qscriptengine.cpp

奇趣公司比较新的qt/emd版本

#if !defined(QT_NO_OPENTYPE) && !defined(Q_WS_QWS)
    QOpenType *openType = item->font->openType();
    if (!openType && item->font->type() == QFontEngine::Multi) {
        openType = static_cast<QFontEngineMulti *>(item->font)->engine(0)->openType();
        if (openType) {
            for (int i = 0; i < item->num_glyphs; ++i) {
                if (item->glyphs[i].glyph & 0xff000000) {
                    openType = 0;
                    break;
                }
            }
        }
    }
    if (openType && openType->supportsScript(item->script)) {
        openType->selectScript(item, item->script, basic_features);

        openType->shape(item);
        return openType->positionAndAdd(item, availableGlyphs);
    }

#endif

    qt_heuristicPosition(item);
    return true;
}

// --------------------------------------------------------------------------------------------------------------------------------------------
//
// Middle eastern languages
//
// --------------------------------------------------------------------------------------------------------------------------------------------

// Uniscribe also defines dlig for Hebrew, but we leave this out for now, as it's mostly
// ligatures one does not want in modern Hebrew (as lam-alef ligatures).
#ifndef QT_NO_OPENTYPE
static const QOpenType::Features hebrew_features[] = {
    { FT_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },
    {0, 0}
};
#endif
#ifndef Q_WS_MAC
/* Hebrew shaping. In the non opentype case we try to use the
   presentation forms specified for Hebrew. Especially for the
   ligatures with Dagesh this gives much better results than we could
   achieve manually.
*/
static bool hebrew_shape(QShaperItem *item)
{
    Q_ASSERT(item->script == QUnicodeTables::Hebrew);

#ifndef QT_NO_OPENTYPE
    QOpenType *openType = item->font->openType();

    if (openType && openType->supportsScript(item->script)) {
        openType->selectScript(item, item->script, hebrew_features);

        const int availableGlyphs = item->num_glyphs;
        if (!item->font->stringToCMap(item->string->unicode()+item->from, item->length, item->glyphs, &item->num_glyphs, QFlag(item->flags)))
            return false;

        heuristicSetGlyphAttributes(item);
        openType->shape(item);
        return openType->positionAndAdd(item, availableGlyphs);
    }
#endif

    enum {
        Dagesh = 0x5bc,
        ShinDot = 0x5c1,
        SinDot = 0x5c2,
        Patah = 0x5b7,
        Qamats = 0x5b8,
        Holam = 0x5b9,
        Rafe = 0x5bf
    };
    unsigned short chars[512];
    QChar *shapedChars = item->length > 256 ? (QChar *)::malloc(2*item->length * sizeof(QChar)) : (QChar *)(void *)chars;

    const QChar *uc = item->string->unicode() + item->from;
    unsigned short *logClusters = item->log_clusters;
    QGlyphLayout *glyphs = item->glyphs;

    *shapedChars = *uc;
    logClusters[0] = 0;
    int slen = 1;
    int cluster_start = 0;
    for (int i = 1; i < item->length; ++i) {
        ushort base = shapedChars[slen-1].unicode();
        ushort shaped = 0;
        bool invalid = false;
        if (uc[i].unicode() == Dagesh) {
            if (base >= 0x5d0
                && base <= 0x5ea
                && base != 0x5d7
                && base != 0x5dd
                && base != 0x5df
                && base != 0x5e2
                && base != 0x5e5) {
                shaped = base - 0x5d0 + 0xfb30;
            } else if (base == 0xfb2a || base == 0xfb2b /* Shin with Shin or Sin dot */) {
                shaped = base + 2;
            } else {
                invalid = true;
            }
        } else if (uc[i].unicode() == ShinDot) {
            if (base == 0x05e9)
                shaped = 0xfb2a;
            else if (base == 0xfb49)
                shaped = 0xfb2c;
            else
                invalid = true;
        } else if (uc[i].unicode() == SinDot) {
            if (base == 0x05e9)
                shaped = 0xfb2b;
            else if (base == 0xfb49)
                shaped = 0xfb2d;
            else
                invalid = true;
        } else if (uc[i].unicode() == Patah) {
            if (base == 0x5d0)
                shaped = 0xfb2e;
        } else if (uc[i].unicode() == Qamats) {
            if (base == 0x5d0)
                shaped = 0xfb2f;
        } else if (uc[i].unicode() == Holam) {
            if (base == 0x5d5)
                shaped = 0xfb4b;
        } else if (uc[i].unicode() == Rafe) {
            if (base == 0x5d1)
                shaped = 0xfb4c;
            else if (base == 0x5db)
                shaped = 0xfb4d;
            else if (base == 0x5e4)
                shaped = 0xfb4e;
        }

        if (invalid) {
            shapedChars[slen] = 0x25cc;
            glyphs[slen].attributes.clusterStart = true;
            glyphs[slen].attributes.mark = false;
            glyphs[slen].attributes.combiningClass = 0;
            cluster_start = slen;
            ++slen;
        }
        if (shaped) {
            if (item->font->canRender((QChar *)&shaped, 1)) {
                shapedChars[slen-1] = QChar(shaped);
            } else
                shaped = 0;
        }
        if (!shaped) {
            shapedChars[slen] = uc[i];
            if (QChar::category(uc[i].unicode()) != QChar::Mark_NonSpacing) {
                glyphs[slen].attributes.clusterStart = true;
                glyphs[slen].attributes.mark = false;
                glyphs[slen].attributes.combiningClass = 0;
                glyphs[slen].attributes.dontPrint = qIsControlChar(uc[i].unicode());
                cluster_start = slen;
            } else {
                glyphs[slen].attributes.clusterStart = false;
                glyphs[slen].attributes.mark = true;
                glyphs[slen].attributes.combiningClass = QChar::combiningClass(uc[i].unicode());
            }
            ++slen;
        }
        logClusters[i] = cluster_start;
    }

    if (!item->font->stringToCMap(shapedChars, slen, glyphs, &item->num_glyphs, QFlag(item->flags))) {
        if (item->length > 256)
            ::free(shapedChars);
        return false;
    }
    for (int i = 0; i < item->num_glyphs; ++i) {
        if (glyphs[i].attributes.mark) {
            glyphs[i].advance.x = 0;
        }
    }
    qt_heuristicPosition(item);

    if (item->length > 256)
        ::free(shapedChars);
    return true;
}
#endif

// these groups correspond to the groups defined in the Unicode standard.
// Some of these groups are equal with regards to both joining and line breaking behaviour,
// and thus have the same enum value
//
// I'm not sure the mapping of syriac to arabic enums is correct with regards to justification, but as
// I couldn't find any better document I'll hope for the best.
enum ArabicGroup {
    // NonJoining
    ArabicNone,
    ArabicSpace,
    // Transparent
    Transparent,
    // Causing
    Center,
    Kashida,

    // Arabic
    // Dual
    Beh,
    Noon,
    Meem = Noon,
    Heh = Noon,
    KnottedHeh = Noon,
    HehGoal = Noon,
    SwashKaf = Noon,
    Yeh,
    Hah,
    Seen,
    Sad = Seen,
    Tah,
    Kaf = Tah,
    Gaf = Tah,
    Lam = Tah,
    Ain,
    Feh = Ain,
    Qaf = Ain,
    // Right
    Alef,
    Waw,
    Dal,
    TehMarbuta = Dal,
    Reh,
    HamzaOnHehGoal,
    YehWithTail = HamzaOnHehGoal,
    YehBarre = HamzaOnHehGoal,

    // Syriac
    // Dual
    Beth = Beh,
    Gamal = Ain,
    Heth = Noon,
    Teth = Hah,
    Yudh = Noon,
    Kaph = Noon,
    Lamadh = Lam,
    Mim = Noon,
    Nun = Noon,
    Semakh = Noon,
    FinalSemakh = Noon,
    SyriacE = Ain,
    Pe = Ain,
    ReversedPe = Hah,
    Qaph = Noon,
    Shin = Noon,
    Fe = Ain,

    // Right
    Alaph = Alef,
    Dalath = Dal,
    He = Dal,
    SyriacWaw = Waw,
    Zain = Alef,
    YudhHe = Waw,
    Sadhe = HamzaOnHehGoal,
    Taw = Dal,

    // Compiler bug? Otherwise ArabicGroupsEnd would be equal to Dal + 1.
    Dummy = HamzaOnHehGoal,
    ArabicGroupsEnd
};

static const unsigned char arabic_group[0x150] = {
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    Transparent, Transparent, Transparent, Transparent,
    Transparent, Transparent, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, Alef, Alef,
    Waw, Alef, Yeh, Alef,
    Beh, TehMarbuta, Beh, Beh,
    Hah, Hah, Hah, Dal,

    Dal, Reh, Reh, Seen,
    Seen, Sad, Sad, Tah,
    Tah, Ain, Ain, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    // 0x640
    Kashida, Feh, Qaf, Kaf,
    Lam, Meem, Noon, Heh,
    Waw, Yeh, Yeh, Transparent,
    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,
    Transparent, Transparent, Transparent, Transparent,
    Transparent, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, Beh, Qaf,

    Transparent, Alef, Alef, Alef,
    ArabicNone, Alef, Waw, Waw,
    Yeh, Beh, Beh, Beh,
    Beh, Beh, Beh, Beh,

    // 0x680
    Beh, Hah, Hah, Hah,
    Hah, Hah, Hah, Hah,
    Dal, Dal, Dal, Dal,
    Dal, Dal, Dal, Dal,

    Dal, Reh, Reh, Reh,
    Reh, Reh, Reh, Reh,
    Reh, Reh, Seen, Seen,
    Seen, Sad, Sad, Tah,

    Ain, Feh, Feh, Feh,
    Feh, Feh, Feh, Qaf,
    Qaf, Gaf, SwashKaf, Gaf,
    Kaf, Kaf, Kaf, Gaf,

    Gaf, Gaf, Gaf, Gaf,
    Gaf, Lam, Lam, Lam,
    Lam, Noon, Noon, Noon,
    Noon, Noon, KnottedHeh, Hah,

    // 0x6c0
    TehMarbuta, HehGoal, HamzaOnHehGoal, HamzaOnHehGoal,
    Waw, Waw, Waw, Waw,
    Waw, Waw, Waw, Waw,
    Yeh, YehWithTail, Yeh, Waw,

    Yeh, Yeh, YehBarre, YehBarre,
    ArabicNone, TehMarbuta, Transparent, Transparent,
    Transparent, Transparent, Transparent, Transparent,
    Transparent, ArabicNone, ArabicNone, Transparent,

    Transparent, Transparent, Transparent, Transparent,
    Transparent, ArabicNone, ArabicNone, Transparent,
    Transparent, ArabicNone, Transparent, Transparent,
    Transparent, Transparent, Dal, Reh,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, Seen, Sad,
    Ain, ArabicNone, ArabicNone, KnottedHeh,

    // 0x700
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,
    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    Alaph, Transparent, Beth, Gamal,
    Gamal, Dalath, Dalath, He,
    SyriacWaw, Zain, Heth, Teth,
    Teth, Yudh, YudhHe, Kaph,

    Lamadh, Mim, Nun, Semakh,
    FinalSemakh, SyriacE, Pe, ReversedPe,
    Sadhe, Qaph, Dalath, Shin,
    Taw, Beth, Gamal, Dalath,

    Transparent, Transparent, Transparent, Transparent,
    Transparent, Transparent, Transparent, Transparent,
    Transparent, Transparent, Transparent, Transparent,
    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,
    Transparent, Transparent, Transparent, Transparent,
    Transparent, Transparent, Transparent, ArabicNone,
    ArabicNone, Zain, Kaph, Fe,
};

static inline ArabicGroup arabicGroup(unsigned short uc)
{
    if (uc >= 0x0600 && uc < 0x750)