BlockDXT.h

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributors: Amorilia (amorilia@users.sourceforge.net)
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/*
 * This file is based on a similar file from the NVIDIA texture tools
 * (http://nvidia-texture-tools.googlecode.com/)
 *
 * Original license from NVIDIA follows.
 */

// Copyright NVIDIA Corporation 2007 -- Ignacio Castano <icastano@nvidia.com>
// 
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.

#ifndef _DDS_BLOCKDXT_H
#define _DDS_BLOCKDXT_H

#include <Common.h>
#include <Color.h>
#include <ColorBlock.h>
#include <Stream.h>

struct BlockDXT1
{
    Color16 col0;
    Color16 col1;
    union {
        uint8 row[4];
        uint indices;
    };

    bool isFourColorMode() const;

    uint evaluatePalette(Color32 color_array[4]) const;
    uint evaluatePaletteNV5x(Color32 color_array[4]) const;

    void evaluatePalette3(Color32 color_array[4]) const;
    void evaluatePalette4(Color32 color_array[4]) const;
    
    void decodeBlock(ColorBlock * block) const;
    void decodeBlockNV5x(ColorBlock * block) const;
    
    void setIndices(int * idx);

    void flip4();
    void flip2();
};

inline bool BlockDXT1::isFourColorMode() const
{
    return col0.u > col1.u;
}


struct AlphaBlockDXT3
{
    union {
        struct {
            uint alpha0 : 4;
            uint alpha1 : 4;
            uint alpha2 : 4;
            uint alpha3 : 4;
            uint alpha4 : 4;
            uint alpha5 : 4;
            uint alpha6 : 4;
            uint alpha7 : 4;
            uint alpha8 : 4;
            uint alpha9 : 4;
            uint alphaA : 4;
            uint alphaB : 4;
            uint alphaC : 4;
            uint alphaD : 4;
            uint alphaE : 4;
            uint alphaF : 4;
        };
        uint16 row[4];
    };
    
    void decodeBlock(ColorBlock * block) const;
    
    void flip4();
    void flip2();
};


struct BlockDXT3
{
    AlphaBlockDXT3 alpha;
    BlockDXT1 color;
    
    void decodeBlock(ColorBlock * block) const;
    void decodeBlockNV5x(ColorBlock * block) const;
    
    void flip4();
    void flip2();
};


struct AlphaBlockDXT5
{
    // uint64 unions do not compile on all platforms
    /*
    union {
        struct {
            uint64 alpha0 : 8;  // 8
            uint64 alpha1 : 8;  // 16
            uint64 bits0 : 3;       // 3 - 19
            uint64 bits1 : 3;   // 6 - 22
            uint64 bits2 : 3;   // 9 - 25
            uint64 bits3 : 3;       // 12 - 28
            uint64 bits4 : 3;       // 15 - 31
            uint64 bits5 : 3;       // 18 - 34
            uint64 bits6 : 3;       // 21 - 37
            uint64 bits7 : 3;       // 24 - 40
            uint64 bits8 : 3;       // 27 - 43
            uint64 bits9 : 3;   // 30 - 46
            uint64 bitsA : 3;   // 33 - 49
            uint64 bitsB : 3;       // 36 - 52
            uint64 bitsC : 3;       // 39 - 55
            uint64 bitsD : 3;       // 42 - 58
            uint64 bitsE : 3;       // 45 - 61
            uint64 bitsF : 3;       // 48 - 64
        };
        uint64 u;
    };
    */
    uint64 u;
    uint8 alpha0() const { return u & 0xffLL; };
    uint8 alpha1() const { return (u >> 8) & 0xffLL; };
    uint8 bits0() const { return (u >> 16) & 0x7LL; };
    uint8 bits1() const { return (u >> 19) & 0x7LL; };
    uint8 bits2() const { return (u >> 22) & 0x7LL; };
    uint8 bits3() const { return (u >> 25) & 0x7LL; };
    uint8 bits4() const { return (u >> 28) & 0x7LL; };
    uint8 bits5() const { return (u >> 31) & 0x7LL; };
    uint8 bits6() const { return (u >> 34) & 0x7LL; };
    uint8 bits7() const { return (u >> 37) & 0x7LL; };
    uint8 bits8() const { return (u >> 40) & 0x7LL; };
    uint8 bits9() const { return (u >> 43) & 0x7LL; };
    uint8 bitsA() const { return (u >> 46) & 0x7LL; };
    uint8 bitsB() const { return (u >> 49) & 0x7LL; };
    uint8 bitsC() const { return (u >> 52) & 0x7LL; };
    uint8 bitsD() const { return (u >> 55) & 0x7LL; };
    uint8 bitsE() const { return (u >> 58) & 0x7LL; };
    uint8 bitsF() const { return (u >> 61) & 0x7LL; };
    
    void evaluatePalette(uint8 alpha[8]) const;
    void evaluatePalette8(uint8 alpha[8]) const;
    void evaluatePalette6(uint8 alpha[8]) const;
    void indices(uint8 index_array[16]) const;

    uint index(uint index) const;
    void setIndex(uint index, uint value);
    
    void decodeBlock(ColorBlock * block) const;
    
    void flip4();
    void flip2();
};


struct BlockDXT5
{
    AlphaBlockDXT5 alpha;
    BlockDXT1 color;
    
    void decodeBlock(ColorBlock * block) const;
    void decodeBlockNV5x(ColorBlock * block) const;
    
    void flip4();
    void flip2();
};

struct BlockATI1
{
    AlphaBlockDXT5 alpha;
    
    void decodeBlock(ColorBlock * block) const;
    
    void flip4();
    void flip2();
};

struct BlockATI2
{
    AlphaBlockDXT5 x;
    AlphaBlockDXT5 y;
    
    void decodeBlock(ColorBlock * block) const;
    
    void flip4();
    void flip2();
};

struct BlockCTX1
{
    uint8 col0[2];
    uint8 col1[2];
    union {
        uint8 row[4];
        uint indices;
    };

    void evaluatePalette(Color32 color_array[4]) const;
    void setIndices(int * idx);

    void decodeBlock(ColorBlock * block) const;
    
    void flip4();
    void flip2();
};

void mem_read(Stream & mem, BlockDXT1 & block);
void mem_read(Stream & mem, AlphaBlockDXT3 & block);
void mem_read(Stream & mem, BlockDXT3 & block);
void mem_read(Stream & mem, AlphaBlockDXT5 & block);
void mem_read(Stream & mem, BlockDXT5 & block);
void mem_read(Stream & mem, BlockATI1 & block);
void mem_read(Stream & mem, BlockATI2 & block);
void mem_read(Stream & mem, BlockCTX1 & block);

#endif // _DDS_BLOCKDXT_H