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Improve shapeTextWithHarfbuzz() logic a bit

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* Move non-specific code to shapeText();
* Make shapeTextWithHarfbuzz() re-use variables obtained in shapeText();
* Make shapeTextWithHarfbuzz() return amount of shaped glyphs
  instead of nothing. Right now, this is not about error reporting,
  since failed shaping causes assertion/crash in most cases.

Change-Id: I2e0c91b9e5de8b19e0bc22ca60add1b1fc6ebdb0
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
This commit is contained in:
Konstantin Ritt 2013-03-23 20:19:54 +02:00 committed by The Qt Project
parent af553b7b1b
commit e006624a42
2 changed files with 63 additions and 85 deletions
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146
src/gui/text/qtextengine.cpp
View File

@ -877,19 +877,48 @@ void QTextEngine::shapeText(int item) const
if (si.num_glyphs)
return;
shapeTextWithHarfbuzz(item);
si.width = 0;
si.glyph_data_offset = layoutData->used;
if (!si.num_glyphs)
return;
QGlyphLayout glyphs = shapedGlyphs(&si);
const ushort *string = reinterpret_cast<const ushort *>(layoutData->string.constData()) + si.position;
const int itemLength = length(item);
if (!ensureSpace(itemLength))
return; // ### report OOM error somehow
QString casedString;
if (si.analysis.flags && si.analysis.flags <= QScriptAnalysis::SmallCaps) {
casedString.resize(itemLength);
ushort *uc = reinterpret_cast<ushort *>(casedString.data());
for (int i = 0; i < itemLength; ++i) {
uint ucs4 = string[i];
if (QChar::isHighSurrogate(ucs4) && i + 1 < itemLength) {
uint low = string[i + 1];
if (QChar::isLowSurrogate(low)) {
++i;
ucs4 = QChar::surrogateToUcs4(ucs4, low);
ucs4 = si.analysis.flags == QScriptAnalysis::Lowercase ? QChar::toLower(ucs4)
: QChar::toUpper(ucs4);
// high part never changes in simple casing
uc[i] = QChar::lowSurrogate(ucs4);
}
} else {
uc[i] = si.analysis.flags == QScriptAnalysis::Lowercase ? QChar::toLower(ucs4)
: QChar::toUpper(ucs4);
}
}
string = reinterpret_cast<const ushort *>(casedString.constData());
}
QFontEngine *fontEngine = this->fontEngine(si, &si.ascent, &si.descent, &si.leading);
bool kerningEnabled;
bool letterSpacingIsAbsolute;
QFixed letterSpacing, wordSpacing;
#ifndef QT_NO_RAWFONT
if (useRawFont) {
QTextCharFormat f = format(&si);
kerningEnabled = f.fontKerning();
wordSpacing = QFixed::fromReal(f.fontWordSpacing());
letterSpacing = QFixed::fromReal(f.fontLetterSpacing());
letterSpacingIsAbsolute = true;
@ -897,6 +926,7 @@ void QTextEngine::shapeText(int item) const
#endif
{
QFont font = this->font(si);
kerningEnabled = font.d->kerning;
letterSpacingIsAbsolute = font.d->letterSpacingIsAbsolute;
letterSpacing = font.d->letterSpacing;
wordSpacing = font.d->wordSpacing;
@ -905,6 +935,13 @@ void QTextEngine::shapeText(int item) const
letterSpacing *= font.d->dpi / qt_defaultDpiY();
}
si.num_glyphs = shapeTextWithHarfbuzz(si, string, itemLength, fontEngine, kerningEnabled);
if (!si.num_glyphs)
return; // ### report shaping errors somehow
layoutData->used += si.num_glyphs;
QGlyphLayout glyphs = shapedGlyphs(&si);
if (letterSpacing != 0) {
for (int i = 1; i < si.num_glyphs; ++i) {
if (glyphs.attributes[i].clusterStart) {
@ -940,14 +977,6 @@ void QTextEngine::shapeText(int item) const
si.width += glyphs.advances_x[i] * !glyphs.attributes[i].dontPrint;
}
static inline bool hasCaseChange(const QScriptItem &si)
{
return si.analysis.flags == QScriptAnalysis::SmallCaps ||
si.analysis.flags == QScriptAnalysis::Uppercase ||
si.analysis.flags == QScriptAnalysis::Lowercase;
}
static inline void moveGlyphData(const QGlyphLayout &destination, const QGlyphLayout &source, int num)
{
if (num > 0 && destination.glyphs != source.glyphs) {
@ -984,79 +1013,34 @@ static bool stringToGlyphs(HB_ShaperItem *item, QGlyphLayout *glyphs, QFontEngin
return result;
}
/// take the item from layoutData->items and
void QTextEngine::shapeTextWithHarfbuzz(int item) const
int QTextEngine::shapeTextWithHarfbuzz(QScriptItem &si, const ushort *string, int itemLength, QFontEngine *fontEngine, bool kerningEnabled) const
{
QScriptItem &si = layoutData->items[item];
si.glyph_data_offset = layoutData->used;
QFontEngine *font = fontEngine(si, &si.ascent, &si.descent, &si.leading);
bool kerningEnabled;
#ifndef QT_NO_RAWFONT
if (useRawFont) {
QTextCharFormat f = format(&si);
kerningEnabled = f.fontKerning();
} else
#endif
kerningEnabled = this->font(si).d->kerning;
HB_ShaperItem entire_shaper_item;
memset(&entire_shaper_item, 0, sizeof(entire_shaper_item));
entire_shaper_item.string = reinterpret_cast<const HB_UChar16 *>(layoutData->string.constData());
entire_shaper_item.stringLength = layoutData->string.length();
entire_shaper_item.string = reinterpret_cast<const HB_UChar16 *>(string);
entire_shaper_item.stringLength = itemLength;
entire_shaper_item.item.script = script_to_hbscript(si.analysis.script);
entire_shaper_item.item.pos = si.position;
entire_shaper_item.item.length = length(item);
entire_shaper_item.item.pos = 0;
entire_shaper_item.item.length = itemLength;
entire_shaper_item.item.bidiLevel = si.analysis.bidiLevel;
QVarLengthArray<HB_UChar16, 256> casedString;
if (hasCaseChange(si)) {
if (casedString.size() < static_cast<int>(entire_shaper_item.item.length))
casedString.resize(entire_shaper_item.item.length);
HB_UChar16 *uc = casedString.data();
for (uint i = 0; i < entire_shaper_item.item.length; ++i) {
uint ucs4 = entire_shaper_item.string[si.position + i];
if (QChar::isHighSurrogate(ucs4)) {
uc[i] = ucs4; // high part never changes in simple casing
if (i + 1 < entire_shaper_item.item.length) {
ushort low = entire_shaper_item.string[si.position + i + 1];
if (QChar::isLowSurrogate(low)) {
ucs4 = QChar::surrogateToUcs4(ucs4, low);
ucs4 = si.analysis.flags == QScriptAnalysis::Lowercase ? QChar::toLower(ucs4)
: QChar::toUpper(ucs4);
uc[++i] = QChar::lowSurrogate(ucs4);
}
}
} else {
uc[i] = si.analysis.flags == QScriptAnalysis::Lowercase ? QChar::toLower(ucs4)
: QChar::toUpper(ucs4);
}
}
entire_shaper_item.item.pos = 0;
entire_shaper_item.string = uc;
entire_shaper_item.stringLength = entire_shaper_item.item.length;
}
entire_shaper_item.shaperFlags = 0;
if (!kerningEnabled)
entire_shaper_item.shaperFlags |= HB_ShaperFlag_NoKerning;
if (option.useDesignMetrics())
entire_shaper_item.shaperFlags |= HB_ShaperFlag_UseDesignMetrics;
entire_shaper_item.num_glyphs = qMax(layoutData->glyphLayout.numGlyphs - layoutData->used, int(entire_shaper_item.item.length));
if (!ensureSpace(entire_shaper_item.num_glyphs))
return;
entire_shaper_item.num_glyphs = itemLength;
QGlyphLayout initialGlyphs = availableGlyphs(&si).mid(0, entire_shaper_item.num_glyphs);
if (!stringToGlyphs(&entire_shaper_item, &initialGlyphs, font)) {
if (!stringToGlyphs(&entire_shaper_item, &initialGlyphs, fontEngine)) {
if (!ensureSpace(entire_shaper_item.num_glyphs))
return;
return 0;
initialGlyphs = availableGlyphs(&si).mid(0, entire_shaper_item.num_glyphs);
if (!stringToGlyphs(&entire_shaper_item, &initialGlyphs, font)) {
if (!stringToGlyphs(&entire_shaper_item, &initialGlyphs, fontEngine)) {
// ############ if this happens there's a bug in the fontengine
return;
return 0;
}
}
@ -1066,7 +1050,7 @@ void QTextEngine::shapeTextWithHarfbuzz(int item) const
itemBoundaries[0] = entire_shaper_item.item.pos;
itemBoundaries[1] = 0;
if (font->type() == QFontEngine::Multi) {
if (fontEngine->type() == QFontEngine::Multi) {
uint lastEngine = 0;
int charIdx = entire_shaper_item.item.pos;
const int stringEnd = charIdx + entire_shaper_item.item.length;
@ -1105,18 +1089,17 @@ void QTextEngine::shapeTextWithHarfbuzz(int item) const
if (shaper_item.num_glyphs < shaper_item.item.length)
shaper_item.num_glyphs = shaper_item.item.length;
QFontEngine *actualFontEngine = font;
QFontEngine *actualFontEngine = fontEngine;
uint engineIdx = 0;
if (font->type() == QFontEngine::Multi) {
if (fontEngine->type() == QFontEngine::Multi) {
engineIdx = uint(availableGlyphs(&si).glyphs[glyph_pos] >> 24);
actualFontEngine = static_cast<QFontEngineMulti *>(font)->engine(engineIdx);
actualFontEngine = static_cast<QFontEngineMulti *>(fontEngine)->engine(engineIdx);
si.ascent = qMax(actualFontEngine->ascent(), si.ascent);
si.descent = qMax(actualFontEngine->descent(), si.descent);
si.leading = qMax(actualFontEngine->leading(), si.leading);
}
si.ascent = qMax(actualFontEngine->ascent(), si.ascent);
si.descent = qMax(actualFontEngine->descent(), si.descent);
si.leading = qMax(actualFontEngine->leading(), si.leading);
shaper_item.font = (HB_Font)actualFontEngine->harfbuzzFont();
shaper_item.face = (HB_Face)actualFontEngine->harfbuzzFace();
@ -1126,7 +1109,7 @@ void QTextEngine::shapeTextWithHarfbuzz(int item) const
do {
if (!ensureSpace(glyph_pos + shaper_item.num_glyphs + remaining_glyphs))
return;
return 0;
const QGlyphLayout g = availableGlyphs(&si).mid(glyph_pos);
if (shaper_item.num_glyphs > shaper_item.item.length)
@ -1143,8 +1126,6 @@ void QTextEngine::shapeTextWithHarfbuzz(int item) const
}
shaper_item.log_clusters = logClusters(&si) + shaper_item.item.pos - entire_shaper_item.item.pos;
// qDebug(" .. num_glyphs=%d, used=%d, item.num_glyphs=%d", num_glyphs, used, shaper_item.num_glyphs);
} while (!qShapeItem(&shaper_item)); // this does the actual shaping via harfbuzz.
QGlyphLayout g = availableGlyphs(&si).mid(glyph_pos, shaper_item.num_glyphs);
@ -1164,10 +1145,7 @@ void QTextEngine::shapeTextWithHarfbuzz(int item) const
glyph_pos += shaper_item.num_glyphs;
}
// qDebug(" -> item: script=%d num_glyphs=%d", shaper_item.script, shaper_item.num_glyphs);
si.num_glyphs = glyph_pos;
layoutData->used += si.num_glyphs;
return glyph_pos;
}
void QTextEngine::init(QTextEngine *e)

2
src/gui/text/qtextengine_p.h
View File

@ -699,7 +699,7 @@ private:
void setBoundary(int strPos) const;
void addRequiredBoundaries() const;
void shapeText(int item) const;
void shapeTextWithHarfbuzz(int item) const;
int shapeTextWithHarfbuzz(QScriptItem &si, const ushort *string, int itemLength, QFontEngine *fontEngine, bool kerningEnabled) const;
void splitItem(int item, int pos) const;
int endOfLine(int lineNum);