/**
 * @file llimagetga.h
 * @brief Image implementation to compresses and decompressed TGA files.
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLIMAGETGA_H
#define LL_LLIMAGETGA_H

#include "llimage.h"

// This class compresses and decompressed TGA (targa) files

class LLImageTGA : public LLImageFormatted
{
protected:
    virtual ~LLImageTGA();

public:
    LLImageTGA();
    LLImageTGA(const std::string& file_name);

    /*virtual*/ std::string getExtension() { return std::string("tga"); }
    /*virtual*/ bool updateData();
    /*virtual*/ bool decode(LLImageRaw* raw_image, F32 decode_time=0.0);
    /*virtual*/ bool encode(const LLImageRaw* raw_image, F32 encode_time=0.0);

    bool             decodeAndProcess(LLImageRaw* raw_image, F32 domain, F32 weight);

private:
    bool             decodeTruecolor( LLImageRaw* raw_image, bool rle, bool flipped );

    bool             decodeTruecolorRle8( LLImageRaw* raw_image );
    bool             decodeTruecolorRle15( LLImageRaw* raw_image );
    bool             decodeTruecolorRle24( LLImageRaw* raw_image );
    bool             decodeTruecolorRle32( LLImageRaw* raw_image, bool &alpha_opaque );

    void             decodeTruecolorPixel15( U8* dst, const U8* src );

    bool             decodeTruecolorNonRle( LLImageRaw* raw_image, bool &alpha_opaque );

    bool             decodeColorMap( LLImageRaw* raw_image, bool rle, bool flipped );

    void             decodeColorMapPixel8(U8* dst, const U8* src);
    void             decodeColorMapPixel15(U8* dst, const U8* src);
    void             decodeColorMapPixel24(U8* dst, const U8* src);
    void             decodeColorMapPixel32(U8* dst, const U8* src);

    bool             loadFile(const std::string& file_name);

private:
    // Class specific data
    U32 mDataOffset; // Offset from start of data to the actual header.

    // Data from header
    U8 mIDLength;       // Length of identifier string
    U8 mColorMapType;   // 0 = No Map
    U8 mImageType;      // Supported: 2 = Uncompressed true color, 3 = uncompressed monochrome without colormap
    U8 mColorMapIndexLo;    // First color map entry (low order byte)
    U8 mColorMapIndexHi;    // First color map entry (high order byte)
    U8 mColorMapLengthLo;   // Color map length (low order byte)
    U8 mColorMapLengthHi;   // Color map length (high order byte)
    U8 mColorMapDepth;  // Size of color map entry (15, 16, 24, or 32 bits)
    U8 mXOffsetLo;      // X offset of image (low order byte)
    U8 mXOffsetHi;      // X offset of image (hi order byte)
    U8 mYOffsetLo;      // Y offset of image (low order byte)
    U8 mYOffsetHi;      // Y offset of image (hi order byte)
    U8 mWidthLo;        // Width (low order byte)
    U8 mWidthHi;        // Width (hi order byte)
    U8 mHeightLo;       // Height (low order byte)
    U8 mHeightHi;       // Height (hi order byte)
    U8 mPixelSize;      // 8, 16, 24, 32 bits per pixel
    U8 mAttributeBits;  // 4 bits: number of attributes per pixel
    U8 mOriginRightBit; // 1 bit: origin, 0 = left, 1 = right
    U8 mOriginTopBit;   // 1 bit: origin, 0 = bottom, 1 = top
    U8 mInterleave;     // 2 bits: interleaved flag, 0 = none, 1 = interleaved 2, 2 = interleaved 4

    U8*     mColorMap;
    S32     mColorMapStart;
    S32     mColorMapLength;
    S32     mColorMapBytesPerEntry;

    bool    mIs15Bit;

    static const U8 s5to8bits[32];
};

#endif