JUCE/modules/juce_graphics/native/juce_linux_Fonts.cpp

/*
  ==============================================================================

   This file is part of the JUCE library - "Jules' Utility Class Extensions"
   Copyright 2004-11 by Raw Material Software Ltd.

  ------------------------------------------------------------------------------

   JUCE can be redistributed and/or modified under the terms of the GNU General
   Public License (Version 2), as published by the Free Software Foundation.
   A copy of the license is included in the JUCE distribution, or can be found
   online at www.gnu.org/licenses.

   JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

  ------------------------------------------------------------------------------

   To release a closed-source product which uses JUCE, commercial licenses are
   available: visit www.rawmaterialsoftware.com/juce for more information.

  ==============================================================================
*/

struct FTLibWrapper     : public ReferenceCountedObject
{
    FTLibWrapper() : library (0)
    {
        if (FT_Init_FreeType (&library) != 0)
        {
            library = 0;
            DBG ("Failed to initialize FreeType");
        }
    }

    ~FTLibWrapper()
    {
        if (library != 0)
            FT_Done_FreeType (library);
    }

    FT_Library library;

    typedef ReferenceCountedObjectPtr <FTLibWrapper> Ptr;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (FTLibWrapper)
};

//==============================================================================
struct FTFaceWrapper     : public ReferenceCountedObject
{
    FTFaceWrapper (const FTLibWrapper::Ptr& ftLib, const File& file, int faceIndex)
        : face (0), library (ftLib)
    {
        if (FT_New_Face (ftLib->library, file.getFullPathName().toUTF8(), faceIndex, &face) != 0)
            face = 0;
    }

    ~FTFaceWrapper()
    {
        if (face != 0)
            FT_Done_Face (face);
    }

    FT_Face face;
    FTLibWrapper::Ptr library;

    typedef ReferenceCountedObjectPtr <FTFaceWrapper> Ptr;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (FTFaceWrapper)
};

//==============================================================================
class LinuxFontFileIterator
{
public:
    LinuxFontFileIterator()
        : index (0)
    {
        fontDirs.addTokens (CharPointer_UTF8 (getenv ("JUCE_FONT_PATH")), ";,", String::empty);
        fontDirs.removeEmptyStrings (true);

        if (fontDirs.size() == 0)
        {
            const ScopedPointer<XmlElement> fontsInfo (XmlDocument::parse (File ("/etc/fonts/fonts.conf")));

            if (fontsInfo != nullptr)
            {
                forEachXmlChildElementWithTagName (*fontsInfo, e, "dir")
                {
                    String fontPath (e->getAllSubText().trim());

                    if (fontPath.isNotEmpty())
                    {
                        if (e->getStringAttribute ("prefix") == "xdg")
                        {
                            String xdgDataHome (SystemStats::getEnvironmentVariable ("XDG_DATA_HOME", String::empty));

                            if (xdgDataHome.trimStart().isEmpty())
                                xdgDataHome = "~/.local/share";

                            fontPath = File (xdgDataHome).getChildFile (fontPath).getFullPathName();
                        }

                        fontDirs.add (fontPath);
                    }
                }
            }
        }

        if (fontDirs.size() == 0)
            fontDirs.add ("/usr/X11R6/lib/X11/fonts");

        fontDirs.removeDuplicates (false);
    }

    bool next()
    {
        if (iter != nullptr)
        {
            while (iter->next())
                if (getFile().hasFileExtension ("ttf;pfb;pcf"))
                    return true;
        }

        if (index >= fontDirs.size())
            return false;

        iter = new DirectoryIterator (File::getCurrentWorkingDirectory()
                                         .getChildFile (fontDirs [index++]), true);
        return next();
    }

    File getFile() const    { jassert (iter != nullptr); return iter->getFile(); }

private:
    StringArray fontDirs;
    int index;
    ScopedPointer<DirectoryIterator> iter;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (LinuxFontFileIterator)
};

//==============================================================================
class FTTypefaceList  : private DeletedAtShutdown
{
public:
    FTTypefaceList()
        : library (new FTLibWrapper())
    {
        LinuxFontFileIterator fontFileIterator;

        while (fontFileIterator.next())
        {
            int faceIndex = 0;
            int numFaces = 0;

            do
            {
                FTFaceWrapper face (library, fontFileIterator.getFile(), faceIndex);

                if (face.face != 0)
                {
                    if (faceIndex == 0)
                        numFaces = face.face->num_faces;

                    if ((face.face->face_flags & FT_FACE_FLAG_SCALABLE) != 0)
                        faces.add (new KnownTypeface (fontFileIterator.getFile(), faceIndex, face));
                }

                ++faceIndex;
            }
            while (faceIndex < numFaces);
        }
    }

    ~FTTypefaceList()
    {
        clearSingletonInstance();
    }

    //==============================================================================
    struct KnownTypeface
    {
        KnownTypeface (const File& f, const int index, const FTFaceWrapper& face)
           : file (f),
             family (face.face->family_name),
             style (face.face->style_name),
             faceIndex (index),
             isMonospaced ((face.face->face_flags & FT_FACE_FLAG_FIXED_WIDTH) != 0),
             isSansSerif (isFaceSansSerif (family))
        {
        }

        const File file;
        const String family, style;
        const int faceIndex;
        const bool isMonospaced, isSansSerif;

        JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (KnownTypeface)
    };

    //==============================================================================
    FTFaceWrapper::Ptr createFace (const String& fontName, const String& fontStyle)
    {
        const KnownTypeface* ftFace = matchTypeface (fontName, fontStyle);

        if (ftFace == nullptr)  ftFace = matchTypeface (fontName, "Regular");
        if (ftFace == nullptr)  ftFace = matchTypeface (fontName, String::empty);

        if (ftFace != nullptr)
        {
            if (FTFaceWrapper::Ptr face = new FTFaceWrapper (library, ftFace->file, ftFace->faceIndex))
            {
                // If there isn't a unicode charmap then select the first one.
                if (FT_Select_Charmap (face->face, ft_encoding_unicode) != 0)
                    FT_Set_Charmap (face->face, face->face->charmaps[0]);

                return face;
            }
        }

        return nullptr;
    }

    //==============================================================================
    StringArray findAllFamilyNames() const
    {
        StringArray s;

        for (int i = 0; i < faces.size(); i++)
            s.addIfNotAlreadyThere (faces.getUnchecked(i)->family);

        return s;
    }

    StringArray findAllTypefaceStyles (const String& family) const
    {
        StringArray s;

        for (int i = 0; i < faces.size(); i++)
        {
            const KnownTypeface* const face = faces.getUnchecked(i);

            if (face->family == family)
                s.addIfNotAlreadyThere (face->style);
        }

        return s;
    }

    void getMonospacedNames (StringArray& monoSpaced) const
    {
        for (int i = 0; i < faces.size(); i++)
            if (faces.getUnchecked(i)->isMonospaced)
                monoSpaced.addIfNotAlreadyThere (faces.getUnchecked(i)->family);
    }

    void getSerifNames (StringArray& serif) const
    {
        for (int i = 0; i < faces.size(); i++)
            if (! faces.getUnchecked(i)->isSansSerif)
                serif.addIfNotAlreadyThere (faces.getUnchecked(i)->family);
    }

    void getSansSerifNames (StringArray& sansSerif) const
    {
        for (int i = 0; i < faces.size(); i++)
            if (faces.getUnchecked(i)->isSansSerif)
                sansSerif.addIfNotAlreadyThere (faces.getUnchecked(i)->family);
    }

    juce_DeclareSingleton_SingleThreaded_Minimal (FTTypefaceList);

private:
    FTLibWrapper::Ptr library;
    OwnedArray<KnownTypeface> faces;

    const KnownTypeface* matchTypeface (const String& familyName, const String& style) const noexcept
    {
        for (int i = 0; i < faces.size(); ++i)
        {
            const KnownTypeface* const face = faces.getUnchecked(i);

            if (face->family == familyName
                  && (face->style.equalsIgnoreCase (style) || style.isEmpty()))
                return face;
        }

        return nullptr;
    }

    static bool isFaceSansSerif (const String& family)
    {
        const char* sansNames[] = { "Sans", "Verdana", "Arial", "Ubuntu" };

        for (int i = 0; i < numElementsInArray (sansNames); ++i)
            if (family.containsIgnoreCase (sansNames[i]))
                return true;

        return false;
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (FTTypefaceList)
};

juce_ImplementSingleton_SingleThreaded (FTTypefaceList)


//==============================================================================
class FreeTypeTypeface   : public CustomTypeface
{
public:
    FreeTypeTypeface (const Font& font)
        : faceWrapper (FTTypefaceList::getInstance()
                           ->createFace (font.getTypefaceName(), font.getTypefaceStyle()))
    {
        if (faceWrapper != nullptr)
        {
            setCharacteristics (font.getTypefaceName(),
                                font.getTypefaceStyle(),
                                faceWrapper->face->ascender / (float) (faceWrapper->face->ascender - faceWrapper->face->descender),
                                L' ');
        }
        else
        {
            DBG ("Failed to create typeface: " << font.toString());
        }
    }

    bool loadGlyphIfPossible (const juce_wchar character)
    {
        if (faceWrapper != nullptr)
        {
            FT_Face face = faceWrapper->face;
            const unsigned int glyphIndex = FT_Get_Char_Index (face, character);

            if (FT_Load_Glyph (face, glyphIndex, FT_LOAD_NO_SCALE | FT_LOAD_NO_BITMAP | FT_LOAD_IGNORE_TRANSFORM) == 0
                  && face->glyph->format == ft_glyph_format_outline)
            {
                const float scale = 1.0f / (float) (face->ascender - face->descender);
                Path destShape;

                if (getGlyphShape (destShape, face->glyph->outline, scale))
                {
                    addGlyph (character, destShape, face->glyph->metrics.horiAdvance * scale);

                    if ((face->face_flags & FT_FACE_FLAG_KERNING) != 0)
                        addKerning (face, character, glyphIndex);

                    return true;
                }
            }
        }

        return false;
    }

private:
    FTFaceWrapper::Ptr faceWrapper;

    bool getGlyphShape (Path& destShape, const FT_Outline& outline, const float scaleX)
    {
        const float scaleY = -scaleX;
        const short* const contours = outline.contours;
        const char* const tags = outline.tags;
        const FT_Vector* const points = outline.points;

        for (int c = 0; c < outline.n_contours; ++c)
        {
            const int startPoint = (c == 0) ? 0 : contours [c - 1] + 1;
            const int endPoint = contours[c];

            for (int p = startPoint; p <= endPoint; ++p)
            {
                const float x = scaleX * points[p].x;
                const float y = scaleY * points[p].y;

                if (p == startPoint)
                {
                    if (FT_CURVE_TAG (tags[p]) == FT_Curve_Tag_Conic)
                    {
                        float x2 = scaleX * points [endPoint].x;
                        float y2 = scaleY * points [endPoint].y;

                        if (FT_CURVE_TAG (tags[endPoint]) != FT_Curve_Tag_On)
                        {
                            x2 = (x + x2) * 0.5f;
                            y2 = (y + y2) * 0.5f;
                        }

                        destShape.startNewSubPath (x2, y2);
                    }
                    else
                    {
                        destShape.startNewSubPath (x, y);
                    }
                }

                if (FT_CURVE_TAG (tags[p]) == FT_Curve_Tag_On)
                {
                    if (p != startPoint)
                        destShape.lineTo (x, y);
                }
                else if (FT_CURVE_TAG (tags[p]) == FT_Curve_Tag_Conic)
                {
                    const int nextIndex = (p == endPoint) ? startPoint : p + 1;
                    float x2 = scaleX * points [nextIndex].x;
                    float y2 = scaleY * points [nextIndex].y;

                    if (FT_CURVE_TAG (tags [nextIndex]) == FT_Curve_Tag_Conic)
                    {
                        x2 = (x + x2) * 0.5f;
                        y2 = (y + y2) * 0.5f;
                    }
                    else
                    {
                        ++p;
                    }

                    destShape.quadraticTo (x, y, x2, y2);
                }
                else if (FT_CURVE_TAG (tags[p]) == FT_Curve_Tag_Cubic)
                {
                    const int next1 = p + 1;
                    const int next2 = (p == (endPoint - 1)) ? startPoint : (p + 2);

                    if (p >= endPoint
                         || FT_CURVE_TAG (tags[next1]) != FT_Curve_Tag_Cubic
                         || FT_CURVE_TAG (tags[next2]) != FT_Curve_Tag_On)
                        return false;

                    const float x2 = scaleX * points [next1].x;
                    const float y2 = scaleY * points [next1].y;
                    const float x3 = scaleX * points [next2].x;
                    const float y3 = scaleY * points [next2].y;

                    destShape.cubicTo (x, y, x2, y2, x3, y3);
                    p += 2;
                }
            }

            destShape.closeSubPath();
        }

        return true;
    }

    void addKerning (FT_Face face, const uint32 character, const uint32 glyphIndex)
    {
        const float height = (float) (face->ascender - face->descender);

        uint32 rightGlyphIndex;
        uint32 rightCharCode = FT_Get_First_Char (face, &rightGlyphIndex);

        while (rightGlyphIndex != 0)
        {
            FT_Vector kerning;

            if (FT_Get_Kerning (face, glyphIndex, rightGlyphIndex, ft_kerning_unscaled, &kerning) == 0
                   && kerning.x != 0)
                addKerningPair (character, rightCharCode, kerning.x / height);

            rightCharCode = FT_Get_Next_Char (face, rightCharCode, &rightGlyphIndex);
        }
    }

    JUCE_DECLARE_NON_COPYABLE (FreeTypeTypeface)
};

//==============================================================================
Typeface::Ptr Typeface::createSystemTypefaceFor (const Font& font)
{
    return new FreeTypeTypeface (font);
}

StringArray Font::findAllTypefaceNames()
{
    return FTTypefaceList::getInstance()->findAllFamilyNames();
}

StringArray Font::findAllTypefaceStyles (const String& family)
{
    return FTTypefaceList::getInstance()->findAllTypefaceStyles (family);
}

//==============================================================================
struct DefaultFontNames
{
    DefaultFontNames()
        : defaultSans  (getDefaultSansSerifFontName()),
          defaultSerif (getDefaultSerifFontName()),
          defaultFixed (getDefaultMonospacedFontName())
    {
    }

    String defaultSans, defaultSerif, defaultFixed;

private:
    static String pickBestFont (const StringArray& names, const char* const* choicesArray)
    {
        const StringArray choices (choicesArray);

        for (int j = 0; j < choices.size(); ++j)
            if (names.contains (choices[j], true))
                return choices[j];

        for (int j = 0; j < choices.size(); ++j)
            for (int i = 0; i < names.size(); ++i)
                if (names[i].startsWithIgnoreCase (choices[j]))
                    return names[i];

        for (int j = 0; j < choices.size(); ++j)
            for (int i = 0; i < names.size(); ++i)
                if (names[i].containsIgnoreCase (choices[j]))
                    return names[i];

        return names[0];
    }

    static String getDefaultSansSerifFontName()
    {
        StringArray allFonts;
        FTTypefaceList::getInstance()->getSansSerifNames (allFonts);

        const char* targets[] = { "Verdana", "Bitstream Vera Sans", "Luxi Sans",
                                  "Liberation Sans", "DejaVu Sans", "Sans", 0 };
        return pickBestFont (allFonts, targets);
    }

    static String getDefaultSerifFontName()
    {
        StringArray allFonts;
        FTTypefaceList::getInstance()->getSerifNames (allFonts);

        const char* targets[] = { "Bitstream Vera Serif", "Times", "Nimbus Roman",
                                  "Liberation Serif", "DejaVu Serif", "Serif", 0 };
        return pickBestFont (allFonts, targets);
    }

    static String getDefaultMonospacedFontName()
    {
        StringArray allFonts;
        FTTypefaceList::getInstance()->getMonospacedNames (allFonts);

        const char* targets[] = { "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Sans Mono",
                                  "Liberation Mono", "Courier", "DejaVu Mono", "Mono", 0 };
        return pickBestFont (allFonts, targets);
    }

    JUCE_DECLARE_NON_COPYABLE (DefaultFontNames)
};

Typeface::Ptr Font::getDefaultTypefaceForFont (const Font& font)
{
    static DefaultFontNames defaultNames;

    String faceName (font.getTypefaceName());

    if (faceName == getDefaultSansSerifFontName())       faceName = defaultNames.defaultSans;
    else if (faceName == getDefaultSerifFontName())      faceName = defaultNames.defaultSerif;
    else if (faceName == getDefaultMonospacedFontName()) faceName = defaultNames.defaultFixed;

    Font f (font);
    f.setTypefaceName (faceName);
    return Typeface::createSystemTypefaceFor (f);
}

bool TextLayout::createNativeLayout (const AttributedString&)
{
    return false;
}