qopentype.cpp

奇趣公司比较新的qt/emd版本

    // reset
    kerning_feature_selected = false;

    if (gpos) {
        HB_GPOS_Clear_Features(gpos);
        FT_UShort script_index;
        FT_Error error = HB_GPOS_Select_Script(gpos, tag, &script_index);
        if (!error) {
#ifdef OT_DEBUG
            {
                HB_FeatureList featurelist = gpos->FeatureList;
                int numfeatures = featurelist.FeatureCount;
                DEBUG("gpos table has %d features", numfeatures);
                for(int i = 0; i < numfeatures; i++) {
                    HB_FeatureRecord *r = featurelist.FeatureRecord + i;
                    FT_UShort feature_index;
                    HB_GPOS_Select_Feature(gpos, r->FeatureTag, script_index, 0xffff, &feature_index);
                    DEBUG("   feature '%s'", tag_to_string(r->FeatureTag));
                }
            }
#endif
            FT_ULong *feature_tag_list_buffer;
            error = HB_GPOS_Query_Features(gpos, script_index, 0xffff, &feature_tag_list_buffer);
            if (!error) {
                FT_ULong *feature_tag_list = feature_tag_list_buffer;
                while (*feature_tag_list) {
                    FT_UShort feature_index;
                    if (*feature_tag_list == FT_MAKE_TAG('k', 'e', 'r', 'n')) {
                        if (!item->kerning_enabled) {
                            ++feature_tag_list;
                            continue;
                        }
                        kerning_feature_selected = true;
                    }
                    error = HB_GPOS_Select_Feature(gpos, *feature_tag_list, script_index, 0xffff, &feature_index);
                    if (!error) {
                        HB_GPOS_Add_Feature(gpos, feature_index, PositioningProperties);
                        has_features = true;
                    }
                    ++feature_tag_list;
                }
                FT_Memory memory = gpos->memory;
                FREE(feature_tag_list_buffer);
            }
        }
    }

    current_script = script;
}


extern void qt_heuristicPosition(QShaperItem *item);

bool QOpenType::shape(QShaperItem *item, const unsigned int *properties)
{
    if (!has_features)
        return true;

    length = item->num_glyphs;

    hb_buffer_clear(hb_buffer);

    if (allocated < length) {
        tmpAttributes = (QGlyphLayout::Attributes *) realloc(tmpAttributes, length*sizeof(QGlyphLayout::Attributes));
        tmpLogClusters = (unsigned int *) realloc(tmpLogClusters, length*sizeof(unsigned int));
        allocated = length;
    }
    for (int i = 0; i < length; ++i) {
        hb_buffer_add_glyph(hb_buffer, item->glyphs[i].glyph, properties ? properties[i] : 0, i);
        tmpAttributes[i] = item->glyphs[i].attributes;
        tmpLogClusters[i] = item->log_clusters[i];
    }

#ifdef OT_DEBUG
    DEBUG("-----------------------------------------");
//     DEBUG("log clusters before shaping:");
//     for (int j = 0; j < length; j++)
//         DEBUG("    log[%d] = %d", j, item->log_clusters[j]);
    DEBUG("original glyphs: %p", item->glyphs);
    for (int i = 0; i < length; ++i)
        DEBUG("   glyph=%4x", hb_buffer->in_string[i].gindex);
//     dump_string(hb_buffer);
#endif

    // ### FT_LOAD_NO_HINTING might give problems here, see comment about MingLiu in qfontengine_ft.cpp
    loadFlags = item->flags & QTextEngine::DesignMetrics ? FT_LOAD_NO_HINTING : FT_LOAD_DEFAULT;

    glyphs_substituted = false;
    if (gsub) {
        uint error = HB_GSUB_Apply_String(gsub, hb_buffer);
        if (error && error != HB_Err_Not_Covered)
            return false;
        glyphs_substituted = (error != HB_Err_Not_Covered);
    }

#ifdef OT_DEBUG
//     DEBUG("log clusters before shaping:");
//     for (int j = 0; j < length; j++)
//         DEBUG("    log[%d] = %d", j, item->log_clusters[j]);
    DEBUG("shaped glyphs:");
    for (int i = 0; i < length; ++i)
        DEBUG("   glyph=%4x", hb_buffer->in_string[i].gindex);
    DEBUG("-----------------------------------------");
//     dump_string(hb_buffer);
#endif

    return true;
}

bool QOpenType::positionAndAdd(QShaperItem *item, int availableGlyphs, bool doLogClusters)
{
    if (!has_features)
        return true;

    bool glyphs_positioned = false;
    if (gpos) {
        switch (fontEngine->type()) {
#ifndef QT_NO_FREETYPE
        case QFontEngine::Freetype:
            face = static_cast<QFontEngineFT *>(fontEngine)->lockFace();
            break;
#endif
#if defined(Q_WS_QWS) && !defined(QT_NO_QWS_QPF2) && !defined(QT_NO_FREETYPE)
        case QFontEngine::QPF2:
            face = static_cast<QFontEngineQPF *>(fontEngine)->lockFace();
            break;
#endif
        default:
            Q_ASSERT(false);
        }
        memset(hb_buffer->positions, 0, hb_buffer->in_length*sizeof(HB_PositionRec));
        // #### check that passing "false,false" is correct
        glyphs_positioned = HB_GPOS_Apply_String(face, gpos, loadFlags, hb_buffer, false, false) != HB_Err_Not_Covered;
        switch (fontEngine->type()) {
        case QFontEngine::Freetype:
#ifndef QT_NO_FREETYPE
            static_cast<QFontEngineFT *>(fontEngine)->unlockFace();
            break;
#endif
#if defined(Q_WS_QWS) && !defined(QT_NO_QWS_QPF2) && !defined(QT_NO_FREETYPE)
        case QFontEngine::QPF2:
            static_cast<QFontEngineQPF *>(fontEngine)->unlockFace();
            break;
#endif
        default:
            break;
        }
    }

    if (!glyphs_substituted && !glyphs_positioned)
        return true; // nothing to do for us

    // make sure we have enough space to write everything back
    if (availableGlyphs < (int)hb_buffer->in_length) {
        item->num_glyphs = hb_buffer->in_length;
        return false;
    }

    QGlyphLayout *glyphs = item->glyphs;

    for (unsigned int i = 0; i < hb_buffer->in_length; ++i) {
        glyphs[i].glyph = hb_buffer->in_string[i].gindex;
        glyphs[i].attributes = tmpAttributes[hb_buffer->in_string[i].cluster];
        if (i && hb_buffer->in_string[i].cluster == hb_buffer->in_string[i-1].cluster)
            glyphs[i].attributes.clusterStart = false;
    }
    item->num_glyphs = hb_buffer->in_length;

    if (doLogClusters) {
        // we can't do this for indic, as we pass the stuf in syllables and it's easier to do it in the shaper.
        unsigned short *logClusters = item->log_clusters;
        int clusterStart = 0;
        int oldCi = 0;
        for (unsigned int i = 0; i < hb_buffer->in_length; ++i) {
            int ci = hb_buffer->in_string[i].cluster;
            //         DEBUG("   ci[%d] = %d mark=%d, cmb=%d, cs=%d",
            //                i, ci, glyphAttributes[i].mark, glyphAttributes[i].combiningClass, glyphAttributes[i].clusterStart);
            if (!glyphs[i].attributes.mark && glyphs[i].attributes.clusterStart && ci != oldCi) {
                for (int j = oldCi; j < ci; j++)
                    logClusters[j] = clusterStart;
                clusterStart = i;
                oldCi = ci;
            }
        }
        for (int j = oldCi; j < length; j++)
            logClusters[j] = clusterStart;
    }

    // calulate the advances for the shaped glyphs
//     DEBUG("unpositioned: ");
    if (glyphs_substituted)
        item->font->recalcAdvances(item->num_glyphs, glyphs, QFlag(item->flags));

    // positioning code:
    if (gpos && glyphs_positioned) {
        HB_Position positions = hb_buffer->positions;

//         DEBUG("positioned glyphs:");
        for (unsigned int i = 0; i < hb_buffer->in_length; i++) {
//             DEBUG("    %d:\t orig advance: (%d/%d)\tadv=(%d/%d)\tpos=(%d/%d)\tback=%d\tnew_advance=%d", i,
//                    glyphs[i].advance.x.toInt(), glyphs[i].advance.y.toInt(),
//                    (int)(positions[i].x_advance >> 6), (int)(positions[i].y_advance >> 6),
//                    (int)(positions[i].x_pos >> 6), (int)(positions[i].y_pos >> 6),
//                    positions[i].back, positions[i].new_advance);
            // ###### fix the case where we have y advances. How do we handle this in Uniscribe?????
            QFixed xValue = QFixed::fromFixed(item->flags & QTextEngine::RightToLeft
                                              ? -positions[i].x_advance : positions[i].x_advance);
            QFixed yValue = QFixed::fromFixed(-positions[i].y_advance);
            if (!(item->flags & QTextEngine::DesignMetrics)) {
                xValue = xValue.round();
                yValue = yValue.round();
            }

            if (positions[i].new_advance) {
                glyphs[i].advance.x = xValue;
                glyphs[i].advance.y = yValue;
            } else {
                glyphs[i].advance.x += xValue;
                glyphs[i].advance.y += yValue;
            }

            int back = 0;
            glyphs[i].offset.x = QFixed::fromFixed(positions[i].x_pos);
            glyphs[i].offset.y = QFixed::fromFixed(positions[i].y_pos);
            while (positions[i - back].back) {
                back += positions[i - back].back;
                glyphs[i].offset.x += QFixed::fromFixed(positions[i - back].x_pos);
                glyphs[i].offset.y += QFixed::fromFixed(positions[i - back].y_pos);
            }
            glyphs[i].offset.y = -glyphs[i].offset.y;

            if (item->flags & QTextEngine::RightToLeft) {
                // ### may need to go back multiple glyphs like in ltr
                back = positions[i].back;
                while (back--) {
                    glyphs[i].offset.x -= glyphs[i-back].advance.x;
                    glyphs[i].offset.y -= -glyphs[i-back].advance.y;
                }
            } else {
                back = 0;
                while (positions[i - back].back) {
                    back += positions[i - back].back;
                    glyphs[i].offset.x -= glyphs[i-back].advance.x;
                    glyphs[i].offset.y -= -glyphs[i-back].advance.y;
                }
            }
//             DEBUG("   ->\tadv=%d\tpos=(%d/%d)",
//                    glyphs[i].advance.x.toInt(), glyphs[i].offset.x.toInt(), glyphs[i].offset.y.toInt());
        }
        item->kerning_applied = kerning_feature_selected;
    } else {
        qt_heuristicPosition(item);
    }

#ifdef OT_DEBUG
    if (doLogClusters) {
        DEBUG("log clusters after shaping:");
        for (int j = 0; j < length; j++)
            DEBUG("    log[%d] = %d", j, item->log_clusters[j]);
    }
    DEBUG("final glyphs:");
    for (int i = 0; i < (int)hb_buffer->in_length; ++i)
        DEBUG("   glyph=%4x char_index=%d mark: %d cmp: %d, clusterStart: %d advance=%d/%d offset=%d/%d",
               glyphs[i].glyph, hb_buffer->in_string[i].cluster, glyphs[i].attributes.mark,
               glyphs[i].attributes.combiningClass, glyphs[i].attributes.clusterStart,
               glyphs[i].advance.x.toInt(), glyphs[i].advance.y.toInt(),
               glyphs[i].offset.x.toInt(), glyphs[i].offset.y.toInt());
    DEBUG("-----------------------------------------");
#endif
    return true;
}

#endif // QT_NO_FREETYPE