Bug#1070406: Qt5: badly clips some fonts when rendering to PDFs
Dixi quod…
>>Now that you dug so deeply, maybe you can try to replace qRound in those
>>three lines that you mentioned with TO_TTF, and check if it fixes the bug
>
>That *and* figure out somehow how to fix the PDF /FontBBox, at
I’m trying this (attached). That does both (by letting toTruetype()
adjust the already-existing scaling factor in the caller) and
applies suitable rounding (normal for normal values, away from zero
for the bounding box so it’s guaranteed to encompass all possible
values). I’ll build it now so I don’t know if it even compiles yet…
bye,
//mirabilos
--
15:41⎜<Lo-lan-do:#fusionforge> Somebody write a testsuite for helloworld :-)
diff -Nru qtbase-opensource-src-5.15.2+dfsg/debian/changelog qtbase-opensource-src-5.15.2+dfsg/debian/changelog
--- qtbase-opensource-src-5.15.2+dfsg/debian/changelog 2021-07-02 17:58:04.000000000 +0200
+++ qtbase-opensource-src-5.15.2+dfsg/debian/changelog 2024-05-05 23:58:03.000000000 +0200
@@ -1,3 +1,10 @@
+qtbase-opensource-src (5.15.2+dfsg-9.0.1) UNRELEASED; urgency=medium
+
+ * Non-maintainer upload.
+ * debian/patches/bug1070406.diff
+
+ -- Thorsten Glaser <tg@mirbsd.de> Sun, 05 May 2024 23:58:03 +0200
+
qtbase-opensource-src (5.15.2+dfsg-9) unstable; urgency=medium
* Revert adding fix-misplacement-of-placeholder-text-in-QLineEdit.diff.
diff -Nru qtbase-opensource-src-5.15.2+dfsg/debian/patches/bug1070406.diff qtbase-opensource-src-5.15.2+dfsg/debian/patches/bug1070406.diff
--- qtbase-opensource-src-5.15.2+dfsg/debian/patches/bug1070406.diff 1970-01-01 01:00:00.000000000 +0100
+++ qtbase-opensource-src-5.15.2+dfsg/debian/patches/bug1070406.diff 2024-05-05 23:57:53.000000000 +0200
@@ -0,0 +1,107 @@
+Description: scale /FontBBox and hhea table when scaling fonts
+ for embedding (the OS/2 table needs handling XXX TODO)
+Author: mirabilos <tg@debian.org>
+Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1070406
+
+--- a/src/gui/painting/qpdf.cpp
++++ b/src/gui/painting/qpdf.cpp
+@@ -1870,11 +1870,20 @@ void QPdfEnginePrivate::writeAttachmentR
+ "endobj\n");
+ }
+
++static inline int roundForBbox(qreal v)
++{
++ return (v < 0) ? floor(v) : ceil(v);
++}
++
+ void QPdfEnginePrivate::embedFont(QFontSubset *font)
+ {
++ QFontEngine::Properties properties = font->fontEngine->properties();
++ QByteArray postscriptName = properties.postscriptName.replace(' ', '_');
++ qreal scale = 1000/properties.emSquare.toReal();
++
+ //qDebug() << "embedFont" << font->object_id;
+ int fontObject = font->object_id;
+- QByteArray fontData = font->toTruetype();
++ QByteArray fontData = font->toTruetype(&scale);
+ #ifdef FONT_DUMP
+ static int i = 0;
+ QString fileName("font%1.ttf");
+@@ -1891,11 +1900,7 @@ void QPdfEnginePrivate::embedFont(QFontS
+ int toUnicode = requestObject();
+ int cidset = requestObject();
+
+- QFontEngine::Properties properties = font->fontEngine->properties();
+- QByteArray postscriptName = properties.postscriptName.replace(' ', '_');
+-
+ {
+- qreal scale = 1000/properties.emSquare.toReal();
+ addXrefEntry(fontDescriptor);
+ QByteArray descriptor;
+ QPdf::ByteStream s(&descriptor);
+@@ -1909,15 +1914,15 @@ void QPdfEnginePrivate::embedFont(QFontS
+ s << '+' << postscriptName << "\n"
+ "/Flags " << 4 << "\n"
+ "/FontBBox ["
+- << properties.boundingBox.x()*scale
+- << -(properties.boundingBox.y() + properties.boundingBox.height())*scale
+- << (properties.boundingBox.x() + properties.boundingBox.width())*scale
+- << -properties.boundingBox.y()*scale << "]\n"
++ << roundForBbox(properties.boundingBox.x()*scale)
++ << roundForBbox(-(properties.boundingBox.y() + properties.boundingBox.height())*scale)
++ << roundForBbox((properties.boundingBox.x() + properties.boundingBox.width())*scale)
++ << roundForBbox(-properties.boundingBox.y()*scale) << "]\n"
+ "/ItalicAngle " << properties.italicAngle.toReal() << "\n"
+- "/Ascent " << properties.ascent.toReal()*scale << "\n"
+- "/Descent " << -properties.descent.toReal()*scale << "\n"
+- "/CapHeight " << properties.capHeight.toReal()*scale << "\n"
+- "/StemV " << properties.lineWidth.toReal()*scale << "\n"
++ "/Ascent " << qRound(properties.ascent.toReal()*scale) << "\n"
++ "/Descent " << qRound(-properties.descent.toReal()*scale) << "\n"
++ "/CapHeight " << qRound(properties.capHeight.toReal()*scale) << "\n"
++ "/StemV " << qRound(properties.lineWidth.toReal()*scale) << "\n"
+ "/FontFile2 " << fontstream << "0 R\n"
+ "/CIDSet " << cidset << "0 R\n"
+ ">>\nendobj\n";
+--- a/src/gui/text/qfontsubset.cpp
++++ b/src/gui/text/qfontsubset.cpp
+@@ -1162,13 +1162,14 @@ static QByteArray bindFont(const QVector
+ if really required.
+ */
+
+-QByteArray QFontSubset::toTruetype() const
++QByteArray QFontSubset::toTruetype(qreal *scalep) const
+ {
+ qttf_font_tables font;
+ memset(&font, 0, sizeof(qttf_font_tables));
+
+ qreal ppem = fontEngine->fontDef.pixelSize;
+ #define TO_TTF(x) qRound(x * 2048. / ppem)
++ *scalep *= 2048. / ppem;
+
+ QFontEngine::Properties properties = fontEngine->properties();
+ // initialize some stuff needed in createWidthArray
+@@ -1188,9 +1189,9 @@ QByteArray QFontSubset::toTruetype() con
+ font.head.macStyle |= (fontEngine->fontDef.styleHint != QFont::StyleNormal) ? 1 : 0;
+
+ // hhea table
+- font.hhea.ascender = qRound(properties.ascent);
+- font.hhea.descender = -qRound(properties.descent);
+- font.hhea.lineGap = qRound(properties.leading);
++ font.hhea.ascender = TO_TTF(properties.ascent);
++ font.hhea.descender = TO_TTF(-properties.descent);
++ font.hhea.lineGap = TO_TTF(properties.leading);
+ font.hhea.maxAdvanceWidth = TO_TTF(fontEngine->maxCharWidth());
+ font.hhea.minLeftSideBearing = TO_TTF(fontEngine->minLeftBearing());
+ font.hhea.minRightSideBearing = TO_TTF(fontEngine->minRightBearing());
+--- a/src/gui/text/qfontsubset_p.h
++++ b/src/gui/text/qfontsubset_p.h
+@@ -72,7 +72,7 @@ public:
+ delete fontEngine;
+ }
+
+- QByteArray toTruetype() const;
++ QByteArray toTruetype(qreal *scalep) const;
+ #ifndef QT_NO_PDF
+ QByteArray widthArray() const;
+ QByteArray createToUnicodeMap() const;
diff -Nru qtbase-opensource-src-5.15.2+dfsg/debian/patches/series qtbase-opensource-src-5.15.2+dfsg/debian/patches/series
--- qtbase-opensource-src-5.15.2+dfsg/debian/patches/series 2021-07-02 17:58:04.000000000 +0200
+++ qtbase-opensource-src-5.15.2+dfsg/debian/patches/series 2024-05-05 23:30:03.000000000 +0200
@@ -18,3 +18,4 @@
path_max.diff
qstorageinfo_linux.diff
cross_build_mysql.diff
+bug1070406.diff
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