other.rgba;
- return *this;
- }
- RGBA rgba;
- uint16_t channel[4];
- };
- static_assert(sizeof(Color) == 8, "BC6h::Color must be 8 bytes long");
- inline int32_t extendSign(int32_t val, size_t size) {
- // Suppose we have a 2-bit integer being stored in 4 bit variable:
- // x = 0b00AB
- //
- // In order to sign extend x, we need to turn the 0s into A's:
- // x_extend = 0bAAAB
- //
- // We can do that by flipping A in x then subtracting 0b0010 from x.
- // Suppose A is 1:
- // x = 0b001B
- // x_flip = 0b000B
- // x_minus = 0b111B
- // Since A is flipped to 0, subtracting the mask sets it and all the bits above it to 1.
- // And if A is 0:
- // x = 0b000B
- // x_flip = 0b001B
- // x_minus = 0b000B
- // We unset the bit we flipped, and touch no other bit
- uint16_t mask = 1u << (size - 1);
- return (val ^ mask) - mask;
- }
- static int constexpr RGBfChannels = 3;
- struct RGBf {
- uint16_t channel[RGBfChannels];
- size_t size[RGBfChannels];
- bool isSigned;
- RGBf() {
- static_assert(RGBfChannels == 3, "RGBf must have exactly 3 channels");
- static_assert(sizeof(channel) / sizeof(channel[0]) == RGBfChannels, "RGBf must have exactly 3 channels");
- static_assert(sizeof(channel) / sizeof(channel[0]) == sizeof(size) / sizeof(size[0]), "RGBf requires equally sized arrays for channels and channel sizes");
- for (int i = 0; i < RGBfChannels; i++) {
- channel[i] = 0;
- size[i] = 0;
- }
- isSigned = false;
- }
- void extendSign() {
- for (int i = 0; i < RGBfChannels; i++) {
- channel[i] = BC6H::extendSign(channel[i], size[i]);
- }
- }
- // Assuming this is the delta, take the base-endpoint and transform this into
- // a proper endpoint.
- //
- // The final computed endpoint is truncated to the base-endpoint's size;
- void resolveDelta(RGBf base) {
- for (int i = 0; i < RGBfChannels; i++) {
- size[i] = base.size[i];
- channel[i] = (base.channel[i] + channel[i]) & ((1 << base.size[i]) - 1);
- }
- // Per the spec:
- // "For signed formats, the results of the delta calculation must be sign
- // extended as well."
- if (isSigned) {
- extendSign();
- }
- }
- void unquantize() {
- if (isSigned) {
- unquantizeSigned();
- } else {
- unquantizeUnsigned();
- }
- }
- void unquantizeUnsigned() {
- for (int i = 0; i < RGBfChannels; i++) {
- if (size[i] >= 15 || channel[i] == 0) {
- continue;
- } else if (channel[i] == ((1u << size[i]) - 1)) {
- channel[i] = 0xFFFFu;
- } else {
- // Need 32 bits to avoid overflow
- uint32_t tmp = channel[i];
- channel[i] = (uint16_t) (((tmp << 16) + 0x8000) >> size[i]);
- }
- size[i] = 16;
- }
- }
- void unquantizeSigned() {
- for (int i = 0; i < RGBfChannels; i++) {
- if (size[i] >= 16 || channel[i] == 0) {
- continue;
- }
- int16_t value = (int16_t)channel[i];
- int32_t result = value;
- bool signBit = value < 0;
- if (signBit) {
- value = -value;
- }
- if (value >= ((1 << (size[i] - 1)) - 1)) {
- result = 0x7FFF;
- } else {
- // Need 32 bits to avoid overflow
- int32_t tmp = value;
- result = (((tmp << 15) + 0x4000) >> (size[i] - 1));
- }
- if (signBit) {
- result = -result;
- }
- channel[i] = (uint16_t) result;
- size[i] = 16;
- }
- }
- };
- struct Data {
- uint64_t low64;
- uint64_t high64;
- Data() = default;
- Data(uint64_t low64, uint64_t high64)
- : low64(low64), high64(high64) {
- }
- // Consumes the lowest N bits from from low64 and high64 where N is:
- // abs(MSB - LSB)
- // MSB and LSB come from the block description of the BC6h spec and specify
- // the location of the bits in the returned bitstring.
- //
- // If MSB < LSB, then the bits are reversed. Otherwise, the bitstring is read and
- // shifted without further modification.
- //
- uint32_t consumeBits(uint32_t MSB, uint32_t LSB) {
- bool reversed = MSB < LSB;
- if (reversed) {
- std::swap(MSB, LSB);
- }
- assert(MSB - LSB + 1 < sizeof(uint32_t) * 8);
- uint32_t numBits = MSB - LSB + 1;
- uint32_t mask = (1 << numBits) - 1;
- // Read the low N bits
- uint32_t bits = (low64 & mask);
- low64 >>= numBits;
- // Put the low N bits of high64 into the high 64-N bits of low64
- low64 |= (high64 & mask) << (sizeof(high64) * 8 - numBits);
- high64 >>= numBits;
- if (reversed) {
- uint32_t tmp = 0;
- for (uint32_t numSwaps = 0; numSwaps < numBits; numSwaps++) {
- tmp <<= 1;
- tmp |= (bits & 1);
- bits >>= 1;
- }
- bits = tmp;
- }
- return bits << LSB;
- }
- };
- struct IndexInfo {
- uint64_t value;
- int numBits;
- };
- // Interpolates between two endpoints, then does a final unquantization step
- Color interpolate(RGBf e0, RGBf e1, const IndexInfo &index, bool isSigned) {
- static constexpr uint32_t weights3[] = {0, 9, 18, 27, 37, 46, 55, 64};
- static constexpr uint32_t weights4[] = {0, 4, 9, 13, 17, 21, 26, 30,
- 34, 38, 43, 47, 51, 55, 60, 64};
- static constexpr uint32_t const *weightsN[] = {
- nullptr, nullptr, nullptr, weights3, weights4
- };
- auto weights = weightsN[index.numBits];
- assert(weights != nullptr);
- Color color;
- uint32_t e0Weight = 64 - weights[index.value];
- uint32_t e1Weight = weights[index.value];
- for (int i = 0; i < RGBfChannels; i++) {
- int32_t e0Channel = e0.channel[i];
- int32_t e1Channel = e1.channel[i];
- if (isSigned) {
- e0Channel = extendSign(e0Channel, 16);
- e1Channel = extendSign(e1Channel, 16);
- }
- int32_t e0Value = e0Channel * e0Weight;
- int32_t e1Value = e1Channel * e1Weight;
- uint32_t tmp = ((e0Value + e1Value + 32) >> 6);
- // Need to unquantize value to limit it to the legal range of half-precision
- // floats. We do this by scaling by 31/32 or 31/64 depending on if the value
- // is signed or unsigned.
- if (isSigned) {
- tmp = ((tmp & 0x80000000) != 0) ? (((~tmp + 1) * 31) >> 5) | 0x8000 : (tmp * 31) >> 5;
- // Don't return -0.0f, just normalize it to 0.0f.
- if (tmp == 0x8000)
- tmp = 0;
- } else {
- tmp = (tmp * 31) >> 6;
- }
- color.channel[i] = (uint16_t) tmp;
- }
- return color;
- }
- enum DataType {
- // Endpoints
- EP0 = 0,
- EP1 = 1,
- EP2 = 2,
- EP3 = 3,
- Mode,
- Partition,
- End,
- };
- enum Channel {
- R = 0,
- G = 1,
- B = 2,
- None,
- };
- struct DeltaBits {
- size_t channel[3];
- constexpr DeltaBits()
- : channel{0, 0, 0} {
- }
- constexpr DeltaBits(size_t r, size_t g, size_t b)
- : channel{r, g, b} {
- }
- };
- struct ModeDesc {
- int number;
- bool hasDelta;
- int partitionCount;
- int endpointBits;
- DeltaBits deltaBits;
- constexpr ModeDesc()
- : number(-1), hasDelta(false), partitionCount(0), endpointBits(0) {
- }
- constexpr ModeDesc(int number, bool hasDelta, int partitionCount, int endpointBits, DeltaBits deltaBits)
- : number(number), hasDelta(hasDelta), partitionCount(partitionCount), endpointBits(endpointBits), deltaBits(deltaBits) {
- }
- };
- struct BlockDesc {
- DataType type;
- Channel channel;
- int MSB;
- int LSB;
- ModeDesc modeDesc;
- constexpr BlockDesc()
- : type(End), channel(None), MSB(0), LSB(0), modeDesc() {
- }
- constexpr BlockDesc(const DataType type, Channel channel, int MSB, int LSB, ModeDesc modeDesc)
- : type(type), channel(channel), MSB(MSB), LSB(LSB), modeDesc(modeDesc) {
- }
- constexpr BlockDesc(DataType type, Channel channel, int MSB, int LSB)
- : type(type), channel(channel), MSB(MSB), LSB(LSB), modeDesc() {
- }
- };
- // Turns a legal mode into an index into the BlockDesc table.
- // Illegal or reserved modes return -1.
- static int modeToIndex(uint8_t mode) {
- if (mode <= 3) {
- return mode;
- } else if ((mode & 0x2) != 0) {
- if (mode <= 18) {
- // Turns 6 into 4, 7 into 5, 10 into 6, etc.
- return (mode / 2) + 1 + (mode & 0x1);
- } else if (mode == 22 || mode == 26 || mode == 30) {
- // Turns 22 into 11, 26 into 12, etc.
- return mode / 4 + 6;
- }
- }
- return -1;
- }
- // Returns a description of the bitfields for each mode from the LSB
- // to the MSB before the index data starts.
- //
- // The numbers come from the BC6h block description. Each BlockDesc in the
- // {Type, Channel, MSB, LSB}
- // * Type describes which endpoint this is, or if this is a mode, a partition
- // number, or the end of the block description.
- // * Channel describes one of the 3 color channels within an endpoint
- // * MSB and LSB specificy:
- // * The size of the bitfield being read
- // * The position of the bitfield within the variable it is being read to
- // * If the bitfield is stored in reverse bit order
- // If MSB < LSB then the bitfield is stored in reverse order. The size of
- // the bitfield is abs(MSB-LSB+1). And the position of the bitfield within
- // the variable is min(LSB, MSB).
- //
- // Invalid or reserved modes return an empty list.
- static constexpr int NumBlocks = 14;
- // The largest number of descriptions within a block.
- static constexpr int MaxBlockDescIndex = 26;
- static constexpr BlockDesc blockDescs[NumBlocks][MaxBlockDescIndex] = {
- // @fmt:off
- // Mode 0, Index 0
- {
- { Mode, None, 1, 0, { 0, true, 2, 10, { 5, 5, 5 } } },
- { EP2, G, 4, 4 }, { EP2, B, 4, 4 }, { EP3, B, 4, 4 },
- { EP0, R, 9, 0 }, { EP0, G, 9, 0 }, { EP0, B, 9, 0 },
- { EP1, R, 4, 0 }, { EP3, G, 4, 4 }, { EP2, G, 3, 0 },
- { EP1, G, 4, 0 }, { EP3, B, 0, 0 }, { EP3, G, 3, 0 },
- { EP1, B, 4, 0 }, { EP3, B, 1, 1 }, { EP2, B, 3, 0 },
- { EP2, R, 4, 0 }, { EP3, B, 2, 2 }, { EP3, R, 4, 0 },
- { EP3, B, 3, 3 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 1, Index 1
- {
- { Mode, None, 1, 0, { 1, true, 2, 7, { 6, 6, 6 } } },
- { EP2, G, 5, 5 }, { EP3, G, 5, 4 }, { EP0, R, 6, 0 },
- { EP3, B, 1, 0 }, { EP2, B, 4, 4 }, { EP0, G, 6, 0 },
- { EP2, B, 5, 5 }, { EP3, B, 2, 2 }, { EP2, G, 4, 4 },
- { EP0, B, 6, 0 }, { EP3, B, 3, 3 }, { EP3, B, 5, 5 },
- { EP3, B, 4, 4 }, { EP1, R, 5, 0 }, { EP2, G, 3, 0 },
- { EP1, G, 5, 0 }, { EP3, G, 3, 0 }, { EP1, B, 5, 0 },
- { EP2, B, 3, 0 }, { EP2, R, 5, 0 }, { EP3, R, 5, 0 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 2, Index 2
- {
- { Mode, None, 4, 0, { 2, true, 2, 11, { 5, 4, 4 } } },
- { EP0, R, 9, 0 }, { EP0, G, 9, 0 }, { EP0, B, 9, 0 },
- { EP1, R, 4, 0 }, { EP0, R, 10, 10 }, { EP2, G, 3, 0 },
- { EP1, G, 3, 0 }, { EP0, G, 10, 10 }, { EP3, B, 0, 0 },
- { EP3, G, 3, 0 }, { EP1, B, 3, 0 }, { EP0, B, 10, 10 },
- { EP3, B, 1, 1 }, { EP2, B, 3, 0 }, { EP2, R, 4, 0 },
- { EP3, B, 2, 2 }, { EP3, R, 4, 0 }, { EP3, B, 3, 3 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 3, Index 3
- {
- { Mode, None, 4, 0, { 3, false, 1, 10, { 0, 0, 0 } } },
- { EP0, R, 9, 0 }, { EP0, G, 9, 0 }, { EP0, B, 9, 0 },
- { EP1, R, 9, 0 }, { EP1, G, 9, 0 }, { EP1, B, 9, 0 },
- { End, None, 0, 0},
- },
- // Mode 6, Index 4
- {
- { Mode, None, 4, 0, { 6, true, 2, 11, { 4, 5, 4 } } }, // 1 1
- { EP0, R, 9, 0 }, { EP0, G, 9, 0 }, { EP0, B, 9, 0 },
- { EP1, R, 3, 0 }, { EP0, R, 10, 10 }, { EP3, G, 4, 4 },
- { EP2, G, 3, 0 }, { EP1, G, 4, 0 }, { EP0, G, 10, 10 },
- { EP3, G, 3, 0 }, { EP1, B, 3, 0 }, { EP0, B, 10, 10 },
- { EP3, B, 1, 1 }, { EP2, B, 3, 0 }, { EP2, R, 3, 0 },
- { EP3, B, 0, 0 }, { EP3, B, 2, 2 }, { EP3, R, 3, 0 }, // 18 19
- { EP2, G, 4, 4 }, { EP3, B, 3, 3 }, // 2 21
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 7, Index 5
- {
- { Mode, None, 4, 0, { 7, true, 1, 11, { 9, 9, 9 } } },
- { EP0, R, 9, 0 }, { EP0, G, 9, 0 }, { EP0, B, 9, 0 },
- { EP1, R, 8, 0 }, { EP0, R, 10, 10 }, { EP1, G, 8, 0 },
- { EP0, G, 10, 10 }, { EP1, B, 8, 0 }, { EP0, B, 10, 10 },
- { End, None, 0, 0},
- },
- // Mode 10, Index 6
- {
- { Mode, None, 4, 0, { 10, true, 2, 11, { 4, 4, 5 } } },
- { EP0, R, 9, 0 }, { EP0, G, 9, 0 }, { EP0, B, 9, 0 },
- { EP1, R, 3, 0 }, { EP0, R, 10, 10 }, { EP2, B, 4, 4 },
- { EP2, G, 3, 0 }, { EP1, G, 3, 0 }, { EP0, G, 10, 10 },
- { EP3, B, 0, 0 }, { EP3, G, 3, 0 }, { EP1, B, 4, 0 },
- { EP0, B, 10, 10 }, { EP2, B, 3, 0 }, { EP2, R, 3, 0 },
- { EP3, B, 1, 1 }, { EP3, B, 2, 2 }, { EP3, R, 3, 0 },
- { EP3, B, 4, 4 }, { EP3, B, 3, 3 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 11, Index 7
- {
- { Mode, None, 4, 0, { 11, true, 1, 12, { 8, 8, 8 } } },
- { EP0, R, 9, 0 }, { EP0, G, 9, 0 }, { EP0, B, 9, 0 },
- { EP1, R, 7, 0 }, { EP0, R, 10, 11 }, { EP1, G, 7, 0 },
- { EP0, G, 10, 11 }, { EP1, B, 7, 0 }, { EP0, B, 10, 11 },
- { End, None, 0, 0},
- },
- // Mode 14, Index 8
- {
- { Mode, None, 4, 0, { 14, true, 2, 9, { 5, 5, 5 } } },
- { EP0, R, 8, 0 }, { EP2, B, 4, 4 }, { EP0, G, 8, 0 },
- { EP2, G, 4, 4 }, { EP0, B, 8, 0 }, { EP3, B, 4, 4 },
- { EP1, R, 4, 0 }, { EP3, G, 4, 4 }, { EP2, G, 3, 0 },
- { EP1, G, 4, 0 }, { EP3, B, 0, 0 }, { EP3, G, 3, 0 },
- { EP1, B, 4, 0 }, { EP3, B, 1, 1 }, { EP2, B, 3, 0 },
- { EP2, R, 4, 0 }, { EP3, B, 2, 2 }, { EP3, R, 4, 0 },
- { EP3, B, 3, 3 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 15, Index 9
- {
- { Mode, None, 4, 0, { 15, true, 1, 16, { 4, 4, 4 } } },
- { EP0, R, 9, 0 }, { EP0, G, 9, 0 }, { EP0, B, 9, 0 },
- { EP1, R, 3, 0 }, { EP0, R, 10, 15 }, { EP1, G, 3, 0 },
- { EP0, G, 10, 15 }, { EP1, B, 3, 0 }, { EP0, B, 10, 15 },
- { End, None, 0, 0},
- },
- // Mode 18, Index 10
- {
- { Mode, None, 4, 0, { 18, true, 2, 8, { 6, 5, 5 } } },
- { EP0, R, 7, 0 }, { EP3, G, 4, 4 }, { EP2, B, 4, 4 },
- { EP0, G, 7, 0 }, { EP3, B, 2, 2 }, { EP2, G, 4, 4 },
- { EP0, B, 7, 0 }, { EP3, B, 3, 3 }, { EP3, B, 4, 4 },
- { EP1, R, 5, 0 }, { EP2, G, 3, 0 }, { EP1, G, 4, 0 },
- { EP3, B, 0, 0 }, { EP3, G, 3, 0 }, { EP1, B, 4, 0 },
- { EP3, B, 1, 1 }, { EP2, B, 3, 0 }, { EP2, R, 5, 0 },
- { EP3, R, 5, 0 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 22, Index 11
- {
- { Mode, None, 4, 0, { 22, true, 2, 8, { 5, 6, 5 } } },
- { EP0, R, 7, 0 }, { EP3, B, 0, 0 }, { EP2, B, 4, 4 },
- { EP0, G, 7, 0 }, { EP2, G, 5, 5 }, { EP2, G, 4, 4 },
- { EP0, B, 7, 0 }, { EP3, G, 5, 5 }, { EP3, B, 4, 4 },
- { EP1, R, 4, 0 }, { EP3, G, 4, 4 }, { EP2, G, 3, 0 },
- { EP1, G, 5, 0 }, { EP3, G, 3, 0 }, { EP1, B, 4, 0 },
- { EP3, B, 1, 1 }, { EP2, B, 3, 0 }, { EP2, R, 4, 0 },
- { EP3, B, 2, 2 }, { EP3, R, 4, 0 }, { EP3, B, 3, 3 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 26, Index 12
- {
- { Mode, None, 4, 0, { 26, true, 2, 8, { 5, 5, 6 } } },
- { EP0, R, 7, 0 }, { EP3, B, 1, 1 }, { EP2, B, 4, 4 },
- { EP0, G, 7, 0 }, { EP2, B, 5, 5 }, { EP2, G, 4, 4 },
- { EP0, B, 7, 0 }, { EP3, B, 5, 5 }, { EP3, B, 4, 4 },
- { EP1, R, 4, 0 }, { EP3, G, 4, 4 }, { EP2, G, 3, 0 },
- { EP1, G, 4, 0 }, { EP3, B, 0, 0 }, { EP3, G, 3, 0 },
- { EP1, B, 5, 0 }, { EP2, B, 3, 0 }, { EP2, R, 4, 0 },
- { EP3, B, 2, 2 }, { EP3, R, 4, 0 }, { EP3, B, 3, 3 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- },
- // Mode 30, Index 13
- {
- { Mode, None, 4, 0, { 30, false, 2, 6, { 0, 0, 0 } } },
- { EP0, R, 5, 0 }, { EP3, G, 4, 4 }, { EP3, B, 0, 0 },
- { EP3, B, 1, 1 }, { EP2, B, 4, 4 }, { EP0, G, 5, 0 },
- { EP2, G, 5, 5 }, { EP2, B, 5, 5 }, { EP3, B, 2, 2 },
- { EP2, G, 4, 4 }, { EP0, B, 5, 0 }, { EP3, G, 5, 5 },
- { EP3, B, 3, 3 }, { EP3, B, 5, 5 }, { EP3, B, 4, 4 },
- { EP1, R, 5, 0 }, { EP2, G, 3, 0 }, { EP1, G, 5, 0 },
- { EP3, G, 3, 0 }, { EP1, B, 5, 0 }, { EP2, B, 3, 0 },
- { EP2, R, 5, 0 }, { EP3, R, 5, 0 },
- { Partition, None, 4, 0 },
- { End, None, 0, 0},
- }
- // @fmt:on
- };
- struct Block {
- uint64_t low64;
- uint64_t high64;
- void decode(uint8_t *dst, size_t dstX, size_t dstY, size_t dstWidth, size_t dstHeight, size_t dstPitch, size_t dstBpp, bool isSigned) const {
- uint8_t mode = 0;
- Data data(low64, high64);
- assert(dstBpp == sizeof(Color));
- if ((data.low64 & 0x2) == 0) {
- mode = data.consumeBits(1, 0);
- } else {
- mode = data.consumeBits(4, 0);
- }
- int blockIndex = modeToIndex(mode);
- // Handle illegal or reserved mode
- if (blockIndex == -1) {
- for (int y = 0; y < 4 && y + dstY < dstHeight; y++) {
- for (int x = 0; x < 4 && x + dstX < dstWidth; x++) {
- auto out = reinterpret_cast<Color *>(dst + sizeof(Color) * x + dstPitch * y);
- out->rgba = {0, 0, 0};
- }
- }
- return;
- }
- const BlockDesc *blockDesc = blockDescs[blockIndex];
- RGBf e[4];
- e[0].isSigned = e[1].isSigned = e[2].isSigned = e[3].isSigned = isSigned;
- int partition = 0;
- ModeDesc modeDesc;
- for (int index = 0; blockDesc[index].type != End; index++) {
- const BlockDesc desc = blockDesc[index];
- switch (desc.type) {
- case Mode:
- modeDesc = desc.modeDesc;
- assert(modeDesc.number == mode);
- e[0].size[0] = e[0].size[1] = e[0].size[2] = modeDesc.endpointBits;
- for (int i = 0; i < RGBfChannels; i++) {
- if (modeDesc.hasDelta) {
- e[1].size[i] = e[2].size[i] = e[3].size[i] = modeDesc.deltaBits.channel[i];
- } else {
- e[1].size[i] = e[2].size[i] = e[3].size[i] = modeDesc.endpointBits;
- }
- }
- break;
- case Partition:
- partition |= data.consumeBits(desc.MSB, desc.LSB);
- break;
- case EP0:
- case EP1:
- case EP2:
- case EP3:
- e[desc.type].channel[desc.channel] |= data.consumeBits(desc.MSB, desc.LSB);
- break;
- default:
- assert(false);
- return;
- }
- }
- // Sign extension
- if (isSigned) {
- for (int ep = 0; ep < modeDesc.partitionCount * 2; ep++) {
- e[ep].extendSign();
- }
- } else if (modeDesc.hasDelta) {
- // Don't sign-extend the base endpoint in an unsigned format.
- for (int ep = 1; ep < modeDesc.partitionCount * 2; ep++) {
- e[ep].extendSign();
- }
- }
- // Turn the deltas into endpoints
- if (modeDesc.hasDelta) {
- for (int ep = 1; ep < modeDesc.partitionCount * 2; ep++) {
- e[ep].resolveDelta(e[0]);
- }
- }
- for (int ep = 0; ep < modeDesc.partitionCount * 2; ep++) {
- e[ep].unquantize();
- }
- // Get the indices, calculate final colors, and output
- for (int y = 0; y < 4; y++) {
- for (int x = 0; x < 4; x++) {
- int pixelNum = x + y * 4;
- IndexInfo idx;
- bool isAnchor = false;
- int firstEndpoint = 0;
- // Bc6H can have either 1 or 2 petitions depending on the mode.
- // The number of petitions affects the number of indices with implicit
- // leading 0 bits and the number of bits per index.
- if (modeDesc.partitionCount == 1) {
- idx.numBits = 4;
- // There's an implicit leading 0 bit for the first idx
- isAnchor = (pixelNum == 0);
- } else {
- idx.numBits = 3;
- // There are 2 indices with implicit leading 0-bits.
- isAnchor = ((pixelNum == 0) || (pixelNum == AnchorTable2[partition]));
- firstEndpoint = PartitionTable2[partition][pixelNum] * 2;
- }
- idx.value = data.consumeBits(idx.numBits - isAnchor - 1, 0);
- // Don't exit the loop early, we need to consume these index bits regardless if
- // we actually output them or not.
- if ((y + dstY >= dstHeight) || (x + dstX >= dstWidth)) {
- continue;
- }
- Color color = interpolate(e[firstEndpoint], e[firstEndpoint + 1], idx, isSigned);
- auto out = reinterpret_cast<Color *>(dst + dstBpp * x + dstPitch * y);
- *out = color;
- }
- }
- }
- };
- } // namespace BC6H
- namespace BC7 {
- // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_texture_compression_bptc.txt
- // https://docs.microsoft.com/en-us/windows/win32/direct3d11/bc7-format
- struct Bitfield {
- int offset;
- int count;
- constexpr Bitfield Then(const int bits) { return {offset + count, bits}; }
- constexpr bool operator==(const Bitfield &rhs) {
- return offset == rhs.offset && count == rhs.count;
- }
- };
- struct Mode {
- const int IDX; // Mode index
- const int NS; // Number of subsets in each partition
- const int PB; // Partition bits
- const int RB; // Rotation bits
- const int ISB; // Index selection bits
- const int CB; // Color bits
- const int AB; // Alpha bits
- const int EPB; // Endpoint P-bits
- const int SPB; // Shared P-bits
- const int IB; // Primary index bits per element
- const int IBC; // Primary index bits total
- const int IB2; // Secondary index bits per element
- constexpr int NumColors() const { return NS * 2; }
- constexpr Bitfield Partition() const { return {IDX + 1, PB}; }
- constexpr Bitfield Rotation() const { return Partition().Then(RB); }
- constexpr Bitfield IndexSelection() const { return Rotation().Then(ISB); }
- constexpr Bitfield Red(int idx) const {
- return IndexSelection().Then(CB * idx).Then(CB);
- }
- constexpr Bitfield Green(int idx) const {
- return Red(NumColors() - 1).Then(CB * idx).Then(CB);
- }
- constexpr Bitfield Blue(int idx) const {
- return Green(NumColors() - 1).Then(CB * idx).Then(CB);
- }
- constexpr Bitfield Alpha(int idx) const {
- return Blue(NumColors() - 1).Then(AB * idx).Then(AB);
- }
- constexpr Bitfield EndpointPBit(int idx) const {
- return Alpha(NumColors() - 1).Then(EPB * idx).Then(EPB);
- }
- constexpr Bitfield SharedPBit0() const {
- return EndpointPBit(NumColors() - 1).Then(SPB);
- }
- constexpr Bitfield SharedPBit1() const {
- return SharedPBit0().Then(SPB);
- }
- constexpr Bitfield PrimaryIndex(int offset, int count) const {
- return SharedPBit1().Then(offset).Then(count);
- }
- constexpr Bitfield SecondaryIndex(int offset, int count) const {
- return SharedPBit1().Then(IBC + offset).Then(count);
- }
- };
- static constexpr Mode Modes[] = {
- // IDX NS PB RB ISB CB AB EPB SPB IB IBC, IB2
- /**/ {0x0, 0x3, 0x4, 0x0, 0x0, 0x4, 0x0, 0x1, 0x0, 0x3, 0x2d, 0x0},
- /**/ {0x1, 0x2, 0x6, 0x0, 0x0, 0x6, 0x0, 0x0, 0x1, 0x3, 0x2e, 0x0},
- /**/ {0x2, 0x3, 0x6, 0x0, 0x0, 0x5, 0x0, 0x0, 0x0, 0x2, 0x1d, 0x0},
- /**/ {0x3, 0x2, 0x6, 0x0, 0x0, 0x7, 0x0, 0x1, 0x0, 0x2, 0x1e, 0x0},
- /**/ {0x4, 0x1, 0x0, 0x2, 0x1, 0x5, 0x6, 0x0, 0x0, 0x2, 0x1f, 0x3},
- /**/ {0x5, 0x1, 0x0, 0x2, 0x0, 0x7, 0x8, 0x0, 0x0, 0x2, 0x1f, 0x2},
- /**/ {0x6, 0x1, 0x0, 0x0, 0x0, 0x7, 0x7, 0x1, 0x0, 0x4, 0x3f, 0x0},
- /**/ {0x7, 0x2, 0x6, 0x0, 0x0, 0x5, 0x5, 0x1, 0x0, 0x2, 0x1e, 0x0},
- /**/ {-1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x00, 0x0},
- };
- static constexpr int MaxPartitions = 64;
- static constexpr int MaxSubsets = 3;
- static constexpr uint8_t PartitionTable2[MaxPartitions][16] = {
- {0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1},
- {0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1},
- {0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1},
- {0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1},
- {0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1},
- {0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1},
- {0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1},
- {0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1},
- {0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1},
- {0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1},
- {0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
- {0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0},
- {0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0},
- {0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
- {0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0},
- {0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0},
- {0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1},
- {0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0},
- {0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0},
- {0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0},
- {0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0},
- {0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0},
- {0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0},
- {0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0},
- {0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0},
- {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1},
- {0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1},
- {0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0},
- {0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0},
- {0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0},
- {0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0},
- {0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1},
- {0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1},
- {0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0},
- {0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0},
- {0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0},
- {0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0},
- {0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0},
- {0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1},
- {0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1},
- {0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0},
- {0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0},
- {0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0},
- {0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0},
- {0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0},
- {0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1},
- {0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1},
- {0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0},
- {0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0},
- {0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1},
- {0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1},
- {0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1},
- {0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1},
- {0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1},
- {0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0},
- {0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0},
- {0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1},
- };
- static constexpr uint8_t PartitionTable3[MaxPartitions][16] = {
- {0, 0, 1, 1, 0, 0, 1, 1, 0, 2, 2, 1, 2, 2, 2, 2},
- {0, 0, 0, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 2, 1},
- {0, 0, 0, 0, 2, 0, 0, 1, 2, 2, 1, 1, 2, 2, 1, 1},
- {0, 2, 2, 2, 0, 0, 2, 2, 0, 0, 1, 1, 0, 1, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2},
- {0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 2, 2, 0, 0, 2, 2},
- {0, 0, 2, 2, 0, 0, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1},
- {0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1},
- {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2},
- {0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2},
- {0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2},
- {0, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2},
- {0, 1, 1, 2, 0, 1, 1, 2, 0, 1, 1, 2, 0, 1, 1, 2},
- {0, 1, 2, 2, 0, 1, 2, 2, 0, 1, 2, 2, 0, 1, 2, 2},
- {0, 0, 1, 1, 0, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 2},
- {0, 0, 1, 1, 2, 0, 0, 1, 2, 2, 0, 0, 2, 2, 2, 0},
- {0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 2, 1, 1, 2, 2},
- {0, 1, 1, 1, 0, 0, 1, 1, 2, 0, 0, 1, 2, 2, 0, 0},
- {0, 0, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2},
- {0, 0, 2, 2, 0, 0, 2, 2, 0, 0, 2, 2, 1, 1, 1, 1},
- {0, 1, 1, 1, 0, 1, 1, 1, 0, 2, 2, 2, 0, 2, 2, 2},
- {0, 0, 0, 1, 0, 0, 0, 1, 2, 2, 2, 1, 2, 2, 2, 1},
- {0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 2, 2, 0, 1, 2, 2},
- {0, 0, 0, 0, 1, 1, 0, 0, 2, 2, 1, 0, 2, 2, 1, 0},
- {0, 1, 2, 2, 0, 1, 2, 2, 0, 0, 1, 1, 0, 0, 0, 0},
- {0, 0, 1, 2, 0, 0, 1, 2, 1, 1, 2, 2, 2, 2, 2, 2},
- {0, 1, 1, 0, 1, 2, 2, 1, 1, 2, 2, 1, 0, 1, 1, 0},
- {0, 0, 0, 0, 0, 1, 1, 0, 1, 2, 2, 1, 1, 2, 2, 1},
- {0, 0, 2, 2, 1, 1, 0, 2, 1, 1, 0, 2, 0, 0, 2, 2},
- {0, 1, 1, 0, 0, 1, 1, 0, 2, 0, 0, 2, 2, 2, 2, 2},
- {0, 0, 1, 1, 0, 1, 2, 2, 0, 1, 2, 2, 0, 0, 1, 1},
- {0, 0, 0, 0, 2, 0, 0, 0, 2, 2, 1, 1, 2, 2, 2, 1},
- {0, 0, 0, 0, 0, 0, 0, 2, 1, 1, 2, 2, 1, 2, 2, 2},
- {0, 2, 2, 2, 0, 0, 2, 2, 0, 0, 1, 2, 0, 0, 1, 1},
- {0, 0, 1, 1, 0, 0, 1, 2, 0, 0, 2, 2, 0, 2, 2, 2},
- {0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 0},
- {0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 0, 0, 0, 0},
- {0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0},
- {0, 1, 2, 0, 2, 0, 1, 2, 1, 2, 0, 1, 0, 1, 2, 0},
- {0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2, 0, 0, 1, 1},
- {0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 0, 0, 0, 0, 1, 1},
- {0, 1, 0, 1, 0, 1, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2},
- {0, 0, 0, 0, 0, 0, 0, 0, 2, 1, 2, 1, 2, 1, 2, 1},
- {0, 0, 2, 2, 1, 1, 2, 2, 0, 0, 2, 2, 1, 1, 2, 2},
- {0, 0, 2, 2, 0, 0, 1, 1, 0, 0, 2, 2, 0, 0, 1, 1},
- {0, 2, 2, 0, 1, 2, 2, 1, 0, 2, 2, 0, 1, 2, 2, 1},
- {0, 1, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 0, 1, 0, 1},
- {0, 0, 0, 0, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1},
- {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 2, 2, 2},
- {0, 2, 2, 2, 0, 1, 1, 1, 0, 2, 2, 2, 0, 1, 1, 1},
- {0, 0, 0, 2, 1, 1, 1, 2, 0, 0, 0, 2, 1, 1, 1, 2},
- {0, 0, 0, 0, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2},
- {0, 2, 2, 2, 0, 1, 1, 1, 0, 1, 1, 1, 0, 2, 2, 2},
- {0, 0, 0, 2, 1, 1, 1, 2, 1, 1, 1, 2, 0, 0, 0, 2},
- {0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 2, 2, 2, 2},
- {0, 0, 0, 0, 0, 0, 0, 0, 2, 1, 1, 2, 2, 1, 1, 2},
- {0, 1, 1, 0, 0, 1, 1, 0, 2, 2, 2, 2, 2, 2, 2, 2},
- {0, 0, 2, 2, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 2, 2},
- {0, 0, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 0, 0, 2, 2},
- {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1, 1, 2},
- {0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 1},
- {0, 2, 2, 2, 1, 2, 2, 2, 0, 2, 2, 2, 1, 2, 2, 2},
- {0, 1, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2},
- {0, 1, 1, 1, 2, 0, 1, 1, 2, 2, 0, 1, 2, 2, 2, 0},
- };
- static constexpr uint8_t AnchorTable2[MaxPartitions] = {
- // @fmt:off
- 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf,
- 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf,
- 0xf, 0x2, 0x8, 0x2, 0x2, 0x8, 0x8, 0xf,
- 0x2, 0x8, 0x2, 0x2, 0x8, 0x8, 0x2, 0x2,
- 0xf, 0xf, 0x6, 0x8, 0x2, 0x8, 0xf, 0xf,
- 0x2, 0x8, 0x2, 0x2, 0x2, 0xf, 0xf, 0x6,
- 0x6, 0x2, 0x6, 0x8, 0xf, 0xf, 0x2, 0x2,
- 0xf, 0xf, 0xf, 0xf, 0xf, 0x2, 0x2, 0xf,
- // @fmt:on
- };
- static constexpr uint8_t AnchorTable3a[MaxPartitions] = {
- // @fmt:off
- 0x3, 0x3, 0xf, 0xf, 0x8, 0x3, 0xf, 0xf,
- 0x8, 0x8, 0x6, 0x6, 0x6, 0x5, 0x3, 0x3,
- 0x3, 0x3, 0x8, 0xf, 0x3, 0x3, 0x6, 0xa,
- 0x5, 0x8, 0x8, 0x6, 0x8, 0x5, 0xf, 0xf,
- 0x8, 0xf, 0x3, 0x5, 0x6, 0xa, 0x8, 0xf,
- 0xf, 0x3, 0xf, 0x5, 0xf, 0xf, 0xf, 0xf,
- 0x3, 0xf, 0x5, 0x5, 0x5, 0x8, 0x5, 0xa,
- 0x5, 0xa, 0x8, 0xd, 0xf, 0xc, 0x3, 0x3,
- // @fmt:on
- };
- static constexpr uint8_t AnchorTable3b[MaxPartitions] = {
- // @fmt:off
- 0xf, 0x8, 0x8, 0x3, 0xf, 0xf, 0x3, 0x8,
- 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0x8,
- 0xf, 0x8, 0xf, 0x3, 0xf, 0x8, 0xf, 0x8,
- 0x3, 0xf, 0x6, 0xa, 0xf, 0xf, 0xa, 0x8,
- 0xf, 0x3, 0xf, 0xa, 0xa, 0x8, 0x9, 0xa,
- 0x6, 0xf, 0x8, 0xf, 0x3, 0x6, 0x6, 0x8,
- 0xf, 0x3, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf,
- 0xf, 0xf, 0xf, 0xf, 0x3, 0xf, 0xf, 0x8,
- // @fmt:on
- };
- struct Color {
- struct RGB {
- RGB() = default;
- RGB(uint8_t r, uint8_t g, uint8_t b)
- : b(b), g(g), r(r) {}
- RGB(int r, int g, int b)
- : b(static_cast<uint8_t>(b)), g(static_cast<uint8_t>(g)), r(static_cast<uint8_t>(r)) {}
- RGB operator<<(int shift) const { return {r << shift, g << shift, b << shift}; }
- RGB operator>>(int shift) const { return {r >> shift, g >> shift, b >> shift}; }
- RGB operator|(int bits) const { return {r | bits, g | bits, b | bits}; }
- RGB operator|(const RGB &rhs) const { return {r | rhs.r, g | rhs.g, b | rhs.b}; }
- RGB operator+(const RGB &rhs) const { return {r + rhs.r, g + rhs.g, b + rhs.b}; }
- uint8_t b;
- uint8_t g;
- uint8_t r;
- };
- RGB rgb;
- uint8_t a;
- };
- static_assert(sizeof(Color) == 4, "Color size must be 4 bytes");
- struct Block {
- constexpr uint64_t Get(const Bitfield &bf) const {
- uint64_t mask = (1ULL << bf.count) - 1;
- if (bf.offset + bf.count <= 64) {
- return (low >> bf.offset) & mask;
- }
- if (bf.offset >= 64) {
- return (high >> (bf.offset - 64)) & mask;
- }
- return ((low >> bf.offset) | (high << (64 - bf.offset))) & mask;
- }
- const Mode &mode() const {
- if ((low & 0b00000001) != 0) {
- return Modes[0];
- }
- if ((low & 0b00000010) != 0) {
- return Modes[1];
- }
- if ((low & 0b00000100) != 0) {
- return Modes[2];
- }
- if ((low & 0b00001000) != 0) {
- return Modes[3];
- }
- if ((low & 0b00010000) != 0) {
- return Modes[4];
- }
- if ((low & 0b00100000) != 0) {
- return Modes[5];
- }
- if ((low & 0b01000000) != 0) {
- return Modes[6];
- }
- if ((low & 0b10000000) != 0) {
- return Modes[7];
- }
- return Modes[8]; // Invalid mode
- }
- struct IndexInfo {
- uint64_t value;
- int numBits;
- };
- uint8_t interpolate(uint8_t e0, uint8_t e1, const IndexInfo &index) const {
- static constexpr uint16_t weights2[] = {0, 21, 43, 64};
- static constexpr uint16_t weights3[] = {0, 9, 18, 27, 37, 46, 55, 64};
- static constexpr uint16_t weights4[] = {0, 4, 9, 13, 17, 21, 26, 30,
- 34, 38, 43, 47, 51, 55, 60, 64};
- static constexpr uint16_t const *weightsN[] = {
- nullptr, nullptr, weights2, weights3, weights4
- };
- auto weights = weightsN[index.numBits];
- assert(weights != nullptr);
- return (uint8_t) (((64 - weights[index.value]) * uint16_t(e0) + weights[index.value] * uint16_t(e1) + 32) >> 6);
- }
- void decode(uint8_t *dst, size_t dstX, size_t dstY, size_t dstWidth, size_t dstHeight, size_t dstPitch) const {
- auto const &mode = this->mode();
- if (mode.IDX < 0) // Invalid mode:
- {
- for (size_t y = 0; y < 4 && y + dstY < dstHeight; y++) {
- for (size_t x = 0; x < 4 && x + dstX < dstWidth; x++) {
- auto out = reinterpret_cast<Color *>(dst + sizeof(Color) * x + dstPitch * y);
- out->rgb = {0, 0, 0};
- out->a = 0;
- }
- }
- return;
- }
- using Endpoint = std::array<Color, 2>;
- std::array<Endpoint, MaxSubsets> subsets;
- for (size_t i = 0; i < mode.NS; i++) {
- auto &subset = subsets[i];
- subset[0].rgb.r = Get(mode.Red(i * 2 + 0));
- subset[0].rgb.g = Get(mode.Green(i * 2 + 0));
- subset[0].rgb.b = Get(mode.Blue(i * 2 + 0));
- subset[0].a = (mode.AB > 0) ? Get(mode.Alpha(i * 2 + 0)) : 255;
- subset[1].rgb.r = Get(mode.Red(i * 2 + 1));
- subset[1].rgb.g = Get(mode.Green(i * 2 + 1));
- subset[1].rgb.b = Get(mode.Blue(i * 2 + 1));
- subset[1].a = (mode.AB > 0) ? Get(mode.Alpha(i * 2 + 1)) : 255;
- }
- if (mode.SPB > 0) {
- auto pbit0 = Get(mode.SharedPBit0());
- auto pbit1 = Get(mode.SharedPBit1());
- subsets[0][0].rgb = (subsets[0][0].rgb << 1) | pbit0;
- subsets[0][1].rgb = (subsets[0][1].rgb << 1) | pbit0;
- subsets[1][0].rgb = (subsets[1][0].rgb << 1) | pbit1;
- subsets[1][1].rgb = (subsets[1][1].rgb << 1) | pbit1;
- }
- if (mode.EPB > 0) {
- for (size_t i = 0; i < mode.NS; i++) {
- auto &subset = subsets[i];
- auto pbit0 = Get(mode.EndpointPBit(i * 2 + 0));
- auto pbit1 = Get(mode.EndpointPBit(i * 2 + 1));
- subset[0].rgb = (subset[0].rgb << 1) | pbit0;
- subset[1].rgb = (subset[1].rgb << 1) | pbit1;
- if (mode.AB > 0) {
- subset[0].a = (subset[0].a << 1) | pbit0;
- subset[1].a = (subset[1].a << 1) | pbit1;
- }
- }
- }
- auto const colorBits = mode.CB + mode.SPB + mode.EPB;
- auto const alphaBits = mode.AB + mode.SPB + mode.EPB;
- for (size_t i = 0; i < mode.NS; i++) {
- auto &subset = subsets[i];
- subset[0].rgb = subset[0].rgb << (8 - colorBits);
- subset[1].rgb = subset[1].rgb << (8 - colorBits);
- subset[0].rgb = subset[0].rgb | (subset[0].rgb >> colorBits);
- subset[1].rgb = subset[1].rgb | (subset[1].rgb >> colorBits);
- if (mode.AB > 0) {
- subset[0].a = subset[0].a << (8 - alphaBits);
- subset[1].a = subset[1].a << (8 - alphaBits);
- subset[0].a = subset[0].a | (subset[0].a >> alphaBits);
- subset[1].a = subset[1].a | (subset[1].a >> alphaBits);
- }
- }
- int colorIndexBitOffset = 0;
- int alphaIndexBitOffset = 0;
- for (int y = 0; y < 4; y++) {
- for (int x = 0; x < 4; x++) {
- auto texelIdx = y * 4 + x;
- auto partitionIdx = Get(mode.Partition());
- assert(partitionIdx < MaxPartitions);
- auto subsetIdx = subsetIndex(mode, partitionIdx, texelIdx);
- assert(subsetIdx < MaxSubsets);
- auto const &subset = subsets[subsetIdx];
- auto anchorIdx = anchorIndex(mode, partitionIdx, subsetIdx);
- auto isAnchor = anchorIdx == texelIdx;
- auto colorIdx = colorIndex(mode, isAnchor, colorIndexBitOffset);
- auto alphaIdx = alphaIndex(mode, isAnchor, alphaIndexBitOffset);
- if (y + dstY >= dstHeight || x + dstX >= dstWidth) {
- // Don't be tempted to skip early at the loops:
- // The calls to colorIndex() and alphaIndex() adjust bit
- // offsets that need to be carefully tracked.
- continue;
- }
- Color output;
- // Note: We flip r and b channels past this point as the texture storage is BGR while the output is RGB
- output.rgb.r = interpolate(subset[0].rgb.b, subset[1].rgb.b, colorIdx);
- output.rgb.g = interpolate(subset[0].rgb.g, subset[1].rgb.g, colorIdx);
- output.rgb.b = interpolate(subset[0].rgb.r, subset[1].rgb.r, colorIdx);
- output.a = interpolate(subset[0].a, subset[1].a, alphaIdx);
- switch (Get(mode.Rotation())) {
- default:
- break;
- case 1:
- std::swap(output.a, output.rgb.b);
- break;
- case 2:
- std::swap(output.a, output.rgb.g);
- break;
- case 3:
- std::swap(output.a, output.rgb.r);
- break;
- }
- auto out = reinterpret_cast<Color *>(dst + sizeof(Color) * x + dstPitch * y);
- *out = output;
- }
- }
- }
- int subsetIndex(const Mode &mode, int partitionIdx, int texelIndex) const {
- switch (mode.NS) {
- default:
- return 0;
- case 2:
- return PartitionTable2[partitionIdx][texelIndex];
- case 3:
- return PartitionTable3[partitionIdx][texelIndex];
- }
- }
- int anchorIndex(const Mode &mode, int partitionIdx, int subsetIdx) const {
- // ARB_texture_compression_bptc states:
- // "In partition zero, the anchor index is always index zero.
- // In other partitions, the anchor index is specified by tables
- // Table.A2 and Table.A3.""
- // Note: This is really confusing - I believe they meant subset instead
- // of partition here.
- switch (subsetIdx) {
- default:
- return 0;
- case 1:
- return mode.NS == 2 ? AnchorTable2[partitionIdx] : AnchorTable3a[partitionIdx];
- case 2:
- return AnchorTable3b[partitionIdx];
- }
- }
- IndexInfo colorIndex(const Mode &mode, bool isAnchor,
- int &indexBitOffset) const {
- // ARB_texture_compression_bptc states:
- // "The index value for interpolating color comes from the secondary
- // index for the texel if the format has an index selection bit and its
- // value is one and from the primary index otherwise.""
- auto idx = Get(mode.IndexSelection());
- assert(idx <= 1);
- bool secondary = idx == 1;
- auto numBits = secondary ? mode.IB2 : mode.IB;
- auto numReadBits = numBits - (isAnchor ? 1 : 0);
- auto index =
- Get(secondary ? mode.SecondaryIndex(indexBitOffset, numReadBits)
- : mode.PrimaryIndex(indexBitOffset, numReadBits));
- indexBitOffset += numReadBits;
- return {index, numBits};
- }
- IndexInfo alphaIndex(const Mode &mode, bool isAnchor,
- int &indexBitOffset) const {
- // ARB_texture_compression_bptc states:
- // "The alpha index comes from the secondary index if the block has a
- // secondary index and the block either doesn't have an index selection
- // bit or that bit is zero and the primary index otherwise."
- auto idx = Get(mode.IndexSelection());
- assert(idx <= 1);
- bool secondary = (mode.IB2 != 0) && (idx == 0);
- auto numBits = secondary ? mode.IB2 : mode.IB;
- auto numReadBits = numBits - (isAnchor ? 1 : 0);
- auto index =
- Get(secondary ? mode.SecondaryIndex(indexBitOffset, numReadBits)
- : mode.PrimaryIndex(indexBitOffset, numReadBits));
- indexBitOffset += numReadBits;
- return {index, numBits};
- }
- // Assumes little-endian
- uint64_t low;
- uint64_t high;
- };
- } // namespace BC7
- } // anonymous namespace
- namespace bcn {
- constexpr size_t R8Bpp{1}; //!< The amount of bytes per pixel in R8
- constexpr size_t R8g8Bpp{2}; //!< The amount of bytes per pixel in R8G8
- constexpr size_t R8g8b8a8Bpp{4}; //!< The amount of bytes per pixel in R8G8B8A8
- constexpr size_t R16g16b16a16Bpp{8}; //!< The amount of bytes per pixel in R16G16B16
- void DecodeBc1(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height) {
- const auto *color{reinterpret_cast<const BC_color *>(src)};
- size_t pitch{R8g8b8a8Bpp * width};
- color->decode(dst, x, y, width, height, pitch, R8g8b8a8Bpp, true, false);
- }
- void DecodeBc2(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height) {
- const auto *alpha{reinterpret_cast<const BC_alpha *>(src)};
- const auto *color{reinterpret_cast<const BC_color *>(src + 8)};
- size_t pitch{R8g8b8a8Bpp * width};
- color->decode(dst, x, y, width, height, pitch, R8g8b8a8Bpp, false, true);
- alpha->decode(dst, x, y, width, height, pitch, R8g8b8a8Bpp);
- }
- void DecodeBc3(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height) {
- const auto *alpha{reinterpret_cast<const BC_channel *>(src)};
- const auto *color{reinterpret_cast<const BC_color *>(src + 8)};
- size_t pitch{R8g8b8a8Bpp * width};
- color->decode(dst, x, y, width, height, pitch, R8g8b8a8Bpp, false, true);
- alpha->decode(dst, x, y, width, height, pitch, R8g8b8a8Bpp, 3, false);
- }
- void DecodeBc4(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height, bool isSigned) {
- const auto *red{reinterpret_cast<const BC_channel *>(src)};
- size_t pitch{R8Bpp * width};
- red->decode(dst, x, y, width, height, pitch, R8Bpp, 0, isSigned);
- }
- void DecodeBc5(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height, bool isSigned) {
- const auto *red{reinterpret_cast<const BC_channel *>(src)};
- const auto *green{reinterpret_cast<const BC_channel *>(src + 8)};
- size_t pitch{R8g8Bpp * width};
- red->decode(dst, x, y, width, height, pitch, R8g8Bpp, 0, isSigned);
- green->decode(dst, x, y, width, height, pitch, R8g8Bpp, 1, isSigned);
- }
- void DecodeBc6(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height, bool isSigned) {
- const auto *block{reinterpret_cast<const BC6H::Block *>(src)};
- size_t pitch{R16g16b16a16Bpp * width};
- block->decode(dst, x, y, width, height, pitch, R16g16b16a16Bpp, isSigned);
- }
- void DecodeBc7(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height) {
- const auto *block{reinterpret_cast<const BC7::Block *>(src)};
- size_t pitch{R8g8b8a8Bpp * width};
- block->decode(dst, x, y, width, height, pitch);
- }
- }
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