qopentype.cpp

基础c代码

            qDebug("script %s has script index %d", tag_to_string(script), script_index);
#endif
            while (features->tag) {
                FT_UShort feature_index;
                error = TT_GSUB_Select_Feature(gsub, features->tag, script_index, 0xffff, &feature_index);
                if (!error) {
#ifdef OT_DEBUG
                    qDebug("  adding feature %s", tag_to_string(features->tag));
#endif
                    TT_GSUB_Add_Feature(gsub, feature_index, features->property);
                }
                ++features;
            }
        }
    }
    
    if (gpos) {
        TT_GPOS_Clear_Features(gpos);
        FT_UShort script_index;
        FT_Error error = TT_GPOS_Select_Script(gpos, tag, &script_index);
        if (!error) {
#ifdef OT_DEBUG
            {
                TTO_FeatureList featurelist = gpos->FeatureList;
                int numfeatures = featurelist.FeatureCount;
                qDebug("gpos table has %d features", numfeatures);
                for(int i = 0; i < numfeatures; i++) {
                    TTO_FeatureRecord *r = featurelist.FeatureRecord + i;
                    FT_UShort feature_index;
                    TT_GPOS_Select_Feature(gpos, r->FeatureTag, script_index, 0xffff, &feature_index);
                    qDebug("   feature '%s'", tag_to_string(r->FeatureTag));
                }
            }
#endif
            FT_ULong *feature_tag_list;
            error = TT_GPOS_Query_Features(gpos, script_index, 0xffff, &feature_tag_list);
            if (!error) {
                while (*feature_tag_list) {
                    FT_UShort feature_index;
                    error = TT_GPOS_Select_Feature(gpos, *feature_tag_list, script_index, 0xffff, &feature_index);
                    if (!error)
                        TT_GPOS_Add_Feature(gpos, feature_index, PositioningProperties);
                    ++feature_tag_list;
                }
            }
        }
    }

    current_script = script;
}

#ifdef OT_DEBUG
static void dump_string(OTL_Buffer buffer)
{
    for (uint i = 0; i < buffer->in_length; ++i) {
        qDebug("    %x: cluster=%d", buffer->in_string[i].gindex, buffer->in_string[i].cluster);
    }
}
#endif

extern void qt_heuristicPosition(QShaperItem *item);

void QOpenType::shape(QShaperItem *item, const unsigned int *properties)
{
    length = item->num_glyphs;

    otl_buffer_clear(otl_buffer);

    tmpAttributes = (QGlyphLayout::Attributes *) realloc(tmpAttributes, length*sizeof(QGlyphLayout::Attributes));
    tmpLogClusters = (unsigned int *) realloc(tmpLogClusters, length*sizeof(unsigned int));
    for (int i = 0; i < length; ++i) {
        otl_buffer_add_glyph(otl_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
    qDebug("-----------------------------------------");
//     qDebug("log clusters before shaping:");
//     for (int j = 0; j < length; j++)
//         qDebug("    log[%d] = %d", j, item->log_clusters[j]);
    qDebug("original glyphs: %p", item->glyphs);
    for (int i = 0; i < length; ++i)
        qDebug("   glyph=%4x", otl_buffer->in_string[i].gindex);
//     dump_string(otl_buffer);
#endif

    loadFlags = item->flags & QTextEngine::DesignMetrics ? FT_LOAD_NO_HINTING : FT_LOAD_DEFAULT;

    if (gsub)
        TT_GSUB_Apply_String(gsub, otl_buffer);

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

bool QOpenType::positionAndAdd(QShaperItem *item, bool doLogClusters)
{
    if (gpos) {
#ifdef Q_WS_X11
        Q_ASSERT(fontEngine->type() == QFontEngine::Freetype);
        face = static_cast<QFontEngineFT *>(fontEngine)->lockFace();
#endif
        memset(otl_buffer->positions, 0, otl_buffer->in_length*sizeof(OTL_PositionRec));
        // #### check that passing "false,false" is correct
        TT_GPOS_Apply_String(face, gpos, loadFlags, otl_buffer, false, false);
#ifdef Q_WS_X11
        static_cast<QFontEngineFT *>(fontEngine)->unlockFace();
#endif
    }
    
    // make sure we have enough space to write everything back
    if (item->num_glyphs < (int)otl_buffer->in_length) {
        item->num_glyphs = otl_buffer->in_length;
        return false;
    }

    QGlyphLayout *glyphs = item->glyphs;

    for (unsigned int i = 0; i < otl_buffer->in_length; ++i) {
        glyphs[i].glyph = otl_buffer->in_string[i].gindex;
        glyphs[i].attributes = tmpAttributes[otl_buffer->in_string[i].cluster];
        if (i && otl_buffer->in_string[i].cluster == otl_buffer->in_string[i-1].cluster)
            glyphs[i].attributes.clusterStart = false;
    }
    item->num_glyphs = otl_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 < otl_buffer->in_length; ++i) {
            int ci = otl_buffer->in_string[i].cluster;
            //         qDebug("   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
//     qDebug("unpositioned: ");
    item->font->recalcAdvances(item->num_glyphs, glyphs, QFlag(item->flags));

    // positioning code:
    if (gpos) {
        OTL_Position positions = otl_buffer->positions;

//         qDebug("positioned glyphs:");
        for (unsigned int i = 0; i < otl_buffer->in_length; i++) {
//             qDebug("    %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?????
            if (positions[i].new_advance) {
                glyphs[i].advance.x = QFixed::fromFixed(item->flags & QTextEngine::RightToLeft
                                          ? -positions[i].x_advance : positions[i].x_advance);
                glyphs[i].advance.y = QFixed::fromFixed(-positions[i].y_advance);
            } else {
                glyphs[i].advance.x += QFixed::fromFixed(item->flags & QTextEngine::RightToLeft
                                           ? -positions[i].x_advance : positions[i].x_advance);
                glyphs[i].advance.y -= QFixed::fromFixed(positions[i].y_advance);
            }
            glyphs[i].offset.x = QFixed::fromFixed(positions[i].x_pos);
            glyphs[i].offset.y = QFixed::fromFixed(-positions[i].y_pos);
            int back = positions[i].back;
            if (item->flags & QTextEngine::RightToLeft) {
                while (back--) {
                    glyphs[i].offset.x -= glyphs[i-back].advance.x;
                    glyphs[i].offset.y -= -glyphs[i-back].advance.y;
                }
            } else {
                while (back) {
                    glyphs[i].offset.x -= glyphs[i-back].advance.x;
                    glyphs[i].offset.y -= -glyphs[i-back].advance.y;
                    --back;
                }
            }
//             qDebug("   ->\tadv=%d\tpos=(%d/%d)",
//                    glyphs[i].advance.x.toInt(), glyphs[i].offset.x.toInt(), glyphs[i].offset.y.toInt());
        }
    } else {
        qt_heuristicPosition(item);
    }

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

#endif // QT_NO_FREETYPE