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-rw-r--r--externals/bc_decoder/bc_decoder.cpp1522
-rw-r--r--externals/bc_decoder/bc_decoder.h43
2 files changed, 1565 insertions, 0 deletions
diff --git a/externals/bc_decoder/bc_decoder.cpp b/externals/bc_decoder/bc_decoder.cpp
new file mode 100644
index 000000000..536c44f34
--- /dev/null
+++ b/externals/bc_decoder/bc_decoder.cpp
@@ -0,0 +1,1522 @@
+// 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);
+ }
+}
diff --git a/externals/bc_decoder/bc_decoder.h b/externals/bc_decoder/bc_decoder.h
new file mode 100644
index 000000000..4f0ead7d3
--- /dev/null
+++ b/externals/bc_decoder/bc_decoder.h
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: MPL-2.0
+// Copyright © 2022 Skyline Team and Contributors (https://github.com/skyline-emu/)
+
+#pragma once
+
+#include <cstdint>
+
+namespace bcn {
+ /**
+ * @brief Decodes a BC1 encoded image to R8G8B8A8
+ */
+ void DecodeBc1(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height);
+
+ /**
+ * @brief Decodes a BC2 encoded image to R8G8B8A8
+ */
+ void DecodeBc2(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height);
+
+ /**
+ * @brief Decodes a BC3 encoded image to R8G8B8A8
+ */
+ void DecodeBc3(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height);
+
+ /**
+ * @brief Decodes a BC4 encoded image to R8
+ */
+ void DecodeBc4(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height, bool isSigned);
+
+ /**
+ * @brief Decodes a BC5 encoded image to R8G8
+ */
+ void DecodeBc5(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height, bool isSigned);
+
+ /**
+ * @brief Decodes a BC6 encoded image to R16G16B16A16
+ */
+ void DecodeBc6(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height, bool isSigned);
+
+ /**
+ * @brief Decodes a BC7 encoded image to R8G8B8A8
+ */
+ void DecodeBc7(const uint8_t *src, uint8_t *dst, size_t x, size_t y, size_t width, size_t height);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 20:09:52 +0100