/**
 
@~English
@page licensing Licensing
 
@section etcdec etcdec.cxx License
 
etcdec.cxx is made available under the terms and conditions of the following
License Agreement.

Software License Agreement

PLEASE REVIEW THE FOLLOWING TERMS AND CONDITIONS PRIOR TO USING THE
ERICSSON TEXTURE COMPRESSION CODEC SOFTWARE (THE "SOFTWARE"). THE USE
OF THE SOFTWARE IS SUBJECT TO THE TERMS AND CONDITIONS OF THE
FOLLOWING SOFTWARE LICENSE AGREEMENT (THE "SLA"). IF YOU DO NOT ACCEPT
SUCH TERMS AND CONDITIONS YOU MAY NOT USE THE SOFTWARE.

Subject to the terms and conditions of the SLA, the licensee of the
Software (the "Licensee") hereby, receives a non-exclusive,
non-transferable, limited, free-of-charge, perpetual and worldwide
license, to copy, use, distribute and modify the Software, but only
for the purpose of developing, manufacturing, selling, using and
distributing products including the Software in binary form, which
products are used for compression and/or decompression according to
the Khronos standard specifications OpenGL, OpenGL ES and
WebGL. Notwithstanding anything of the above, Licensee may distribute
[etcdec.cxx] in source code form provided (i) it is in unmodified
form; and (ii) it is included in software owned by Licensee.

If Licensee institutes, or threatens to institute, patent litigation
against Ericsson or Ericsson's affiliates for using the Software for
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property rights owned by Ericsson or its affiliates and provided under
the Khronos framework, Ericsson shall have the right to terminate this
SLA with immediate effect. Moreover, if Licensee institutes, or
threatens to institute, patent litigation against any other licensee
of the Software for using the Software in products within the scope of
the Khronos framework, Ericsson shall have the right to terminate this
SLA with immediate effect. However, should Licensee institute, or
threaten to institute, patent litigation against any other licensee of
the Software based on such other licensee's use of any other software
together with the Software, then Ericsson shall have no right to
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not to the software or product itself.

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ANY KIND, EXTENDS NO WARRANTIES OR CONDITIONS OF ANY KIND, EITHER
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IMPLIED OR STATUTORY WARRANTIES OR CONDITIONS OF TITLE,
MERCHANTABILITY, SATISFACTORY QUALITY, SUITABILITY, AND FITNESS FOR A
PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
OF THE SOFTWARE IS WITH THE LICENSEE. SHOULD THE SOFTWARE PROVE
DEFECTIVE, THE LICENSEE ASSUMES THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION. ERICSSON MAKES NO WARRANTY THAT THE MANUFACTURE,
SALE, OFFERING FOR SALE, DISTRIBUTION, LEASE, USE OR IMPORTATION UNDER
THE SLA WILL BE FREE FROM INFRINGEMENT OF PATENTS, COPYRIGHTS OR OTHER
INTELLECTUAL PROPERTY RIGHTS OF OTHERS, AND THE VALIDITY OF THE
LICENSE AND THE SLA ARE SUBJECT TO LICENSEE'S SOLE RESPONSIBILITY TO
MAKE SUCH DETERMINATION AND ACQUIRE SUCH LICENSES AS MAY BE NECESSARY
WITH RESPECT TO PATENTS, COPYRIGHT AND OTHER INTELLECTUAL PROPERTY OF
THIRD PARTIES.

THE LICENSEE ACKNOWLEDGES AND ACCEPTS THAT THE SOFTWARE (I) IS NOT
LICENSED FOR; (II) IS NOT DESIGNED FOR OR INTENDED FOR; AND (III) MAY
NOT BE USED FOR; ANY MISSION CRITICAL APPLICATIONS SUCH AS, BUT NOT
LIMITED TO OPERATION OF NUCLEAR OR HEALTHCARE COMPUTER SYSTEMS AND/OR
NETWORKS, AIRCRAFT OR TRAIN CONTROL AND/OR COMMUNICATION SYSTEMS OR
ANY OTHER COMPUTER SYSTEMS AND/OR NETWORKS OR CONTROL AND/OR
COMMUNICATION SYSTEMS ALL IN WHICH CASE THE FAILURE OF THE SOFTWARE
COULD LEAD TO DEATH, PERSONAL INJURY, OR SEVERE PHYSICAL, MATERIAL OR
ENVIRONMENTAL DAMAGE. LICENSEE'S RIGHTS UNDER THIS LICENSE WILL
TERMINATE AUTOMATICALLY AND IMMEDIATELY WITHOUT NOTICE IF LICENSEE
FAILS TO COMPLY WITH THIS PARAGRAPH.

IN NO EVENT SHALL ERICSSON BE LIABLE FOR ANY DAMAGES WHATSOEVER,
INCLUDING BUT NOT LIMITED TO PERSONAL INJURY, ANY GENERAL, SPECIAL,
INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF OR IN
CONNECTION WITH THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING
BUT NOT LIMITED TO LOSS OF PROFITS, BUSINESS INTERUPTIONS, OR ANY
OTHER COMMERCIAL DAMAGES OR LOSSES, LOSS OF DATA OR DATA BEING
RENDERED INACCURATE OR LOSSES SUSTAINED BY THE LICENSEE OR THIRD
PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER
SOFTWARE) REGARDLESS OF THE THEORY OF LIABILITY (CONTRACT, TORT, OR
OTHERWISE), EVEN IF THE LICENSEE OR ANY OTHER PARTY HAS BEEN ADVISED
OF THE POSSIBILITY OF SUCH DAMAGES.

Licensee acknowledges that "ERICSSON ///" is the corporate trademark
of Telefonaktiebolaget LM Ericsson and that both "Ericsson" and the
figure "///" are important features of the trade names of
Telefonaktiebolaget LM Ericsson. Nothing contained in these terms and
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interest in the word "Ericsson" or the figure "///". No delay or
omission by Ericsson to exercise any right or power shall impair any
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subsequent breach.

This SLA shall be governed by the substantive law of Sweden. Any
dispute, controversy or claim arising out of or in connection with
this SLA, or the breach, termination or invalidity thereof, shall be
submitted to the exclusive jurisdiction of the Swedish Courts.

*/

//// etcpack v2.74
//// 
//// NO WARRANTY 
//// 
//// BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE THE PROGRAM IS PROVIDED
//// "AS IS". ERICSSON MAKES NO REPRESENTATIONS OF ANY KIND, EXTENDS NO
//// WARRANTIES OR CONDITIONS OF ANY KIND; EITHER EXPRESS, IMPLIED OR
//// STATUTORY; INCLUDING, BUT NOT LIMITED TO, EXPRESS, IMPLIED OR
//// STATUTORY WARRANTIES OR CONDITIONS OF TITLE, MERCHANTABILITY,
//// SATISFACTORY QUALITY, SUITABILITY AND FITNESS FOR A PARTICULAR
//// PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
//// PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
//// THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. ERICSSON
//// MAKES NO WARRANTY THAT THE MANUFACTURE, SALE, OFFERING FOR SALE,
//// DISTRIBUTION, LEASE, USE OR IMPORTATION UNDER THE LICENSE WILL BE FREE
//// FROM INFRINGEMENT OF PATENTS, COPYRIGHTS OR OTHER INTELLECTUAL
//// PROPERTY RIGHTS OF OTHERS, AND THE VALIDITY OF THE LICENSE IS SUBJECT
//// TO YOUR SOLE RESPONSIBILITY TO MAKE SUCH DETERMINATION AND ACQUIRE
//// SUCH LICENSES AS MAY BE NECESSARY WITH RESPECT TO PATENTS, COPYRIGHT
//// AND OTHER INTELLECTUAL PROPERTY OF THIRD PARTIES.
//// 
//// FOR THE AVOIDANCE OF DOUBT THE PROGRAM (I) IS NOT LICENSED FOR; (II)
//// IS NOT DESIGNED FOR OR INTENDED FOR; AND (III) MAY NOT BE USED FOR;
//// ANY MISSION CRITICAL APPLICATIONS SUCH AS, BUT NOT LIMITED TO
//// OPERATION OF NUCLEAR OR HEALTHCARE COMPUTER SYSTEMS AND/OR NETWORKS,
//// AIRCRAFT OR TRAIN CONTROL AND/OR COMMUNICATION SYSTEMS OR ANY OTHER
//// COMPUTER SYSTEMS AND/OR NETWORKS OR CONTROL AND/OR COMMUNICATION
//// SYSTEMS ALL IN WHICH CASE THE FAILURE OF THE PROGRAM COULD LEAD TO
//// DEATH, PERSONAL INJURY, OR SEVERE PHYSICAL, MATERIAL OR ENVIRONMENTAL
//// DAMAGE. YOUR RIGHTS UNDER THIS LICENSE WILL TERMINATE AUTOMATICALLY
//// AND IMMEDIATELY WITHOUT NOTICE IF YOU FAIL TO COMPLY WITH THIS
//// PARAGRAPH.
//// 
//// IN NO EVENT WILL ERICSSON, BE LIABLE FOR ANY DAMAGES WHATSOEVER,
//// INCLUDING BUT NOT LIMITED TO PERSONAL INJURY, ANY GENERAL, SPECIAL,
//// INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF OR IN
//// CONNECTION WITH THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT
//// NOT LIMITED TO LOSS OF PROFITS, BUSINESS INTERUPTIONS, OR ANY OTHER
//// COMMERCIAL DAMAGES OR LOSSES, LOSS OF DATA OR DATA BEING RENDERED
//// INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF
//// THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) REGARDLESS OF THE
//// THEORY OF LIABILITY (CONTRACT, TORT OR OTHERWISE), EVEN IF SUCH HOLDER
//// OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
//// 
//// (C) Ericsson AB 2005-2013. All Rights Reserved.
//// 

#include <stdio.h>
#include <stdlib.h>

#define UNREFERENCED_PARAMETER(x)   ((void)x)

// Typedefs
typedef unsigned char uint8;
typedef unsigned short uint16;
typedef short int16;

// Macros to help with bit extraction/insertion
#define SHIFT(size,startpos) ((startpos)-(size)+1)
#define MASK(size, startpos) (((2<<(size-1))-1) << SHIFT(size,startpos))
#define PUTBITS( dest, data, size, startpos) dest = ((dest & ~MASK(size, startpos)) | ((data << SHIFT(size, startpos)) & MASK(size,startpos)))
#define SHIFTHIGH(size, startpos) (((startpos)-32)-(size)+1)
#define MASKHIGH(size, startpos) (((1<<(size))-1) << SHIFTHIGH(size,startpos))
#define PUTBITSHIGH(dest, data, size, startpos) dest = ((dest & ~MASKHIGH(size, startpos)) | ((data << SHIFTHIGH(size, startpos)) & MASKHIGH(size,startpos)))
#define GETBITS(source, size, startpos)  (( (source) >> ((startpos)-(size)+1) ) & ((1<<(size)) -1))
#define GETBITSHIGH(source, size, startpos)  (( (source) >> (((startpos)-32)-(size)+1) ) & ((1<<(size)) -1))
#ifndef PGMOUT
#define PGMOUT 1
#endif
// Thumb macros and definitions
#define    R_BITS59T 4
#define G_BITS59T 4
#define    B_BITS59T 4
#define    R_BITS58H 4
#define G_BITS58H 4
#define    B_BITS58H 4
#define    MAXIMUM_ERROR (255*255*16*1000)
#define R 0
#define G 1
#define B 2
#define BLOCKHEIGHT 4
#define BLOCKWIDTH 4
#define BINPOW(power) (1<<(power))
#define    TABLE_BITS_59T 3
#define    TABLE_BITS_58H 3

// Helper Macros
#define CLAMP(ll,x,ul) (((x)<(ll)) ? (ll) : (((x)>(ul)) ? (ul) : (x)))
#define JAS_ROUND(x) (((x) < 0.0 ) ? ((int)((x)-0.5)) : ((int)((x)+0.5)))

#define RED_CHANNEL(img,width,x,y,channels)   img[channels*(y*width+x)+0]
#define GREEN_CHANNEL(img,width,x,y,channels) img[channels*(y*width+x)+1]
#define BLUE_CHANNEL(img,width,x,y,channels)  img[channels*(y*width+x)+2]
#define ALPHA_CHANNEL(img,width,x,y,channels)  img[channels*(y*width+x)+3]


// Global tables
static uint8 table59T[8] = {3,6,11,16,23,32,41,64};  // 3-bit table for the 59 bit T-mode
static uint8 table58H[8] = {3,6,11,16,23,32,41,64};  // 3-bit table for the 58 bit H-mode
static int compressParams[16][4] = {{-8, -2,  2, 8}, {-8, -2,  2, 8}, {-17, -5, 5, 17}, {-17, -5, 5, 17}, {-29, -9, 9, 29}, {-29, -9, 9, 29}, {-42, -13, 13, 42}, {-42, -13, 13, 42}, {-60, -18, 18, 60}, {-60, -18, 18, 60}, {-80, -24, 24, 80}, {-80, -24, 24, 80}, {-106, -33, 33, 106}, {-106, -33, 33, 106}, {-183, -47, 47, 183}, {-183, -47, 47, 183}};
static int unscramble[4] = {2, 3, 1, 0};
int alphaTableInitialized = 0;
int alphaTable[256][8];
int alphaBase[16][4] = {    
              {-15,-9,-6,-3},
                            {-13,-10,-7,-3},
                            {-13,-8,-5,-2},
                            {-13,-6,-4,-2},
                            {-12,-8,-6,-3},
                            {-11,-9,-7,-3},
                            {-11,-8,-7,-4},
                            {-11,-8,-5,-3},
                            { -10,-8,-6,-2},
                            { -10,-8,-5,-2},
                            { -10,-8,-4,-2},
                            { -10,-7,-5,-2},
                            { -10,-7,-4,-3},
                            { -10,-3,-2, -1},
                            { -9,-8,-6,-4},
                            { -9,-7,-5,-3}
                                            };

// Global variables
int formatSigned = 0;

// Enums
 enum{PATTERN_H = 0, 
      PATTERN_T = 1};


// Code used to create the valtab
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void setupAlphaTable() 
{
  if(alphaTableInitialized)
    return;
  alphaTableInitialized = 1;

    //read table used for alpha compression
    int buf;
    for(int i = 16; i<32; i++) 
    {
        for(int j=0; j<8; j++) 
        {
            buf=alphaBase[i-16][3-j%4];
            if(j<4)
                alphaTable[i][j]=buf;
            else
                alphaTable[i][j]=(-buf-1);
        }
    }
    
    //beyond the first 16 values, the rest of the table is implicit.. so calculate that!
    for(int i=0; i<256; i++) 
    {
        //fill remaining slots in table with multiples of the first ones.
        int mul = i/16;
        int old = 16+i%16;
        for(int j = 0; j<8; j++) 
        {
            alphaTable[i][j]=alphaTable[old][j]*mul;
            //note: we don't do clamping here, though we could, because we'll be clamped afterwards anyway.
        }
    }
}

// Read a word in big endian style
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void read_big_endian_2byte_word(unsigned short *blockadr, FILE *f)
{
    uint8 bytes[2];
    unsigned short block;

    fread(&bytes[0], 1, 1, f);
    fread(&bytes[1], 1, 1, f);

    block = 0;
    block |= bytes[0];
    block = block << 8;
    block |= bytes[1];

    blockadr[0] = block;
}

// Read a word in big endian style
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void read_big_endian_4byte_word(unsigned int *blockadr, FILE *f)
{
    uint8 bytes[4];
    unsigned int block;

    fread(&bytes[0], 1, 1, f);
    fread(&bytes[1], 1, 1, f);
    fread(&bytes[2], 1, 1, f);
    fread(&bytes[3], 1, 1, f);

    block = 0;
    block |= bytes[0];
    block = block << 8;
    block |= bytes[1];
    block = block << 8;
    block |= bytes[2];
    block = block << 8;
    block |= bytes[3];

    blockadr[0] = block;
}

// The format stores the bits for the three extra modes in a roundabout way to be able to
// fit them without increasing the bit rate. This function converts them into something
// that is easier to work with. 
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void unstuff57bits(unsigned int planar_word1, unsigned int planar_word2, unsigned int &planar57_word1, unsigned int &planar57_word2)
{
    // Get bits from twotimer configuration for 57 bits
    // 
    // Go to this bit layout:
    //
    //      63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 
    //      -----------------------------------------------------------------------------------------------
    //     |R0               |G01G02              |B01B02  ;B03     |RH1           |RH2|GH                 |
    //      -----------------------------------------------------------------------------------------------
    //
    //      31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
    //      -----------------------------------------------------------------------------------------------
    //     |BH               |RV               |GV                  |BV                | not used          |   
    //      -----------------------------------------------------------------------------------------------
    //
    //  From this:
    // 
    //      63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 
    //      ------------------------------------------------------------------------------------------------
    //     |//|R0               |G01|/|G02              |B01|/ // //|B02  |//|B03     |RH1           |df|RH2|
    //      ------------------------------------------------------------------------------------------------
    //
    //      31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
    //      -----------------------------------------------------------------------------------------------
    //     |GH                  |BH               |RV               |GV                   |BV              |
    //      -----------------------------------------------------------------------------------------------
    //
    //      63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34  33  32 
    //      ---------------------------------------------------------------------------------------------------
    //     | base col1    | dcol 2 | base col1    | dcol 2 | base col 1   | dcol 2 | table  | table  |diff|flip|
    //     | R1' (5 bits) | dR2    | G1' (5 bits) | dG2    | B1' (5 bits) | dB2    | cw 1   | cw 2   |bit |bit |
    //      ---------------------------------------------------------------------------------------------------

    uint8 RO, GO1, GO2, BO1, BO2, BO3, RH1, RH2, GH, BH, RV, GV, BV;

    RO  = GETBITSHIGH( planar_word1, 6, 62);
    GO1 = GETBITSHIGH( planar_word1, 1, 56);
    GO2 = GETBITSHIGH( planar_word1, 6, 54);
    BO1 = GETBITSHIGH( planar_word1, 1, 48);
    BO2 = GETBITSHIGH( planar_word1, 2, 44);
    BO3 = GETBITSHIGH( planar_word1, 3, 41);
    RH1 = GETBITSHIGH( planar_word1, 5, 38);
    RH2 = GETBITSHIGH( planar_word1, 1, 32);
    GH  = GETBITS(     planar_word2, 7, 31);
    BH  = GETBITS(     planar_word2, 6, 24);
    RV  = GETBITS(     planar_word2, 6, 18);
    GV  = GETBITS(     planar_word2, 7, 12);
    BV  = GETBITS(     planar_word2, 6,  5);

    planar57_word1 = 0; planar57_word2 = 0;
    PUTBITSHIGH( planar57_word1, RO,  6, 63);
    PUTBITSHIGH( planar57_word1, GO1, 1, 57);
    PUTBITSHIGH( planar57_word1, GO2, 6, 56);
    PUTBITSHIGH( planar57_word1, BO1, 1, 50);
    PUTBITSHIGH( planar57_word1, BO2, 2, 49);
    PUTBITSHIGH( planar57_word1, BO3, 3, 47);
    PUTBITSHIGH( planar57_word1, RH1, 5, 44);
    PUTBITSHIGH( planar57_word1, RH2, 1, 39);
    PUTBITSHIGH( planar57_word1, GH, 7, 38);
    PUTBITS(     planar57_word2, BH, 6, 31);
    PUTBITS(     planar57_word2, RV, 6, 25);
    PUTBITS(     planar57_word2, GV, 7, 19);
    PUTBITS(     planar57_word2, BV, 6, 12);
}

// The format stores the bits for the three extra modes in a roundabout way to be able to
// fit them without increasing the bit rate. This function converts them into something
// that is easier to work with. 
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void unstuff58bits(unsigned int thumbH_word1, unsigned int thumbH_word2, unsigned int &thumbH58_word1, unsigned int &thumbH58_word2)
{
    // Go to this layout:
    //
    //     |63 62 61 60 59 58|57 56 55 54 53 52 51|50 49|48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33|32   |
    //     |-------empty-----|part0---------------|part1|part2------------------------------------------|part3|
    //
    //  from this:
    // 
    //      63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 
    //      --------------------------------------------------------------------------------------------------|
    //     |//|part0               |// // //|part1|//|part2                                          |df|part3|
    //      --------------------------------------------------------------------------------------------------|

    unsigned int part0, part1, part2, part3;

    // move parts
    part0 = GETBITSHIGH( thumbH_word1, 7, 62);
    part1 = GETBITSHIGH( thumbH_word1, 2, 52);
    part2 = GETBITSHIGH( thumbH_word1,16, 49);
    part3 = GETBITSHIGH( thumbH_word1, 1, 32);
    thumbH58_word1 = 0;
    PUTBITSHIGH( thumbH58_word1, part0,  7, 57);
    PUTBITSHIGH( thumbH58_word1, part1,  2, 50);
    PUTBITSHIGH( thumbH58_word1, part2, 16, 48);
    PUTBITSHIGH( thumbH58_word1, part3,  1, 32);

    thumbH58_word2 = thumbH_word2;
}

// The format stores the bits for the three extra modes in a roundabout way to be able to
// fit them without increasing the bit rate. This function converts them into something
// that is easier to work with. 
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void unstuff59bits(unsigned int thumbT_word1, unsigned int thumbT_word2, unsigned int &thumbT59_word1, unsigned int &thumbT59_word2)
{
    // Get bits from twotimer configuration 59 bits. 
    // 
    // Go to this bit layout:
    //
    //     |63 62 61 60 59|58 57 56 55|54 53 52 51|50 49 48 47|46 45 44 43|42 41 40 39|38 37 36 35|34 33 32|
    //     |----empty-----|---red 0---|--green 0--|--blue 0---|---red 1---|--green 1--|--blue 1---|--dist--|
    //
    //     |31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00|
    //     |----------------------------------------index bits---------------------------------------------|
    //
    //
    //  From this:
    // 
    //      63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 
    //      -----------------------------------------------------------------------------------------------
    //     |// // //|R0a  |//|R0b  |G0         |B0         |R1         |G1         |B1          |da  |df|db|
    //      -----------------------------------------------------------------------------------------------
    //
    //     |31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00|
    //     |----------------------------------------index bits---------------------------------------------|
    //
    //      63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 
    //      -----------------------------------------------------------------------------------------------
    //     | base col1    | dcol 2 | base col1    | dcol 2 | base col 1   | dcol 2 | table  | table  |df|fp|
    //     | R1' (5 bits) | dR2    | G1' (5 bits) | dG2    | B1' (5 bits) | dB2    | cw 1   | cw 2   |bt|bt|
    //      ------------------------------------------------------------------------------------------------

    uint8 R0a;

    // Fix middle part
    thumbT59_word1 = thumbT_word1 >> 1;
    // Fix db (lowest bit of d)
    PUTBITSHIGH( thumbT59_word1, thumbT_word1,  1, 32);
    // Fix R0a (top two bits of R0)
    R0a = GETBITSHIGH( thumbT_word1, 2, 60);
    PUTBITSHIGH( thumbT59_word1, R0a,  2, 58);

    // Zero top part (not needed)
    PUTBITSHIGH( thumbT59_word1, 0,  5, 63);

    thumbT59_word2 = thumbT_word2;
}

// The color bits are expanded to the full color
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressColor(int R_B, int G_B, int B_B, uint8 (colors_RGB444)[2][3], uint8 (colors)[2][3]) 
{
    // The color should be retrieved as:
    //
    // c = round(255/(r_bits^2-1))*comp_color
    //
    // This is similar to bit replication
    // 
    // Note -- this code only work for bit replication from 4 bits and up --- 3 bits needs
    // two copy operations.

     colors[0][R] = (colors_RGB444[0][R] << (8 - R_B)) | (colors_RGB444[0][R] >> (R_B - (8-R_B)) );
     colors[0][G] = (colors_RGB444[0][G] << (8 - G_B)) | (colors_RGB444[0][G] >> (G_B - (8-G_B)) );
     colors[0][B] = (colors_RGB444[0][B] << (8 - B_B)) | (colors_RGB444[0][B] >> (B_B - (8-B_B)) );
     colors[1][R] = (colors_RGB444[1][R] << (8 - R_B)) | (colors_RGB444[1][R] >> (R_B - (8-R_B)) );
     colors[1][G] = (colors_RGB444[1][G] << (8 - G_B)) | (colors_RGB444[1][G] >> (G_B - (8-G_B)) );
     colors[1][B] = (colors_RGB444[1][B] << (8 - B_B)) | (colors_RGB444[1][B] >> (B_B - (8-B_B)) );
}

void calculatePaintColors59T(uint8 d, uint8 p, uint8 (colors)[2][3], uint8 (possible_colors)[4][3]) 
{
    //////////////////////////////////////////////
    //
    //        C3      C1        C4----C1---C2
    //        |        |              |
    //        |        |              |
    //        |-------|              |
    //        |        |              |
    //        |        |              |
    //        C4      C2              C3
    //
    //////////////////////////////////////////////

    // C4
    possible_colors[3][R] = CLAMP(0,colors[1][R] - table59T[d],255);
    possible_colors[3][G] = CLAMP(0,colors[1][G] - table59T[d],255);
    possible_colors[3][B] = CLAMP(0,colors[1][B] - table59T[d],255);
    
    if (p == PATTERN_T) 
    {
        // C3
        possible_colors[0][R] = colors[0][R];
        possible_colors[0][G] = colors[0][G];
        possible_colors[0][B] = colors[0][B];
        // C2
        possible_colors[1][R] = CLAMP(0,colors[1][R] + table59T[d],255);
        possible_colors[1][G] = CLAMP(0,colors[1][G] + table59T[d],255);
        possible_colors[1][B] = CLAMP(0,colors[1][B] + table59T[d],255);
        // C1
        possible_colors[2][R] = colors[1][R];
        possible_colors[2][G] = colors[1][G];
        possible_colors[2][B] = colors[1][B];

    } 
    else 
    {
        printf("Invalid pattern. Terminating");
        exit(1);
    }
}
// Decompress a T-mode block (simple packing)
// Simple 59T packing:
//|63 62 61 60 59|58 57 56 55|54 53 52 51|50 49 48 47|46 45 44 43|42 41 40 39|38 37 36 35|34 33 32|
//|----empty-----|---red 0---|--green 0--|--blue 0---|---red 1---|--green 1--|--blue 1---|--dist--|
//
//|31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00|
//|----------------------------------------index bits---------------------------------------------|
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockTHUMB59Tc(unsigned int block_part1, unsigned int block_part2, uint8 *img,int width,int height,int startx,int starty, int channels)
{

    UNREFERENCED_PARAMETER(height);
    uint8 colorsRGB444[2][3];
    uint8 colors[2][3];
    uint8 paint_colors[4][3];
    uint8 distance;
    uint8 block_mask[4][4];

    // First decode left part of block.
    colorsRGB444[0][R]= GETBITSHIGH(block_part1, 4, 58);
    colorsRGB444[0][G]= GETBITSHIGH(block_part1, 4, 54);
    colorsRGB444[0][B]= GETBITSHIGH(block_part1, 4, 50);

    colorsRGB444[1][R]= GETBITSHIGH(block_part1, 4, 46);
    colorsRGB444[1][G]= GETBITSHIGH(block_part1, 4, 42);
    colorsRGB444[1][B]= GETBITSHIGH(block_part1, 4, 38);

    distance   = GETBITSHIGH(block_part1, TABLE_BITS_59T, 34);

    // Extend the two colors to RGB888    
    decompressColor(R_BITS59T, G_BITS59T, B_BITS59T, colorsRGB444, colors);    
    calculatePaintColors59T(distance, PATTERN_T, colors, paint_colors);
    
    // Choose one of the four paint colors for each texel
    for (uint8 x = 0; x < BLOCKWIDTH; ++x) 
    {
        for (uint8 y = 0; y < BLOCKHEIGHT; ++y) 
        {
            //block_mask[x][y] = GETBITS(block_part2,2,31-(y*4+x)*2);
            block_mask[x][y] = GETBITS(block_part2,1,(y+x*4)+16)<<1;
            block_mask[x][y] |= GETBITS(block_part2,1,(y+x*4));
            img[channels*((starty+y)*width+startx+x)+R] =
                CLAMP(0,paint_colors[block_mask[x][y]][R],255); // RED
            img[channels*((starty+y)*width+startx+x)+G] =
                CLAMP(0,paint_colors[block_mask[x][y]][G],255); // GREEN
            img[channels*((starty+y)*width+startx+x)+B] =
                CLAMP(0,paint_colors[block_mask[x][y]][B],255); // BLUE
        }
    }
}

void decompressBlockTHUMB59T(unsigned int block_part1, unsigned int block_part2, uint8 *img, int width, int height, int startx, int starty)
{
  decompressBlockTHUMB59Tc(block_part1, block_part2, img, width, height, startx, starty, 3);
}

// Calculate the paint colors from the block colors 
// using a distance d and one of the H- or T-patterns.
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void calculatePaintColors58H(uint8 d, uint8 p, uint8 (colors)[2][3], uint8 (possible_colors)[4][3]) 
{
    
    //////////////////////////////////////////////
    //
    //        C3      C1        C4----C1---C2
    //        |        |              |
    //        |        |              |
    //        |-------|              |
    //        |        |              |
    //        |        |              |
    //        C4      C2              C3
    //
    //////////////////////////////////////////////

    // C4
    possible_colors[3][R] = CLAMP(0,colors[1][R] - table58H[d],255);
    possible_colors[3][G] = CLAMP(0,colors[1][G] - table58H[d],255);
    possible_colors[3][B] = CLAMP(0,colors[1][B] - table58H[d],255);
    
    if (p == PATTERN_H) 
    { 
        // C1
        possible_colors[0][R] = CLAMP(0,colors[0][R] + table58H[d],255);
        possible_colors[0][G] = CLAMP(0,colors[0][G] + table58H[d],255);
        possible_colors[0][B] = CLAMP(0,colors[0][B] + table58H[d],255);
        // C2
        possible_colors[1][R] = CLAMP(0,colors[0][R] - table58H[d],255);
        possible_colors[1][G] = CLAMP(0,colors[0][G] - table58H[d],255);
        possible_colors[1][B] = CLAMP(0,colors[0][B] - table58H[d],255);
        // C3
        possible_colors[2][R] = CLAMP(0,colors[1][R] + table58H[d],255);
        possible_colors[2][G] = CLAMP(0,colors[1][G] + table58H[d],255);
        possible_colors[2][B] = CLAMP(0,colors[1][B] + table58H[d],255);
    } 
    else 
    {
        printf("Invalid pattern. Terminating");
        exit(1);
    }
}

// Decompress an H-mode block 
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockTHUMB58Hc(unsigned int block_part1, unsigned int block_part2, uint8 *img, int width, int height, int startx, int starty, int channels)
{

    UNREFERENCED_PARAMETER(height);
    unsigned int col0, col1;
    uint8 colors[2][3];
    uint8 colorsRGB444[2][3];
    uint8 paint_colors[4][3];
    uint8 distance;
    uint8 block_mask[4][4];
    
    // First decode left part of block.
    colorsRGB444[0][R]= GETBITSHIGH(block_part1, 4, 57);
    colorsRGB444[0][G]= GETBITSHIGH(block_part1, 4, 53);
    colorsRGB444[0][B]= GETBITSHIGH(block_part1, 4, 49);

    colorsRGB444[1][R]= GETBITSHIGH(block_part1, 4, 45);
    colorsRGB444[1][G]= GETBITSHIGH(block_part1, 4, 41);
    colorsRGB444[1][B]= GETBITSHIGH(block_part1, 4, 37);

    distance = 0;
    distance = (GETBITSHIGH(block_part1, 2, 33)) << 1;

    col0 = GETBITSHIGH(block_part1, 12, 57);
    col1 = GETBITSHIGH(block_part1, 12, 45);

    if(col0 >= col1)
    {
        distance |= 1;
    }

    // Extend the two colors to RGB888    
    decompressColor(R_BITS58H, G_BITS58H, B_BITS58H, colorsRGB444, colors);    
    
    calculatePaintColors58H(distance, PATTERN_H, colors, paint_colors);
    
    // Choose one of the four paint colors for each texel
    for (uint8 x = 0; x < BLOCKWIDTH; ++x) 
    {
        for (uint8 y = 0; y < BLOCKHEIGHT; ++y) 
        {
            //block_mask[x][y] = GETBITS(block_part2,2,31-(y*4+x)*2);
            block_mask[x][y] = GETBITS(block_part2,1,(y+x*4)+16)<<1;
            block_mask[x][y] |= GETBITS(block_part2,1,(y+x*4));
            img[channels*((starty+y)*width+startx+x)+R] =
                CLAMP(0,paint_colors[block_mask[x][y]][R],255); // RED
            img[channels*((starty+y)*width+startx+x)+G] =
                CLAMP(0,paint_colors[block_mask[x][y]][G],255); // GREEN
            img[channels*((starty+y)*width+startx+x)+B] =
                CLAMP(0,paint_colors[block_mask[x][y]][B],255); // BLUE
        }
    }
}
void decompressBlockTHUMB58H(unsigned int block_part1, unsigned int block_part2, uint8 *img, int width, int height, int startx, int starty)
{
  decompressBlockTHUMB58Hc(block_part1, block_part2, img, width, height, startx, starty, 3);
}

// Decompress the planar mode.
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockPlanar57c(unsigned int compressed57_1, unsigned int compressed57_2, uint8 *img, int width, int height, int startx, int starty, int channels)
{

    UNREFERENCED_PARAMETER(height);
    uint8 colorO[3], colorH[3], colorV[3];

    colorO[0] = GETBITSHIGH( compressed57_1, 6, 63);
    colorO[1] = GETBITSHIGH( compressed57_1, 7, 57);
    colorO[2] = GETBITSHIGH( compressed57_1, 6, 50);
    colorH[0] = GETBITSHIGH( compressed57_1, 6, 44);
    colorH[1] = GETBITSHIGH( compressed57_1, 7, 38);
    colorH[2] = GETBITS(     compressed57_2, 6, 31);
    colorV[0] = GETBITS(     compressed57_2, 6, 25);
    colorV[1] = GETBITS(     compressed57_2, 7, 19);
    colorV[2] = GETBITS(     compressed57_2, 6, 12);

    colorO[0] = (colorO[0] << 2) | (colorO[0] >> 4);
    colorO[1] = (colorO[1] << 1) | (colorO[1] >> 6);
    colorO[2] = (colorO[2] << 2) | (colorO[2] >> 4);

    colorH[0] = (colorH[0] << 2) | (colorH[0] >> 4);
    colorH[1] = (colorH[1] << 1) | (colorH[1] >> 6);
    colorH[2] = (colorH[2] << 2) | (colorH[2] >> 4);

    colorV[0] = (colorV[0] << 2) | (colorV[0] >> 4);
    colorV[1] = (colorV[1] << 1) | (colorV[1] >> 6);
    colorV[2] = (colorV[2] << 2) | (colorV[2] >> 4);

    int xx, yy;

    for( xx=0; xx<4; xx++)
    {
        for( yy=0; yy<4; yy++)
        {
            img[channels*width*(starty+yy) + channels*(startx+xx) + 0] = (uint8)CLAMP(0, ((xx*(colorH[0]-colorO[0]) + yy*(colorV[0]-colorO[0]) + 4*colorO[0] + 2) >> 2),255);
            img[channels*width*(starty+yy) + channels*(startx+xx) + 1] = (uint8)CLAMP(0, ((xx*(colorH[1]-colorO[1]) + yy*(colorV[1]-colorO[1]) + 4*colorO[1] + 2) >> 2),255);
            img[channels*width*(starty+yy) + channels*(startx+xx) + 2] = (uint8)CLAMP(0, ((xx*(colorH[2]-colorO[2]) + yy*(colorV[2]-colorO[2]) + 4*colorO[2] + 2) >> 2),255);

            //Equivalent method
            /*img[channels*width*(starty+yy) + channels*(startx+xx) + 0] = (int)CLAMP(0, JAS_ROUND((xx*(colorH[0]-colorO[0])/4.0 + yy*(colorV[0]-colorO[0])/4.0 + colorO[0])), 255);
            img[channels*width*(starty+yy) + channels*(startx+xx) + 1] = (int)CLAMP(0, JAS_ROUND((xx*(colorH[1]-colorO[1])/4.0 + yy*(colorV[1]-colorO[1])/4.0 + colorO[1])), 255);
            img[channels*width*(starty+yy) + channels*(startx+xx) + 2] = (int)CLAMP(0, JAS_ROUND((xx*(colorH[2]-colorO[2])/4.0 + yy*(colorV[2]-colorO[2])/4.0 + colorO[2])), 255);*/
            
        }
    }
}
void decompressBlockPlanar57(unsigned int compressed57_1, unsigned int compressed57_2, uint8 *img, int width, int height, int startx, int starty)
{
  decompressBlockPlanar57c(compressed57_1, compressed57_2, img, width, height, startx, starty, 3);
}
// Decompress an ETC1 block (or ETC2 using individual or differential mode).
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockDiffFlipC(unsigned int block_part1, unsigned int block_part2, uint8 *img, int width, int height, int startx, int starty, int channels)
{

    UNREFERENCED_PARAMETER(height);
    uint8 avg_color[3], enc_color1[3], enc_color2[3];
    signed char diff[3];
    int table;
    int index,shift;
    int r,g,b;
    int diffbit;
    int flipbit;

    diffbit = (GETBITSHIGH(block_part1, 1, 33));
    flipbit = (GETBITSHIGH(block_part1, 1, 32));

    if( !diffbit )
    {
        // We have diffbit = 0.

        // First decode left part of block.
        avg_color[0]= GETBITSHIGH(block_part1, 4, 63);
        avg_color[1]= GETBITSHIGH(block_part1, 4, 55);
        avg_color[2]= GETBITSHIGH(block_part1, 4, 47);

        // Here, we should really multiply by 17 instead of 16. This can
        // be done by just copying the four lower bits to the upper ones
        // while keeping the lower bits.
        avg_color[0] |= (avg_color[0] <<4);
        avg_color[1] |= (avg_color[1] <<4);
        avg_color[2] |= (avg_color[2] <<4);

        table = GETBITSHIGH(block_part1, 3, 39) << 1;

        unsigned int pixel_indices_MSB, pixel_indices_LSB;
            
        pixel_indices_MSB = GETBITS(block_part2, 16, 31);
        pixel_indices_LSB = GETBITS(block_part2, 16, 15);

        if( (flipbit) == 0 )
        {
            // We should not flip
            shift = 0;
            for(int x=startx; x<startx+2; x++)
            {
                for(int y=starty; y<starty+4; y++)
                {
                    index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                    index |= ((pixel_indices_LSB >> shift) & 1);
                    shift++;
                    index=unscramble[index];

                     r = RED_CHANNEL(img, width, x, y, channels)  = (uint8)CLAMP(0, avg_color[0] + compressParams[table][index], 255);
                     g = GREEN_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0, avg_color[1] + compressParams[table][index], 255);
                     b = BLUE_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0,avg_color[2]+compressParams[table][index],255);
                }
            }
        }
        else
        {
            // We should flip
            shift = 0;
            for(int x=startx; x<startx+4; x++)
            {
                for(int y=starty; y<starty+2; y++)
                {
                    index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                    index |= ((pixel_indices_LSB >> shift) & 1);
                    shift++;
                    index=unscramble[index];

                     r = RED_CHANNEL(img, width, x, y, channels)  = (uint8)CLAMP(0, avg_color[0] + compressParams[table][index], 255);
                     g = GREEN_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0, avg_color[1] + compressParams[table][index], 255);
                     b = BLUE_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0,avg_color[2]+compressParams[table][index],255);
                }
                shift+=2;
            }
        }

        // Now decode other part of block. 
        avg_color[0]= GETBITSHIGH(block_part1, 4, 59);
        avg_color[1]= GETBITSHIGH(block_part1, 4, 51);
        avg_color[2]= GETBITSHIGH(block_part1, 4, 43);

        // Here, we should really multiply by 17 instead of 16. This can
        // be done by just copying the four lower bits to the upper ones
        // while keeping the lower bits.
        avg_color[0] |= (avg_color[0] <<4);
        avg_color[1] |= (avg_color[1] <<4);
        avg_color[2] |= (avg_color[2] <<4);

        table = GETBITSHIGH(block_part1, 3, 36) << 1;
        pixel_indices_MSB = GETBITS(block_part2, 16, 31);
        pixel_indices_LSB = GETBITS(block_part2, 16, 15);

        if( (flipbit) == 0 )
        {
            // We should not flip
            shift=8;
            for(int x=startx+2; x<startx+4; x++)
            {
                for(int y=starty; y<starty+4; y++)
                {
                    index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                    index |= ((pixel_indices_LSB >> shift) & 1);
                    shift++;
                    index=unscramble[index];

                     r = RED_CHANNEL(img, width, x, y, channels)  = (uint8)CLAMP(0, avg_color[0] + compressParams[table][index], 255);
                     g = GREEN_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0, avg_color[1] + compressParams[table][index], 255);
                     b = BLUE_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0,avg_color[2]+compressParams[table][index],255);
                }
            }
        }
        else
        {
            // We should flip
            shift=2;
            for(int x=startx; x<startx+4; x++)
            {
                for(int y=starty+2; y<starty+4; y++)
                {
                    index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                    index |= ((pixel_indices_LSB >> shift) & 1);
                    shift++;
                    index=unscramble[index];

                     r = RED_CHANNEL(img, width, x, y, channels)  = (uint8)CLAMP(0, avg_color[0] + compressParams[table][index], 255);
                     g = GREEN_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0, avg_color[1] + compressParams[table][index], 255);
                     b = BLUE_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0,avg_color[2]+compressParams[table][index],255);
                }
                shift += 2;
            }
        }
    }
    else
    {
        // We have diffbit = 1. 

//      63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34  33  32 
//      ---------------------------------------------------------------------------------------------------
//     | base col1    | dcol 2 | base col1    | dcol 2 | base col 1   | dcol 2 | table  | table  |diff|flip|
//     | R1' (5 bits) | dR2    | G1' (5 bits) | dG2    | B1' (5 bits) | dB2    | cw 1   | cw 2   |bit |bit |
//      ---------------------------------------------------------------------------------------------------
// 
// 
//     c) bit layout in bits 31 through 0 (in both cases)
// 
//      31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3   2   1  0
//      --------------------------------------------------------------------------------------------------
//     |       most significant pixel index bits       |         least significant pixel index bits       |  
//     | p| o| n| m| l| k| j| i| h| g| f| e| d| c| b| a| p| o| n| m| l| k| j| i| h| g| f| e| d| c | b | a |
//      --------------------------------------------------------------------------------------------------      

        // First decode left part of block.
        enc_color1[0]= GETBITSHIGH(block_part1, 5, 63);
        enc_color1[1]= GETBITSHIGH(block_part1, 5, 55);
        enc_color1[2]= GETBITSHIGH(block_part1, 5, 47);

        // Expand from 5 to 8 bits
        avg_color[0] = (enc_color1[0] <<3) | (enc_color1[0] >> 2);
        avg_color[1] = (enc_color1[1] <<3) | (enc_color1[1] >> 2);
        avg_color[2] = (enc_color1[2] <<3) | (enc_color1[2] >> 2);

        table = GETBITSHIGH(block_part1, 3, 39) << 1;

        unsigned int pixel_indices_MSB, pixel_indices_LSB;
            
        pixel_indices_MSB = GETBITS(block_part2, 16, 31);
        pixel_indices_LSB = GETBITS(block_part2, 16, 15);

        if( (flipbit) == 0 )
        {
            // We should not flip
            shift = 0;
            for(int x=startx; x<startx+2; x++)
            {
                for(int y=starty; y<starty+4; y++)
                {
                    index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                    index |= ((pixel_indices_LSB >> shift) & 1);
                    shift++;
                    index=unscramble[index];

                     r = RED_CHANNEL(img, width, x, y, channels)  = (uint8)CLAMP(0, avg_color[0] + compressParams[table][index], 255);
                     g = GREEN_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0, avg_color[1] + compressParams[table][index], 255);
                     b = BLUE_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0,avg_color[2]+compressParams[table][index],255);
                }
            }
        }
        else
        {
            // We should flip
            shift = 0;
            for(int x=startx; x<startx+4; x++)
            {
                for(int y=starty; y<starty+2; y++)
                {
                    index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                    index |= ((pixel_indices_LSB >> shift) & 1);
                    shift++;
                    index=unscramble[index];

                     r = RED_CHANNEL(img, width, x, y, channels)  = (uint8)CLAMP(0, avg_color[0] + compressParams[table][index], 255);
                     g = GREEN_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0, avg_color[1] + compressParams[table][index], 255);
                     b = BLUE_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0,avg_color[2]+compressParams[table][index],255);
                }
                shift+=2;
            }
        }

        // Now decode right part of block. 
        diff[0]= GETBITSHIGH(block_part1, 3, 58);
        diff[1]= GETBITSHIGH(block_part1, 3, 50);
        diff[2]= GETBITSHIGH(block_part1, 3, 42);

        // Extend sign bit to entire byte. 
        diff[0] = (diff[0] << 5);
        diff[1] = (diff[1] << 5);
        diff[2] = (diff[2] << 5);
        diff[0] = diff[0] >> 5;
        diff[1] = diff[1] >> 5;
        diff[2] = diff[2] >> 5;

        //  Calculale second color
        enc_color2[0]= enc_color1[0] + diff[0];
        enc_color2[1]= enc_color1[1] + diff[1];
        enc_color2[2]= enc_color1[2] + diff[2];

        // Expand from 5 to 8 bits
        avg_color[0] = (enc_color2[0] <<3) | (enc_color2[0] >> 2);
        avg_color[1] = (enc_color2[1] <<3) | (enc_color2[1] >> 2);
        avg_color[2] = (enc_color2[2] <<3) | (enc_color2[2] >> 2);

        table = GETBITSHIGH(block_part1, 3, 36) << 1;
        pixel_indices_MSB = GETBITS(block_part2, 16, 31);
        pixel_indices_LSB = GETBITS(block_part2, 16, 15);

        if( (flipbit) == 0 )
        {
            // We should not flip
            shift=8;
            for(int x=startx+2; x<startx+4; x++)
            {
                for(int y=starty; y<starty+4; y++)
                {
                    index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                    index |= ((pixel_indices_LSB >> shift) & 1);
                    shift++;
                    index=unscramble[index];

                     r = RED_CHANNEL(img, width, x, y, channels)  = (uint8)CLAMP(0, avg_color[0] + compressParams[table][index], 255);
                     g = GREEN_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0, avg_color[1] + compressParams[table][index], 255);
                     b = BLUE_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0,avg_color[2]+compressParams[table][index],255);
                }
            }
        }
        else
        {
            // We should flip
            shift=2;
            for(int x=startx; x<startx+4; x++)
            {
                for(int y=starty+2; y<starty+4; y++)
                {
                    index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                    index |= ((pixel_indices_LSB >> shift) & 1);
                    shift++;
                    index=unscramble[index];

                     r = RED_CHANNEL(img, width, x, y, channels)  = (uint8)CLAMP(0, avg_color[0] + compressParams[table][index], 255);
                     g = GREEN_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0, avg_color[1] + compressParams[table][index], 255);
                     b = BLUE_CHANNEL(img, width, x, y, channels) = (uint8)CLAMP(0,avg_color[2]+compressParams[table][index],255);
                }
                shift += 2;
            }
        }
    }
}
void decompressBlockDiffFlip(unsigned int block_part1, unsigned int block_part2, uint8 *img, int width, int height, int startx, int starty)
{
    decompressBlockDiffFlipC(block_part1, block_part2, img, width, height, startx, starty, 3);
}

// Decompress an ETC2 RGB block
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockETC2c(unsigned int block_part1, unsigned int block_part2, uint8 *img, int width, int height, int startx, int starty, int channels)
{
    int diffbit;
    signed char color1[3];
    signed char diff[3];
    signed char red, green, blue;

    diffbit = (GETBITSHIGH(block_part1, 1, 33));

    if( diffbit )
    {
        // We have diffbit = 1;

        // Base color
        color1[0]= GETBITSHIGH(block_part1, 5, 63);
        color1[1]= GETBITSHIGH(block_part1, 5, 55);
        color1[2]= GETBITSHIGH(block_part1, 5, 47);

        // Diff color
        diff[0]= GETBITSHIGH(block_part1, 3, 58);
        diff[1]= GETBITSHIGH(block_part1, 3, 50);
        diff[2]= GETBITSHIGH(block_part1, 3, 42);

        // Extend sign bit to entire byte. 
        diff[0] = (diff[0] << 5);
        diff[1] = (diff[1] << 5);
        diff[2] = (diff[2] << 5);
        diff[0] = diff[0] >> 5;
        diff[1] = diff[1] >> 5;
        diff[2] = diff[2] >> 5;

        red   = color1[0] + diff[0];
        green = color1[1] + diff[1];
        blue  = color1[2] + diff[2];

        if(red < 0 || red > 31)
        {
            unsigned int block59_part1, block59_part2;
            unstuff59bits(block_part1, block_part2, block59_part1, block59_part2);
            decompressBlockTHUMB59Tc(block59_part1, block59_part2, img, width, height, startx, starty, channels);
        }
        else if (green < 0 || green > 31)
        {
            unsigned int block58_part1, block58_part2;
            unstuff58bits(block_part1, block_part2, block58_part1, block58_part2);
            decompressBlockTHUMB58Hc(block58_part1, block58_part2, img, width, height, startx, starty, channels);
        }
        else if(blue < 0 || blue > 31)
        {
            unsigned int block57_part1, block57_part2;

            unstuff57bits(block_part1, block_part2, block57_part1, block57_part2);
            decompressBlockPlanar57c(block57_part1, block57_part2, img, width, height, startx, starty, channels);
        }
        else
        {
             decompressBlockDiffFlipC(block_part1, block_part2, img, width, height, startx, starty, channels);
        }
    }
    else
    {
        // We have diffbit = 0;
        decompressBlockDiffFlipC(block_part1, block_part2, img, width, height, startx, starty, channels);
    }
}
void decompressBlockETC2(unsigned int block_part1, unsigned int block_part2, uint8 *img, int width, int height, int startx, int starty)
{
    decompressBlockETC2c(block_part1, block_part2, img, width, height, startx, starty, 3);
}
// Decompress an ETC2 block with punchthrough alpha
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockDifferentialWithAlphaC(unsigned int block_part1, unsigned int block_part2, uint8* img, uint8* alpha, int width, int height, int startx, int starty, int channelsRGB)
{

    UNREFERENCED_PARAMETER(height);

    uint8 avg_color[3], enc_color1[3], enc_color2[3];
    signed char diff[3];
    int table;
    int index,shift;
    int r,g,b;
    int diffbit;
    int flipbit;
    int channelsA;

    if(channelsRGB == 3)
    {
        // We will decode the alpha data to a separate memory area. 
        channelsA = 1;
    }
    else
    {
        // We will decode the RGB data and the alpha data to the same memory area, 
        // interleaved as RGBA. 
        channelsA = 4;
        alpha = &img[0+3];
    }

    //the diffbit now encodes whether or not the entire alpha channel is 255.
    diffbit = (GETBITSHIGH(block_part1, 1, 33));
    flipbit = (GETBITSHIGH(block_part1, 1, 32));

    // First decode left part of block.
    enc_color1[0]= GETBITSHIGH(block_part1, 5, 63);
    enc_color1[1]= GETBITSHIGH(block_part1, 5, 55);
    enc_color1[2]= GETBITSHIGH(block_part1, 5, 47);

    // Expand from 5 to 8 bits
    avg_color[0] = (enc_color1[0] <<3) | (enc_color1[0] >> 2);
    avg_color[1] = (enc_color1[1] <<3) | (enc_color1[1] >> 2);
    avg_color[2] = (enc_color1[2] <<3) | (enc_color1[2] >> 2);

    table = GETBITSHIGH(block_part1, 3, 39) << 1;

    unsigned int pixel_indices_MSB, pixel_indices_LSB;
        
    pixel_indices_MSB = GETBITS(block_part2, 16, 31);
    pixel_indices_LSB = GETBITS(block_part2, 16, 15);

    if( (flipbit) == 0 )
    {
        // We should not flip
        shift = 0;
        for(int x=startx; x<startx+2; x++)
        {
            for(int y=starty; y<starty+4; y++)
            {
                index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                index |= ((pixel_indices_LSB >> shift) & 1);
                shift++;
                index=unscramble[index];

                int mod = compressParams[table][index];
                if(diffbit==0&&(index==1||index==2)) 
                {
                    mod=0;
                }
                
                r=RED_CHANNEL(img,width,x,y,channelsRGB)  = (uint8)CLAMP(0, avg_color[0] + mod, 255);
                g = GREEN_CHANNEL(img, width, x, y, channelsRGB) = (uint8)CLAMP(0, avg_color[1] + mod, 255);
                b = BLUE_CHANNEL(img, width, x, y, channelsRGB) = (uint8)CLAMP(0,avg_color[2]+mod,255);
                if(diffbit==0&&index==1) 
                {
                    alpha[(y*width+x)*channelsA]=0;
                    r=RED_CHANNEL(img,width,x,y,channelsRGB)=0;
                    g=GREEN_CHANNEL(img,width,x,y,channelsRGB)=0;
                    b=BLUE_CHANNEL(img,width,x,y,channelsRGB)=0;
                }
                else 
                {
                    alpha[(y*width+x)*channelsA]=255;
                }

            }
        }
    }
    else
    {
        // We should flip
        shift = 0;
        for(int x=startx; x<startx+4; x++)
        {
            for(int y=starty; y<starty+2; y++)
            {
                index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                index |= ((pixel_indices_LSB >> shift) & 1);
                shift++;
                index=unscramble[index];
                int mod = compressParams[table][index];
                if(diffbit==0&&(index==1||index==2)) 
                {
                    mod=0;
                }
                r=RED_CHANNEL(img,width,x,y,channelsRGB)  = (uint8)CLAMP(0, avg_color[0] + mod, 255);
                g = GREEN_CHANNEL(img, width, x, y, channelsRGB) = (uint8)CLAMP(0, avg_color[1] + mod, 255);
                b = BLUE_CHANNEL(img, width, x, y, channelsRGB) = (uint8)CLAMP(0,avg_color[2]+mod,255);
                if(diffbit==0&&index==1) 
                {
                    alpha[(y*width+x)*channelsA]=0;
                    r=RED_CHANNEL(img,width,x,y,channelsRGB)=0;
                    g=GREEN_CHANNEL(img,width,x,y,channelsRGB)=0;
                    b=BLUE_CHANNEL(img,width,x,y,channelsRGB)=0;
                }
                else 
                {
                    alpha[(y*width+x)*channelsA]=255;
                }
            }
            shift+=2;
        }
    }
    // Now decode right part of block. 
    diff[0]= GETBITSHIGH(block_part1, 3, 58);
    diff[1]= GETBITSHIGH(block_part1, 3, 50);
    diff[2]= GETBITSHIGH(block_part1, 3, 42);

    // Extend sign bit to entire byte. 
    diff[0] = (diff[0] << 5);
    diff[1] = (diff[1] << 5);
    diff[2] = (diff[2] << 5);
    diff[0] = diff[0] >> 5;
    diff[1] = diff[1] >> 5;
    diff[2] = diff[2] >> 5;

    //  Calculate second color
    enc_color2[0]= enc_color1[0] + diff[0];
    enc_color2[1]= enc_color1[1] + diff[1];
    enc_color2[2]= enc_color1[2] + diff[2];

    // Expand from 5 to 8 bits
    avg_color[0] = (enc_color2[0] <<3) | (enc_color2[0] >> 2);
    avg_color[1] = (enc_color2[1] <<3) | (enc_color2[1] >> 2);
    avg_color[2] = (enc_color2[2] <<3) | (enc_color2[2] >> 2);

    table = GETBITSHIGH(block_part1, 3, 36) << 1;
    pixel_indices_MSB = GETBITS(block_part2, 16, 31);
    pixel_indices_LSB = GETBITS(block_part2, 16, 15);

    if( (flipbit) == 0 )
    {
        // We should not flip
        shift=8;
        for(int x=startx+2; x<startx+4; x++)
        {
            for(int y=starty; y<starty+4; y++)
            {
                index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                index |= ((pixel_indices_LSB >> shift) & 1);
                shift++;
                index=unscramble[index];
                int mod = compressParams[table][index];
                if(diffbit==0&&(index==1||index==2)) 
                {
                    mod=0;
                }
                
                r = RED_CHANNEL(img, width, x, y, channelsRGB)  = (uint8)CLAMP(0, avg_color[0] + mod, 255);
                g = GREEN_CHANNEL(img, width, x, y, channelsRGB) = (uint8)CLAMP(0, avg_color[1] + mod, 255);
                b = BLUE_CHANNEL(img, width, x, y, channelsRGB) = (uint8)CLAMP(0,avg_color[2]+mod,255);
                if(diffbit==0&&index==1) 
                {
                    alpha[(y*width+x)*channelsA]=0;
                    r=RED_CHANNEL(img,width,x,y,channelsRGB)=0;
                    g=GREEN_CHANNEL(img,width,x,y,channelsRGB)=0;
                    b=BLUE_CHANNEL(img,width,x,y,channelsRGB)=0;
                }
                else 
                {
                    alpha[(y*width+x)*channelsA]=255;
                }
            }
        }
    }
    else
    {
        // We should flip
        shift=2;
        for(int x=startx; x<startx+4; x++)
        {
            for(int y=starty+2; y<starty+4; y++)
            {
                index  = ((pixel_indices_MSB >> shift) & 1) << 1;
                index |= ((pixel_indices_LSB >> shift) & 1);
                shift++;
                index=unscramble[index];
                int mod = compressParams[table][index];
                if(diffbit==0&&(index==1||index==2)) 
                {
                    mod=0;
                }
                
                r = RED_CHANNEL(img, width, x, y, channelsRGB)  = (uint8)CLAMP(0, avg_color[0] + mod, 255);
                g = GREEN_CHANNEL(img, width, x, y, channelsRGB) = (uint8)CLAMP(0, avg_color[1] + mod, 255);
                b = BLUE_CHANNEL(img, width, x, y, channelsRGB) = (uint8)CLAMP(0,avg_color[2]+mod,255);
                if(diffbit==0&&index==1) 
                {
                    alpha[(y*width+x)*channelsA]=0;
                    r=RED_CHANNEL(img,width,x,y,channelsRGB)=0;
                    g=GREEN_CHANNEL(img,width,x,y,channelsRGB)=0;
                    b=BLUE_CHANNEL(img,width,x,y,channelsRGB)=0;
                }
                else 
                {
                    alpha[(y*width+x)*channelsA]=255;
                }
            }
            shift += 2;
        }
    }
}
void decompressBlockDifferentialWithAlpha(unsigned int block_part1, unsigned int block_part2, uint8* img, uint8* alpha, int width, int height, int startx, int starty)
{
    decompressBlockDifferentialWithAlphaC(block_part1, block_part2, img, alpha, width, height, startx, starty, 3);
}


// similar to regular decompression, but alpha channel is set to 0 if pixel index is 2, otherwise 255.
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockTHUMB59TAlphaC(unsigned int block_part1, unsigned int block_part2, uint8 *img, uint8* alpha, int width, int height, int startx, int starty, int channelsRGB)
{

    UNREFERENCED_PARAMETER(height);

    uint8 colorsRGB444[2][3];
    uint8 colors[2][3];
    uint8 paint_colors[4][3];
    uint8 distance;
    uint8 block_mask[4][4];
    int channelsA;

    if(channelsRGB == 3)
    {
        // We will decode the alpha data to a separate memory area. 
        channelsA = 1;
    }
    else
    {
        // We will decode the RGB data and the alpha data to the same memory area, 
        // interleaved as RGBA. 
        channelsA = 4;
        alpha = &img[0+3];
    }

    // First decode left part of block.
    colorsRGB444[0][R]= GETBITSHIGH(block_part1, 4, 58);
    colorsRGB444[0][G]= GETBITSHIGH(block_part1, 4, 54);
    colorsRGB444[0][B]= GETBITSHIGH(block_part1, 4, 50);

    colorsRGB444[1][R]= GETBITSHIGH(block_part1, 4, 46);
    colorsRGB444[1][G]= GETBITSHIGH(block_part1, 4, 42);
    colorsRGB444[1][B]= GETBITSHIGH(block_part1, 4, 38);

    distance   = GETBITSHIGH(block_part1, TABLE_BITS_59T, 34);

    // Extend the two colors to RGB888    
    decompressColor(R_BITS59T, G_BITS59T, B_BITS59T, colorsRGB444, colors);    
    calculatePaintColors59T(distance, PATTERN_T, colors, paint_colors);
    
    // Choose one of the four paint colors for each texel
    for (uint8 x = 0; x < BLOCKWIDTH; ++x) 
    {
        for (uint8 y = 0; y < BLOCKHEIGHT; ++y) 
        {
            //block_mask[x][y] = GETBITS(block_part2,2,31-(y*4+x)*2);
            block_mask[x][y] = GETBITS(block_part2,1,(y+x*4)+16)<<1;
            block_mask[x][y] |= GETBITS(block_part2,1,(y+x*4));
            img[channelsRGB*((starty+y)*width+startx+x)+R] = 
                CLAMP(0,paint_colors[block_mask[x][y]][R],255); // RED
            img[channelsRGB*((starty+y)*width+startx+x)+G] =
                CLAMP(0,paint_colors[block_mask[x][y]][G],255); // GREEN
            img[channelsRGB*((starty+y)*width+startx+x)+B] =
                CLAMP(0,paint_colors[block_mask[x][y]][B],255); // BLUE
            if(block_mask[x][y]==2)  
            {
                alpha[channelsA*(x+startx+(y+starty)*width)]=0;
                img[channelsRGB*((starty+y)*width+startx+x)+R] =0;
                img[channelsRGB*((starty+y)*width+startx+x)+G] =0;
                img[channelsRGB*((starty+y)*width+startx+x)+B] =0;
            }
            else
                alpha[channelsA*(x+startx+(y+starty)*width)]=255;
        }
    }
}
void decompressBlockTHUMB59TAlpha(unsigned int block_part1, unsigned int block_part2, uint8 *img, uint8* alpha, int width, int height, int startx, int starty)
{
    decompressBlockTHUMB59TAlphaC(block_part1, block_part2, img, alpha, width, height, startx, starty, 3);
}


// Decompress an H-mode block with alpha
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockTHUMB58HAlphaC(unsigned int block_part1, unsigned int block_part2, uint8 *img, uint8* alpha, int width, int height, int startx, int starty, int channelsRGB)
{

    UNREFERENCED_PARAMETER(height);

    unsigned int col0, col1;
    uint8 colors[2][3];
    uint8 colorsRGB444[2][3];
    uint8 paint_colors[4][3];
    uint8 distance;
    uint8 block_mask[4][4];
    int channelsA;    

    if(channelsRGB == 3)
    {
        // We will decode the alpha data to a separate memory area. 
        channelsA = 1;
    }
    else
    {
        // We will decode the RGB data and the alpha data to the same memory area, 
        // interleaved as RGBA. 
        channelsA = 4;
        alpha = &img[0+3];
    }

    // First decode left part of block.
    colorsRGB444[0][R]= GETBITSHIGH(block_part1, 4, 57);
    colorsRGB444[0][G]= GETBITSHIGH(block_part1, 4, 53);
    colorsRGB444[0][B]= GETBITSHIGH(block_part1, 4, 49);

    colorsRGB444[1][R]= GETBITSHIGH(block_part1, 4, 45);
    colorsRGB444[1][G]= GETBITSHIGH(block_part1, 4, 41);
    colorsRGB444[1][B]= GETBITSHIGH(block_part1, 4, 37);

    distance = 0;
    distance = (GETBITSHIGH(block_part1, 2, 33)) << 1;

    col0 = GETBITSHIGH(block_part1, 12, 57);
    col1 = GETBITSHIGH(block_part1, 12, 45);

    if(col0 >= col1)
    {
        distance |= 1;
    }

    // Extend the two colors to RGB888    
    decompressColor(R_BITS58H, G_BITS58H, B_BITS58H, colorsRGB444, colors);    
    
    calculatePaintColors58H(distance, PATTERN_H, colors, paint_colors);
    
    // Choose one of the four paint colors for each texel
    for (uint8 x = 0; x < BLOCKWIDTH; ++x) 
    {
        for (uint8 y = 0; y < BLOCKHEIGHT; ++y) 
        {
            //block_mask[x][y] = GETBITS(block_part2,2,31-(y*4+x)*2);
            block_mask[x][y] = GETBITS(block_part2,1,(y+x*4)+16)<<1;
            block_mask[x][y] |= GETBITS(block_part2,1,(y+x*4));
            img[channelsRGB*((starty+y)*width+startx+x)+R] =
                CLAMP(0,paint_colors[block_mask[x][y]][R],255); // RED
            img[channelsRGB*((starty+y)*width+startx+x)+G] =
                CLAMP(0,paint_colors[block_mask[x][y]][G],255); // GREEN
            img[channelsRGB*((starty+y)*width+startx+x)+B] =
                CLAMP(0,paint_colors[block_mask[x][y]][B],255); // BLUE
            
            if(block_mask[x][y]==2)  
            {
                alpha[channelsA*(x+startx+(y+starty)*width)]=0;
                img[channelsRGB*((starty+y)*width+startx+x)+R] =0;
                img[channelsRGB*((starty+y)*width+startx+x)+G] =0;
                img[channelsRGB*((starty+y)*width+startx+x)+B] =0;
            }
            else
                alpha[channelsA*(x+startx+(y+starty)*width)]=255;
        }
    }
}
void decompressBlockTHUMB58HAlpha(unsigned int block_part1, unsigned int block_part2, uint8 *img, uint8* alpha, int width, int height, int startx, int starty)
{
    decompressBlockTHUMB58HAlphaC(block_part1, block_part2, img, alpha, width, height, startx, starty, 3);
}
// Decompression function for ETC2_RGBA1 format.
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockETC21BitAlphaC(unsigned int block_part1, unsigned int block_part2, uint8 *img, uint8* alphaimg, int width, int height, int startx, int starty, int channelsRGB)
{
    int diffbit;
    signed char color1[3];
    signed char diff[3];
    signed char red, green, blue;
    int channelsA;    

    if(channelsRGB == 3)
    {
        // We will decode the alpha data to a separate memory area. 
        channelsA = 1;
    }
    else
    {
        // We will decode the RGB data and the alpha data to the same memory area, 
        // interleaved as RGBA. 
        channelsA = 4;
        alphaimg = &img[0+3];
    }

    diffbit = (GETBITSHIGH(block_part1, 1, 33));

    if( diffbit )
    {
        // We have diffbit = 1, meaning no transparent pixels. regular decompression.

        // Base color
        color1[0]= GETBITSHIGH(block_part1, 5, 63);
        color1[1]= GETBITSHIGH(block_part1, 5, 55);
        color1[2]= GETBITSHIGH(block_part1, 5, 47);

        // Diff color
        diff[0]= GETBITSHIGH(block_part1, 3, 58);
        diff[1]= GETBITSHIGH(block_part1, 3, 50);
        diff[2]= GETBITSHIGH(block_part1, 3, 42);

        // Extend sign bit to entire byte. 
        diff[0] = (diff[0] << 5);
        diff[1] = (diff[1] << 5);
        diff[2] = (diff[2] << 5);
        diff[0] = diff[0] >> 5;
        diff[1] = diff[1] >> 5;
        diff[2] = diff[2] >> 5;

        red   = color1[0] + diff[0];
        green = color1[1] + diff[1];
        blue  = color1[2] + diff[2];

        if(red < 0 || red > 31)
        {
            unsigned int block59_part1, block59_part2;
            unstuff59bits(block_part1, block_part2, block59_part1, block59_part2);
            decompressBlockTHUMB59Tc(block59_part1, block59_part2, img, width, height, startx, starty, channelsRGB);
        }
        else if (green < 0 || green > 31)
        {
            unsigned int block58_part1, block58_part2;
            unstuff58bits(block_part1, block_part2, block58_part1, block58_part2);
            decompressBlockTHUMB58Hc(block58_part1, block58_part2, img, width, height, startx, starty, channelsRGB);
        }
        else if(blue < 0 || blue > 31)
        {
            unsigned int block57_part1, block57_part2;

            unstuff57bits(block_part1, block_part2, block57_part1, block57_part2);
            decompressBlockPlanar57c(block57_part1, block57_part2, img, width, height, startx, starty, channelsRGB);
        }
        else
        {
             decompressBlockDifferentialWithAlphaC(block_part1, block_part2, img, alphaimg, width, height, startx, starty, channelsRGB);
        }
        for(int x=startx; x<startx+4; x++) 
        {
            for(int y=starty; y<starty+4; y++) 
            {
                alphaimg[channelsA*(x+y*width)]=255;
            }
        }
    }
    else
    {
        // We have diffbit = 0, transparent pixels. Only T-, H- or regular diff-mode possible.
        
        // Base color
        color1[0]= GETBITSHIGH(block_part1, 5, 63);
        color1[1]= GETBITSHIGH(block_part1, 5, 55);
        color1[2]= GETBITSHIGH(block_part1, 5, 47);

        // Diff color
        diff[0]= GETBITSHIGH(block_part1, 3, 58);
        diff[1]= GETBITSHIGH(block_part1, 3, 50);
        diff[2]= GETBITSHIGH(block_part1, 3, 42);

        // Extend sign bit to entire byte. 
        diff[0] = (diff[0] << 5);
        diff[1] = (diff[1] << 5);
        diff[2] = (diff[2] << 5);
        diff[0] = diff[0] >> 5;
        diff[1] = diff[1] >> 5;
        diff[2] = diff[2] >> 5;

        red   = color1[0] + diff[0];
        green = color1[1] + diff[1];
        blue  = color1[2] + diff[2];
        if(red < 0 || red > 31)
        {
            unsigned int block59_part1, block59_part2;
            unstuff59bits(block_part1, block_part2, block59_part1, block59_part2);
            decompressBlockTHUMB59TAlphaC(block59_part1, block59_part2, img, alphaimg, width, height, startx, starty, channelsRGB);
        }
        else if(green < 0 || green > 31) 
        {
            unsigned int block58_part1, block58_part2;
            unstuff58bits(block_part1, block_part2, block58_part1, block58_part2);
            decompressBlockTHUMB58HAlphaC(block58_part1, block58_part2, img, alphaimg, width, height, startx, starty, channelsRGB);
        }
        else if(blue < 0 || blue > 31)
        {
            unsigned int block57_part1, block57_part2;

            unstuff57bits(block_part1, block_part2, block57_part1, block57_part2);
            decompressBlockPlanar57c(block57_part1, block57_part2, img, width, height, startx, starty, channelsRGB);
            for(int x=startx; x<startx+4; x++) 
            {
                for(int y=starty; y<starty+4; y++) 
                {
                    alphaimg[channelsA*(x+y*width)]=255;
                }
            }
        }
        else
            decompressBlockDifferentialWithAlphaC(block_part1, block_part2, img,alphaimg, width, height, startx, starty, channelsRGB);
    }
}
void decompressBlockETC21BitAlpha(unsigned int block_part1, unsigned int block_part2, uint8 *img, uint8* alphaimg, int width, int height, int startx, int starty)
{
  decompressBlockETC21BitAlphaC(block_part1, block_part2, img, alphaimg, width, height, startx, starty, 3);
}
//
//    Utility functions used for alpha compression
//

// bit number frompos is extracted from input, and moved to bit number topos in the return value.
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
uint8 getbit(uint8 input, int frompos, int topos) 
{
    //uint8 output=0;
    if(frompos>topos)
        return ((1<<frompos)&input)>>(frompos-topos);
    return ((1<<frompos)&input)<<(topos-frompos);
}

// takes as input a value, returns the value clamped to the interval [0,255].
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
int clamp(int val) 
{
    if(val<0)
        val=0;
    if(val>255)
        val=255;
    return val;
}

// Decodes tha alpha component in a block coded with GL_COMPRESSED_RGBA8_ETC2_EAC.
// Note that this decoding is slightly different from that of GL_COMPRESSED_R11_EAC.
// However, a hardware decoder can share gates between the two formats as explained
// in the specification under GL_COMPRESSED_R11_EAC.
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockAlphaC(uint8* data, uint8* img, int width, int height, int ix, int iy, int channels) 
{

    UNREFERENCED_PARAMETER(height);

    int alpha = data[0];
    int table = data[1];
    
    int bit=0;
    int byte=2;
    //extract an alpha value for each pixel.
    for(int x=0; x<4; x++) 
    {
        for(int y=0; y<4; y++) 
        {
            //Extract table index
            int index=0;
            for(int bitpos=0; bitpos<3; bitpos++) 
            {
                index|=getbit(data[byte],7-bit,2-bitpos);
                bit++;
                if(bit>7) 
                {
                    bit=0;
                    byte++;
                }
            }
            img[(ix+x+(iy+y)*width)*channels]=(uint8)clamp(alpha +alphaTable[table][index]);
        }
    }
}
void decompressBlockAlpha(uint8* data, uint8* img, int width, int height, int ix, int iy) 
{
    decompressBlockAlphaC(data, img, width, height, ix, iy, 1);
}

// Does decompression and then immediately converts from 11 bit signed to a 16-bit format.
// 
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
int16 get16bits11signed(int base, int table, int mul, int index) 
{
    int elevenbase = base-128;
    if(elevenbase==-128)
        elevenbase=-127;
    elevenbase*=8;
    //i want the positive value here
    int tabVal = -alphaBase[table][3-index%4]-1;
    //and the sign, please
    int sign = 1-(index/4);
    
    if(sign)
        tabVal=tabVal+1;
    int elevenTabVal = tabVal*8;

    if(mul!=0)
        elevenTabVal*=mul;
    else
        elevenTabVal/=8;

    if(sign)
        elevenTabVal=-elevenTabVal;

    //calculate sum
    int elevenbits = elevenbase+elevenTabVal;

    //clamp..
    if(elevenbits>=1024)
        elevenbits=1023;
    else if(elevenbits<-1023)
        elevenbits=-1023;
    //this is the value we would actually output.. 
    //but there aren't any good 11-bit file or uncompressed GL formats
    //so we extend to 15 bits signed.
    sign = elevenbits<0;
    elevenbits=abs(elevenbits);
    int16 fifteenbits = (uint16)((elevenbits<<5)+(elevenbits>>5));
    int16 sixteenbits=fifteenbits;

    if(sign)
        sixteenbits=-sixteenbits;
    
    return sixteenbits;
}

// Does decompression and then immediately converts from 11 bit signed to a 16-bit format 
// Calculates the 11 bit value represented by base, table, mul and index, and extends it to 16 bits.
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
uint16 get16bits11bits(int base, int table, int mul, int index) 
{
    int elevenbase = base*8+4;

    //i want the positive value here
    int tabVal = -alphaBase[table][3-index%4]-1;
    //and the sign, please
    int sign = 1-(index/4);
    
    if(sign)
        tabVal=tabVal+1;
    int elevenTabVal = tabVal*8;

    if(mul!=0)
        elevenTabVal*=mul;
    else
        elevenTabVal/=8;

    if(sign)
        elevenTabVal=-elevenTabVal;

    //calculate sum
    int elevenbits = elevenbase+elevenTabVal;

    //clamp..
    if(elevenbits>=256*8)
        elevenbits=256*8-1;
    else if(elevenbits<0)
        elevenbits=0;
    //elevenbits now contains the 11 bit alpha value as defined in the spec.

    //extend to 16 bits before returning, since we don't have any good 11-bit file formats.
    uint16 sixteenbits = (uint16)((elevenbits<<5)+(elevenbits>>6));

    return sixteenbits;
}

// Decompresses a block using one of the GL_COMPRESSED_R11_EAC or GL_COMPRESSED_SIGNED_R11_EAC-formats
// NO WARRANTY --- SEE STATEMENT IN TOP OF FILE (C) Ericsson AB 2005-2013. All Rights Reserved.
void decompressBlockAlpha16bitC(uint8* data, uint8* img, int width, int height, int ix, int iy, int channels) 
{
    UNREFERENCED_PARAMETER(height);

    int alpha = data[0];
    int table = data[1];

    if(formatSigned) 
    {
        //if we have a signed format, the base value is given as a signed byte. We convert it to (0-255) here,
        //so more code can be shared with the unsigned mode.
        alpha = *((signed char*)(&data[0]));
        alpha = alpha+128;
    }

    int bit=0;
    int byte=2;
    //extract an alpha value for each pixel.
    for(int x=0; x<4; x++) 
    {
        for(int y=0; y<4; y++) 
        {
            //Extract table index
            int index=0;
            for(int bitpos=0; bitpos<3; bitpos++) 
            {
                index|=getbit(data[byte],7-bit,2-bitpos);
                bit++;
                if(bit>7) 
                {
                    bit=0;
                    byte++;
                }
            }
            int windex = channels*(2*(ix+x+(iy+y)*width));
#if !PGMOUT
            if(formatSigned)
            {
                *(int16 *)&img[windex] = get16bits11signed(alpha,(table%16),(table/16),index);
            }
            else
            {
                *(uint16 *)&img[windex] = get16bits11bits(alpha,(table%16),(table/16),index);
            }
#else
            //make data compatible with the .pgm format. See the comment in compressBlockAlpha16() for details.
            uint16 uSixteen;
            if (formatSigned)
            {
                //the pgm-format only allows unsigned images,
                //so we add 2^15 to get a 16-bit value.
                uSixteen = get16bits11signed(alpha,(table%16),(table/16),index) + 256*128;
            }
            else
            {
                uSixteen = get16bits11bits(alpha,(table%16),(table/16),index);
            }
            //byte swap for pgm
            img[windex]   = (uint8)(uSixteen/256);
            img[windex+1] = uSixteen%256;
#endif

        }
    }            
}

void decompressBlockAlpha16bit(uint8* data, uint8* img, int width, int height, int ix, int iy)
{
    decompressBlockAlpha16bitC(data, img, width, height, ix, iy, 1);
}
