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// 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
//
// v1.03 - 5/12/13 - Initial public release
# include "rg_etc1.h"
# include <stdlib.h>
# include <string.h>
# include <assert.h>
//#include <stdio.h>
# include <math.h>
# include <stdio.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
{
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inline long labs ( long val ) {
return val < 0 ? - val : val ;
}
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inline int intabs ( int val ) {
return val < 0 ? - val : val ;
}
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 = intabs ( 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 = intabs ( 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 ) ;
2015-03-19 05:05:24 +00:00
uint err = labs ( v - static_cast < int > ( color ) ) ;
2014-02-10 01:10:30 +00:00
//printf("err: %d - %u = %u\n",v,color,err);
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 ;
2015-02-17 02:58:41 +00:00
RG_ETC1_ASSERT ( best_use_color4 | | ( ( rg_etc1 : : minimum ( dr , dg , db ) > = cETC1ColorDeltaMin ) & & ( rg_etc1 : : maximum ( dr , dg , db ) < = cETC1ColorDeltaMax ) ) ) ;
2014-02-10 01:10:30 +00:00
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