qscriptengine.cpp

奇趣公司比较新的qt/emd版本

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#include "qscriptengine_p.h"

#include "qdebug.h"
#include "qstring.h"
#include "qrect.h"
#include "qfont.h"
#include <private/qunicodetables_p.h>
#include "qtextengine_p.h"
#include "qfontengine_p.h"
#include <stdlib.h>
#include <qvarlengtharray.h>
#ifndef QT_NO_OPENTYPE
#include "qopentype_p.h"
#endif

#undef None
#undef Pre
#undef Above
#undef Below

// --------------------------------------------------------------------------------------------------------------------------------------------
//
// Basic processing
//
// --------------------------------------------------------------------------------------------------------------------------------------------

static inline void positionCluster(QShaperItem *item, int gfrom,  int glast)
{
    int nmarks = glast - gfrom;
    if (nmarks <= 0) {
        qWarning("Qt: No marks to position in positionCluster()");
        return;
    }

    QGlyphLayout *glyphs = item->glyphs;
    QFontEngine *f = item->font;

    glyph_metrics_t baseInfo = f->boundingBox(glyphs[gfrom].glyph);

    if (item->script == QUnicodeTables::Hebrew)
        // we need to attach below the baseline, because of the hebrew iud.
        baseInfo.height = qMax(baseInfo.height, -baseInfo.y);

    QRectF baseRect(baseInfo.x.toReal(), baseInfo.y.toReal(), baseInfo.width.toReal(), baseInfo.height.toReal());

//     qDebug("---> positionCluster: cluster from %d to %d", gfrom, glast);
//     qDebug("baseInfo: %f/%f (%f/%f) off=%f/%f", baseInfo.x, baseInfo.y, baseInfo.width, baseInfo.height, baseInfo.xoff, baseInfo.yoff);

    qreal size = (f->ascent()/10).toReal();
    qreal offsetBase = (size - 4) / 4 + qMin<qreal>(size, 4) + 1;
//     qDebug("offset = %f", offsetBase);

    bool rightToLeft = item->flags & QTextEngine::RightToLeft;

    int i;
    unsigned char lastCmb = 0;
    QRectF attachmentRect;

    for(i = 1; i <= nmarks; i++) {
        glyph_t mark = glyphs[gfrom+i].glyph;
        QPointF p;
        glyph_metrics_t markInfo = f->boundingBox(mark);
        QRectF markRect(markInfo.x.toReal(), markInfo.y.toReal(), markInfo.width.toReal(), markInfo.height.toReal());
//          qDebug("markInfo: %f/%f (%f/%f) off=%f/%f", markInfo.x, markInfo.y, markInfo.width, markInfo.height, markInfo.xoff, markInfo.yoff);

        qreal offset = offsetBase;
        unsigned char cmb = glyphs[gfrom+i].attributes.combiningClass;

        // ### maybe the whole position determination should move down to heuristicSetGlyphAttributes. Would save some
        // bits  in the glyphAttributes structure.
        if (cmb < 200) {
            // fixed position classes. We approximate by mapping to one of the others.
            // currently I added only the ones for arabic, hebrew, lao and thai.

            // for Lao and Thai marks with class 0, see below (heuristicSetGlyphAttributes)

            // add a bit more offset to arabic, a bit hacky
            if (cmb >= 27 && cmb <= 36 && offset < 3)
                offset +=1;
            // below
            if ((cmb >= 10 && cmb <= 18) ||
                 cmb == 20 || cmb == 22 ||
                 cmb == 29 || cmb == 32)
                cmb = QChar::Combining_Below;
            // above
            else if (cmb == 23 || cmb == 27 || cmb == 28 ||
                      cmb == 30 || cmb == 31 || (cmb >= 33 && cmb <= 36))
                cmb = QChar::Combining_Above;
            //below-right
            else if (cmb == 9 || cmb == 103 || cmb == 118)
                cmb = QChar::Combining_BelowRight;
            // above-right
            else if (cmb == 24 || cmb == 107 || cmb == 122)
                cmb = QChar::Combining_AboveRight;
            else if (cmb == 25)
                cmb = QChar::Combining_AboveLeft;
            // fixed:
            //  19 21

        }

        // combining marks of different class don't interact. Reset the rectangle.
        if (cmb != lastCmb) {
            //qDebug("resetting rect");
            attachmentRect = baseRect;
        }

        switch(cmb) {
        case QChar::Combining_DoubleBelow:
                // ### wrong in rtl context!
        case QChar::Combining_BelowLeft:
            p += QPointF(0, offset);
        case QChar::Combining_BelowLeftAttached:
            p += attachmentRect.bottomLeft() - markRect.topLeft();
            break;
        case QChar::Combining_Below:
            p += QPointF(0, offset);
        case QChar::Combining_BelowAttached:
            p += attachmentRect.bottomLeft() - markRect.topLeft();
            p += QPointF((attachmentRect.width() - markRect.width())/2 , 0);
            break;
            case QChar::Combining_BelowRight:
            p += QPointF(0, offset);
        case QChar::Combining_BelowRightAttached:
            p += attachmentRect.bottomRight() - markRect.topRight();
            break;
            case QChar::Combining_Left:
            p += QPointF(-offset, 0);
        case QChar::Combining_LeftAttached:
            break;
            case QChar::Combining_Right:
            p += QPointF(offset, 0);
        case QChar::Combining_RightAttached:
            break;
        case QChar::Combining_DoubleAbove:
            // ### wrong in RTL context!
        case QChar::Combining_AboveLeft:
            p += QPointF(0, -offset);
        case QChar::Combining_AboveLeftAttached:
            p += attachmentRect.topLeft() - markRect.bottomLeft();
            break;
        case QChar::Combining_Above:
            p += QPointF(0, -offset);
        case QChar::Combining_AboveAttached:
            p += attachmentRect.topLeft() - markRect.bottomLeft();
            p += QPointF((attachmentRect.width() - markRect.width())/2 , 0);
            break;
        case QChar::Combining_AboveRight:
            p += QPointF(0, -offset);
        case QChar::Combining_AboveRightAttached:
            p += attachmentRect.topRight() - markRect.bottomRight();
            break;

        case QChar::Combining_IotaSubscript:
            default:
                break;
        }
//          qDebug("char=%x combiningClass = %d offset=%f/%f", mark, cmb, p.x(), p.y());
        markRect.translate(p.x(), p.y());
        attachmentRect |= markRect;
        lastCmb = cmb;
        if (rightToLeft) {
            glyphs[gfrom+i].offset.x = QFixed::fromReal(p.x());
            glyphs[gfrom+i].offset.y = QFixed::fromReal(p.y());
        } else {
            glyphs[gfrom+i].offset.x = QFixed::fromReal(p.x()) - baseInfo.xoff;
            glyphs[gfrom+i].offset.y = QFixed::fromReal(p.y()) - baseInfo.yoff;
        }
        glyphs[gfrom+i].advance = QFixedPoint();
    }
}


void qt_heuristicPosition(QShaperItem *item)
{
    QGlyphLayout *glyphs = item->glyphs;

    int cEnd = -1;
    int i = item->num_glyphs;
    while (i--) {
        if (cEnd == -1 && glyphs[i].attributes.mark) {
            cEnd = i;
        } else if (cEnd != -1 && !glyphs[i].attributes.mark) {
            positionCluster(item, i, cEnd);
            cEnd = -1;
        }
    }
}



// set the glyph attributes heuristically. Assumes a 1 to 1 relationship between chars and glyphs
// and no reordering.
// also computes logClusters heuristically
static void heuristicSetGlyphAttributes(QShaperItem *item, const QChar *uc, int length)
{
    // ### zeroWidth and justification are missing here!!!!!

    Q_ASSERT(item->num_glyphs <= length);

//     qDebug("QScriptEngine::heuristicSetGlyphAttributes, num_glyphs=%d", item->num_glyphs);
    QGlyphLayout *glyphs = item->glyphs;
    unsigned short *logClusters = item->log_clusters;


    // the mac font engine does the setup already in stringToCMap
#ifndef Q_WS_MAC
    int glyph_pos = 0;
    for (int i = 0; i < length; i++) {
        if (uc[i].unicode() >= 0xd800 && uc[i].unicode() < 0xdc00 && i < length-1
            && uc[i+1].unicode() >= 0xdc00 && uc[i+1].unicode() < 0xe000) {
            logClusters[i] = glyph_pos;
            logClusters[++i] = glyph_pos;
        } else {
            logClusters[i] = glyph_pos;
        }
        ++glyph_pos;
    }
    Q_ASSERT(glyph_pos == item->num_glyphs);
#endif

    // first char in a run is never (treated as) a mark
#if !defined(Q_WS_MAC)
    int cStart = 0;
#endif
    const bool symbolFont = item->font->symbol;
    glyphs[0].attributes.mark = false;
    glyphs[0].attributes.clusterStart = true;
    glyphs[0].attributes.dontPrint = (!symbolFont && uc[0].unicode() == 0x00ad) || qIsControlChar(uc[0].unicode());

    int pos = 0;
    int lastCat = QChar::category(uc[0].unicode());
    for (int i = 1; i < length; ++i) {
        if (logClusters[i] == pos)
            // same glyph
            continue;
        ++pos;
        while (pos < logClusters[i]) {
            // the mac engine already has attributes setup properly
#if !defined(Q_WS_MAC)
            glyphs[pos].attributes = glyphs[pos-1].attributes;
#endif
            ++pos;
        }
        // hide soft-hyphens by default
        if ((!symbolFont && uc[i].unicode() == 0x00ad) || qIsControlChar(uc[i].unicode()))
            glyphs[pos].attributes.dontPrint = true;
        const QUnicodeTables::Properties *prop = QUnicodeTables::properties(uc[i].unicode());
        int cat = prop->category;
#if !defined(Q_WS_MAC)
        if (cat != QChar::Mark_NonSpacing) {
            glyphs[pos].attributes.mark = false;
            glyphs[pos].attributes.clusterStart = true;
            glyphs[pos].attributes.combiningClass = 0;
            cStart = logClusters[i];
        } else {
            int cmb = prop->combiningClass;

            if (cmb == 0) {
                // Fix 0 combining classes
                if ((uc[pos].unicode() & 0xff00) == 0x0e00) {
                    // thai or lao
                    unsigned char col = uc[pos].cell();
                    if (col == 0x31 ||
                         col == 0x34 ||
                         col == 0x35 ||
                         col == 0x36 ||
                         col == 0x37 ||
                         col == 0x47 ||
                         col == 0x4c ||
                         col == 0x4d ||
                         col == 0x4e) {
                        cmb = QChar::Combining_AboveRight;
                    } else if (col == 0xb1 ||
                                col == 0xb4 ||
                                col == 0xb5 ||
                                col == 0xb6 ||
                                col == 0xb7 ||
                                col == 0xbb ||
                                col == 0xcc ||
                                col == 0xcd) {
                        cmb = QChar::Combining_Above;
                    } else if (col == 0xbc) {
                        cmb = QChar::Combining_Below;
                    }
                }
            }

            glyphs[pos].attributes.mark = true;
            glyphs[pos].attributes.clusterStart = false;
            glyphs[pos].attributes.combiningClass = cmb;
            logClusters[i] = cStart;
            glyphs[pos].advance = QFixedPoint();
        }
#endif
        // one gets an inter character justification point if the current char is not a non spacing mark.
        // as then the current char belongs to the last one and one gets a space justification point
        // after the space char.
        if (lastCat == QChar::Separator_Space)
            glyphs[pos-1].attributes.justification = QGlyphLayout::Space;
        else if (cat != QChar::Mark_NonSpacing)
            glyphs[pos-1].attributes.justification = QGlyphLayout::Character;
        else
            glyphs[pos-1].attributes.justification = QGlyphLayout::NoJustification;

        lastCat = cat;
    }
    pos = logClusters[length-1];
    if (lastCat == QChar::Separator_Space)
        glyphs[pos].attributes.justification = QGlyphLayout::Space;
    else
        glyphs[pos].attributes.justification = QGlyphLayout::Character;
}

static void heuristicSetGlyphAttributes(QShaperItem *item)
{
    heuristicSetGlyphAttributes(item, item->string->unicode() + item->from, item->length);
}

enum {
    CcmpProperty = 0x1
};

#ifndef QT_NO_OPENTYPE
static const QOpenType::Features basic_features[] = {
    { FT_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },
    { FT_MAKE_TAG('l', 'i', 'g', 'a'), CcmpProperty },
    { FT_MAKE_TAG('c', 'l', 'i', 'g'), CcmpProperty },
    {0, 0}
};
#endif

static bool basic_shape(QShaperItem *item)
{

#if !defined(QT_NO_OPENTYPE) && !defined(Q_WS_QWS)
    const int availableGlyphs = item->num_glyphs;
#endif

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

    // disable open type shaping for simple scripts on embedded, as it's computationally rahter expensive