qfreetypefontdatabase.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qfreetypefontdatabase_p.h"
 
#include <QtGui/private/qguiapplication_p.h>
#include <qpa/qplatformscreen.h>
 
#include <QtCore/QFile>
#include <QtCore/QLibraryInfo>
#include <QtCore/QDir>
#include <QtCore/QtEndian>
#include <QtCore/QLoggingCategory>
#include <QtCore/QUuid>
 
#undef QT_NO_FREETYPE
#include "qfontengine_ft_p.h"
 
#include <ft2build.h>
#include FT_TRUETYPE_TABLES_H
#include FT_ERRORS_H
 
#include FT_MULTIPLE_MASTERS_H
#include FT_SFNT_NAMES_H
#include FT_TRUETYPE_IDS_H
 
QT_BEGIN_NAMESPACE
 
Q_DECLARE_LOGGING_CATEGORY(lcFontDb)
 
using namespace Qt::StringLiterals;
 
void QFreeTypeFontDatabase::populateFontDatabase()
{
    QString fontpath = fontDir();
    QDir dir(fontpath);
 
    if (!dir.exists()) {
        qWarning("QFontDatabase: Cannot find font directory %s.\n"
                 "Note that Qt no longer ships fonts. Deploy some (from https://dejavu-fonts.github.io/ for example) or switch to fontconfig.",
                 qPrintable(fontpath));
        return;
    }
 
    static const QString nameFilters[] = {
        u"*.ttf"_s,
        u"*.pfa"_s,
        u"*.pfb"_s,
        u"*.otf"_s,
    };
 
    const auto fis = dir.entryInfoList(QStringList::fromReadOnlyData(nameFilters), QDir::Files);
    for (const QFileInfo &fi : fis) {
        const QByteArray file = QFile::encodeName(fi.absoluteFilePath());
        QFreeTypeFontDatabase::addTTFile(QByteArray(), file);
    }
}
 
QFontEngine *QFreeTypeFontDatabase::fontEngine(const QFontDef &fontDef, void *usrPtr)
{
    FontFile *fontfile = static_cast<FontFile *>(usrPtr);
    QFontEngine::FaceId faceId;
    faceId.filename = QFile::encodeName(fontfile->fileName);
    faceId.index = fontfile->indexValue;
    faceId.instanceIndex = fontfile->instanceIndex;
    faceId.variableAxes = fontDef.variableAxisValues;
 
    // Make sure the FaceId compares uniquely in cases where a
    // file name is not provided.
    if (faceId.filename.isEmpty()) {
        QUuid::Id128Bytes id{};
        memcpy(&id, &usrPtr, sizeof(usrPtr));
        faceId.uuid = QUuid(id).toByteArray();
    }
 
    return QFontEngineFT::create(fontDef, faceId, fontfile->data);
}
 
QFontEngine *QFreeTypeFontDatabase::fontEngine(const QByteArray &fontData, qreal pixelSize,
                                                QFont::HintingPreference hintingPreference)
{
    return QFontEngineFT::create(fontData, pixelSize, hintingPreference, {});
}
 
QStringList QFreeTypeFontDatabase::addApplicationFont(const QByteArray &fontData, const QString &fileName, QFontDatabasePrivate::ApplicationFont *applicationFont)
{
    return QFreeTypeFontDatabase::addTTFile(fontData, fileName.toLocal8Bit(), applicationFont);
}
 
void QFreeTypeFontDatabase::releaseHandle(void *handle)
{
    FontFile *file = static_cast<FontFile *>(handle);
    delete file;
}
 
extern FT_Library qt_getFreetype();
 
void QFreeTypeFontDatabase::addNamedInstancesForFace(void *face_,
                                                     int faceIndex,
                                                     const QString &family,
                                                     const QString &styleName,
                                                     QFont::Weight weight,
                                                     QFont::Stretch stretch,
                                                     QFont::Style style,
                                                     bool fixedPitch,
                                                     const QSupportedWritingSystems &writingSystems,
                                                     const QByteArray &fileName,
                                                     const QByteArray &fontData)
{
    FT_Face face = reinterpret_cast<FT_Face>(face_);
 
    // Note: The following does not actually depend on API from 2.9, but the
    // FT_Set_Named_Instance() was added in 2.9, so to avoid populating the database with
    // named instances that cannot be selected, we disable the feature on older Freetype
    // versions.
#if (FREETYPE_MAJOR*10000 + FREETYPE_MINOR*100 + FREETYPE_PATCH) >= 20900
    FT_MM_Var *var = nullptr;
    FT_Get_MM_Var(face, &var);
    if (var != nullptr) {
        std::unique_ptr<FT_MM_Var, void(*)(FT_MM_Var*)> varGuard(var, [](FT_MM_Var *res) {
            FT_Done_MM_Var(qt_getFreetype(), res);
        });
 
        for (FT_UInt i = 0; i < var->num_namedstyles; ++i) {
           FT_UInt id = var->namedstyle[i].strid;
 
           QFont::Weight instanceWeight = weight;
           QFont::Stretch instanceStretch = stretch;
           QFont::Style instanceStyle = style;
           for (FT_UInt axis = 0; axis < var->num_axis; ++axis) {
               if (var->axis[axis].tag == QFont::Tag("wght").value()) {
                   instanceWeight = QFont::Weight(var->namedstyle[i].coords[axis] >> 16);
               } else if (var->axis[axis].tag == QFont::Tag("wdth").value()) {
                   instanceStretch = QFont::Stretch(var->namedstyle[i].coords[axis] >> 16);
               }  else if (var->axis[axis].tag == QFont::Tag("ital").value()) {
                   FT_UInt ital = var->namedstyle[i].coords[axis] >> 16;
                   if (ital == 1)
                       instanceStyle = QFont::StyleItalic;
                   else
                       instanceStyle = QFont::StyleNormal;
               }
           }
 
           FT_UInt count = FT_Get_Sfnt_Name_Count(face);
           for (FT_UInt j = 0; j < count; ++j) {
               FT_SfntName name;
               if (FT_Get_Sfnt_Name(face, j, &name))
                   continue;
 
               if (name.name_id != id)
                   continue;
 
               // Only support Unicode for now
               if (name.encoding_id != TT_MS_ID_UNICODE_CS)
                   continue;
 
               // Sfnt names stored as UTF-16BE
               QString instanceName;
               for (FT_UInt k = 0; k < name.string_len; k += 2)
                   instanceName += QChar((name.string[k] << 8) + name.string[k + 1]);
               if (instanceName != styleName) {
                   FontFile *variantFontFile = new FontFile{
                       QFile::decodeName(fileName),
                       faceIndex,
                       int(i),
                       fontData
                   };
 
                   qCDebug(lcFontDb) << "Registering named instance" << i
                                     << ":" << instanceName
                                     << "for font family" << family
                                     << "with weight" << instanceWeight
                                     << ", style" << instanceStyle
                                     << ", stretch" << instanceStretch;
 
                   registerFont(family,
                                instanceName,
                                QString(),
                                instanceWeight,
                                instanceStyle,
                                instanceStretch,
                                true,
                                true,
                                0,
                                fixedPitch,
                                writingSystems,
                                variantFontFile);
               }
           }
        }
    }
#else
    Q_UNUSED(face);
    Q_UNUSED(family);
    Q_UNUSED(styleName);
    Q_UNUSED(weight);
    Q_UNUSED(stretch);
    Q_UNUSED(style);
    Q_UNUSED(fixedPitch);
    Q_UNUSED(writingSystems);
    Q_UNUSED(fontData);
#endif
 
}
 
QStringList QFreeTypeFontDatabase::addTTFile(const QByteArray &fontData, const QByteArray &file, QFontDatabasePrivate::ApplicationFont *applicationFont)
{
    FT_Library library = qt_getFreetype();
 
    int index = 0;
    int numFaces = 0;
    QStringList families;
    do {
        FT_Face face;
        FT_Error error;
        if (!fontData.isEmpty()) {
            error = FT_New_Memory_Face(library, (const FT_Byte *)fontData.constData(), fontData.size(), index, &face);
        } else {
            error = FT_New_Face(library, file.constData(), index, &face);
        }
        if (error != FT_Err_Ok) {
            qDebug() << "FT_New_Face failed with index" << index << ':' << Qt::hex << error;
            break;
        }
        numFaces = face->num_faces;
 
        QFont::Weight weight = QFont::Normal;
 
        QFont::Style style = QFont::StyleNormal;
        if (face->style_flags & FT_STYLE_FLAG_ITALIC)
            style = QFont::StyleItalic;
 
        if (face->style_flags & FT_STYLE_FLAG_BOLD)
            weight = QFont::Bold;
 
        bool fixedPitch = (face->face_flags & FT_FACE_FLAG_FIXED_WIDTH);
        QSupportedWritingSystems writingSystems;
        // detect symbol fonts
        for (int i = 0; i < face->num_charmaps; ++i) {
            FT_CharMap cm = face->charmaps[i];
            if (cm->encoding == FT_ENCODING_ADOBE_CUSTOM
                    || cm->encoding == FT_ENCODING_MS_SYMBOL) {
                writingSystems.setSupported(QFontDatabase::Symbol);
                break;
            }
        }
 
        QFont::Stretch stretch = QFont::Unstretched;
        TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(face, ft_sfnt_os2);
        if (os2) {
            quint32 unicodeRange[4] = {
                quint32(os2->ulUnicodeRange1),
                quint32(os2->ulUnicodeRange2),
                quint32(os2->ulUnicodeRange3),
                quint32(os2->ulUnicodeRange4)
            };
            quint32 codePageRange[2] = {
                quint32(os2->ulCodePageRange1),
                quint32(os2->ulCodePageRange2)
            };
 
            writingSystems = QPlatformFontDatabase::writingSystemsFromTrueTypeBits(unicodeRange, codePageRange);
 
            if (os2->usWeightClass) {
                weight = static_cast<QFont::Weight>(os2->usWeightClass);
            } else if (os2->panose[2]) {
                int w = os2->panose[2];
                if (w <= 1)
                    weight = QFont::Thin;
                else if (w <= 2)
                    weight = QFont::ExtraLight;
                else if (w <= 3)
                    weight = QFont::Light;
                else if (w <= 5)
                    weight = QFont::Normal;
                else if (w <= 6)
                    weight = QFont::Medium;
                else if (w <= 7)
                    weight = QFont::DemiBold;
                else if (w <= 8)
                    weight = QFont::Bold;
                else if (w <= 9)
                    weight = QFont::ExtraBold;
                else if (w <= 10)
                    weight = QFont::Black;
            }
 
            switch (os2->usWidthClass) {
            case 1:
                stretch = QFont::UltraCondensed;
                break;
            case 2:
                stretch = QFont::ExtraCondensed;
                break;
            case 3:
                stretch = QFont::Condensed;
                break;
            case 4:
                stretch = QFont::SemiCondensed;
                break;
            case 5:
                stretch = QFont::Unstretched;
                break;
            case 6:
                stretch = QFont::SemiExpanded;
                break;
            case 7:
                stretch = QFont::Expanded;
                break;
            case 8:
                stretch = QFont::ExtraExpanded;
                break;
            case 9:
                stretch = QFont::UltraExpanded;
                break;
            }
        }
 
        QString family = QString::fromLatin1(face->family_name);
        FontFile *fontFile = new FontFile{
            QFile::decodeName(file),
            index,
            -1,
            fontData
        };
 
        QString styleName = QString::fromLatin1(face->style_name);
 
        if (applicationFont != nullptr) {
            QFontDatabasePrivate::ApplicationFont::Properties properties;
            properties.familyName = family;
            properties.styleName = styleName;
            properties.weight = weight;
            properties.stretch = stretch;
            properties.style = style;
 
            applicationFont->properties.append(properties);
        }
 
        registerFont(family, styleName, QString(), weight, style, stretch, true, true, 0, fixedPitch, writingSystems, fontFile);
 
        addNamedInstancesForFace(face, index, family, styleName, weight, stretch, style, fixedPitch, writingSystems, file, fontData);
 
        families.append(family);
 
        FT_Done_Face(face);
        ++index;
    } while (index < numFaces);
    return families;
}
 
bool QFreeTypeFontDatabase::supportsVariableApplicationFonts() const
{
#if (FREETYPE_MAJOR*10000 + FREETYPE_MINOR*100 + FREETYPE_PATCH) >= 20900
    return true;
#else
    return false;
#endif
}
 
QT_END_NAMESPACE