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Fix synthesized bold on Windows

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There were a couple of problems with synthesizing boldness on
Windows: For the DirectWrite font database, this was not implemented
at all, so this change adds support for it.

For the default GDI font database, the font engine is correctly created
for a font with synthetic bold, but the function that retrieves the
contours from the font does not apply the transformation. So when
generating the distance fields for Qt Quick, we would get the
unemboldened contours. The fix for this is simply to fall back to
using DirectWrite for fonts that require any synthetization. This will
later become the default anyway.

Pick-to: 6.5
Fixes: QTBUG-119995
Change-Id: I5b4e3b19d0d71c6599746172da0bee41e8fb3940
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 05de036a8855adbdd882942d2fb61c231b02bf5a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 2243b815e06027f38da9c08aec7e43e8d1c85557)
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
This commit is contained in:
Eskil Abrahamsen Blomfeldt 2023-12-14 11:10:51 +01:00
parent a599c69dc5
commit 30995a6e7c
2 changed files with 58 additions and 1 deletions
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54
src/gui/text/windows/qwindowsdirectwritefontdatabase.cpp
View File

@ -18,6 +18,32 @@ QT_BEGIN_NAMESPACE
// Defined in gui/text/qfontdatabase.cpp
Q_GUI_EXPORT QFontDatabase::WritingSystem qt_writing_system_for_script(int script);
template<typename T>
struct DirectWriteScope {
DirectWriteScope(T *res = nullptr) : m_res(res) {}
~DirectWriteScope() {
if (m_res != nullptr)
m_res->Release();
}
T **operator&()
{
return &m_res;
}
T *operator->()
{
return m_res;
}
T *operator*() {
return m_res;
}
private:
T *m_res;
};
QWindowsDirectWriteFontDatabase::QWindowsDirectWriteFontDatabase()
{
qCDebug(lcQpaFonts) << "Creating DirectWrite database";
@ -217,6 +243,34 @@ QFontEngine *QWindowsDirectWriteFontDatabase::fontEngine(const QFontDef &fontDef
IDWriteFontFace *face = reinterpret_cast<IDWriteFontFace *>(handle);
Q_ASSERT(face != nullptr);
DWRITE_FONT_SIMULATIONS simulations = DWRITE_FONT_SIMULATIONS_NONE;
if (fontDef.weight >= QFont::DemiBold || fontDef.style != QFont::StyleNormal) {
DirectWriteScope<IDWriteFontFace3> face3;
if (SUCCEEDED(face->QueryInterface(__uuidof(IDWriteFontFace3),
reinterpret_cast<void **>(&face3)))) {
if (fontDef.weight >= QFont::DemiBold && face3->GetWeight() < DWRITE_FONT_WEIGHT_DEMI_BOLD)
simulations |= DWRITE_FONT_SIMULATIONS_BOLD;
if (fontDef.style != QFont::StyleNormal && face3->GetStyle() == DWRITE_FONT_STYLE_NORMAL)
simulations |= DWRITE_FONT_SIMULATIONS_OBLIQUE;
}
}
DirectWriteScope<IDWriteFontFace5> newFace;
if (simulations != DWRITE_FONT_SIMULATIONS_NONE) {
DirectWriteScope<IDWriteFontFace5> face5;
if (SUCCEEDED(face->QueryInterface(__uuidof(IDWriteFontFace5),
reinterpret_cast<void **>(&face5)))) {
DirectWriteScope<IDWriteFontResource> font;
if (SUCCEEDED(face5->GetFontResource(&font))) {
if (SUCCEEDED(font->CreateFontFace(simulations, nullptr, 0, &newFace)))
face = *newFace;
else
qCWarning(lcQpaFonts) << "DirectWrite: Can't create font face for variable axis values";
}
}
}
QWindowsFontEngineDirectWrite *fontEngine = new QWindowsFontEngineDirectWrite(face, fontDef.pixelSize, data());
fontEngine->initFontInfo(fontDef, defaultVerticalDPI());

5
src/gui/text/windows/qwindowsfontdatabase.cpp
View File

@ -1230,6 +1230,7 @@ QFontEngine *QWindowsFontDatabase::createEngine(const QFontDef &request, const Q
HRESULT hr = data->directWriteGdiInterop->CreateFontFaceFromHdc(data->hdc, &directWriteFontFace);
if (SUCCEEDED(hr)) {
bool isColorFont = false;
bool needsSimulation = false;
#if QT_CONFIG(direct2d)
IDWriteFontFace2 *directWriteFontFace2 = nullptr;
if (SUCCEEDED(directWriteFontFace->QueryInterface(__uuidof(IDWriteFontFace2),
@ -1237,10 +1238,12 @@ QFontEngine *QWindowsFontDatabase::createEngine(const QFontDef &request, const Q
if (directWriteFontFace2->IsColorFont())
isColorFont = directWriteFontFace2->GetPaletteEntryCount() > 0;
needsSimulation = directWriteFontFace2->GetSimulations() != DWRITE_FONT_SIMULATIONS_NONE;
directWriteFontFace2->Release();
}
#endif // direct2d
useDw = useDw || useDirectWrite(hintingPreference, fam, isColorFont);
useDw = useDw || useDirectWrite(hintingPreference, fam, isColorFont) || needsSimulation;
qCDebug(lcQpaFonts)
<< __FUNCTION__ << request.families.first() << request.pointSize << "pt"
<< "hintingPreference=" << hintingPreference << "color=" << isColorFont