diff options
Diffstat (limited to 'src/gui/text/qfont.cpp')
| -rw-r--r-- | src/gui/text/qfont.cpp | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/src/gui/text/qfont.cpp b/src/gui/text/qfont.cpp index 7fd590c355..c8881a9bf8 100644 --- a/src/gui/text/qfont.cpp +++ b/src/gui/text/qfont.cpp @@ -1462,6 +1462,31 @@ QFont::StyleHint QFont::styleHint() const \value NoAntialias don't antialias the fonts. \value NoSubpixelAntialias avoid subpixel antialiasing on the fonts if possible. \value PreferAntialias antialias if possible. + \value [since 6.8] ContextFontMerging If the selected font does not contain a certain character, + then Qt automatically chooses a similar-looking fallback font that contains the + character. By default this is done on a character-by-character basis. This means that in + certain uncommon cases, multiple fonts may be used to represent one string of text even + if it's in the same script. Setting \c ContextFontMerging will try finding the fallback + font that matches the largest subset of the input string instead. This will be more + expensive for strings where missing glyphs occur, but may give more consistent results. + If \c NoFontMerging is set, then \c ContextFontMerging will have no effect. + \value [since 6.8] PreferTypoLineMetrics For compatibility reasons, OpenType fonts contain + two competing sets of the vertical line metrics that provide the + \l{QFontMetricsF::ascent()}{ascent}, \l{QFontMetricsF::descent()}{descent} and + \l{QFontMetricsF::leading()}{leading} of the font. These are often referred to as the + \l{https://learn.microsoft.com/en-us/typography/opentype/spec/os2#uswinascent}{win} + (Windows) metrics and the + \l{https://learn.microsoft.com/en-us/typography/opentype/spec/os2#sta}{typo} + (typographical) metrics. While the specification recommends using the \c typo metrics for + line spacing, many applications prefer the \c win metrics unless the \c{USE_TYPO_METRICS} + flag is set in the + \l{https://learn.microsoft.com/en-us/typography/opentype/spec/os2#fsselection}{fsSelection} + field of the font. For backwards-compatibility reasons, this is also the case for Qt + applications. This is not an issue for fonts that set the \c{USE_TYPO_METRICS} flag to + indicate that the \c{typo} metrics are valid, nor for fonts where the \c{win} metrics + and \c{typo} metrics match up. However, for certain fonts the \c{win} metrics may be + larger than the preferable line spacing and the \c{USE_TYPO_METRICS} flag may be unset + by mistake. For such fonts, setting \c{PreferTypoLineMetrics} may give superior results. \value NoFontMerging If the font selected for a certain writing system does not contain a character requested to draw, then Qt automatically chooses a similar looking font that contains the character. The NoFontMerging flag disables this feature. @@ -2427,9 +2452,7 @@ std::optional<QFont::Tag> QFont::Tag::fromString(QAnyStringView view) noexcept By default, no variable axes are set. - \note In order to use variable axes on Windows, the application has to run with either the - FreeType or DirectWrite font databases. See the documentation for - QGuiApplication::QGuiApplication() for more information on how to select these technologies. + \note On Windows, variable axes are not supported if the optional GDI font backend is in use. \sa unsetVariableAxis */ @@ -3266,7 +3289,7 @@ bool QFontInfo::fixedPitch() const QChar ch[2] = { u'i', u'm' }; QGlyphLayoutArray<2> g; int l = 2; - if (!engine->stringToCMap(ch, 2, &g, &l, {})) + if (engine->stringToCMap(ch, 2, &g, &l, {}) < 0) Q_UNREACHABLE(); Q_ASSERT(l == 2); engine->fontDef.fixedPitch = g.advances[0] == g.advances[1]; |