Function DecodePAABuffer

engine/Poseidon/Graphics/Textures/PAADecoder.cpp:403–546

}

DecodedImage DecodePAABuffer(const void* data, size_t size, bool isPaa)
{
    DecodedImage img;
    QIStream in(static_cast<const char*>(data), static_cast<int>(size));

    int desc = fgetiw(in);
    bool alpha = false;
    PacFormat format = PacFormatFromDesc(desc, alpha);
    if (format == PacFormatN)
    {
        in.seekg(-2, QIOS::cur);
        format = isPaa ? PacARGB4444 : PacP8;
    }

    PacPalette pal;
    int offsets[16];
    for (int i = 0; i < 16; i++)
        offsets[i] = -1;
    if (pal.Load(in, offsets, 16))
        return img;

    PacLevelMem mip;
    if (offsets[0] >= 0)
        mip.SetStart(offsets[0]);
    if (mip.Init(in, format) != 0)
        return img;

    img.width = mip._w;
    img.height = mip._h;
    // Dimensions come from the mip header; reject absurd sizes before width*height*4
    // overflows int (a tiny rgba alloc the decoders then overrun) or drives a huge
    // allocation. PAA textures are far below this cap.
    if (img.width <= 0 || img.height <= 0 || img.width > 8192 || img.height > 8192)
    {
        return img;
    }
    img.rgba.resize(img.width * img.height * 4);

    bool isDXT = (format >= PacDXT1 && format <= PacDXT5);

    if (format == PacARGB8888)
    {
        // ARGB8888: raw data, no LZSS. Convert ARGB → RGBA.
        mip.SeekLevel(in);
        int mw = fgetiw(in), mh = fgetiw(in);
        if (mw == 0 && mh == 0)
        {
            img.rgba.clear();
            return img;
        }
        int dSize = fgeti24(in);
        std::vector<uint8_t> rawData(dSize);
        in.read(reinterpret_cast<char*>(rawData.data()), dSize);
        // The conversion loop below reads width*height*4 raw bytes; reject a payload
        // too small to cover them rather than read past rawData (heap over-read).
        if (static_cast<int>(rawData.size()) < img.width * img.height * 4)
        {
            img.rgba.clear();