fontcachewin.cpp

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        LOGFONT logFont;
        logFont.lfCharSet = DEFAULT_CHARSET;
        memcpy(logFont.lfFaceName, linkedFonts->at(linkedFontIndex).characters(), linkedFonts->at(linkedFontIndex).length() * sizeof(WCHAR));
        logFont.lfFaceName[linkedFonts->at(linkedFontIndex).length()] = 0;
        EnumFontFamiliesEx(hdc, &logFont, linkedFontEnumProc, reinterpret_cast<LPARAM>(&hfont), 0);
        linkedFontIndex++;
    }

    if (hfont) {
        if (!familyName.isEmpty()) {
            FontPlatformData* result = getCachedFontPlatformData(font.fontDescription(), familyName);
            if (result)
                fontData = getCachedFontData(result);
        }

        SelectObject(hdc, oldFont);
        DeleteObject(hfont);
    }

    ReleaseDC(0, hdc);
    return fontData;
}

FontPlatformData* FontCache::getSimilarFontPlatformData(const Font& font)
{
    return 0;
}

FontPlatformData* FontCache::getLastResortFallbackFont(const FontDescription& fontDescription)
{
    // FIXME: Would be even better to somehow get the user's default font here.  For now we'll pick
    // the default that the user would get without changing any prefs.
    static AtomicString timesStr("Times New Roman");
    return getCachedFontPlatformData(fontDescription, timesStr);
}

static LONG toGDIFontWeight(FontWeight fontWeight)
{
    static LONG gdiFontWeights[] = {
        FW_THIN,        // FontWeight100
        FW_EXTRALIGHT,  // FontWeight200
        FW_LIGHT,       // FontWeight300
        FW_NORMAL,      // FontWeight400
        FW_MEDIUM,      // FontWeight500
        FW_SEMIBOLD,    // FontWeight600
        FW_BOLD,        // FontWeight700
        FW_EXTRABOLD,   // FontWeight800
        FW_HEAVY        // FontWeight900
    };
    return gdiFontWeights[fontWeight];
}

static inline bool isGDIFontWeightBold(LONG gdiFontWeight)
{
    return gdiFontWeight >= FW_SEMIBOLD;
}

static LONG adjustedGDIFontWeight(LONG gdiFontWeight, const String& family)
{
    static AtomicString lucidaStr("Lucida Grande");
    if (equalIgnoringCase(family, lucidaStr)) {
        if (gdiFontWeight == FW_NORMAL)
            return FW_MEDIUM;
        if (gdiFontWeight == FW_BOLD)
            return FW_SEMIBOLD;
    }
    return gdiFontWeight;
}

struct MatchImprovingProcData {
    MatchImprovingProcData(LONG desiredWeight, bool desiredItalic)
        : m_desiredWeight(desiredWeight)
        , m_desiredItalic(desiredItalic)
        , m_hasMatched(false)
    {
    }

    LONG m_desiredWeight;
    bool m_desiredItalic;
    bool m_hasMatched;
    LOGFONT m_chosen;
};

static int CALLBACK matchImprovingEnumProc(CONST LOGFONT* candidate, CONST TEXTMETRIC* metrics, DWORD fontType, LPARAM lParam)
{
    MatchImprovingProcData* matchData = reinterpret_cast<MatchImprovingProcData*>(lParam);

    if (!matchData->m_hasMatched) {
        matchData->m_hasMatched = true;
        matchData->m_chosen = *candidate;
        return 1;
    }

    if (!candidate->lfItalic != !matchData->m_chosen.lfItalic) {
        if (!candidate->lfItalic == !matchData->m_desiredItalic)
            matchData->m_chosen = *candidate;

        return 1;
    }

    unsigned chosenWeightDeltaMagnitude = abs(matchData->m_chosen.lfWeight - matchData->m_desiredWeight);
    unsigned candidateWeightDeltaMagnitude = abs(candidate->lfWeight - matchData->m_desiredWeight);

    // If both are the same distance from the desired weight, prefer the candidate if it is further from regular.
    if (chosenWeightDeltaMagnitude == candidateWeightDeltaMagnitude && abs(candidate->lfWeight - FW_NORMAL) > abs(matchData->m_chosen.lfWeight - FW_NORMAL)) {
        matchData->m_chosen = *candidate;
        return 1;
    }

    // Otherwise, prefer the one closer to the desired weight.
    if (candidateWeightDeltaMagnitude < chosenWeightDeltaMagnitude)
        matchData->m_chosen = *candidate;

    return 1;
}

static HFONT createGDIFont(const AtomicString& family, LONG desiredWeight, bool desiredItalic, int size)
{
    HDC hdc = GetDC(0);

    LOGFONT logFont;
    logFont.lfCharSet = DEFAULT_CHARSET;
    unsigned familyLength = min(family.length(), static_cast<unsigned>(LF_FACESIZE - 1));
    memcpy(logFont.lfFaceName, family.characters(), familyLength * sizeof(UChar));
    logFont.lfFaceName[familyLength] = 0;
    logFont.lfPitchAndFamily = 0;

    MatchImprovingProcData matchData(desiredWeight, desiredItalic);
    EnumFontFamiliesEx(hdc, &logFont, matchImprovingEnumProc, reinterpret_cast<LPARAM>(&matchData), 0);

    ReleaseDC(0, hdc);

    if (!matchData.m_hasMatched)
        return 0;

    matchData.m_chosen.lfHeight = -size;
    matchData.m_chosen.lfWidth = 0;
    matchData.m_chosen.lfEscapement = 0;
    matchData.m_chosen.lfOrientation = 0;
    matchData.m_chosen.lfUnderline = false;
    matchData.m_chosen.lfStrikeOut = false;
    matchData.m_chosen.lfCharSet = DEFAULT_CHARSET;
#if PLATFORM(CG) || PLATFORM(CAIRO)
    matchData.m_chosen.lfOutPrecision = OUT_TT_ONLY_PRECIS;
#else
    matchData.m_chosen.lfOutPrecision = OUT_TT_PRECIS;
#endif
    matchData.m_chosen.lfQuality = DEFAULT_QUALITY;
    matchData.m_chosen.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;

    HFONT result = CreateFontIndirect(&matchData.m_chosen);
    if (!result)
        return 0;

    HDC dc = GetDC(0);
    SaveDC(dc);
    SelectObject(dc, result);
    WCHAR actualName[LF_FACESIZE];
    GetTextFace(dc, LF_FACESIZE, actualName);
    RestoreDC(dc, -1);
    ReleaseDC(0, dc);

    if (wcsicmp(matchData.m_chosen.lfFaceName, actualName)) {
        DeleteObject(result);
        result = 0;
    }

    return result;
}

struct TraitsInFamilyProcData {
    TraitsInFamilyProcData(const AtomicString& familyName)
        : m_familyName(familyName)
    {
    }

    const AtomicString& m_familyName;
    HashSet<unsigned> m_traitsMasks;
};

static int CALLBACK traitsInFamilyEnumProc(CONST LOGFONT* logFont, CONST TEXTMETRIC* metrics, DWORD fontType, LPARAM lParam)
{
    TraitsInFamilyProcData* procData = reinterpret_cast<TraitsInFamilyProcData*>(lParam);

    unsigned traitsMask = 0;
    traitsMask |= logFont->lfItalic ? FontStyleItalicMask : FontStyleNormalMask;
    traitsMask |= FontVariantNormalMask;
    LONG weight = adjustedGDIFontWeight(logFont->lfWeight, procData->m_familyName);
    traitsMask |= weight == FW_THIN ? FontWeight100Mask :
        weight == FW_EXTRALIGHT ? FontWeight200Mask :
        weight == FW_LIGHT ? FontWeight300Mask :
        weight == FW_NORMAL ? FontWeight400Mask :
        weight == FW_MEDIUM ? FontWeight500Mask :
        weight == FW_SEMIBOLD ? FontWeight600Mask :
        weight == FW_BOLD ? FontWeight700Mask :
        weight == FW_EXTRABOLD ? FontWeight800Mask :
                                 FontWeight900Mask;
    procData->m_traitsMasks.add(traitsMask);
    return 1;
}
void FontCache::getTraitsInFamily(const AtomicString& familyName, Vector<unsigned>& traitsMasks)
{
    HDC hdc = GetDC(0);

    LOGFONT logFont;
    logFont.lfCharSet = DEFAULT_CHARSET;
    unsigned familyLength = min(familyName.length(), static_cast<unsigned>(LF_FACESIZE - 1));
    memcpy(logFont.lfFaceName, familyName.characters(), familyLength * sizeof(UChar));
    logFont.lfFaceName[familyLength] = 0;
    logFont.lfPitchAndFamily = 0;

    TraitsInFamilyProcData procData(familyName);
    EnumFontFamiliesEx(hdc, &logFont, traitsInFamilyEnumProc, reinterpret_cast<LPARAM>(&procData), 0);
    copyToVector(procData.m_traitsMasks, traitsMasks);

    ReleaseDC(0, hdc);
}

FontPlatformData* FontCache::createFontPlatformData(const FontDescription& fontDescription, const AtomicString& family)
{
    bool isLucidaGrande = false;
    static AtomicString lucidaStr("Lucida Grande");
    if (equalIgnoringCase(family, lucidaStr))
        isLucidaGrande = true;

    bool useGDI = fontDescription.renderingMode() == AlternateRenderingMode && !isLucidaGrande;

    // The logical size constant is 32. We do this for subpixel precision when rendering using Uniscribe.
    // This masks rounding errors related to the HFONT metrics being  different from the CGFont metrics.
    // FIXME: We will eventually want subpixel precision for GDI mode, but the scaled rendering doesn't
    // look as nice. That may be solvable though.
    LONG weight = adjustedGDIFontWeight(toGDIFontWeight(fontDescription.weight()), family);
    HFONT hfont = createGDIFont(family, weight, fontDescription.italic(), fontDescription.computedPixelSize() * (useGDI ? 1 : 32));

    if (!hfont)
        return 0;

    if (isLucidaGrande)
        useGDI = false; // Never use GDI for Lucida Grande.

    LOGFONT logFont;
    GetObject(hfont, sizeof(LOGFONT), &logFont);

    bool synthesizeBold = isGDIFontWeightBold(weight) && !isGDIFontWeightBold(logFont.lfWeight);
    bool synthesizeItalic = fontDescription.italic() && !logFont.lfItalic;

    FontPlatformData* result = new FontPlatformData(hfont, fontDescription.computedPixelSize(), synthesizeBold, synthesizeItalic, useGDI);

#if PLATFORM(CG)
    bool fontCreationFailed = !result->cgFont();
#elif PLATFORM(CAIRO)
    bool fontCreationFailed = !result->fontFace();
#endif

    if (fontCreationFailed) {
        // The creation of the CGFontRef failed for some reason.  We already asserted in debug builds, but to make
        // absolutely sure that we don't use this font, go ahead and return 0 so that we can fall back to the next
        // font.
        delete result;
        DeleteObject(hfont);
        return 0;
    }        

    return result;
}

}