qfontengine_qpf.cpp

奇趣公司比较新的qt/emd版本

    Q_ASSERT(freetype);
    freetype->lock();
    FT_Face face = freetype->face;

    // ### not perfect
    const int ysize = fontDef.pixelSize << 6;
    const int xsize = ysize;

    if (freetype->xsize != xsize || freetype->ysize != ysize) {
        FT_Set_Char_Size(face, xsize, ysize, 0, 0);
        freetype->xsize = xsize;
        freetype->ysize = ysize;
    }
    FT_Matrix identityMatrix;
    identityMatrix.xx = 0x10000;
    identityMatrix.yy = 0x10000;
    identityMatrix.xy = 0;
    identityMatrix.yx = 0;
    if (freetype->matrix.xx != identityMatrix.xx ||
        freetype->matrix.yy != identityMatrix.yy ||
        freetype->matrix.xy != identityMatrix.xy ||
        freetype->matrix.yx != identityMatrix.yx) {
        freetype->matrix = identityMatrix;
        FT_Set_Transform(face, &freetype->matrix, 0);
    }
    return face;
}

void QFontEngineQPF::unlockFace() const
{
    freetype->unlock();
}

QOpenType *QFontEngineQPF::openType() const
{
    if (!freetype)
        return 0;
    if (_openType)
         return _openType;

    FT_Face face = lockFace();
    if (!face || !FT_IS_SFNT(face)) {
        unlockFace();
        return 0;
    }

    _openType = new QOpenType(const_cast<QFontEngineQPF *>(this), face);
    unlockFace();
    return _openType;
}

void QFontEngineQPF::doKerning(int num_glyphs, QGlyphLayout *g, QTextEngine::ShaperFlags flags) const
{
    if (!kerning_pairs_loaded) {
        kerning_pairs_loaded = true;
        if (freetype && freetype->face->size->metrics.x_ppem != 0) {
            lockFace();
            QFixed scalingFactor(freetype->face->units_per_EM/freetype->face->size->metrics.x_ppem);
            unlockFace();
            const_cast<QFontEngineQPF *>(this)->loadKerningPairs(scalingFactor);
        }
    }
    QFontEngine::doKerning(num_glyphs, g, flags);
}

void QFontEngineQPF::ensureGlyphsLoaded(const QGlyphLayout *glyphs, int len)
{
    if (readOnly)
        return;
    bool locked = false;
    for (int i = 0; i < len; ++i) {
        if (!glyphs[i].glyph)
            continue;
        const Glyph *g = findGlyph(glyphs[i].glyph);
        if (g)
            continue;
        if (!locked) {
            if (!lockFile())
                return;
            locked = true;
            g = findGlyph(glyphs[i].glyph);
            if (g)
                continue;
        }
        loadGlyph(glyphs[i].glyph);
    }
    if (locked) {
        unlockFile();
#if defined(DEBUG_FONTENGINE)
        qDebug() << "Finished rendering glyphs\n";
#endif
    }
}

void QFontEngineQPF::loadGlyph(glyph_t glyph)
{
    quint32 glyphPos = ~0;

    if (!renderingFontEngine)
        return;

    QImage img = renderingFontEngine->alphaMapForGlyph(glyph).convertToFormat(QImage::Format_Indexed8);
    glyph_metrics_t metrics = renderingFontEngine->boundingBox(glyph);
    renderingFontEngine->removeGlyphFromCache(glyph);

    off_t oldSize = ::lseek(fd, 0, SEEK_END);
    if (oldSize == (off_t)-1)
        return;

    Glyph g;
    g.width = img.width();
    g.height = img.height();
    g.bytesPerLine = img.bytesPerLine();
    g.x = qRound(metrics.x);
    g.y = qRound(metrics.y);
    g.advance = qRound(metrics.xoff);

    ::write(fd, &g, sizeof(g));
    ::write(fd, img.bits(), img.numBytes());

    glyphPos = oldSize - glyphDataOffset;
#if 0 && defined(DEBUG_FONTENGINE)
    qDebug() << "glyphPos for new glyph" << glyph << "is" << glyphPos << "oldSize" << oldSize << "glyphDataOffset" << glyphDataOffset;
#endif

    quint32 *gmap = (quint32 *)(fontData + glyphMapOffset);
    gmap[glyph] = qToBigEndian(glyphPos);

    glyphDataSize = glyphPos + sizeof(g) + img.numBytes();
    quint32 *blockSizePtr = (quint32 *)(fontData + glyphDataOffset - 4);
    *blockSizePtr = qToBigEndian(glyphDataSize);
}

bool QFontEngineQPF::lockFile()
{
    // #### this does not handle the case when the process holding the
    // lock hangs for some reason
    struct flock lock;
    lock.l_type = F_WRLCK;
    lock.l_whence = SEEK_SET;
    lock.l_start = 0;
    lock.l_len = 0; // lock the whole file
    while (fcntl(fd, F_SETLKW, &lock) != 0) {
        if (errno == EINTR)
            continue;
        perror("locking qpf");
        return false;
    }
    Header *header = (Header *)fontData;
    if (header->lock) {
        lock.l_type = F_UNLCK;
        if (fcntl(fd, F_SETLK, &lock) != 0)
            perror("unlocking possibly corrupt qpf");
        return false;
    }
#if defined(Q_WS_QWS)
    extern int qws_client_id;
    // qws_client_id == 0 means we're the server. in this case we just
    // set the id to 1
    header->lock = qws_client_id ? qws_client_id : 1;
#else
    header->lock = 1;
#endif
    return true;
}

void QFontEngineQPF::unlockFile()
{
    ((Header *)fontData)->lock = 0;

    struct flock lock;
    lock.l_type = F_UNLCK;
    lock.l_whence = SEEK_SET;
    lock.l_start = 0;
    lock.l_len = 0; // lock the whole file
    if (fcntl(fd, F_SETLK, &lock) != 0) {
        perror("unlocking qpf");
    }

    remapFontData();
}

void QFontEngineQPF::remapFontData()
{
    off_t newFileSize = ::lseek(fd, 0, SEEK_END);
    if (newFileSize == (off_t)-1) {
#ifdef DEBUG_FONTENGINE
        perror("QFontEngineQPF::remapFontData: lseek failed");
#endif
        fontData = 0;
        return;
    }

#ifndef QT_NO_MREMAP
    fontData = static_cast<uchar *>(::mremap(const_cast<uchar *>(fontData), dataSize, newFileSize, MREMAP_MAYMOVE));
    if (!fontData || fontData == (const uchar *)MAP_FAILED) {
#  if defined(DEBUG_FONTENGINE)
        perror("QFontEngineQPF::remapFontData(): mremap failed");
#  endif
        fontData = 0;
    }

    if (!fontData)
#endif // QT_NO_MREMAP
    {
        int status = ::munmap((void *)fontData, dataSize);
        if (status != 0)
            qErrnoWarning(status, "QFontEngineQPF::remapFomrData: munmap failed!");

        fontData = (const uchar *)::mmap(0, newFileSize, PROT_READ | (renderingFontEngine ? PROT_WRITE : 0),
                                         MAP_SHARED, fd, 0);
        if (!fontData || fontData == (const uchar *)MAP_FAILED) {
#  if defined(DEBUG_FONTENGINE)
            perror("mmap failed");
#  endif
            fontData = 0;
            return;
        }
    }

    dataSize = newFileSize;
    glyphDataSize = newFileSize - glyphDataOffset;
#if defined(DEBUG_FONTENGINE)
    qDebug() << "remapped the font file to" << newFileSize << "bytes";
#endif
}

#endif // QT_NO_FREETYPE

void QPFGenerator::generate()
{
    writeHeader();
    writeGMap();
    writeBlock(QFontEngineQPF::GlyphBlock, QByteArray());

    dev->seek(4); // position of header.lock
    writeUInt32(0);
}

void QPFGenerator::writeHeader()
{
    QFontEngineQPF::Header header;

    header.magic[0] = 'Q';
    header.magic[1] = 'P';
    header.magic[2] = 'F';
    header.magic[3] = '2';
    header.lock = 1;
    header.majorVersion = QFontEngineQPF::CurrentMajorVersion;
    header.minorVersion = QFontEngineQPF::CurrentMinorVersion;
    header.dataSize = 0;
    dev->write((const char *)&header, sizeof(header));

    writeTaggedString(QFontEngineQPF::Tag_FontName, fe->fontDef.family.toUtf8());

    QFontEngine::FaceId face = fe->faceId();
    writeTaggedString(QFontEngineQPF::Tag_FileName, face.filename);
    writeTaggedUInt32(QFontEngineQPF::Tag_FileIndex, face.index);

    {
        const QByteArray head = fe->getSfntTable(MAKE_TAG('h', 'e', 'a', 'd'));
        const quint32 revision = qFromBigEndian<quint32>(reinterpret_cast<const uchar *>(head.constData()) + 4);
        writeTaggedUInt32(QFontEngineQPF::Tag_FontRevision, revision);
    }

    writeTaggedQFixed(QFontEngineQPF::Tag_Ascent, fe->ascent());
    writeTaggedQFixed(QFontEngineQPF::Tag_Descent, fe->descent());
    writeTaggedQFixed(QFontEngineQPF::Tag_Leading, fe->leading());
    writeTaggedQFixed(QFontEngineQPF::Tag_XHeight, fe->xHeight());
    writeTaggedQFixed(QFontEngineQPF::Tag_AverageCharWidth, fe->averageCharWidth());
    writeTaggedQFixed(QFontEngineQPF::Tag_MaxCharWidth, QFixed::fromReal(fe->maxCharWidth()));
    writeTaggedQFixed(QFontEngineQPF::Tag_LineThickness, fe->lineThickness());
    writeTaggedQFixed(QFontEngineQPF::Tag_MinLeftBearing, QFixed::fromReal(fe->minLeftBearing()));
    writeTaggedQFixed(QFontEngineQPF::Tag_MinRightBearing, QFixed::fromReal(fe->minRightBearing()));
    writeTaggedQFixed(QFontEngineQPF::Tag_UnderlinePosition, fe->underlinePosition());
    writeTaggedUInt8(QFontEngineQPF::Tag_PixelSize, fe->fontDef.pixelSize);
    writeTaggedUInt8(QFontEngineQPF::Tag_Weight, fe->fontDef.weight);
    writeTaggedUInt8(QFontEngineQPF::Tag_Style, fe->fontDef.style);

    writeTaggedUInt8(QFontEngineQPF::Tag_GlyphFormat, QFontEngineQPF::AlphamapGlyphs);

    writeTaggedString(QFontEngineQPF::Tag_EndOfHeader, QByteArray());
    align4();

    const quint64 size = dev->pos();
    header.dataSize = qToBigEndian<quint16>(size - sizeof(header));
    dev->seek(0);
    dev->write((const char *)&header, sizeof(header));
    dev->seek(size);
}

void QPFGenerator::writeGMap()
{
    const quint16 glyphCount = fe->glyphCount();

    writeUInt16(QFontEngineQPF::GMapBlock);
    writeUInt16(0); // padding
    writeUInt32(glyphCount * 4);

    QByteArray &buffer = dev->buffer();
    const int numBytes = glyphCount * sizeof(quint32);
    qint64 pos = buffer.size();
    buffer.resize(pos + numBytes);
    qMemSet(buffer.data() + pos, 0xff, numBytes);
    dev->seek(pos + numBytes);
}

void QPFGenerator::writeBlock(QFontEngineQPF::BlockTag tag, const QByteArray &data)
{
    writeUInt16(tag);
    writeUInt16(0); // padding
    const int padSize = ((data.size() + 3) / 4) * 4 - data.size();
    writeUInt32(data.size() + padSize);
    dev->write(data);
    for (int i = 0; i < padSize; ++i)
        writeUInt8(0);
}

void QPFGenerator::writeTaggedString(QFontEngineQPF::HeaderTag tag, const QByteArray &string)
{
    writeUInt16(tag);
    writeUInt16(string.length());
    dev->write(string);
}

void QPFGenerator::writeTaggedUInt32(QFontEngineQPF::HeaderTag tag, quint32 value)
{
    writeUInt16(tag);
    writeUInt16(sizeof(value));
    writeUInt32(value);
}

void QPFGenerator::writeTaggedUInt8(QFontEngineQPF::HeaderTag tag, quint8 value)
{
    writeUInt16(tag);
    writeUInt16(sizeof(value));
    writeUInt8(value);
}

void QPFGenerator::writeTaggedQFixed(QFontEngineQPF::HeaderTag tag, QFixed value)
{
    writeUInt16(tag);
    writeUInt16(sizeof(quint32));
    writeUInt32(value.value());
}

#endif // QT_NO_QWS_QPF

QFontEngineMultiQWS::QFontEngineMultiQWS(QFontEngine *fe, int _script, const QStringList &fallbacks)
    : QFontEngineMulti(fallbacks.size() + 1),
      fallbackFamilies(fallbacks), script(_script)
{
    engines[0] = fe;
    fe->ref.ref();
    fontDef = engines[0]->fontDef;
}

void QFontEngineMultiQWS::loadEngine(int at)
{
    Q_ASSERT(at < engines.size());
    Q_ASSERT(engines.at(at) == 0);

    QFontDef request = fontDef;
    request.styleStrategy |= QFont::NoFontMerging;
    request.family = fallbackFamilies.at(at-1);
    engines[at] = QFontDatabase::findFont(script,
                                          /*fontprivate*/0,
                                          request);
    Q_ASSERT(engines[at]);
    engines[at]->ref.ref();
    engines[at]->fontDef = request;
}

void QFontEngineMultiQWS::draw(QPaintEngine */*p*/, qreal /*x*/, qreal /*y*/, const QTextItemInt &/*si*/)
{
    qFatal("QFontEngineMultiQWS::draw should never be called!");
}