diff options
| author | Denton Woods <denton.woods@gmail.com> | 2017-01-02 16:18:40 -0600 |
|---|---|---|
| committer | Denton Woods <denton.woods@gmail.com> | 2017-01-02 16:18:40 -0600 |
| commit | 9c54838773116bcaf296542cd92e7331b7b0f142 (patch) | |
| tree | e302185e2901c6a2f8d8d775df701c5b3e20a5cd | |
| parent | 978bcfd9a0f4d68bbd0219ebd0c0a6b10c1a89ff (diff) | |
| download | devil-9c54838773116bcaf296542cd92e7331b7b0f142.tar.gz | |
- Added ETC1 support to KTX reading
| -rw-r--r-- | DevIL/src-IL/include/rg_etc1.h | 76 | ||||
| -rw-r--r-- | DevIL/src-IL/src/il_ktx.cpp | 178 | ||||
| -rw-r--r-- | DevIL/src-IL/src/rg_etc1.cpp | 2446 |
3 files changed, 2651 insertions, 49 deletions
diff --git a/DevIL/src-IL/include/rg_etc1.h b/DevIL/src-IL/include/rg_etc1.h new file mode 100644 index 00000000..9ce89a6c --- /dev/null +++ b/DevIL/src-IL/include/rg_etc1.h @@ -0,0 +1,76 @@ +// File: rg_etc1.h - Fast, high quality ETC1 block packer/unpacker - Rich Geldreich <richgel99@gmail.com> +// Please see ZLIB license at the end of this file. +#pragma once + +namespace rg_etc1 +{ + // Unpacks an 8-byte ETC1 compressed block to a block of 4x4 32bpp RGBA pixels. + // Returns false if the block is invalid. Invalid blocks will still be unpacked with clamping. + // This function is thread safe, and does not dynamically allocate any memory. + // If preserve_alpha is true, the alpha channel of the destination pixels will not be overwritten. Otherwise, alpha will be set to 255. + bool unpack_etc1_block(const void *pETC1_block, unsigned int* pDst_pixels_rgba, bool preserve_alpha = false); + + // Quality setting = the higher the quality, the slower. + // To pack large textures, it is highly recommended to call pack_etc1_block() in parallel, on different blocks, from multiple threads (particularly when using cHighQuality). + enum etc1_quality + { + cLowQuality, + cMediumQuality, + cHighQuality, + }; + + struct etc1_pack_params + { + etc1_quality m_quality; + bool m_dithering; + + inline etc1_pack_params() + { + clear(); + } + + void clear() + { + m_quality = cHighQuality; + m_dithering = false; + } + }; + + // Important: pack_etc1_block_init() must be called before calling pack_etc1_block(). + void pack_etc1_block_init(); + + // Packs a 4x4 block of 32bpp RGBA pixels to an 8-byte ETC1 block. + // 32-bit RGBA pixels must always be arranged as (R,G,B,A) (R first, A last) in memory, independent of platform endianness. A should always be 255. + // Returns squared error of result. + // This function is thread safe, and does not dynamically allocate any memory. + // pack_etc1_block() does not currently support "perceptual" colorspace metrics - it primarily optimizes for RGB RMSE. + unsigned int pack_etc1_block(void* pETC1_block, const unsigned int* pSrc_pixels_rgba, etc1_pack_params& pack_params); + +} // namespace rg_etc1 + +//------------------------------------------------------------------------------ +// +// rg_etc1 uses the ZLIB license: +// http://opensource.org/licenses/Zlib +// +// Copyright (c) 2012 Rich Geldreich +// +// This software is provided 'as-is', without any express or implied +// warranty. In no event will the authors be held liable for any damages +// arising from the use of this software. +// +// Permission is granted to anyone to use this software for any purpose, +// including commercial applications, and to alter it and redistribute it +// freely, subject to the following restrictions: +// +// 1. The origin of this software must not be misrepresented; you must not +// claim that you wrote the original software. If you use this software +// in a product, an acknowledgment in the product documentation would be +// appreciated but is not required. +// +// 2. Altered source versions must be plainly marked as such, and must not be +// misrepresented as being the original software. +// +// 3. This notice may not be removed or altered from any source distribution. +// +//------------------------------------------------------------------------------ diff --git a/DevIL/src-IL/src/il_ktx.cpp b/DevIL/src-IL/src/il_ktx.cpp index c8890aa3..c424810a 100644 --- a/DevIL/src-IL/src/il_ktx.cpp +++ b/DevIL/src-IL/src/il_ktx.cpp @@ -14,6 +14,7 @@ #include "il_internal.h" #ifndef IL_NO_KTX #include "il_bits.h" +#include "rg_etc1.h" ILboolean iIsValidKtx(void); @@ -58,11 +59,25 @@ typedef struct KTX_HEAD //#define I_GL_4_BYTES 0x1409 #define I_GL_DOUBLE 0x140A #define I_GL_HALF 0x140B + #define I_GL_ALPHA 0x1906 #define I_GL_RGB 0x1907 #define I_GL_RGBA 0x1908 #define I_GL_LUMINANCE 0x1909 #define I_GL_LUMINANCE_ALPHA 0x190A +// From gl2ext.h +#define I_GL_ETC1_RGB8_OES 0x8D64 +// From https://www.opengl.org/registry/specs/ARB/ES3_compatibility.txt +#define I_GL_COMPRESSED_RGB8_ETC2 0x9274 +#define I_GL_COMPRESSED_SRGB8_ETC2 0x9275 +#define I_GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2 0x9276 +#define I_GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2 0x9277 +#define I_GL_COMPRESSED_RGBA8_ETC2_EAC 0x9278 +#define I_GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC 0x9279 +#define I_GL_COMPRESSED_R11_EAC 0x9270 +#define I_GL_COMPRESSED_SIGNED_R11_EAC 0x9271 +#define I_GL_COMPRESSED_RG11_EAC 0x9272 +#define I_GL_COMPRESSED_SIGNED_RG11_EAC 0x9273 @@ -172,6 +187,7 @@ ILboolean iLoadKtxInternal() ILuint imageSize; ILenum Format, Type; ILubyte Bpp, Bpc; + ILboolean Compressed; char FileIdentifier[12] = { //0xAB, 0x4B, 0x54, 0x58, 0x20, 0x31, 0x31, 0xBB, 0x0D, 0x0A, 0x1A, 0x0A '«', 'K', 'T', 'X', ' ', '1', '1', '»', '\r', '\n', '\x1A', '\n' @@ -201,24 +217,22 @@ ILboolean iLoadKtxInternal() Header.numberOfFaces = GetLittleUInt(); Header.numberOfMipmapLevels = GetLittleUInt(); Header.bytesOfKeyValueData = GetLittleUInt(); - + imageSize = GetLittleUInt(); if (memcmp(Header.identifier, FileIdentifier, 12) || Header.endianness != 0x04030201) { ilSetError(IL_ILLEGAL_FILE_VALUE); return IL_FALSE; } - //@TODO: Additional types - //@TODO: Really needed with the switch statements below? - if ((Header.glType != I_GL_UNSIGNED_BYTE && Header.glType != I_GL_HALF) || Header.glTypeSize != 1) { + + if (Header.glTypeSize != 1) { //@TODO: Cases when this is different? ilSetError(IL_ILLEGAL_FILE_VALUE); return IL_FALSE; } - //@TODO: Additional formats - //@TODO: Really needed with the switch statements below? - if (Header.glFormat <= I_GL_ALPHA || Header.glFormat >= I_GL_LUMINANCE_ALPHA || Header.glInternalFormat != Header.glFormat /*|| Header.glBaseInternalFormat != Header.glFormat*/) { + //@TODO: Really needed? + /*if (Header.glInternalFormat != Header.glFormat || Header.glBaseInternalFormat != Header.glFormat) { ilSetError(IL_ILLEGAL_FILE_VALUE); return IL_FALSE; - } + }*/ //@TODO: Mipmaps, etc. if (Header.numberOfArrayElements != 0 || Header.numberOfFaces != 1 || Header.numberOfMipmapLevels != 1) { @@ -229,58 +243,124 @@ ILboolean iLoadKtxInternal() if (iseek(Header.bytesOfKeyValueData, IL_SEEK_CUR)) return IL_FALSE; - switch (Header.glType) + //@TODO: Additional formats + if (Header.glFormat != 0) // Uncompressed formats { - case I_GL_UNSIGNED_BYTE: - Bpc = 1; - Type = IL_UNSIGNED_BYTE; - break; - case I_GL_HALF: - Bpc = 2; - Type = IL_HALF; - break; - default: - ilSetError(IL_ILLEGAL_FILE_VALUE); - return IL_FALSE; + switch (Header.glFormat) + { + case I_GL_LUMINANCE: + Bpp = 1; + Format = IL_LUMINANCE; + Compressed = IL_FALSE; + break; + case I_GL_LUMINANCE_ALPHA: + Bpp = 2; + Format = IL_LUMINANCE_ALPHA; + Compressed = IL_FALSE; + break; + case I_GL_RGB: + Bpp = 3; + Format = IL_RGB; + Compressed = IL_FALSE; + break; + case I_GL_RGBA: + Bpp = 4; + Format = IL_RGBA; + Compressed = IL_FALSE; + break; + default: + ilSetError(IL_ILLEGAL_FILE_VALUE); + return IL_FALSE; + } } - - switch (Header.glFormat) + else // Compressed formats - Note that type must be set here! { - case I_GL_LUMINANCE: - Bpp = 1; - Format = IL_LUMINANCE; - break; - case I_GL_LUMINANCE_ALPHA: - Bpp = 2; - Format = IL_LUMINANCE_ALPHA; - break; - case I_GL_RGB: - Bpp = 3; - Format = IL_RGB; - break; - case I_GL_RGBA: - Bpp = 4; - Format = IL_RGBA; - break; - default: - ilSetError(IL_ILLEGAL_FILE_VALUE); - return IL_FALSE; + switch (Header.glInternalFormat) + { + case I_GL_ETC1_RGB8_OES: + Bpp = 4; + Format = IL_RGBA; + Compressed = IL_TRUE; + Type = IL_UNSIGNED_BYTE; + break; + default: + ilSetError(IL_ILLEGAL_FILE_VALUE); + return IL_FALSE; + } } - //@TODO: More than just RGBA if (!ilTexImage(Header.pixelWidth, Header.pixelHeight, 1, Bpp, Format, Type, NULL)) { return IL_FALSE; } iCurImage->Origin = IL_ORIGIN_UPPER_LEFT; - imageSize = GetLittleUInt(); - if (imageSize != Header.pixelWidth * Header.pixelHeight * Bpp * Bpc) { - ilSetError(IL_ILLEGAL_FILE_VALUE); - return IL_FALSE; - } + if (!Compressed) + { + //@TODO: Additional types + switch (Header.glType) + { + case I_GL_UNSIGNED_BYTE: + Bpc = 1; + Type = IL_UNSIGNED_BYTE; + break; + case I_GL_HALF: + Bpc = 2; + Type = IL_HALF; + break; + default: + ilSetError(IL_ILLEGAL_FILE_VALUE); + return IL_FALSE; + } + + if (imageSize != Header.pixelWidth * Header.pixelHeight * Bpp * Bpc) { + ilSetError(IL_ILLEGAL_FILE_VALUE); + return IL_FALSE; + } - if (iread(iCurImage->Data, Bpp*Bpc, Header.pixelWidth * Header.pixelHeight) != Header.pixelWidth * Header.pixelHeight) - return IL_FALSE; + if (iread(iCurImage->Data, Bpp*Bpc, Header.pixelWidth * Header.pixelHeight) != Header.pixelWidth * Header.pixelHeight) + return IL_FALSE; + } + else { // Compressed formats require different handling + switch (Header.glInternalFormat) + { + case I_GL_ETC1_RGB8_OES: + ILubyte *FullBuffer = (ILubyte*)ialloc(Header.pixelWidth * Header.pixelHeight / 2); + ILuint UnpackBuff[16*4]; + ILuint *Data = (ILuint*)iCurImage->Data; // Easier copies + + if (FullBuffer == NULL) + return IL_FALSE; + if (imageSize != Header.pixelWidth * Header.pixelHeight / 2) { + ilSetError(IL_ILLEGAL_FILE_VALUE); + return IL_FALSE; + } + if (iread(FullBuffer, 1, imageSize) != imageSize) + return IL_FALSE; + + ILuint BlockPos = 0; + for (ILuint y = 0; y < iCurImage->Height; y+=4) + { + for (ILuint x = 0; x < iCurImage->Width; x+=4) + { + ILuint ImagePos = y * iCurImage->Width + x; + rg_etc1::unpack_etc1_block(&FullBuffer[BlockPos], (ILuint*)UnpackBuff, false); + ILuint c = 0; + for (ILuint y1 = 0; y1 < 4; y1++) + { + for (ILuint x1 = 0; x1 < 4; x1++) + { + Data[ImagePos + y1*iCurImage->Width + x1] = UnpackBuff[c++]; + } + } + BlockPos += 8; + } + } + + ifree(FullBuffer); + break; + } + //return IL_FALSE; + } return ilFixImage(); } diff --git a/DevIL/src-IL/src/rg_etc1.cpp b/DevIL/src-IL/src/rg_etc1.cpp new file mode 100644 index 00000000..8e28b53f --- /dev/null +++ b/DevIL/src-IL/src/rg_etc1.cpp @@ -0,0 +1,2446 @@ +// File: rg_etc1.cpp - Fast, high quality ETC1 block packer/unpacker - Rich Geldreich <richgel99@gmail.com> +// Please see ZLIB license at the end of rg_etc1.h. +// +// For more information Ericsson Texture Compression (ETC/ETC1), see: +// http://www.khronos.org/registry/gles/extensions/OES/OES_compressed_ETC1_RGB8_texture.txt +// +// v1.04 - 5/15/14 - Fix signed vs. unsigned subtraction problem (noticed when compiled with gcc) in pack_etc1_block_init(). +// This issue would cause an assert when this func. was called in debug. (Note this module was developed/testing with MSVC, +// I still need to test it throughly when compiled with gcc.) +// +// v1.03 - 5/12/13 - Initial public release +#include "rg_etc1.h" + +#include <stdlib.h> +#include <memory.h> +#include <assert.h> +//#include <stdio.h> +#include <math.h> + +#pragma warning (disable: 4201) // nonstandard extension used : nameless struct/union + +#if defined(_DEBUG) || defined(DEBUG) +#define RG_ETC1_BUILD_DEBUG +#endif + +#define RG_ETC1_ASSERT assert + +namespace rg_etc1 +{ + typedef unsigned char uint8; + typedef unsigned short uint16; + typedef unsigned int uint; + typedef unsigned int uint32; + typedef long long int64; + typedef unsigned long long uint64; + + const uint32 cUINT32_MAX = 0xFFFFFFFFU; + const uint64 cUINT64_MAX = 0xFFFFFFFFFFFFFFFFULL; //0xFFFFFFFFFFFFFFFFui64; + + template<typename T> inline T minimum(T a, T b) { return (a < b) ? a : b; } + template<typename T> inline T minimum(T a, T b, T c) { return minimum(minimum(a, b), c); } + template<typename T> inline T maximum(T a, T b) { return (a > b) ? a : b; } + template<typename T> inline T maximum(T a, T b, T c) { return maximum(maximum(a, b), c); } + template<typename T> inline T clamp(T value, T low, T high) { return (value < low) ? low : ((value > high) ? high : value); } + template<typename T> inline T square(T value) { return value * value; } + template<typename T> inline void zero_object(T& obj) { memset((void*)&obj, 0, sizeof(obj)); } + template<typename T> inline void zero_this(T* pObj) { memset((void*)pObj, 0, sizeof(*pObj)); } + + template<class T, size_t N> T decay_array_to_subtype(T (&a)[N]); + +#define RG_ETC1_ARRAY_SIZE(X) (sizeof(X) / sizeof(decay_array_to_subtype(X))) + + enum eNoClamp { cNoClamp }; + + struct color_quad_u8 + { + static inline int clamp(int v) { if (v & 0xFFFFFF00U) v = (~(static_cast<int>(v) >> 31)) & 0xFF; return v; } + + struct component_traits { enum { cSigned = false, cFloat = false, cMin = 0U, cMax = 255U }; }; + + public: + typedef unsigned char component_t; + typedef int parameter_t; + + enum { cNumComps = 4 }; + + union + { + struct + { + component_t r; + component_t g; + component_t b; + component_t a; + }; + + component_t c[cNumComps]; + + uint32 m_u32; + }; + + inline color_quad_u8() + { + } + + inline color_quad_u8(const color_quad_u8& other) : m_u32(other.m_u32) + { + } + + explicit inline color_quad_u8(parameter_t y, parameter_t alpha = component_traits::cMax) + { + set(y, alpha); + } + + inline color_quad_u8(parameter_t red, parameter_t green, parameter_t blue, parameter_t alpha = component_traits::cMax) + { + set(red, green, blue, alpha); + } + + explicit inline color_quad_u8(eNoClamp, parameter_t y, parameter_t alpha = component_traits::cMax) + { + set_noclamp_y_alpha(y, alpha); + } + + inline color_quad_u8(eNoClamp, parameter_t red, parameter_t green, parameter_t blue, parameter_t alpha = component_traits::cMax) + { + set_noclamp_rgba(red, green, blue, alpha); + } + + inline void clear() + { + m_u32 = 0; + } + + inline color_quad_u8& operator= (const color_quad_u8& other) + { + m_u32 = other.m_u32; + return *this; + } + + inline color_quad_u8& set_rgb(const color_quad_u8& other) + { + r = other.r; + g = other.g; + b = other.b; + return *this; + } + + inline color_quad_u8& operator= (parameter_t y) + { + set(y, component_traits::cMax); + return *this; + } + + inline color_quad_u8& set(parameter_t y, parameter_t alpha = component_traits::cMax) + { + y = clamp(y); + alpha = clamp(alpha); + r = static_cast<component_t>(y); + g = static_cast<component_t>(y); + b = static_cast<component_t>(y); + a = static_cast<component_t>(alpha); + return *this; + } + + inline color_quad_u8& set_noclamp_y_alpha(parameter_t y, parameter_t alpha = component_traits::cMax) + { + RG_ETC1_ASSERT( (y >= component_traits::cMin) && (y <= component_traits::cMax) ); + RG_ETC1_ASSERT( (alpha >= component_traits::cMin) && (alpha <= component_traits::cMax) ); + + r = static_cast<component_t>(y); + g = static_cast<component_t>(y); + b = static_cast<component_t>(y); + a = static_cast<component_t>(alpha); + return *this; + } + + inline color_quad_u8& set(parameter_t red, parameter_t green, parameter_t blue, parameter_t alpha = component_traits::cMax) + { + r = static_cast<component_t>(clamp(red)); + g = static_cast<component_t>(clamp(green)); + b = static_cast<component_t>(clamp(blue)); + a = static_cast<component_t>(clamp(alpha)); + return *this; + } + + inline color_quad_u8& set_noclamp_rgba(parameter_t red, parameter_t green, parameter_t blue, parameter_t alpha) + { + RG_ETC1_ASSERT( (red >= component_traits::cMin) && (red <= component_traits::cMax) ); + RG_ETC1_ASSERT( (green >= component_traits::cMin) && (green <= component_traits::cMax) ); + RG_ETC1_ASSERT( (blue >= component_traits::cMin) && (blue <= component_traits::cMax) ); + RG_ETC1_ASSERT( (alpha >= component_traits::cMin) && (alpha <= component_traits::cMax) ); + + r = static_cast<component_t>(red); + g = static_cast<component_t>(green); + b = static_cast<component_t>(blue); + a = static_cast<component_t>(alpha); + return *this; + } + + inline color_quad_u8& set_noclamp_rgb(parameter_t red, parameter_t green, parameter_t blue) + { + RG_ETC1_ASSERT( (red >= component_traits::cMin) && (red <= component_traits::cMax) ); + RG_ETC1_ASSERT( (green >= component_traits::cMin) && (green <= component_traits::cMax) ); + RG_ETC1_ASSERT( (blue >= component_traits::cMin) && (blue <= component_traits::cMax) ); + + r = static_cast<component_t>(red); + g = static_cast<component_t>(green); + b = static_cast<component_t>(blue); + return *this; + } + + static inline parameter_t get_min_comp() { return component_traits::cMin; } + static inline parameter_t get_max_comp() { return component_traits::cMax; } + static inline bool get_comps_are_signed() { return component_traits::cSigned; } + + inline component_t operator[] (uint i) const { RG_ETC1_ASSERT(i < cNumComps); return c[i]; } + inline component_t& operator[] (uint i) { RG_ETC1_ASSERT(i < cNumComps); return c[i]; } + + inline color_quad_u8& set_component(uint i, parameter_t f) + { + RG_ETC1_ASSERT(i < cNumComps); + + c[i] = static_cast<component_t>(clamp(f)); + + return *this; + } + + inline color_quad_u8& set_grayscale(parameter_t l) + { + component_t x = static_cast<component_t>(clamp(l)); + c[0] = x; + c[1] = x; + c[2] = x; + return *this; + } + + inline color_quad_u8& clamp(const color_quad_u8& l, const color_quad_u8& h) + { + for (uint i = 0; i < cNumComps; i++) + c[i] = static_cast<component_t>(rg_etc1::clamp<parameter_t>(c[i], l[i], h[i])); + return *this; + } + + inline color_quad_u8& clamp(parameter_t l, parameter_t h) + { + for (uint i = 0; i < cNumComps; i++) + c[i] = static_cast<component_t>(rg_etc1::clamp<parameter_t>(c[i], l, h)); + return *this; + } + + // Returns CCIR 601 luma (consistent with color_utils::RGB_To_Y). + inline parameter_t get_luma() const + { + return static_cast<parameter_t>((19595U * r + 38470U * g + 7471U * b + 32768U) >> 16U); + } + + // Returns REC 709 luma. + inline parameter_t get_luma_rec709() const + { + return static_cast<parameter_t>((13938U * r + 46869U * g + 4729U * b + 32768U) >> 16U); + } + + inline uint squared_distance_rgb(const color_quad_u8& c) const + { + return rg_etc1::square(r - c.r) + rg_etc1::square(g - c.g) + rg_etc1::square(b - c.b); + } + + inline uint squared_distance_rgba(const color_quad_u8& c) const + { + return rg_etc1::square(r - c.r) + rg_etc1::square(g - c.g) + rg_etc1::square(b - c.b) + rg_etc1::square(a - c.a); + } + + inline bool rgb_equals(const color_quad_u8& rhs) const + { + return (r == rhs.r) && (g == rhs.g) && (b == rhs.b); + } + + inline bool operator== (const color_quad_u8& rhs) const + { + return m_u32 == rhs.m_u32; + } + + color_quad_u8& operator+= (const color_quad_u8& other) + { + for (uint i = 0; i < 4; i++) + c[i] = static_cast<component_t>(clamp(c[i] + other.c[i])); + return *this; + } + + color_quad_u8& operator-= (const color_quad_u8& other) + { + for (uint i = 0; i < 4; i++) + c[i] = static_cast<component_t>(clamp(c[i] - other.c[i])); + return *this; + } + + friend color_quad_u8 operator+ (const color_quad_u8& lhs, const color_quad_u8& rhs) + { + color_quad_u8 result(lhs); + result += rhs; + return result; + } + + friend color_quad_u8 operator- (const color_quad_u8& lhs, const color_quad_u8& rhs) + { + color_quad_u8 result(lhs); + result -= rhs; + return result; + } + }; // class color_quad_u8 + + struct vec3F + { + float m_s[3]; + + inline vec3F() { } + inline vec3F(float s) { m_s[0] = s; m_s[1] = s; m_s[2] = s; } + inline vec3F(float x, float y, float z) { m_s[0] = x; m_s[1] = y; m_s[2] = z; } + + inline float operator[] (uint i) const { RG_ETC1_ASSERT(i < 3); return m_s[i]; } + + inline vec3F& operator += (const vec3F& other) { for (uint i = 0; i < 3; i++) m_s[i] += other.m_s[i]; return *this; } + + inline vec3F& operator *= (float s) { for (uint i = 0; i < 3; i++) m_s[i] *= s; return *this; } + }; + + enum etc_constants + { + cETC1BytesPerBlock = 8U, + + cETC1SelectorBits = 2U, + cETC1SelectorValues = 1U << cETC1SelectorBits, + cETC1SelectorMask = cETC1SelectorValues - 1U, + + cETC1BlockShift = 2U, + cETC1BlockSize = 1U << cETC1BlockShift, + + cETC1LSBSelectorIndicesBitOffset = 0, + cETC1MSBSelectorIndicesBitOffset = 16, + + cETC1FlipBitOffset = 32, + cETC1DiffBitOffset = 33, + + cETC1IntenModifierNumBits = 3, + cETC1IntenModifierValues = 1 << cETC1IntenModifierNumBits, + cETC1RightIntenModifierTableBitOffset = 34, + cETC1LeftIntenModifierTableBitOffset = 37, + + // Base+Delta encoding (5 bit bases, 3 bit delta) + cETC1BaseColorCompNumBits = 5, + cETC1BaseColorCompMax = 1 << cETC1BaseColorCompNumBits, + + cETC1DeltaColorCompNumBits = 3, + cETC1DeltaColorComp = 1 << cETC1DeltaColorCompNumBits, + cETC1DeltaColorCompMax = 1 << cETC1DeltaColorCompNumBits, + + cETC1BaseColor5RBitOffset = 59, + cETC1BaseColor5GBitOffset = 51, + cETC1BaseColor5BBitOffset = 43, + + cETC1DeltaColor3RBitOffset = 56, + cETC1DeltaColor3GBitOffset = 48, + cETC1DeltaColor3BBitOffset = 40, + + // Absolute (non-delta) encoding (two 4-bit per component bases) + cETC1AbsColorCompNumBits = 4, + cETC1AbsColorCompMax = 1 << cETC1AbsColorCompNumBits, + + cETC1AbsColor4R1BitOffset = 60, + cETC1AbsColor4G1BitOffset = 52, + cETC1AbsColor4B1BitOffset = 44, + + cETC1AbsColor4R2BitOffset = 56, + cETC1AbsColor4G2BitOffset = 48, + cETC1AbsColor4B2BitOffset = 40, + + cETC1ColorDeltaMin = -4, + cETC1ColorDeltaMax = 3, + + // Delta3: + // 0 1 2 3 4 5 6 7 + // 000 001 010 011 100 101 110 111 + // 0 1 2 3 -4 -3 -2 -1 + }; + + static uint8 g_quant5_tab[256+16]; + + static const int g_etc1_inten_tables[cETC1IntenModifierValues][cETC1SelectorValues] = + { + { -8, -2, 2, 8 }, { -17, -5, 5, 17 }, { -29, -9, 9, 29 }, { -42, -13, 13, 42 }, + { -60, -18, 18, 60 }, { -80, -24, 24, 80 }, { -106, -33, 33, 106 }, { -183, -47, 47, 183 } + }; + + static const uint8 g_etc1_to_selector_index[cETC1SelectorValues] = { 2, 3, 1, 0 }; + static const uint8 g_selector_index_to_etc1[cETC1SelectorValues] = { 3, 2, 0, 1 }; + + // Given an ETC1 diff/inten_table/selector, and an 8-bit desired color, this table encodes the best packed_color in the low byte, and the abs error in the high byte. + static uint16 g_etc1_inverse_lookup[2*8*4][256]; // [diff/inten_table/selector][desired_color] + + // g_color8_to_etc_block_config[color][table_index] = Supplies for each 8-bit color value a list of packed ETC1 diff/intensity table/selectors/packed_colors that map to that color. + // To pack: diff | (inten << 1) | (selector << 4) | (packed_c << 8) + static const uint16 g_color8_to_etc_block_config_0_255[2][33] = + { + { 0x0000, 0x0010, 0x0002, 0x0012, 0x0004, 0x0014, 0x0006, 0x0016, 0x0008, 0x0018, 0x000A, 0x001A, 0x000C, 0x001C, 0x000E, 0x001E, + 0x0001, 0x0011, 0x0003, 0x0013, 0x0005, 0x0015, 0x0007, 0x0017, 0x0009, 0x0019, 0x000B, 0x001B, 0x000D, 0x001D, 0x000F, 0x001F, 0xFFFF }, + { 0x0F20, 0x0F30, 0x0E32, 0x0F22, 0x0E34, 0x0F24, 0x0D36, 0x0F26, 0x0C38, 0x0E28, 0x0B3A, 0x0E2A, 0x093C, 0x0E2C, 0x053E, 0x0D2E, + 0x1E31, 0x1F21, 0x1D33, 0x1F23, 0x1C35, 0x1E25, 0x1A37, 0x1E27, 0x1839, 0x1D29, 0x163B, 0x1C2B, 0x133D, 0x1B2D, 0x093F, 0x1A2F, 0xFFFF }, + }; + + // Really only [254][11]. + static const uint16 g_color8_to_etc_block_config_1_to_254[254][12] = + { + { 0x021C, 0x0D0D, 0xFFFF }, { 0x0020, 0x0021, 0x0A0B, 0x061F, 0xFFFF }, { 0x0113, 0x0217, 0xFFFF }, { 0x0116, 0x031E, + 0x0B0E, 0x0405, 0xFFFF }, { 0x0022, 0x0204, 0x050A, 0x0023, 0xFFFF }, { 0x0111, 0x0319, 0x0809, 0x170F, 0xFFFF }, { + 0x0303, 0x0215, 0x0607, 0xFFFF }, { 0x0030, 0x0114, 0x0408, 0x0031, 0x0201, 0x051D, 0xFFFF }, { 0x0100, 0x0024, 0x0306, + 0x0025, 0x041B, 0x0E0D, 0xFFFF }, { 0x021A, 0x0121, 0x0B0B, 0x071F, 0xFFFF }, { 0x0213, 0x0317, 0xFFFF }, { 0x0112, + 0x0505, 0xFFFF }, { 0x0026, 0x070C, 0x0123, 0x0027, 0xFFFF }, { 0x0211, 0x0909, 0xFFFF }, { 0x0110, 0x0315, 0x0707, + 0x0419, 0x180F, 0xFFFF }, { 0x0218, 0x0131, 0x0301, 0x0403, 0x061D, 0xFFFF }, { 0x0032, 0x0202, 0x0033, 0x0125, 0x051B, + 0x0F0D, 0xFFFF }, { 0x0028, 0x031C, 0x0221, 0x0029, 0xFFFF }, { 0x0120, 0x0313, 0x0C0B, 0x081F, 0xFFFF }, { 0x0605, + 0x0417, 0xFFFF }, { 0x0216, 0x041E, 0x0C0E, 0x0223, 0x0127, 0xFFFF }, { 0x0122, 0x0304, 0x060A, 0x0311, 0x0A09, 0xFFFF + }, { 0x0519, 0x190F, 0xFFFF }, { 0x002A, 0x0231, 0x0503, 0x0415, 0x0807, 0x002B, 0x071D, 0xFFFF }, { 0x0130, 0x0214, + 0x0508, 0x0401, 0x0133, 0x0225, 0x061B, 0xFFFF }, { 0x0200, 0x0124, 0x0406, 0x0321, 0x0129, 0x100D, 0xFFFF }, { 0x031A, + 0x0D0B, 0x091F, 0xFFFF }, { 0x0413, 0x0705, 0x0517, 0xFFFF }, { 0x0212, 0x0034, 0x0323, 0x0035, 0x0227, 0xFFFF }, { + 0x0126, 0x080C, 0x0B09, 0xFFFF }, { 0x0411, 0x0619, 0x1A0F, 0xFFFF }, { 0x0210, 0x0331, 0x0603, 0x0515, 0x0907, 0x012B, + 0xFFFF }, { 0x0318, 0x002C, 0x0501, 0x0233, 0x0325, 0x071B, 0x002D, 0x081D, 0xFFFF }, { 0x0132, 0x0302, 0x0229, 0x110D, + 0xFFFF }, { 0x0128, 0x041C, 0x0421, 0x0E0B, 0x0A1F, 0xFFFF }, { 0x0220, 0x0513, 0x0617, 0xFFFF }, { 0x0135, 0x0805, + 0x0327, 0xFFFF }, { 0x0316, 0x051E, 0x0D0E, 0x0423, 0xFFFF }, { 0x0222, 0x0404, 0x070A, 0x0511, 0x0719, 0x0C09, 0x1B0F, + 0xFFFF }, { 0x0703, 0x0615, 0x0A07, 0x022B, 0xFFFF }, { 0x012A, 0x0431, 0x0601, 0x0333, 0x012D, 0x091D, 0xFFFF }, { + 0x0230, 0x0314, 0x0036, 0x0608, 0x0425, 0x0037, 0x0329, 0x081B, 0x120D, 0xFFFF }, { 0x0300, 0x0224, 0x0506, 0x0521, + 0x0F0B, 0x0B1F, 0xFFFF }, { 0x041A, 0x0613, 0x0717, 0xFFFF }, { 0x0235, 0x0905, 0xFFFF }, { 0x0312, 0x0134, 0x0523, + 0x0427, 0xFFFF }, { 0x0226, 0x090C, 0x002E, 0x0611, 0x0D09, 0x002F, 0xFFFF }, { 0x0715, 0x0B07, 0x0819, 0x032B, 0x1C0F, + 0xFFFF }, { 0x0310, 0x0531, 0x0701, 0x0803, 0x022D, 0x0A1D, 0xFFFF }, { 0x0418, 0x012C, 0x0433, 0x0525, 0x0137, 0x091B, + 0x130D, 0xFFFF }, { 0x0232, 0x0402, 0x0621, 0x0429, 0xFFFF }, { 0x0228, 0x051C, 0x0713, 0x100B, 0x0C1F, 0xFFFF }, { + 0x0320, 0x0335, 0x0A05, 0x0817, 0xFFFF }, { 0x0623, 0x0527, 0xFFFF }, { 0x0416, 0x061E, 0x0E0E, 0x0711, 0x0E09, 0x012F, + 0xFFFF }, { 0x0322, 0x0504, 0x080A, 0x0919, 0x1D0F, 0xFFFF }, { 0x0631, 0x0903, 0x0815, 0x0C07, 0x042B, 0x032D, 0x0B1D, + 0xFFFF }, { 0x022A, 0x0801, 0x0533, 0x0625, 0x0237, 0x0A1B, 0xFFFF }, { 0x0330, 0x0414, 0x0136, 0x0708, 0x0721, 0x0529, + 0x140D, 0xFFFF }, { 0x0400, 0x0324, 0x0606, 0x0038, 0x0039, 0x110B, 0x0D1F, 0xFFFF }, { 0x051A, 0x0813, 0x0B05, 0x0917, + 0xFFFF }, { 0x0723, 0x0435, 0x0627, 0xFFFF }, { 0x0412, 0x0234, 0x0F09, 0x022F, 0xFFFF }, { 0x0326, 0x0A0C, 0x012E, + 0x0811, 0x0A19, 0x1E0F, 0xFFFF }, { 0x0731, 0x0A03, 0x0915, 0x0D07, 0x052B, 0xFFFF }, { 0x0410, 0x0901, 0x0633, 0x0725, + 0x0337, 0x0B1B, 0x042D, 0x0C1D, 0xFFFF }, { 0x0518, 0x022C, 0x0629, 0x150D, 0xFFFF }, { 0x0332, 0x0502, 0x0821, 0x0139, + 0x120B, 0x0E1F, 0xFFFF }, { 0x0328, 0x061C, 0x0913, 0x0A17, 0xFFFF }, { 0x0420, 0x0535, 0x0C05, 0x0727, 0xFFFF }, { + 0x0823, 0x032F, 0xFFFF }, { 0x0516, 0x071E, 0x0F0E, 0x0911, 0x0B19, 0x1009, 0x1F0F, 0xFFFF }, { 0x0422, 0x0604, 0x090A, + 0x0B03, 0x0A15, 0x0E07, 0x062B, 0xFFFF }, { 0x0831, 0x0A01, 0x0733, 0x052D, 0x0D1D, 0xFFFF }, { 0x032A, 0x0825, 0x0437, + 0x0729, 0x0C1B, 0x160D, 0xFFFF }, { 0x0430, 0x0514, 0x0236, 0x0808, 0x0921, 0x0239, 0x130B, 0x0F1F, 0xFFFF }, { 0x0500, + 0x0424, 0x0706, 0x0138, 0x0A13, 0x0B17, 0xFFFF }, { 0x061A, 0x0635, 0x0D05, 0xFFFF }, { 0x0923, 0x0827, 0xFFFF }, { + 0x0512, 0x0334, 0x003A, 0x0A11, 0x1109, 0x003B, 0x042F, 0xFFFF }, { 0x0426, 0x0B0C, 0x022E, 0x0B15, 0x0F07, 0x0C19, + 0x072B, 0xFFFF }, { 0x0931, 0x0B01, 0x0C03, 0x062D, 0x0E1D, 0xFFFF }, { 0x0510, 0x0833, 0x0925, 0x0537, 0x0D1B, 0x170D, + 0xFFFF }, { 0x0618, 0x032C, 0x0A21, 0x0339, 0x0829, 0xFFFF }, { 0x0432, 0x0602, 0x0B13, 0x140B, 0x101F, 0xFFFF }, { + 0x0428, 0x071C, 0x0735, 0x0E05, 0x0C17, 0xFFFF }, { 0x0520, 0x0A23, 0x0927, 0xFFFF }, { 0x0B11, 0x1209, 0x013B, 0x052F, + 0xFFFF }, { 0x0616, 0x081E, 0x0D19, 0xFFFF }, { 0x0522, 0x0704, 0x0A0A, 0x0A31, 0x0D03, 0x0C15, 0x1007, 0x082B, 0x072D, + 0x0F1D, 0xFFFF }, { 0x0C01, 0x0933, 0x0A25, 0x0637, 0x0E1B, 0xFFFF }, { 0x042A, 0x0B21, 0x0929, 0x180D, 0xFFFF }, { + 0x0530, 0x0614, 0x0336, 0x0908, 0x0439, 0x150B, 0x111F, 0xFFFF }, { 0x0600, 0x0524, 0x0806, 0x0238, 0x0C13, 0x0F05, + 0x0D17, 0xFFFF }, { 0x071A, 0x0B23, 0x0835, 0x0A27, 0xFFFF }, { 0x1309, 0x023B, 0x062F, 0xFFFF }, { 0x0612, 0x0434, + 0x013A, 0x0C11, 0x0E19, 0xFFFF }, { 0x0526, 0x0C0C, 0x032E, 0x0B31, 0x0E03, 0x0D15, 0x1107, 0x092B, 0xFFFF }, { 0x0D01, + 0x0A33, 0x0B25, 0x0737, 0x0F1B, 0x082D, 0x101D, 0xFFFF }, { 0x0610, 0x0A29, 0x190D, 0xFFFF }, { 0x0718, 0x042C, 0x0C21, + 0x0539, 0x160B, 0x121F, 0xFFFF }, { 0x0532, 0x0702, 0x0D13, 0x0E17, 0xFFFF }, { 0x0528, 0x081C, 0x0935, 0x1005, 0x0B27, + 0xFFFF }, { 0x0620, 0x0C23, 0x033B, 0x072F, 0xFFFF }, { 0x0D11, 0x0F19, 0x1409, 0xFFFF }, { 0x0716, 0x003C, 0x091E, + 0x0F03, 0x0E15, 0x1207, 0x0A2B, 0x003D, 0xFFFF }, { 0x0622, 0x0804, 0x0B0A, 0x0C31, 0x0E01, 0x0B33, 0x092D, 0x111D, + 0xFFFF }, { 0x0C25, 0x0837, 0x0B29, 0x101B, 0x1A0D, 0xFFFF }, { 0x052A, 0x0D21, 0x0639, 0x170B, 0x131F, 0xFFFF }, { + 0x0630, 0x0714, 0x0436, 0x0A08, 0x0E13, 0x0F17, 0xFFFF }, { 0x0700, 0x0624, 0x0906, 0x0338, 0x0A35, 0x1105, 0xFFFF }, { + 0x081A, 0x0D23, 0x0C27, 0xFFFF }, { 0x0E11, 0x1509, 0x043B, 0x082F, 0xFFFF }, { 0x0712, 0x0534, 0x023A, 0x0F15, 0x1307, + 0x1019, 0x0B2B, 0x013D, 0xFFFF }, { 0x0626, 0x0D0C, 0x042E, 0x0D31, 0x0F01, 0x1003, 0x0A2D, 0x121D, 0xFFFF }, { 0x0C33, + 0x0D25, 0x0937, 0x111B, 0x1B0D, 0xFFFF }, { 0x0710, 0x0E21, 0x0739, 0x0C29, 0xFFFF }, { 0x0818, 0x052C, 0x0F13, 0x180B, + 0x141F, 0xFFFF }, { 0x0632, 0x0802, 0x0B35, 0x1205, 0x1017, 0xFFFF }, { 0x0628, 0x091C, 0x0E23, 0x0D27, 0xFFFF }, { + 0x0720, 0x0F11, 0x1609, 0x053B, 0x092F, 0xFFFF }, { 0x1119, 0x023D, 0xFFFF }, { 0x0816, 0x013C, 0x0A1E, 0x0E31, 0x1103, + 0x1015, 0x1407, 0x0C2B, 0x0B2D, 0x131D, 0xFFFF }, { 0x0722, 0x0904, 0x0C0A, 0x1001, 0x0D33, 0x0E25, 0x0A37, 0x121B, + 0xFFFF }, { 0x0F21, 0x0D29, 0x1C0D, 0xFFFF }, { 0x062A, 0x0839, 0x190B, 0x151F, 0xFFFF }, { 0x0730, 0x0814, 0x0536, + 0x0B08, 0x1013, 0x1305, 0x1117, 0xFFFF }, { 0x0800, 0x0724, 0x0A06, 0x0438, 0x0F23, 0x0C35, 0x0E27, 0xFFFF }, { 0x091A, + 0x1709, 0x063B, 0x0A2F, 0xFFFF }, { 0x1011, 0x1219, 0x033D, 0xFFFF }, { 0x0812, 0x0634, 0x033A, 0x0F31, 0x1203, 0x1115, + 0x1507, 0x0D2B, 0xFFFF }, { 0x0726, 0x0E0C, 0x052E, 0x1101, 0x0E33, 0x0F25, 0x0B37, 0x131B, 0x0C2D, 0x141D, 0xFFFF }, { + 0x0E29, 0x1D0D, 0xFFFF }, { 0x0810, 0x1021, 0x0939, 0x1A0B, 0x161F, 0xFFFF }, { 0x0918, 0x062C, 0x1113, 0x1217, 0xFFFF + }, { 0x0732, 0x0902, 0x0D35, 0x1405, 0x0F27, 0xFFFF }, { 0x0728, 0x0A1C, 0x1023, 0x073B, 0x0B2F, 0xFFFF }, { 0x0820, + 0x1111, 0x1319, 0x1809, 0xFFFF }, { 0x1303, 0x1215, 0x1607, 0x0E2B, 0x043D, 0xFFFF }, { 0x0916, 0x023C, 0x0B1E, 0x1031, + 0x1201, 0x0F33, 0x0D2D, 0x151D, 0xFFFF }, { 0x0822, 0x0A04, 0x0D0A, 0x1025, 0x0C37, 0x0F29, 0x141B, 0x1E0D, 0xFFFF }, { + 0x1121, 0x0A39, 0x1B0B, 0x171F, 0xFFFF }, { 0x072A, 0x1213, 0x1317, 0xFFFF }, { 0x0830, 0x0914, 0x0636, 0x0C08, 0x0E35, + 0x1505, 0xFFFF }, { 0x0900, 0x0824, 0x0B06, 0x0538, 0x1123, 0x1027, 0xFFFF }, { 0x0A1A, 0x1211, 0x1909, 0x083B, 0x0C2F, + 0xFFFF }, { 0x1315, 0x1707, 0x1419, 0x0F2B, 0x053D, 0xFFFF }, { 0x0912, 0x0734, 0x043A, 0x1131, 0x1301, 0x1403, 0x0E2D, + 0x161D, 0xFFFF }, { 0x0826, 0x0F0C, 0x062E, 0x1033, 0x1125, 0x0D37, 0x151B, 0x1F0D, 0xFFFF }, { 0x1221, 0x0B39, 0x1029, + 0xFFFF }, { 0x0910, 0x1313, 0x1C0B, 0x181F, 0xFFFF }, { 0x0A18, 0x072C, 0x0F35, 0x1605, 0x1417, 0xFFFF }, { 0x0832, + 0x0A02, 0x1223, 0x1127, 0xFFFF }, { 0x0828, 0x0B1C, 0x1311, 0x1A09, 0x093B, 0x0D2F, 0xFFFF }, { 0x0920, 0x1519, 0x063D, + 0xFFFF }, { 0x1231, 0x1503, 0x1415, 0x1807, 0x102B, 0x0F2D, 0x171D, 0xFFFF }, { 0x0A16, 0x033C, 0x0C1E, 0x1401, 0x1133, + 0x1225, 0x0E37, 0x161B, 0xFFFF }, { 0x0922, 0x0B04, 0x0E0A, 0x1321, 0x1129, 0xFFFF }, { 0x0C39, 0x1D0B, 0x191F, 0xFFFF + }, { 0x082A, 0x1413, 0x1705, 0x1517, 0xFFFF }, { 0x0930, 0x0A14, 0x0736, 0x0D08, 0x1323, 0x1035, 0x1227, 0xFFFF }, { + 0x0A00, 0x0924, 0x0C06, 0x0638, 0x1B09, 0x0A3B, 0x0E2F, 0xFFFF }, { 0x0B1A, 0x1411, 0x1619, 0x073D, 0xFFFF }, { 0x1331, + 0x1603, 0x1515, 0x1907, 0x112B, 0xFFFF }, { 0x0A12, 0x0834, 0x053A, 0x1501, 0x1233, 0x1325, 0x0F37, 0x171B, 0x102D, + 0x181D, 0xFFFF }, { 0x0926, 0x072E, 0x1229, 0xFFFF }, { 0x1421, 0x0D39, 0x1E0B, 0x1A1F, 0xFFFF }, { 0x0A10, 0x1513, + 0x1617, 0xFFFF }, { 0x0B18, 0x082C, 0x1135, 0x1805, 0x1327, 0xFFFF }, { 0x0932, 0x0B02, 0x1423, 0x0B3B, 0x0F2F, 0xFFFF + }, { 0x0928, 0x0C1C, 0x1511, 0x1719, 0x1C09, 0xFFFF }, { 0x0A20, 0x1703, 0x1615, 0x1A07, 0x122B, 0x083D, 0xFFFF }, { + 0x1431, 0x1601, 0x1333, 0x112D, 0x191D, 0xFFFF }, { 0x0B16, 0x043C, 0x0D1E, 0x1425, 0x1037, 0x1329, 0x181B, 0xFFFF }, { + 0x0A22, 0x0C04, 0x0F0A, 0x1521, 0x0E39, 0x1F0B, 0x1B1F, 0xFFFF }, { 0x1613, 0x1717, 0xFFFF }, { 0x092A, 0x1235, 0x1905, + 0xFFFF }, { 0x0A30, 0x0B14, 0x0836, 0x0E08, 0x1523, 0x1427, 0xFFFF }, { 0x0B00, 0x0A24, 0x0D06, 0x0738, 0x1611, 0x1D09, + 0x0C3B, 0x102F, 0xFFFF }, { 0x0C1A, 0x1715, 0x1B07, 0x1819, 0x132B, 0x093D, 0xFFFF }, { 0x1531, 0x1701, 0x1803, 0x122D, + 0x1A1D, 0xFFFF }, { 0x0B12, 0x0934, 0x063A, 0x1433, 0x1525, 0x1137, 0x191B, 0xFFFF }, { 0x0A26, 0x003E, 0x082E, 0x1621, + 0x0F39, 0x1429, 0x003F, 0xFFFF }, { 0x1713, 0x1C1F, 0xFFFF }, { 0x0B10, 0x1335, 0x1A05, 0x1817, 0xFFFF }, { 0x0C18, + 0x092C, 0x1623, 0x1527, 0xFFFF }, { 0x0A32, 0x0C02, 0x1711, 0x1E09, 0x0D3B, 0x112F, 0xFFFF }, { 0x0A28, 0x0D1C, 0x1919, + 0x0A3D, 0xFFFF }, { 0x0B20, 0x1631, 0x1903, 0x1815, 0x1C07, 0x142B, 0x132D, 0x1B1D, 0xFFFF }, { 0x1801, 0x1533, 0x1625, + 0x1237, 0x1A1B, 0xFFFF }, { 0x0C16, 0x053C, 0x0E1E, 0x1721, 0x1529, 0x013F, 0xFFFF }, { 0x0B22, 0x0D04, 0x1039, 0x1D1F, + 0xFFFF }, { 0x1813, 0x1B05, 0x1917, 0xFFFF }, { 0x0A2A, 0x1723, 0x1435, 0x1627, 0xFFFF }, { 0x0B30, 0x0C14, 0x0936, + 0x0F08, 0x1F09, 0x0E3B, 0x122F, 0xFFFF }, { 0x0C00, 0x0B24, 0x0E06, 0x0838, 0x1811, 0x1A19, 0x0B3D, 0xFFFF }, { 0x0D1A, + 0x1731, 0x1A03, 0x1915, 0x1D07, 0x152B, 0xFFFF }, { 0x1901, 0x1633, 0x1725, 0x1337, 0x1B1B, 0x142D, 0x1C1D, 0xFFFF }, { + 0x0C12, 0x0A34, 0x073A, 0x1629, 0x023F, 0xFFFF }, { 0x0B26, 0x013E, 0x092E, 0x1821, 0x1139, 0x1E1F, 0xFFFF }, { 0x1913, + 0x1A17, 0xFFFF }, { 0x0C10, 0x1535, 0x1C05, 0x1727, 0xFFFF }, { 0x0D18, 0x0A2C, 0x1823, 0x0F3B, 0x132F, 0xFFFF }, { + 0x0B32, 0x0D02, 0x1911, 0x1B19, 0xFFFF }, { 0x0B28, 0x0E1C, 0x1B03, 0x1A15, 0x1E07, 0x162B, 0x0C3D, 0xFFFF }, { 0x0C20, + 0x1831, 0x1A01, 0x1733, 0x152D, 0x1D1D, 0xFFFF }, { 0x1825, 0x1437, 0x1729, 0x1C1B, 0x033F, 0xFFFF }, { 0x0D16, 0x063C, + 0x0F1E, 0x1921, 0x1239, 0x1F1F, 0xFFFF }, { 0x0C22, 0x0E04, 0x1A13, 0x1B17, 0xFFFF }, { 0x1635, 0x1D05, 0xFFFF }, { + 0x0B2A, 0x1923, 0x1827, 0xFFFF }, { 0x0C30, 0x0D14, 0x0A36, 0x1A11, 0x103B, 0x142F, 0xFFFF }, { 0x0D00, 0x0C24, 0x0F06, + 0x0938, 0x1B15, 0x1F07, 0x1C19, 0x172B, 0x0D3D, 0xFFFF }, { 0x0E1A, 0x1931, 0x1B01, 0x1C03, 0x162D, 0x1E1D, 0xFFFF }, { + 0x1833, 0x1925, 0x1537, 0x1D1B, 0xFFFF }, { 0x0D12, 0x0B34, 0x083A, 0x1A21, 0x1339, 0x1829, 0x043F, 0xFFFF }, { 0x0C26, + 0x023E, 0x0A2E, 0x1B13, 0xFFFF }, { 0x1735, 0x1E05, 0x1C17, 0xFFFF }, { 0x0D10, 0x1A23, 0x1927, 0xFFFF }, { 0x0E18, + 0x0B2C, 0x1B11, 0x113B, 0x152F, 0xFFFF }, { 0x0C32, 0x0E02, 0x1D19, 0x0E3D, 0xFFFF }, { 0x0C28, 0x0F1C, 0x1A31, 0x1D03, + 0x1C15, 0x182B, 0x172D, 0x1F1D, 0xFFFF }, { 0x0D20, 0x1C01, 0x1933, 0x1A25, 0x1637, 0x1E1B, 0xFFFF }, { 0x1B21, 0x1929, + 0x053F, 0xFFFF }, { 0x0E16, 0x073C, 0x1439, 0xFFFF }, { 0x0D22, 0x0F04, 0x1C13, 0x1F05, 0x1D17, 0xFFFF }, { 0x1B23, + 0x1835, 0x1A27, 0xFFFF }, { 0x0C2A, 0x123B, 0x162F, 0xFFFF }, { 0x0D30, 0x0E14, 0x0B36, 0x1C11, 0x1E19, 0x0F3D, 0xFFFF + }, { 0x0E00, 0x0D24, 0x0A38, 0x1B31, 0x1E03, 0x1D15, 0x192B, 0xFFFF }, { 0x0F1A, 0x1D01, 0x1A33, 0x1B25, 0x1737, 0x1F1B, + 0x182D, 0xFFFF }, { 0x1A29, 0x063F, 0xFFFF }, { 0x0E12, 0x0C34, 0x093A, 0x1C21, 0x1539, 0xFFFF }, { 0x0D26, 0x033E, + 0x0B2E, 0x1D13, 0x1E17, 0xFFFF }, { 0x1935, 0x1B27, 0xFFFF }, { 0x0E10, 0x1C23, 0x133B, 0x172F, 0xFFFF }, { 0x0F18, + 0x0C2C, 0x1D11, 0x1F19, 0xFFFF }, { 0x0D32, 0x0F02, 0x1F03, 0x1E15, 0x1A2B, 0x103D, 0xFFFF }, { 0x0D28, 0x1C31, 0x1E01, + 0x1B33, 0x192D, 0xFFFF }, { 0x0E20, 0x1C25, 0x1837, 0x1B29, 0x073F, 0xFFFF }, { 0x1D21, 0x1639, 0xFFFF }, { 0x0F16, + 0x083C, 0x1E13, 0x1F17, 0xFFFF }, { 0x0E22, 0x1A35, 0xFFFF }, { 0x1D23, 0x1C27, 0xFFFF }, { 0x0D2A, 0x1E11, 0x143B, + 0x182F, 0xFFFF }, { 0x0E30, 0x0F14, 0x0C36, 0x1F15, 0x1B2B, 0x113D, 0xFFFF }, { 0x0F00, 0x0E24, 0x0B38, 0x1D31, 0x1F01, + 0x1A2D, 0xFFFF }, { 0x1C33, 0x1D25, 0x1937, 0xFFFF }, { 0x1E21, 0x1739, 0x1C29, 0x083F, 0xFFFF }, { 0x0F12, 0x0D34, + 0x0A3A, 0x1F13, 0xFFFF }, { 0x0E26, 0x043E, 0x0C2E, 0x1B35, 0xFFFF }, { 0x1E23, 0x1D27, 0xFFFF }, { 0x0F10, 0x1F11, + 0x153B, 0x192F, 0xFFFF }, { 0x0D2C, 0x123D, 0xFFFF }, + }; + + struct etc1_block + { + // big endian uint64: + // bit ofs: 56 48 40 32 24 16 8 0 + // byte ofs: b0, b1, b2, b3, b4, b5, b6, b7 + union + { + uint64 m_uint64; + uint8 m_bytes[8]; + }; + + uint8 m_low_color[2]; + uint8 m_high_color[2]; + + enum { cNumSelectorBytes = 4 }; + uint8 m_selectors[cNumSelectorBytes]; + + inline void clear() + { + zero_this(this); + } + + inline uint get_byte_bits(uint ofs, uint num) const + { + RG_ETC1_ASSERT((ofs + num) <= 64U); + RG_ETC1_ASSERT(num && (num <= 8U)); + RG_ETC1_ASSERT((ofs >> 3) == ((ofs + num - 1) >> 3)); + const uint byte_ofs = 7 - (ofs >> 3); + const uint byte_bit_ofs = ofs & 7; + return (m_bytes[byte_ofs] >> byte_bit_ofs) & ((1 << num) - 1); + } + + inline void set_byte_bits(uint ofs, uint num, uint bits) + { + RG_ETC1_ASSERT((ofs + num) <= 64U); + RG_ETC1_ASSERT(num && (num < 32U)); + RG_ETC1_ASSERT((ofs >> 3) == ((ofs + num - 1) >> 3)); + RG_ETC1_ASSERT(bits < (1U << num)); + const uint byte_ofs = 7 - (ofs >> 3); + const uint byte_bit_ofs = ofs & 7; + const uint mask = (1 << num) - 1; + m_bytes[byte_ofs] &= ~(mask << byte_bit_ofs); + m_bytes[byte_ofs] |= (bits << byte_bit_ofs); + } + + // false = left/right subblocks + // true = upper/lower subblocks + inline bool get_flip_bit() const + { + return (m_bytes[3] & 1) != 0; + } + + inline void set_flip_bit(bool flip) + { + m_bytes[3] &= ~1; + m_bytes[3] |= static_cast<uint8>(flip); + } + + inline bool get_diff_bit() const + { + return (m_bytes[3] & 2) != 0; + } + + inline void set_diff_bit(bool diff) + { + m_bytes[3] &= ~2; + m_bytes[3] |= (static_cast<uint>(diff) << 1); + } + + // Returns intensity modifier table (0-7) used by subblock subblock_id. + // subblock_id=0 left/top (CW 1), 1=right/bottom (CW 2) + inline uint get_inten_table(uint subblock_id) const + { + RG_ETC1_ASSERT(subblock_id < 2); + const uint ofs = subblock_id ? 2 : 5; + return (m_bytes[3] >> ofs) & 7; + } + + // Sets intensity modifier table (0-7) used by subblock subblock_id (0 or 1) + inline void set_inten_table(uint subblock_id, uint t) + { + RG_ETC1_ASSERT(subblock_id < 2); + RG_ETC1_ASSERT(t < 8); + const uint ofs = subblock_id ? 2 : 5; + m_bytes[3] &= ~(7 << ofs); + m_bytes[3] |= (t << ofs); + } + + // Returned selector value ranges from 0-3 and is a direct index into g_etc1_inten_tables. + inline uint get_selector(uint x, uint y) const + { + RG_ETC1_ASSERT((x | y) < 4); + + const uint bit_index = x * 4 + y; + const uint byte_bit_ofs = bit_index & 7; + const uint8 *p = &m_bytes[7 - (bit_index >> 3)]; + const uint lsb = (p[0] >> byte_bit_ofs) & 1; + const uint msb = (p[-2] >> byte_bit_ofs) & 1; + const uint val = lsb | (msb << 1); + + return g_etc1_to_selector_index[val]; + } + + // Selector "val" ranges from 0-3 and is a direct index into g_etc1_inten_tables. + inline void set_selector(uint x, uint y, uint val) + { + RG_ETC1_ASSERT((x | y | val) < 4); + const uint bit_index = x * 4 + y; + + uint8 *p = &m_bytes[7 - (bit_index >> 3)]; + + const uint byte_bit_ofs = bit_index & 7; + const uint mask = 1 << byte_bit_ofs; + + const uint etc1_val = g_selector_index_to_etc1[val]; + + const uint lsb = etc1_val & 1; + const uint msb = etc1_val >> 1; + + p[0] &= ~mask; + p[0] |= (lsb << byte_bit_ofs); + + p[-2] &= ~mask; + p[-2] |= (msb << byte_bit_ofs); + } + + inline void set_base4_color(uint idx, uint16 c) + { + if (idx) + { + set_byte_bits(cETC1AbsColor4R2BitOffset, 4, (c >> 8) & 15); + set_byte_bits(cETC1AbsColor4G2BitOffset, 4, (c >> 4) & 15); + set_byte_bits(cETC1AbsColor4B2BitOffset, 4, c & 15); + } + else + { + set_byte_bits(cETC1AbsColor4R1BitOffset, 4, (c >> 8) & 15); + set_byte_bits(cETC1AbsColor4G1BitOffset, 4, (c >> 4) & 15); + set_byte_bits(cETC1AbsColor4B1BitOffset, 4, c & 15); + } + } + + inline uint16 get_base4_color(uint idx) const + { + uint r, g, b; + if (idx) + { + r = get_byte_bits(cETC1AbsColor4R2BitOffset, 4); + g = get_byte_bits(cETC1AbsColor4G2BitOffset, 4); + b = get_byte_bits(cETC1AbsColor4B2BitOffset, 4); + } + else + { + r = get_byte_bits(cETC1AbsColor4R1BitOffset, 4); + g = get_byte_bits(cETC1AbsColor4G1BitOffset, 4); + b = get_byte_bits(cETC1AbsColor4B1BitOffset, 4); + } + return static_cast<uint16>(b | (g << 4U) | (r << 8U)); + } + + inline void set_base5_color(uint16 c) + { + set_byte_bits(cETC1BaseColor5RBitOffset, 5, (c >> 10) & 31); + set_byte_bits(cETC1BaseColor5GBitOffset, 5, (c >> 5) & 31); + set_byte_bits(cETC1BaseColor5BBitOffset, 5, c & 31); + } + + inline uint16 get_base5_color() const + { + const uint r = get_byte_bits(cETC1BaseColor5RBitOffset, 5); + const uint g = get_byte_bits(cETC1BaseColor5GBitOffset, 5); + const uint b = get_byte_bits(cETC1BaseColor5BBitOffset, 5); + return static_cast<uint16>(b | (g << 5U) | (r << 10U)); + } + + void set_delta3_color(uint16 c) + { + set_byte_bits(cETC1DeltaColor3RBitOffset, 3, (c >> 6) & 7); + set_byte_bits(cETC1DeltaColor3GBitOffset, 3, (c >> 3) & 7); + set_byte_bits(cETC1DeltaColor3BBitOffset, 3, c & 7); + } + + inline uint16 get_delta3_color() const + { + const uint r = get_byte_bits(cETC1DeltaColor3RBitOffset, 3); + const uint g = get_byte_bits(cETC1DeltaColor3GBitOffset, 3); + const uint b = get_byte_bits(cETC1DeltaColor3BBitOffset, 3); + return static_cast<uint16>(b | (g << 3U) | (r << 6U)); + } + + // Base color 5 + static uint16 pack_color5(const color_quad_u8& color, bool scaled, uint bias = 127U); + static uint16 pack_color5(uint r, uint g, uint b, bool scaled, uint bias = 127U); + + static color_quad_u8 unpack_color5(uint16 packed_color5, bool scaled, uint alpha = 255U); + static void unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color, bool scaled); + + static bool unpack_color5(color_quad_u8& result, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha = 255U); + static bool unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha = 255U); + + // Delta color 3 + // Inputs range from -4 to 3 (cETC1ColorDeltaMin to cETC1ColorDeltaMax) + static uint16 pack_delta3(int r, int g, int b); + + // Results range from -4 to 3 (cETC1ColorDeltaMin to cETC1ColorDeltaMax) + static void unpack_delta3(int& r, int& g, int& b, uint16 packed_delta3); + + // Abs color 4 + static uint16 pack_color4(const color_quad_u8& color, bool scaled, uint bias = 127U); + static uint16 pack_color4(uint r, uint g, uint b, bool scaled, uint bias = 127U); + + static color_quad_u8 unpack_color4(uint16 packed_color4, bool scaled, uint alpha = 255U); + static void unpack_color4(uint& r, uint& g, uint& b, uint16 packed_color4, bool scaled); + + // subblock colors + static void get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint table_idx); + static bool get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint16 packed_delta3, uint table_idx); + static void get_abs_subblock_colors(color_quad_u8* pDst, uint16 packed_color4, uint table_idx); + + static inline void unscaled_to_scaled_color(color_quad_u8& dst, const color_quad_u8& src, bool color4) + { + if (color4) + { + dst.r = src.r | (src.r << 4); + dst.g = src.g | (src.g << 4); + dst.b = src.b | (src.b << 4); + } + else + { + dst.r = (src.r >> 2) | (src.r << 3); + dst.g = (src.g >> 2) | (src.g << 3); + dst.b = (src.b >> 2) | (src.b << 3); + } + dst.a = src.a; + } + }; + + // Returns pointer to sorted array. + template<typename T, typename Q> + T* indirect_radix_sort(uint num_indices, T* pIndices0, T* pIndices1, const Q* pKeys, uint key_ofs, uint key_size, bool init_indices) + { + RG_ETC1_ASSERT((key_ofs >= 0) && (key_ofs < sizeof(T))); + RG_ETC1_ASSERT((key_size >= 1) && (key_size <= 4)); + + if (init_indices) + { + T* p = pIndices0; + T* q = pIndices0 + (num_indices >> 1) * 2; + uint i; + for (i = 0; p != q; p += 2, i += 2) + { + p[0] = static_cast<T>(i); + p[1] = static_cast<T>(i + 1); + } + + if (num_indices & 1) + *p = static_cast<T>(i); + } + + uint hist[256 * 4]; + + memset(hist, 0, sizeof(hist[0]) * 256 * key_size); + +#define RG_ETC1_GET_KEY(p) (*(const uint*)((const uint8*)(pKeys + *(p)) + key_ofs)) +#define RG_ETC1_GET_KEY_FROM_INDEX(i) (*(const uint*)((const uint8*)(pKeys + (i)) + key_ofs)) + + if (key_size == 4) + { + T* p = pIndices0; + T* q = pIndices0 + num_indices; + for ( ; p != q; p++) + { + const uint key = RG_ETC1_GET_KEY(p); + + hist[ key & 0xFF]++; + hist[256 + ((key >> 8) & 0xFF)]++; + hist[512 + ((key >> 16) & 0xFF)]++; + hist[768 + ((key >> 24) & 0xFF)]++; + } + } + else if (key_size == 3) + { + T* p = pIndices0; + T* q = pIndices0 + num_indices; + for ( ; p != q; p++) + { + const uint key = RG_ETC1_GET_KEY(p); + + hist[ key & 0xFF]++; + hist[256 + ((key >> 8) & 0xFF)]++; + hist[512 + ((key >> 16) & 0xFF)]++; + } + } + else if (key_size == 2) + { + T* p = pIndices0; + T* q = pIndices0 + (num_indices >> 1) * 2; + + for ( ; p != q; p += 2) + { + const uint key0 = RG_ETC1_GET_KEY(p); + const uint key1 = RG_ETC1_GET_KEY(p+1); + + hist[ key0 & 0xFF]++; + hist[256 + ((key0 >> 8) & 0xFF)]++; + + hist[ key1 & 0xFF]++; + hist[256 + ((key1 >> 8) & 0xFF)]++; + } + + if (num_indices & 1) + { + const uint key = RG_ETC1_GET_KEY(p); + + hist[ key & 0xFF]++; + hist[256 + ((key >> 8) & 0xFF)]++; + } + } + else + { + RG_ETC1_ASSERT(key_size == 1); + if (key_size != 1) + return NULL; + + T* p = pIndices0; + T* q = pIndices0 + (num_indices >> 1) * 2; + + for ( ; p != q; p += 2) + { + const uint key0 = RG_ETC1_GET_KEY(p); + const uint key1 = RG_ETC1_GET_KEY(p+1); + + hist[key0 & 0xFF]++; + hist[key1 & 0xFF]++; + } + + if (num_indices & 1) + { + const uint key = RG_ETC1_GET_KEY(p); + + hist[key & 0xFF]++; + } + } + + T* pCur = pIndices0; + T* pNew = pIndices1; + + for (uint pass = 0; pass < key_size; pass++) + { + const uint* pHist = &hist[pass << 8]; + + uint offsets[256]; + + uint cur_ofs = 0; + for (uint i = 0; i < 256; i += 2) + { + offsets[i] = cur_ofs; + cur_ofs += pHist[i]; + + offsets[i+1] = cur_ofs; + cur_ofs += pHist[i+1]; + } + + const uint pass_shift = pass << 3; + + T* p = pCur; + T* q = pCur + (num_indices >> 1) * 2; + + for ( ; p != q; p += 2) + { + uint index0 = p[0]; + uint index1 = p[1]; + + uint c0 = (RG_ETC1_GET_KEY_FROM_INDEX(index0) >> pass_shift) & 0xFF; + uint c1 = (RG_ETC1_GET_KEY_FROM_INDEX(index1) >> pass_shift) & 0xFF; + + if (c0 == c1) + { + uint dst_offset0 = offsets[c0]; + + offsets[c0] = dst_offset0 + 2; + + pNew[dst_offset0] = static_cast<T>(index0); + pNew[dst_offset0 + 1] = static_cast<T>(index1); + } + else + { + uint dst_offset0 = offsets[c0]++; + uint dst_offset1 = offsets[c1]++; + + pNew[dst_offset0] = static_cast<T>(index0); + pNew[dst_offset1] = static_cast<T>(index1); + } + } + + if (num_indices & 1) + { + uint index = *p; + uint c = (RG_ETC1_GET_KEY_FROM_INDEX(index) >> pass_shift) & 0xFF; + + uint dst_offset = offsets[c]; + offsets[c] = dst_offset + 1; + + pNew[dst_offset] = static_cast<T>(index); + } + + T* t = pCur; + pCur = pNew; + pNew = t; + } + + return pCur; + } + +#undef RG_ETC1_GET_KEY +#undef RG_ETC1_GET_KEY_FROM_INDEX + + uint16 etc1_block::pack_color5(const color_quad_u8& color, bool scaled, uint bias) + { + return pack_color5(color.r, color.g, color.b, scaled, bias); + } + + uint16 etc1_block::pack_color5(uint r, uint g, uint b, bool scaled, uint bias) + { + if (scaled) + { + r = (r * 31U + bias) / 255U; + g = (g * 31U + bias) / 255U; + b = (b * 31U + bias) / 255U; + } + + r = rg_etc1::minimum(r, 31U); + g = rg_etc1::minimum(g, 31U); + b = rg_etc1::minimum(b, 31U); + + return static_cast<uint16>(b | (g << 5U) | (r << 10U)); + } + + color_quad_u8 etc1_block::unpack_color5(uint16 packed_color5, bool scaled, uint alpha) + { + uint b = packed_color5 & 31U; + uint g = (packed_color5 >> 5U) & 31U; + uint r = (packed_color5 >> 10U) & 31U; + + if (scaled) + { + b = (b << 3U) | (b >> 2U); + g = (g << 3U) | (g >> 2U); + r = (r << 3U) | (r >> 2U); + } + + return color_quad_u8(cNoClamp, r, g, b, rg_etc1::minimum(alpha, 255U)); + } + + void etc1_block::unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color5, bool scaled) + { + color_quad_u8 c(unpack_color5(packed_color5, scaled, 0)); + r = c.r; + g = c.g; + b = c.b; + } + + bool etc1_block::unpack_color5(color_quad_u8& result, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha) + { + int dc_r, dc_g, dc_b; + unpack_delta3(dc_r, dc_g, dc_b, packed_delta3); + + int b = (packed_color5 & 31U) + dc_b; + int g = ((packed_color5 >> 5U) & 31U) + dc_g; + int r = ((packed_color5 >> 10U) & 31U) + dc_r; + + bool success = true; + if (static_cast<uint>(r | g | b) > 31U) + { + success = false; + r = rg_etc1::clamp<int>(r, 0, 31); + g = rg_etc1::clamp<int>(g, 0, 31); + b = rg_etc1::clamp<int>(b, 0, 31); + } + + if (scaled) + { + b = (b << 3U) | (b >> 2U); + g = (g << 3U) | (g >> 2U); + r = (r << 3U) | (r >> 2U); + } + + result.set_noclamp_rgba(r, g, b, rg_etc1::minimum(alpha, 255U)); + return success; + } + + bool etc1_block::unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha) + { + color_quad_u8 result; + const bool success = unpack_color5(result, packed_color5, packed_delta3, scaled, alpha); + r = result.r; + g = result.g; + b = result.b; + return success; + } + + uint16 etc1_block::pack_delta3(int r, int g, int b) + { + RG_ETC1_ASSERT((r >= cETC1ColorDeltaMin) && (r <= cETC1ColorDeltaMax)); + RG_ETC1_ASSERT((g >= cETC1ColorDeltaMin) && (g <= cETC1ColorDeltaMax)); + RG_ETC1_ASSERT((b >= cETC1ColorDeltaMin) && (b <= cETC1ColorDeltaMax)); + if (r < 0) r += 8; + if (g < 0) g += 8; + if (b < 0) b += 8; + return static_cast<uint16>(b | (g << 3) | (r << 6)); + } + + void etc1_block::unpack_delta3(int& r, int& g, int& b, uint16 packed_delta3) + { + r = (packed_delta3 >> 6) & 7; + g = (packed_delta3 >> 3) & 7; + b = packed_delta3 & 7; + if (r >= 4) r -= 8; + if (g >= 4) g -= 8; + if (b >= 4) b -= 8; + } + + uint16 etc1_block::pack_color4(const color_quad_u8& color, bool scaled, uint bias) + { + return pack_color4(color.r, color.g, color.b, scaled, bias); + } + + uint16 etc1_block::pack_color4(uint r, uint g, uint b, bool scaled, uint bias) + { + if (scaled) + { + r = (r * 15U + bias) / 255U; + g = (g * 15U + bias) / 255U; + b = (b * 15U + bias) / 255U; + } + + r = rg_etc1::minimum(r, 15U); + g = rg_etc1::minimum(g, 15U); + b = rg_etc1::minimum(b, 15U); + + return static_cast<uint16>(b | (g << 4U) | (r << 8U)); + } + + color_quad_u8 etc1_block::unpack_color4(uint16 packed_color4, bool scaled, uint alpha) + { + uint b = packed_color4 & 15U; + uint g = (packed_color4 >> 4U) & 15U; + uint r = (packed_color4 >> 8U) & 15U; + + if (scaled) + { + b = (b << 4U) | b; + g = (g << 4U) | g; + r = (r << 4U) | r; + } + + return color_quad_u8(cNoClamp, r, g, b, rg_etc1::minimum(alpha, 255U)); + } + + void etc1_block::unpack_color4(uint& r, uint& g, uint& b, uint16 packed_color4, bool scaled) + { + color_quad_u8 c(unpack_color4(packed_color4, scaled, 0)); + r = c.r; + g = c.g; + b = c.b; + } + + void etc1_block::get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint table_idx) + { + RG_ETC1_ASSERT(table_idx < cETC1IntenModifierValues); + const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0]; + + uint r, g, b; + unpack_color5(r, g, b, packed_color5, true); + + const int ir = static_cast<int>(r), ig = static_cast<int>(g), ib = static_cast<int>(b); + + const int y0 = pInten_modifer_table[0]; + pDst[0].set(ir + y0, ig + y0, ib + y0); + + const int y1 = pInten_modifer_table[1]; + pDst[1].set(ir + y1, ig + y1, ib + y1); + + const int y2 = pInten_modifer_table[2]; + pDst[2].set(ir + y2, ig + y2, ib + y2); + + const int y3 = pInten_modifer_table[3]; + pDst[3].set(ir + y3, ig + y3, ib + y3); + } + + bool etc1_block::get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint16 packed_delta3, uint table_idx) + { + RG_ETC1_ASSERT(table_idx < cETC1IntenModifierValues); + const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0]; + + uint r, g, b; + bool success = unpack_color5(r, g, b, packed_color5, packed_delta3, true); + + const int ir = static_cast<int>(r), ig = static_cast<int>(g), ib = static_cast<int>(b); + + const int y0 = pInten_modifer_table[0]; + pDst[0].set(ir + y0, ig + y0, ib + y0); + + const int y1 = pInten_modifer_table[1]; + pDst[1].set(ir + y1, ig + y1, ib + y1); + + const int y2 = pInten_modifer_table[2]; + pDst[2].set(ir + y2, ig + y2, ib + y2); + + const int y3 = pInten_modifer_table[3]; + pDst[3].set(ir + y3, ig + y3, ib + y3); + + return success; + } + + void etc1_block::get_abs_subblock_colors(color_quad_u8* pDst, uint16 packed_color4, uint table_idx) + { + RG_ETC1_ASSERT(table_idx < cETC1IntenModifierValues); + const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0]; + + uint r, g, b; + unpack_color4(r, g, b, packed_color4, true); + + const int ir = static_cast<int>(r), ig = static_cast<int>(g), ib = static_cast<int>(b); + + const int y0 = pInten_modifer_table[0]; + pDst[0].set(ir + y0, ig + y0, ib + y0); + + const int y1 = pInten_modifer_table[1]; + pDst[1].set(ir + y1, ig + y1, ib + y1); + + const int y2 = pInten_modifer_table[2]; + pDst[2].set(ir + y2, ig + y2, ib + y2); + + const int y3 = pInten_modifer_table[3]; + pDst[3].set(ir + y3, ig + y3, ib + y3); + } + + bool unpack_etc1_block(const void* pETC1_block, unsigned int* pDst_pixels_rgba, bool preserve_alpha) + { + color_quad_u8* pDst = reinterpret_cast<color_quad_u8*>(pDst_pixels_rgba); + const etc1_block& block = *static_cast<const etc1_block*>(pETC1_block); + + const bool diff_flag = block.get_diff_bit(); + const bool flip_flag = block.get_flip_bit(); + const uint table_index0 = block.get_inten_table(0); + const uint table_index1 = block.get_inten_table(1); + + color_quad_u8 subblock_colors0[4]; + color_quad_u8 subblock_colors1[4]; + bool success = true; + + if (diff_flag) + { + const uint16 base_color5 = block.get_base5_color(); + const uint16 delta_color3 = block.get_delta3_color(); + etc1_block::get_diff_subblock_colors(subblock_colors0, base_color5, table_index0); + + if (!etc1_block::get_diff_subblock_colors(subblock_colors1, base_color5, delta_color3, table_index1)) + success = false; + } + else + { + const uint16 base_color4_0 = block.get_base4_color(0); + etc1_block::get_abs_subblock_colors(subblock_colors0, base_color4_0, table_index0); + + const uint16 base_color4_1 = block.get_base4_color(1); + etc1_block::get_abs_subblock_colors(subblock_colors1, base_color4_1, table_index1); + } + + if (preserve_alpha) + { + if (flip_flag) + { + for (uint y = 0; y < 2; y++) + { + pDst[0].set_rgb(subblock_colors0[block.get_selector(0, y)]); + pDst[1].set_rgb(subblock_colors0[block.get_selector(1, y)]); + pDst[2].set_rgb(subblock_colors0[block.get_selector(2, y)]); + pDst[3].set_rgb(subblock_colors0[block.get_selector(3, y)]); + pDst += 4; + } + + for (uint y = 2; y < 4; y++) + { + pDst[0].set_rgb(subblock_colors1[block.get_selector(0, y)]); + pDst[1].set_rgb(subblock_colors1[block.get_selector(1, y)]); + pDst[2].set_rgb(subblock_colors1[block.get_selector(2, y)]); + pDst[3].set_rgb(subblock_colors1[block.get_selector(3, y)]); + pDst += 4; + } + } + else + { + for (uint y = 0; y < 4; y++) + { + pDst[0].set_rgb(subblock_colors0[block.get_selector(0, y)]); + pDst[1].set_rgb(subblock_colors0[block.get_selector(1, y)]); + pDst[2].set_rgb(subblock_colors1[block.get_selector(2, y)]); + pDst[3].set_rgb(subblock_colors1[block.get_selector(3, y)]); + pDst += 4; + } + } + } + else + { + if (flip_flag) + { + // 0000 + // 0000 + // 1111 + // 1111 + for (uint y = 0; y < 2; y++) + { + pDst[0] = subblock_colors0[block.get_selector(0, y)]; + pDst[1] = subblock_colors0[block.get_selector(1, y)]; + pDst[2] = subblock_colors0[block.get_selector(2, y)]; + pDst[3] = subblock_colors0[block.get_selector(3, y)]; + pDst += 4; + } + + for (uint y = 2; y < 4; y++) + { + pDst[0] = subblock_colors1[block.get_selector(0, y)]; + pDst[1] = subblock_colors1[block.get_selector(1, y)]; + pDst[2] = subblock_colors1[block.get_selector(2, y)]; + pDst[3] = subblock_colors1[block.get_selector(3, y)]; + pDst += 4; + } + } + else + { + // 0011 + // 0011 + // 0011 + // 0011 + for (uint y = 0; y < 4; y++) + { + pDst[0] = subblock_colors0[block.get_selector(0, y)]; + pDst[1] = subblock_colors0[block.get_selector(1, y)]; + pDst[2] = subblock_colors1[block.get_selector(2, y)]; + pDst[3] = subblock_colors1[block.get_selector(3, y)]; + pDst += 4; + } + } + } + + return success; + } + + struct etc1_solution_coordinates + { + inline etc1_solution_coordinates() : + m_unscaled_color(0, 0, 0, 0), + m_inten_table(0), + m_color4(false) + { + } + + inline etc1_solution_coordinates(uint r, uint g, uint b, uint inten_table, bool color4) : + m_unscaled_color(r, g, b, 255), + m_inten_table(inten_table), + m_color4(color4) + { + } + + inline etc1_solution_coordinates(const color_quad_u8& c, uint inten_table, bool color4) : + m_unscaled_color(c), + m_inten_table(inten_table), + m_color4(color4) + { + } + + inline etc1_solution_coordinates(const etc1_solution_coordinates& other) + { + *this = other; + } + + inline etc1_solution_coordinates& operator= (const etc1_solution_coordinates& rhs) + { + m_unscaled_color = rhs.m_unscaled_color; + m_inten_table = rhs.m_inten_table; + m_color4 = rhs.m_color4; + return *this; + } + + inline void clear() + { + m_unscaled_color.clear(); + m_inten_table = 0; + m_color4 = false; + } + + inline color_quad_u8 get_scaled_color() const + { + int br, bg, bb; + if (m_color4) + { + br = m_unscaled_color.r | (m_unscaled_color.r << 4); + bg = m_unscaled_color.g | (m_unscaled_color.g << 4); + bb = m_unscaled_color.b | (m_unscaled_color.b << 4); + } + else + { + br = (m_unscaled_color.r >> 2) | (m_unscaled_color.r << 3); + bg = (m_unscaled_color.g >> 2) | (m_unscaled_color.g << 3); + bb = (m_unscaled_color.b >> 2) | (m_unscaled_color.b << 3); + } + return color_quad_u8(br, bg, bb); + } + + inline void get_block_colors(color_quad_u8* pBlock_colors) + { + int br, bg, bb; + if (m_color4) + { + br = m_unscaled_color.r | (m_unscaled_color.r << 4); + bg = m_unscaled_color.g | (m_unscaled_color.g << 4); + bb = m_unscaled_color.b | (m_unscaled_color.b << 4); + } + else + { + br = (m_unscaled_color.r >> 2) | (m_unscaled_color.r << 3); + bg = (m_unscaled_color.g >> 2) | (m_unscaled_color.g << 3); + bb = (m_unscaled_color.b >> 2) | (m_unscaled_color.b << 3); + } + const int* pInten_table = g_etc1_inten_tables[m_inten_table]; + pBlock_colors[0].set(br + pInten_table[0], bg + pInten_table[0], bb + pInten_table[0]); + pBlock_colors[1].set(br + pInten_table[1], bg + pInten_table[1], bb + pInten_table[1]); + pBlock_colors[2].set(br + pInten_table[2], bg + pInten_table[2], bb + pInten_table[2]); + pBlock_colors[3].set(br + pInten_table[3], bg + pInten_table[3], bb + pInten_table[3]); + } + + color_quad_u8 m_unscaled_color; + uint m_inten_table; + bool m_color4; + }; + + class etc1_optimizer + { + etc1_optimizer(const etc1_optimizer&); + etc1_optimizer& operator= (const etc1_optimizer&); + + public: + etc1_optimizer() + { + clear(); + } + + void clear() + { + m_pParams = NULL; + m_pResult = NULL; + m_pSorted_luma = NULL; + m_pSorted_luma_indices = NULL; + } + + struct params : etc1_pack_params + { + params() + { + clear(); + } + + params(const etc1_pack_params& base_params) : + etc1_pack_params(base_params) + { + clear_optimizer_params(); + } + + void clear() + { + etc1_pack_params::clear(); + clear_optimizer_params(); + } + + void clear_optimizer_params() + { + m_num_src_pixels = 0; + m_pSrc_pixels = 0; + + m_use_color4 = false; + static const int s_default_scan_delta[] = { 0 }; + m_pScan_deltas = s_default_scan_delta; + m_scan_delta_size = 1; + + m_base_color5.clear(); + m_constrain_against_base_color5 = false; + } + + uint m_num_src_pixels; + const color_quad_u8* m_pSrc_pixels; + + bool m_use_color4; + const int* m_pScan_deltas; + uint m_scan_delta_size; + + color_quad_u8 m_base_color5; + bool m_constrain_against_base_color5; + }; + + struct results + { + uint64 m_error; + color_quad_u8 m_block_color_unscaled; + uint m_block_inten_table; + uint m_n; + uint8* m_pSelectors; + bool m_block_color4; + + inline results& operator= (const results& rhs) + { + m_block_color_unscaled = rhs.m_block_color_unscaled; + m_block_color4 = rhs.m_block_color4; + m_block_inten_table = rhs.m_block_inten_table; + m_error = rhs.m_error; + RG_ETC1_ASSERT(m_n == rhs.m_n); + memcpy(m_pSelectors, rhs.m_pSelectors, rhs.m_n); + return *this; + } + }; + + void init(const params& params, results& result); + bool compute(); + + private: + struct potential_solution + { + potential_solution() : m_coords(), m_error(cUINT64_MAX), m_valid(false) + { + } + + etc1_solution_coordinates m_coords; + uint8 m_selectors[8]; + uint64 m_error; + bool m_valid; + + void clear() + { + m_coords.clear(); + m_error = cUINT64_MAX; + m_valid = false; + } + }; + + const params* m_pParams; + results* m_pResult; + + int m_limit; + + vec3F m_avg_color; + int m_br, m_bg, m_bb; + uint16 m_luma[8]; + uint32 m_sorted_luma[2][8]; + const uint32* m_pSorted_luma_indices; + uint32* m_pSorted_luma; + + uint8 m_selectors[8]; + uint8 m_best_selectors[8]; + + potential_solution m_best_solution; + potential_solution m_trial_solution; + uint8 m_temp_selectors[8]; + + bool evaluate_solution(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution); + bool evaluate_solution_fast(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution); + }; + + bool etc1_optimizer::compute() + { + const uint n = m_pParams->m_num_src_pixels; + const int scan_delta_size = m_pParams->m_scan_delta_size; + + // Scan through a subset of the 3D lattice centered around the avg block color trying each 3D (555 or 444) lattice point as a potential block color. + // Each time a better solution is found try to refine the current solution's block color based of the current selectors and intensity table index. + for (int zdi = 0; zdi < scan_delta_size; zdi++) + { + const int zd = m_pParams->m_pScan_deltas[zdi]; + const int mbb = m_bb + zd; + if (mbb < 0) continue; else if (mbb > m_limit) break; + + for (int ydi = 0; ydi < scan_delta_size; ydi++) + { + const int yd = m_pParams->m_pScan_deltas[ydi]; + const int mbg = m_bg + yd; + if (mbg < 0) continue; else if (mbg > m_limit) break; + + for (int xdi = 0; xdi < scan_delta_size; xdi++) + { + const int xd = m_pParams->m_pScan_deltas[xdi]; + const int mbr = m_br + xd; + if (mbr < 0) continue; else if (mbr > m_limit) break; + + etc1_solution_coordinates coords(mbr, mbg, mbb, 0, m_pParams->m_use_color4); + if (m_pParams->m_quality == cHighQuality) + { + if (!evaluate_solution(coords, m_trial_solution, &m_best_solution)) + continue; + } + else + { + if (!evaluate_solution_fast(coords, m_trial_solution, &m_best_solution)) + continue; + } + + // Now we have the input block, the avg. color of the input pixels, a set of trial selector indices, and the block color+intensity index. + // Now, for each component, attempt to refine the current solution by solving a simple linear equation. For example, for 4 colors: + // The goal is: + // pixel0 - (block_color+inten_table[selector0]) + pixel1 - (block_color+inten_table[selector1]) + pixel2 - (block_color+inten_table[selector2]) + pixel3 - (block_color+inten_table[selector3]) = 0 + // Rearranging this: + // (pixel0 + pixel1 + pixel2 + pixel3) - (block_color+inten_table[selector0]) - (block_color+inten_table[selector1]) - (block_color+inten_table[selector2]) - (block_color+inten_table[selector3]) = 0 + // (pixel0 + pixel1 + pixel2 + pixel3) - block_color - inten_table[selector0] - block_color-inten_table[selector1] - block_color-inten_table[selector2] - block_color-inten_table[selector3] = 0 + // (pixel0 + pixel1 + pixel2 + pixel3) - 4*block_color - inten_table[selector0] - inten_table[selector1] - inten_table[selector2] - inten_table[selector3] = 0 + // (pixel0 + pixel1 + pixel2 + pixel3) - 4*block_color - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3]) = 0 + // (pixel0 + pixel1 + pixel2 + pixel3)/4 - block_color - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3])/4 = 0 + // block_color = (pixel0 + pixel1 + pixel2 + pixel3)/4 - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3])/4 + // So what this means: + // optimal_block_color = avg_input - avg_inten_delta + // So the optimal block color can be computed by taking the average block color and subtracting the current average of the intensity delta. + // Unfortunately, optimal_block_color must then be quantized to 555 or 444 so it's not always possible to improve matters using this formula. + // Also, the above formula is for unclamped intensity deltas. The actual implementation takes into account clamping. + + const uint max_refinement_trials = (m_pParams->m_quality == cLowQuality) ? 2 : (((xd | yd | zd) == 0) ? 4 : 2); + for (uint refinement_trial = 0; refinement_trial < max_refinement_trials; refinement_trial++) + { + const uint8* pSelectors = m_best_solution.m_selectors; + const int* pInten_table = g_etc1_inten_tables[m_best_solution.m_coords.m_inten_table]; + + int delta_sum_r = 0, delta_sum_g = 0, delta_sum_b = 0; + const color_quad_u8 base_color(m_best_solution.m_coords.get_scaled_color()); + for (uint r = 0; r < n; r++) + { + const uint s = *pSelectors++; + const int yd = pInten_table[s]; + // Compute actual delta being applied to each pixel, taking into account clamping. + delta_sum_r += rg_etc1::clamp<int>(base_color.r + yd, 0, 255) - base_color.r; + delta_sum_g += rg_etc1::clamp<int>(base_color.g + yd, 0, 255) - base_color.g; + delta_sum_b += rg_etc1::clamp<int>(base_color.b + yd, 0, 255) - base_color.b; + } + if ((!delta_sum_r) && (!delta_sum_g) && (!delta_sum_b)) + break; + const float avg_delta_r_f = static_cast<float>(delta_sum_r) / n; + const float avg_delta_g_f = static_cast<float>(delta_sum_g) / n; + const float avg_delta_b_f = static_cast<float>(delta_sum_b) / n; + const int br1 = rg_etc1::clamp<int>(static_cast<uint>((m_avg_color[0] - avg_delta_r_f) * m_limit / 255.0f + .5f), 0, m_limit); + const int bg1 = rg_etc1::clamp<int>(static_cast<uint>((m_avg_color[1] - avg_delta_g_f) * m_limit / 255.0f + .5f), 0, m_limit); + const int bb1 = rg_etc1::clamp<int>(static_cast<uint>((m_avg_color[2] - avg_delta_b_f) * m_limit / 255.0f + .5f), 0, m_limit); + + bool skip = false; + + if ((mbr == br1) && (mbg == bg1) && (mbb == bb1)) + skip = true; + else if ((br1 == m_best_solution.m_coords.m_unscaled_color.r) && (bg1 == m_best_solution.m_coords.m_unscaled_color.g) && (bb1 == m_best_solution.m_coords.m_unscaled_color.b)) + skip = true; + else if ((m_br == br1) && (m_bg == bg1) && (m_bb == bb1)) + skip = true; + + if (skip) + break; + + etc1_solution_coordinates coords1(br1, bg1, bb1, 0, m_pParams->m_use_color4); + if (m_pParams->m_quality == cHighQuality) + { + if (!evaluate_solution(coords1, m_trial_solution, &m_best_solution)) + break; + } + else + { + if (!evaluate_solution_fast(coords1, m_trial_solution, &m_best_solution)) + break; + } + + } // refinement_trial + + } // xdi + } // ydi + } // zdi + + if (!m_best_solution.m_valid) + { + m_pResult->m_error = cUINT32_MAX; + return false; + } + + const uint8* pSelectors = m_best_solution.m_selectors; + +#ifdef RG_ETC1_BUILD_DEBUG + { + color_quad_u8 block_colors[4]; + m_best_solution.m_coords.get_block_colors(block_colors); + + const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels; + uint64 actual_error = 0; + for (uint i = 0; i < n; i++) + actual_error += pSrc_pixels[i].squared_distance_rgb(block_colors[pSelectors[i]]); + + RG_ETC1_ASSERT(actual_error == m_best_solution.m_error); + } +#endif + + m_pResult->m_error = m_best_solution.m_error; + + m_pResult->m_block_color_unscaled = m_best_solution.m_coords.m_unscaled_color; + m_pResult->m_block_color4 = m_best_solution.m_coords.m_color4; + + m_pResult->m_block_inten_table = m_best_solution.m_coords.m_inten_table; + memcpy(m_pResult->m_pSelectors, pSelectors, n); + m_pResult->m_n = n; + + return true; + } + + void etc1_optimizer::init(const params& p, results& r) + { + // This version is hardcoded for 8 pixel subblocks. + RG_ETC1_ASSERT(p.m_num_src_pixels == 8); + + m_pParams = &p; + m_pResult = &r; + + const uint n = 8; + + m_limit = m_pParams->m_use_color4 ? 15 : 31; + + vec3F avg_color(0.0f); + + for (uint i = 0; i < n; i++) + { + const color_quad_u8& c = m_pParams->m_pSrc_pixels[i]; + const vec3F fc(c.r, c.g, c.b); + + avg_color += fc; + + m_luma[i] = static_cast<uint16>(c.r + c.g + c.b); + m_sorted_luma[0][i] = i; + } + avg_color *= (1.0f / static_cast<float>(n)); + m_avg_color = avg_color; + + m_br = rg_etc1::clamp<int>(static_cast<uint>(m_avg_color[0] * m_limit / 255.0f + .5f), 0, m_limit); + m_bg = rg_etc1::clamp<int>(static_cast<uint>(m_avg_color[1] * m_limit / 255.0f + .5f), 0, m_limit); + m_bb = rg_etc1::clamp<int>(static_cast<uint>(m_avg_color[2] * m_limit / 255.0f + .5f), 0, m_limit); + + if (m_pParams->m_quality <= cMediumQuality) + { + m_pSorted_luma_indices = indirect_radix_sort(n, m_sorted_luma[0], m_sorted_luma[1], m_luma, 0, sizeof(m_luma[0]), false); + m_pSorted_luma = m_sorted_luma[0]; + if (m_pSorted_luma_indices == m_sorted_luma[0]) + m_pSorted_luma = m_sorted_luma[1]; + + for (uint i = 0; i < n; i++) + m_pSorted_luma[i] = m_luma[m_pSorted_luma_indices[i]]; + } + + m_best_solution.m_coords.clear(); + m_best_solution.m_valid = false; + m_best_solution.m_error = cUINT64_MAX; + } + + bool etc1_optimizer::evaluate_solution(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution) + { + trial_solution.m_valid = false; + + if (m_pParams->m_constrain_against_base_color5) + { + const int dr = coords.m_unscaled_color.r - m_pParams->m_base_color5.r; + const int dg = coords.m_unscaled_color.g - m_pParams->m_base_color5.g; + const int db = coords.m_unscaled_color.b - m_pParams->m_base_color5.b; + + if ((rg_etc1::minimum(dr, dg, db) < cETC1ColorDeltaMin) || (rg_etc1::maximum(dr, dg, db) > cETC1ColorDeltaMax)) + return false; + } + + const color_quad_u8 base_color(coords.get_scaled_color()); + + const uint n = 8; + + trial_solution.m_error = cUINT64_MAX; + + for (uint inten_table = 0; inten_table < cETC1IntenModifierValues; inten_table++) + { + const int* pInten_table = g_etc1_inten_tables[inten_table]; + + color_quad_u8 block_colors[4]; + for (uint s = 0; s < 4; s++) + { + const int yd = pInten_table[s]; + block_colors[s].set(base_color.r + yd, base_color.g + yd, base_color.b + yd, 0); + } + + uint64 total_error = 0; + + const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels; + for (uint c = 0; c < n; c++) + { + const color_quad_u8& src_pixel = *pSrc_pixels++; + + uint best_selector_index = 0; + uint best_error = rg_etc1::square(src_pixel.r - block_colors[0].r) + rg_etc1::square(src_pixel.g - block_colors[0].g) + rg_etc1::square(src_pixel.b - block_colors[0].b); + + uint trial_error = rg_etc1::square(src_pixel.r - block_colors[1].r) + rg_etc1::square(src_pixel.g - block_colors[1].g) + rg_etc1::square(src_pixel.b - block_colors[1].b); + if (trial_error < best_error) + { + best_error = trial_error; + best_selector_index = 1; + } + + trial_error = rg_etc1::square(src_pixel.r - block_colors[2].r) + rg_etc1::square(src_pixel.g - block_colors[2].g) + rg_etc1::square(src_pixel.b - block_colors[2].b); + if (trial_error < best_error) + { + best_error = trial_error; + best_selector_index = 2; + } + + trial_error = rg_etc1::square(src_pixel.r - block_colors[3].r) + rg_etc1::square(src_pixel.g - block_colors[3].g) + rg_etc1::square(src_pixel.b - block_colors[3].b); + if (trial_error < best_error) + { + best_error = trial_error; + best_selector_index = 3; + } + + m_temp_selectors[c] = static_cast<uint8>(best_selector_index); + + total_error += best_error; + if (total_error >= trial_solution.m_error) + break; + } + + if (total_error < trial_solution.m_error) + { + trial_solution.m_error = total_error; + trial_solution.m_coords.m_inten_table = inten_table; + memcpy(trial_solution.m_selectors, m_temp_selectors, 8); + trial_solution.m_valid = true; + } + } + trial_solution.m_coords.m_unscaled_color = coords.m_unscaled_color; + trial_solution.m_coords.m_color4 = m_pParams->m_use_color4; + + bool success = false; + if (pBest_solution) + { + if (trial_solution.m_error < pBest_solution->m_error) + { + *pBest_solution = trial_solution; + success = true; + } + } + + return success; + } + + bool etc1_optimizer::evaluate_solution_fast(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution) + { + if (m_pParams->m_constrain_against_base_color5) + { + const int dr = coords.m_unscaled_color.r - m_pParams->m_base_color5.r; + const int dg = coords.m_unscaled_color.g - m_pParams->m_base_color5.g; + const int db = coords.m_unscaled_color.b - m_pParams->m_base_color5.b; + + if ((rg_etc1::minimum(dr, dg, db) < cETC1ColorDeltaMin) || (rg_etc1::maximum(dr, dg, db) > cETC1ColorDeltaMax)) + { + trial_solution.m_valid = false; + return false; + } + } + + const color_quad_u8 base_color(coords.get_scaled_color()); + + const uint n = 8; + + trial_solution.m_error = cUINT64_MAX; + + for (int inten_table = cETC1IntenModifierValues - 1; inten_table >= 0; --inten_table) + { + const int* pInten_table = g_etc1_inten_tables[inten_table]; + + uint block_inten[4]; + color_quad_u8 block_colors[4]; + for (uint s = 0; s < 4; s++) + { + const int yd = pInten_table[s]; + color_quad_u8 block_color(base_color.r + yd, base_color.g + yd, base_color.b + yd, 0); + block_colors[s] = block_color; + block_inten[s] = block_color.r + block_color.g + block_color.b; + } + + // evaluate_solution_fast() enforces/assumesd a total ordering of the input colors along the intensity (1,1,1) axis to more quickly classify the inputs to selectors. + // The inputs colors have been presorted along the projection onto this axis, and ETC1 block colors are always ordered along the intensity axis, so this classification is fast. + // 0 1 2 3 + // 01 12 23 + const uint block_inten_midpoints[3] = { block_inten[0] + block_inten[1], block_inten[1] + block_inten[2], block_inten[2] + block_inten[3] }; + + uint64 total_error = 0; + const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels; + if ((m_pSorted_luma[n - 1] * 2) < block_inten_midpoints[0]) + { + if (block_inten[0] > m_pSorted_luma[n - 1]) + { + const uint min_error = labs(block_inten[0] - m_pSorted_luma[n - 1]); + if (min_error >= trial_solution.m_error) + continue; + } + + memset(&m_temp_selectors[0], 0, n); + + for (uint c = 0; c < n; c++) + total_error += block_colors[0].squared_distance_rgb(pSrc_pixels[c]); + } + else if ((m_pSorted_luma[0] * 2) >= block_inten_midpoints[2]) + { + if (m_pSorted_luma[0] > block_inten[3]) + { + const uint min_error = labs(m_pSorted_luma[0] - block_inten[3]); + if (min_error >= trial_solution.m_error) + continue; + } + + memset(&m_temp_selectors[0], 3, n); + + for (uint c = 0; c < n; c++) + total_error += block_colors[3].squared_distance_rgb(pSrc_pixels[c]); + } + else + { + uint cur_selector = 0, c; + for (c = 0; c < n; c++) + { + const uint y = m_pSorted_luma[c]; + while ((y * 2) >= block_inten_midpoints[cur_selector]) + if (++cur_selector > 2) + goto done; + const uint sorted_pixel_index = m_pSorted_luma_indices[c]; + m_temp_selectors[sorted_pixel_index] = static_cast<uint8>(cur_selector); + total_error += block_colors[cur_selector].squared_distance_rgb(pSrc_pixels[sorted_pixel_index]); + } +done: + while (c < n) + { + const uint sorted_pixel_index = m_pSorted_luma_indices[c]; + m_temp_selectors[sorted_pixel_index] = 3; + total_error += block_colors[3].squared_distance_rgb(pSrc_pixels[sorted_pixel_index]); + ++c; + } + } + + if (total_error < trial_solution.m_error) + { + trial_solution.m_error = total_error; + trial_solution.m_coords.m_inten_table = inten_table; + memcpy(trial_solution.m_selectors, m_temp_selectors, n); + trial_solution.m_valid = true; + if (!total_error) + break; + } + } + trial_solution.m_coords.m_unscaled_color = coords.m_unscaled_color; + trial_solution.m_coords.m_color4 = m_pParams->m_use_color4; + + bool success = false; + if (pBest_solution) + { + if (trial_solution.m_error < pBest_solution->m_error) + { + *pBest_solution = trial_solution; + success = true; + } + } + + return success; + } + + static uint etc1_decode_value(uint diff, uint inten, uint selector, uint packed_c) + { + const uint limit = diff ? 32 : 16; limit; + RG_ETC1_ASSERT((diff < 2) && (inten < 8) && (selector < 4) && (packed_c < limit)); + int c; + if (diff) + c = (packed_c >> 2) | (packed_c << 3); + else + c = packed_c | (packed_c << 4); + c += g_etc1_inten_tables[inten][selector]; + c = rg_etc1::clamp<int>(c, 0, 255); + return c; + } + + static inline int mul_8bit(int a, int b) { int t = a*b + 128; return (t + (t >> 8)) >> 8; } + + void pack_etc1_block_init() + { + for (uint diff = 0; diff < 2; diff++) + { + const uint limit = diff ? 32 : 16; + + for (uint inten = 0; inten < 8; inten++) + { + for (uint selector = 0; selector < 4; selector++) + { + const uint inverse_table_index = diff + (inten << 1) + (selector << 4); + for (uint color = 0; color < 256; color++) + { + uint best_error = cUINT32_MAX, best_packed_c = 0; + for (uint packed_c = 0; packed_c < limit; packed_c++) + { + int v = etc1_decode_value(diff, inten, selector, packed_c); + uint err = labs(v - static_cast<int>(color)); + if (err < best_error) + { + best_error = err; + best_packed_c = packed_c; + if (!best_error) + break; + } + } + RG_ETC1_ASSERT(best_error <= 255); + g_etc1_inverse_lookup[inverse_table_index][color] = static_cast<uint16>(best_packed_c | (best_error << 8)); + } + } + } + } + + uint expand5[32]; + for(int i = 0; i < 32; i++) + expand5[i] = (i << 3) | (i >> 2); + + for(int i = 0; i < 256 + 16; i++) + { + int v = clamp<int>(i - 8, 0, 255); + g_quant5_tab[i] = static_cast<uint8>(expand5[mul_8bit(v,31)]); + } + } + + // Packs solid color blocks efficiently using a set of small precomputed tables. + // For random 888 inputs, MSE results are better than Erricson's ETC1 packer in "slow" mode ~9.5% of the time, is slightly worse only ~.01% of the time, and is equal the rest of the time. + static uint64 pack_etc1_block_solid_color(etc1_block& block, const uint8* pColor, etc1_pack_params& pack_params) + { + pack_params; + RG_ETC1_ASSERT(g_etc1_inverse_lookup[0][255]); + + static uint s_next_comp[4] = { 1, 2, 0, 1 }; + + uint best_error = cUINT32_MAX, best_i = 0; + int best_x = 0, best_packed_c1 = 0, best_packed_c2 = 0; + + // For each possible 8-bit value, there is a precomputed list of diff/inten/selector configurations that allow that 8-bit value to be encoded with no error. + for (uint i = 0; i < 3; i++) + { + const uint c1 = pColor[s_next_comp[i]], c2 = pColor[s_next_comp[i + 1]]; + + const int delta_range = 1; + for (int delta = -delta_range; delta <= delta_range; delta++) + { + const int c_plus_delta = rg_etc1::clamp<int>(pColor[i] + delta, 0, 255); + + const uint16* pTable; + if (!c_plus_delta) + pTable = g_color8_to_etc_block_config_0_255[0]; + else if (c_plus_delta == 255) + pTable = g_color8_to_etc_block_config_0_255[1]; + else + pTable = g_color8_to_etc_block_config_1_to_254[c_plus_delta - 1]; + + do + { + const uint x = *pTable++; + +#ifdef RG_ETC1_BUILD_DEBUG + const uint diff = x & 1; + const uint inten = (x >> 1) & 7; + const uint selector = (x >> 4) & 3; + const uint p0 = (x >> 8) & 255; + RG_ETC1_ASSERT(etc1_decode_value(diff, inten, selector, p0) == (uint)c_plus_delta); +#endif + + const uint16* pInverse_table = g_etc1_inverse_lookup[x & 0xFF]; + uint16 p1 = pInverse_table[c1]; + uint16 p2 = pInverse_table[c2]; + const uint trial_error = rg_etc1::square(c_plus_delta - pColor[i]) + rg_etc1::square(p1 >> 8) + rg_etc1::square(p2 >> 8); + if (trial_error < best_error) + { + best_error = trial_error; + best_x = x; + best_packed_c1 = p1 & 0xFF; + best_packed_c2 = p2 & 0xFF; + best_i = i; + if (!best_error) + goto found_perfect_match; + } + } while (*pTable != 0xFFFF); + } + } +found_perfect_match: + + const uint diff = best_x & 1; + const uint inten = (best_x >> 1) & 7; + + block.m_bytes[3] = static_cast<uint8>(((inten | (inten << 3)) << 2) | (diff << 1)); + + const uint etc1_selector = g_selector_index_to_etc1[(best_x >> 4) & 3]; + *reinterpret_cast<uint16*>(&block.m_bytes[4]) = (etc1_selector & 2) ? 0xFFFF : 0; + *reinterpret_cast<uint16*>(&block.m_bytes[6]) = (etc1_selector & 1) ? 0xFFFF : 0; + + const uint best_packed_c0 = (best_x >> 8) & 255; + if (diff) + { + block.m_bytes[best_i] = static_cast<uint8>(best_packed_c0 << 3); + block.m_bytes[s_next_comp[best_i]] = static_cast<uint8>(best_packed_c1 << 3); + block.m_bytes[s_next_comp[best_i+1]] = static_cast<uint8>(best_packed_c2 << 3); + } + else + { + block.m_bytes[best_i] = static_cast<uint8>(best_packed_c0 | (best_packed_c0 << 4)); + block.m_bytes[s_next_comp[best_i]] = static_cast<uint8>(best_packed_c1 | (best_packed_c1 << 4)); + block.m_bytes[s_next_comp[best_i+1]] = static_cast<uint8>(best_packed_c2 | (best_packed_c2 << 4)); + } + + return best_error; + } + + static uint pack_etc1_block_solid_color_constrained( + etc1_optimizer::results& results, + uint num_colors, const uint8* pColor, + etc1_pack_params& pack_params, + bool use_diff, + const color_quad_u8* pBase_color5_unscaled) + { + RG_ETC1_ASSERT(g_etc1_inverse_lookup[0][255]); + + pack_params; + static uint s_next_comp[4] = { 1, 2, 0, 1 }; + + uint best_error = cUINT32_MAX, best_i = 0; + int best_x = 0, best_packed_c1 = 0, best_packed_c2 = 0; + + // For each possible 8-bit value, there is a precomputed list of diff/inten/selector configurations that allow that 8-bit value to be encoded with no error. + for (uint i = 0; i < 3; i++) + { + const uint c1 = pColor[s_next_comp[i]], c2 = pColor[s_next_comp[i + 1]]; + + const int delta_range = 1; + for (int delta = -delta_range; delta <= delta_range; delta++) + { + const int c_plus_delta = rg_etc1::clamp<int>(pColor[i] + delta, 0, 255); + + const uint16* pTable; + if (!c_plus_delta) + pTable = g_color8_to_etc_block_config_0_255[0]; + else if (c_plus_delta == 255) + pTable = g_color8_to_etc_block_config_0_255[1]; + else + pTable = g_color8_to_etc_block_config_1_to_254[c_plus_delta - 1]; + + do + { + const uint x = *pTable++; + const uint diff = x & 1; + if (static_cast<uint>(use_diff) != diff) + { + if (*pTable == 0xFFFF) + break; + continue; + } + + if ((diff) && (pBase_color5_unscaled)) + { + const int p0 = (x >> 8) & 255; + int delta = p0 - static_cast<int>(pBase_color5_unscaled->c[i]); + if ((delta < cETC1ColorDeltaMin) || (delta > cETC1ColorDeltaMax)) + { + if (*pTable == 0xFFFF) + break; + continue; + } + } + +#ifdef RG_ETC1_BUILD_DEBUG + { + const uint inten = (x >> 1) & 7; + const uint selector = (x >> 4) & 3; + const uint p0 = (x >> 8) & 255; + RG_ETC1_ASSERT(etc1_decode_value(diff, inten, selector, p0) == (uint)c_plus_delta); + } +#endif + + const uint16* pInverse_table = g_etc1_inverse_lookup[x & 0xFF]; + uint16 p1 = pInverse_table[c1]; + uint16 p2 = pInverse_table[c2]; + + if ((diff) && (pBase_color5_unscaled)) + { + int delta1 = (p1 & 0xFF) - static_cast<int>(pBase_color5_unscaled->c[s_next_comp[i]]); + int delta2 = (p2 & 0xFF) - static_cast<int>(pBase_color5_unscaled->c[s_next_comp[i + 1]]); + if ((delta1 < cETC1ColorDeltaMin) || (delta1 > cETC1ColorDeltaMax) || (delta2 < cETC1ColorDeltaMin) || (delta2 > cETC1ColorDeltaMax)) + { + if (*pTable == 0xFFFF) + break; + continue; + } + } + + const uint trial_error = rg_etc1::square(c_plus_delta - pColor[i]) + rg_etc1::square(p1 >> 8) + rg_etc1::square(p2 >> 8); + if (trial_error < best_error) + { + best_error = trial_error; + best_x = x; + best_packed_c1 = p1 & 0xFF; + best_packed_c2 = p2 & 0xFF; + best_i = i; + if (!best_error) + goto found_perfect_match; + } + } while (*pTable != 0xFFFF); + } + } +found_perfect_match: + + if (best_error == cUINT32_MAX) + return best_error; + + best_error *= num_colors; + + results.m_n = num_colors; + results.m_block_color4 = !(best_x & 1); + results.m_block_inten_table = (best_x >> 1) & 7; + memset(results.m_pSelectors, (best_x >> 4) & 3, num_colors); + + const uint best_packed_c0 = (best_x >> 8) & 255; + results.m_block_color_unscaled[best_i] = static_cast<uint8>(best_packed_c0); + results.m_block_color_unscaled[s_next_comp[best_i]] = static_cast<uint8>(best_packed_c1); + results.m_block_color_unscaled[s_next_comp[best_i + 1]] = static_cast<uint8>(best_packed_c2); + results.m_error = best_error; + + return best_error; + } + + // Function originally from RYG's public domain real-time DXT1 compressor, modified for 555. + static void dither_block_555(color_quad_u8* dest, const color_quad_u8* block) + { + int err[8],*ep1 = err,*ep2 = err+4; + uint8 *quant = g_quant5_tab+8; + + memset(dest, 0xFF, sizeof(color_quad_u8)*16); + + // process channels seperately + for(int ch=0;ch<3;ch++) + { + uint8* bp = (uint8*)block; + uint8* dp = (uint8*)dest; + + bp += ch; dp += ch; + + memset(err,0, sizeof(err)); + for(int y = 0; y < 4; y++) + { + // pixel 0 + dp[ 0] = quant[bp[ 0] + ((3*ep2[1] + 5*ep2[0]) >> 4)]; + ep1[0] = bp[ 0] - dp[ 0]; + + // pixel 1 + dp[ 4] = quant[bp[ 4] + ((7*ep1[0] + 3*ep2[2] + 5*ep2[1] + ep2[0]) >> 4)]; + ep1[1] = bp[ 4] - dp[ 4]; + + // pixel 2 + dp[ 8] = quant[bp[ 8] + ((7*ep1[1] + 3*ep2[3] + 5*ep2[2] + ep2[1]) >> 4)]; + ep1[2] = bp[ 8] - dp[ 8]; + + // pixel 3 + dp[12] = quant[bp[12] + ((7*ep1[2] + 5*ep2[3] + ep2[2]) >> 4)]; + ep1[3] = bp[12] - dp[12]; + + // advance to next line + int* tmp = ep1; ep1 = ep2; ep2 = tmp; + bp += 16; + dp += 16; + } + } + } + + unsigned int pack_etc1_block(void* pETC1_block, const unsigned int* pSrc_pixels_rgba, etc1_pack_params& pack_params) + { + const color_quad_u8* pSrc_pixels = reinterpret_cast<const color_quad_u8*>(pSrc_pixels_rgba); + etc1_block& dst_block = *static_cast<etc1_block*>(pETC1_block); + +#ifdef RG_ETC1_BUILD_DEBUG + // Ensure all alpha values are 0xFF. + for (uint i = 0; i < 16; i++) + { + RG_ETC1_ASSERT(pSrc_pixels[i].a == 255); + } +#endif + + color_quad_u8 src_pixel0(pSrc_pixels[0]); + + // Check for solid block. + const uint32 first_pixel_u32 = pSrc_pixels->m_u32; + int r; + for (r = 15; r >= 1; --r) + if (pSrc_pixels[r].m_u32 != first_pixel_u32) + break; + if (!r) + return static_cast<unsigned int>(16 * pack_etc1_block_solid_color(dst_block, &pSrc_pixels[0].r, pack_params)); + + color_quad_u8 dithered_pixels[16]; + if (pack_params.m_dithering) + { + dither_block_555(dithered_pixels, pSrc_pixels); + pSrc_pixels = dithered_pixels; + } + + etc1_optimizer optimizer; + + uint64 best_error = cUINT64_MAX; + uint best_flip = false, best_use_color4 = false; + + uint8 best_selectors[2][8]; + etc1_optimizer::results best_results[2]; + for (uint i = 0; i < 2; i++) + { + best_results[i].m_n = 8; + best_results[i].m_pSelectors = best_selectors[i]; + } + + uint8 selectors[3][8]; + etc1_optimizer::results results[3]; + + for (uint i = 0; i < 3; i++) + { + results[i].m_n = 8; + results[i].m_pSelectors = selectors[i]; + } + + color_quad_u8 subblock_pixels[8]; + + etc1_optimizer::params params(pack_params); + params.m_num_src_pixels = 8; + params.m_pSrc_pixels = subblock_pixels; + + for (uint flip = 0; flip < 2; flip++) + { + for (uint use_color4 = 0; use_color4 < 2; use_color4++) + { + uint64 trial_error = 0; + + uint subblock; + for (subblock = 0; subblock < 2; subblock++) + { + if (flip) + memcpy(subblock_pixels, pSrc_pixels + subblock * 8, sizeof(color_quad_u8) * 8); + else + { + const color_quad_u8* pSrc_col = pSrc_pixels + subblock * 2; + subblock_pixels[0] = pSrc_col[0]; subblock_pixels[1] = pSrc_col[4]; subblock_pixels[2] = pSrc_col[8]; subblock_pixels[3] = pSrc_col[12]; + subblock_pixels[4] = pSrc_col[1]; subblock_pixels[5] = pSrc_col[5]; subblock_pixels[6] = pSrc_col[9]; subblock_pixels[7] = pSrc_col[13]; + } + + results[2].m_error = cUINT64_MAX; + if ((params.m_quality >= cMediumQuality) && ((subblock) || (use_color4))) + { + const uint32 subblock_pixel0_u32 = subblock_pixels[0].m_u32; + for (r = 7; r >= 1; --r) + if (subblock_pixels[r].m_u32 != subblock_pixel0_u32) + break; + if (!r) + { + pack_etc1_block_solid_color_constrained(results[2], 8, &subblock_pixels[0].r, pack_params, !use_color4, (subblock && !use_color4) ? &results[0].m_block_color_unscaled : NULL); + } + } + + params.m_use_color4 = (use_color4 != 0); + params.m_constrain_against_base_color5 = false; + + if ((!use_color4) && (subblock)) + { + params.m_constrain_against_base_color5 = true; + params.m_base_color5 = results[0].m_block_color_unscaled; + } + + if (params.m_quality == cHighQuality) + { + static const int s_scan_delta_0_to_4[] = { -4, -3, -2, -1, 0, 1, 2, 3, 4 }; + params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_0_to_4); + params.m_pScan_deltas = s_scan_delta_0_to_4; + } + else if (params.m_quality == cMediumQuality) + { + static const int s_scan_delta_0_to_1[] = { -1, 0, 1 }; + params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_0_to_1); + params.m_pScan_deltas = s_scan_delta_0_to_1; + } + else + { + static const int s_scan_delta_0[] = { 0 }; + params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_0); + params.m_pScan_deltas = s_scan_delta_0; + } + + optimizer.init(params, results[subblock]); + if (!optimizer.compute()) + break; + + if (params.m_quality >= cMediumQuality) + { + // TODO: Fix fairly arbitrary/unrefined thresholds that control how far away to scan for potentially better solutions. + const uint refinement_error_thresh0 = 3000; + const uint refinement_error_thresh1 = 6000; + if (results[subblock].m_error > refinement_error_thresh0) + { + if (params.m_quality == cMediumQuality) + { + static const int s_scan_delta_2_to_3[] = { -3, -2, 2, 3 }; + params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_2_to_3); + params.m_pScan_deltas = s_scan_delta_2_to_3; + } + else + { + static const int s_scan_delta_5_to_5[] = { -5, 5 }; + static const int s_scan_delta_5_to_8[] = { -8, -7, -6, -5, 5, 6, 7, 8 }; + if (results[subblock].m_error > refinement_error_thresh1) + { + params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_5_to_8); + params.m_pScan_deltas = s_scan_delta_5_to_8; + } + else + { + params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_5_to_5); + params.m_pScan_deltas = s_scan_delta_5_to_5; + } + } + + if (!optimizer.compute()) + break; + } + + if (results[2].m_error < results[subblock].m_error) + results[subblock] = results[2]; + } + + trial_error += results[subblock].m_error; + if (trial_error >= best_error) + break; + } + + if (subblock < 2) + continue; + + best_error = trial_error; + best_results[0] = results[0]; + best_results[1] = results[1]; + best_flip = flip; + best_use_color4 = use_color4; + + } // use_color4 + + } // flip + + int dr = best_results[1].m_block_color_unscaled.r - best_results[0].m_block_color_unscaled.r; + int dg = best_results[1].m_block_color_unscaled.g - best_results[0].m_block_color_unscaled.g; + int db = best_results[1].m_block_color_unscaled.b - best_results[0].m_block_color_unscaled.b; + RG_ETC1_ASSERT(best_use_color4 || (rg_etc1::minimum(dr, dg, db) >= cETC1ColorDeltaMin) && (rg_etc1::maximum(dr, dg, db) <= cETC1ColorDeltaMax)); + + if (best_use_color4) + { + dst_block.m_bytes[0] = static_cast<uint8>(best_results[1].m_block_color_unscaled.r | (best_results[0].m_block_color_unscaled.r << 4)); + dst_block.m_bytes[1] = static_cast<uint8>(best_results[1].m_block_color_unscaled.g | (best_results[0].m_block_color_unscaled.g << 4)); + dst_block.m_bytes[2] = static_cast<uint8>(best_results[1].m_block_color_unscaled.b | (best_results[0].m_block_color_unscaled.b << 4)); + } + else + { + if (dr < 0) dr += 8; dst_block.m_bytes[0] = static_cast<uint8>((best_results[0].m_block_color_unscaled.r << 3) | dr); + if (dg < 0) dg += 8; dst_block.m_bytes[1] = static_cast<uint8>((best_results[0].m_block_color_unscaled.g << 3) | dg); + if (db < 0) db += 8; dst_block.m_bytes[2] = static_cast<uint8>((best_results[0].m_block_color_unscaled.b << 3) | db); + } + + dst_block.m_bytes[3] = static_cast<uint8>( (best_results[1].m_block_inten_table << 2) | (best_results[0].m_block_inten_table << 5) | ((~best_use_color4 & 1) << 1) | best_flip ); + + uint selector0 = 0, selector1 = 0; + if (best_flip) + { + // flipped: + // { 0, 0 }, { 1, 0 }, { 2, 0 }, { 3, 0 }, + // { 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 } + // + // { 0, 2 }, { 1, 2 }, { 2, 2 }, { 3, 2 }, + // { 0, 3 }, { 1, 3 }, { 2, 3 }, { 3, 3 } + const uint8* pSelectors0 = best_results[0].m_pSelectors; + const uint8* pSelectors1 = best_results[1].m_pSelectors; + for (int x = 3; x >= 0; --x) + { + uint b; + b = g_selector_index_to_etc1[pSelectors1[4 + x]]; + selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); + + b = g_selector_index_to_etc1[pSelectors1[x]]; + selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); + + b = g_selector_index_to_etc1[pSelectors0[4 + x]]; + selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); + + b = g_selector_index_to_etc1[pSelectors0[x]]; + selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); + } + } + else + { + // non-flipped: + // { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 }, + // { 1, 0 }, { 1, 1 }, { 1, 2 }, { 1, 3 } + // + // { 2, 0 }, { 2, 1 }, { 2, 2 }, { 2, 3 }, + // { 3, 0 }, { 3, 1 }, { 3, 2 }, { 3, 3 } + for (int subblock = 1; subblock >= 0; --subblock) + { + const uint8* pSelectors = best_results[subblock].m_pSelectors + 4; + for (uint i = 0; i < 2; i++) + { + uint b; + b = g_selector_index_to_etc1[pSelectors[3]]; + selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); + + b = g_selector_index_to_etc1[pSelectors[2]]; + selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); + + b = g_selector_index_to_etc1[pSelectors[1]]; + selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1); + + b = g_selector_index_to_etc1[pSelectors[0]]; + selector0 = (selector0 << 1) | (b & 1);selector1 = (selector1 << 1) | (b >> 1); + + pSelectors -= 4; + } + } + } + + dst_block.m_bytes[4] = static_cast<uint8>(selector1 >> 8); dst_block.m_bytes[5] = static_cast<uint8>(selector1 & 0xFF); + dst_block.m_bytes[6] = static_cast<uint8>(selector0 >> 8); dst_block.m_bytes[7] = static_cast<uint8>(selector0 & 0xFF); + + return static_cast<unsigned int>(best_error); + } + +} // namespace rg_etc1 |