Add function QGlyphRun::setRawData()

To provide an optimized way of constructing QGlyphRun objects with no
copying or allocation, we add function setRawData() (naming inspired by
QByteArray::setRawData()). Data retrieved from QRawFont can be passed
directly into this. The logic is now that the data pointers in
QGlyphRunPrivate should always point to the current valid data and is
what will be used in comparisons and drawing calls. The vectors are
optimizations to avoid unnecessary copying if the user wants to use
the QVector based API (which makes it easier to manage the memory.)
This reflected in the functions that return QVectors, which will
return the stored vector if and only if it is identical to the
current pointer. Otherwise we will have to copy the memory.

The internal addition operators in QGlyphRun have been removed since
they really provide no real optimization and have an unclear definition
if the two glyph runs are based on different fonts.

Reviewed-by: Jiang Jiang

6 files changed, 111 insertions, 53 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index d2b35c8..1bd9303 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -5801,10 +5801,12 @@ void QPainter::drawGlyphRun(const QPointF &position, const QGlyphRun &glyphRun)
     if (!font.isValid())
         return;
 
-    QVector<quint32> glyphIndexes = glyphRun.glyphIndexes();
-    QVector<QPointF> glyphPositions = glyphRun.positions();
+    QGlyphRunPrivate *glyphRun_d = QGlyphRunPrivate::get(glyphRun);
 
-    int count = qMin(glyphIndexes.size(), glyphPositions.size());
+    const quint32 *glyphIndexes = glyphRun_d->glyphIndexData;
+    const QPointF *glyphPositions = glyphRun_d->glyphPositionData;
+
+    int count = qMin(glyphRun_d->glyphIndexDataSize, glyphRun_d->glyphPositionDataSize);
     QVarLengthArray<QFixedPoint, 128> fixedPointPositions(count);
 
     QRawFontPrivate *fontD = QRawFontPrivate::get(font);
@@ -5818,17 +5820,18 @@ void QPainter::drawGlyphRun(const QPointF &position, const QGlyphRun &glyphRun)
     }
 
     for (int i=0; i<count; ++i) {
-        QPointF processedPosition = position + glyphPositions.at(i);
+        QPointF processedPosition = position + glyphPositions[i];
         if (!supportsTransformations)
             processedPosition = d->state->transform().map(processedPosition);
         fixedPointPositions[i] = QFixedPoint::fromPointF(processedPosition);
     }
 
-    d->drawGlyphs(glyphIndexes.data(), fixedPointPositions.data(), count, font, glyphRun.overline(),
+    d->drawGlyphs(glyphIndexes, fixedPointPositions.data(), count, font, glyphRun.overline(),
                   glyphRun.underline(), glyphRun.strikeOut());
 }
 
-void QPainterPrivate::drawGlyphs(quint32 *glyphArray, QFixedPoint *positions, int glyphCount,
+void QPainterPrivate::drawGlyphs(const quint32 *glyphArray, QFixedPoint *positions,
+                                 int glyphCount,
                                  const QRawFont &font, bool overline, bool underline,
                                  bool strikeOut)
 {
diff --git a/src/gui/painting/qpainter_p.h b/src/gui/painting/qpainter_p.h
index 35cdf86..79d4b4b 100644
--- a/src/gui/painting/qpainter_p.h
+++ b/src/gui/painting/qpainter_p.h
@@ -232,7 +232,7 @@ public:
     void drawOpaqueBackground(const QPainterPath &path, DrawOperation operation);
 
 #if !defined(QT_NO_RAWFONT)
-    void drawGlyphs(quint32 *glyphArray, QFixedPoint *positionArray, int glyphCount,
+    void drawGlyphs(const quint32 *glyphArray, QFixedPoint *positionArray, int glyphCount,
                     const QRawFont &font, bool overline = false, bool underline = false,
                     bool strikeOut = false);
 #endif
diff --git a/src/gui/text/qglyphrun.cpp b/src/gui/text/qglyphrun.cpp
index 05e3b6b..2865d91 100644
--- a/src/gui/text/qglyphrun.cpp
+++ b/src/gui/text/qglyphrun.cpp
@@ -132,13 +132,27 @@ QGlyphRun &QGlyphRun::operator=(const QGlyphRun &other)
 */
 bool QGlyphRun::operator==(const QGlyphRun &other) const
 {
-    return ((d == other.d)
-            || (d->glyphIndexes == other.d->glyphIndexes
-                && d->glyphPositions == other.d->glyphPositions
-                && d->overline == other.d->overline
-                && d->underline == other.d->underline
-                && d->strikeOut == other.d->strikeOut
-                && d->rawFont == other.d->rawFont));
+    if (d == other.d)
+        return true;
+
+    if ((d->glyphIndexDataSize != other.d->glyphIndexDataSize)
+     || (d->glyphPositionDataSize != other.d->glyphPositionDataSize)) {
+        return false;
+    }
+
+    for (int i=0; i<qMax(d->glyphIndexDataSize, d->glyphPositionDataSize); ++i) {
+        if (i < d->glyphIndexDataSize && d->glyphIndexData[i] != other.d->glyphIndexData[i])
+           return false;
+
+        if (i < d->glyphPositionDataSize && d->glyphPositionData[i] != other.d->glyphPositionData[i])
+           return false;
+    }
+
+
+    return (d->overline == other.d->overline
+            && d->underline == other.d->underline
+            && d->strikeOut == other.d->strikeOut
+            && d->rawFont == other.d->rawFont);
 }
 
 /*!
@@ -151,36 +165,6 @@ bool QGlyphRun::operator!=(const QGlyphRun &other) const
 }
 
 /*!
-    \internal
-
-    Adds together the lists of glyph indexes and positions in \a other and this QGlyphRun
-    object and returns the result. The font in the returned QGlyphRun will be the same as in
-    this QGlyphRun object.
-*/
-QGlyphRun QGlyphRun::operator+(const QGlyphRun &other) const
-{
-    QGlyphRun ret(*this);
-    ret += other;
-    return ret;
-}
-
-/*!
-    \internal
-
-    Appends the glyph indexes and positions in \a other to this QGlyphRun object and returns
-    a reference to the current object.
-*/
-QGlyphRun &QGlyphRun::operator+=(const QGlyphRun &other)
-{
-    detach();
-
-    d->glyphIndexes += other.d->glyphIndexes;
-    d->glyphPositions += other.d->glyphPositions;
-
-    return *this;
-}
-
-/*!
     Returns the font selected for this QGlyphRun object.
 
     \sa setRawFont()
@@ -208,7 +192,13 @@ void QGlyphRun::setRawFont(const QRawFont &rawFont)
 */
 QVector<quint32> QGlyphRun::glyphIndexes() const
 {
-    return d->glyphIndexes;
+    if (d->glyphIndexes.constData() == d->glyphIndexData) {
+        return d->glyphIndexes;
+    } else {
+        QVector<quint32> indexes(d->glyphIndexDataSize);
+        qMemCopy(indexes.data(), d->glyphIndexData, d->glyphIndexDataSize * sizeof(quint32));
+        return indexes;
+    }
 }
 
 /*!
@@ -218,7 +208,9 @@ QVector<quint32> QGlyphRun::glyphIndexes() const
 void QGlyphRun::setGlyphIndexes(const QVector<quint32> &glyphIndexes)
 {
     detach();
-    d->glyphIndexes = glyphIndexes;
+    d->glyphIndexes = glyphIndexes; // Keep a reference to the QVector to avoid copying
+    d->glyphIndexData = glyphIndexes.constData();
+    d->glyphIndexDataSize = glyphIndexes.size();
 }
 
 /*!
@@ -226,7 +218,14 @@ void QGlyphRun::setGlyphIndexes(const QVector<quint32> &glyphIndexes)
 */
 QVector<QPointF> QGlyphRun::positions() const
 {
-    return d->glyphPositions;
+    if (d->glyphPositions.constData() == d->glyphPositionData) {
+        return d->glyphPositions;
+    } else {
+        QVector<QPointF> glyphPositions(d->glyphPositionDataSize);
+        qMemCopy(glyphPositions.data(), d->glyphPositionData,
+                 d->glyphPositionDataSize * sizeof(QPointF));
+        return glyphPositions;
+    }
 }
 
 /*!
@@ -236,7 +235,9 @@ QVector<QPointF> QGlyphRun::positions() const
 void QGlyphRun::setPositions(const QVector<QPointF> &positions)
 {
     detach();
-    d->glyphPositions = positions;
+    d->glyphPositions = positions; // Keep a reference to the vector to avoid copying
+    d->glyphPositionData = positions.constData();
+    d->glyphPositionDataSize = positions.size();
 }
 
 /*!
@@ -245,12 +246,33 @@ void QGlyphRun::setPositions(const QVector<QPointF> &positions)
 void QGlyphRun::clear()
 {
     detach();
-    d->glyphPositions = QVector<QPointF>();
-    d->glyphIndexes = QVector<quint32>();
     d->rawFont = QRawFont();
     d->strikeOut = false;
     d->overline = false;
     d->underline = false;
+
+    setPositions(QVector<QPointF>());
+    setGlyphIndexes(QVector<quint32>());
+}
+
+/*!
+    Sets the glyph indexes and positions of this QGlyphRun to use the first \a size
+    elements in the arrays \a glyphIndexArray and \a glyphPositionArray. The data is
+    \e not copied. The caller must guarantee that the arrays are not deleted as long
+    as this QGlyphRun and any copies of it exists.
+
+    \sa setGlyphIndexes(), setPositions()
+*/
+void QGlyphRun::setRawData(const quint32 *glyphIndexArray, const QPointF *glyphPositionArray,
+                           int size)
+{
+    detach();
+    d->glyphIndexes.clear();
+    d->glyphPositions.clear();
+
+    d->glyphIndexData = glyphIndexArray;
+    d->glyphPositionData = glyphPositionArray;
+    d->glyphIndexDataSize = d->glyphPositionDataSize = size;
 }
 
 /*!
diff --git a/src/gui/text/qglyphrun.h b/src/gui/text/qglyphrun.h
index e43f1ef..cf407a8 100644
--- a/src/gui/text/qglyphrun.h
+++ b/src/gui/text/qglyphrun.h
@@ -66,6 +66,10 @@ public:
     QRawFont rawFont() const;
     void setRawFont(const QRawFont &rawFont);
 
+    void setRawData(const quint32 *glyphIndexArray,
+                    const QPointF *glyphPositionArray,
+                    int size);
+
     QVector<quint32> glyphIndexes() const;
     void setGlyphIndexes(const QVector<quint32> &glyphIndexes);
 
diff --git a/src/gui/text/qglyphrun_p.h b/src/gui/text/qglyphrun_p.h
index 533679d..1cb63b2 100644
--- a/src/gui/text/qglyphrun_p.h
+++ b/src/gui/text/qglyphrun_p.h
@@ -71,6 +71,10 @@ public:
         : overline(false)
         , underline(false)
         , strikeOut(false)
+        , glyphIndexData(glyphIndexes.constData())
+        , glyphIndexDataSize(0)
+        , glyphPositionData(glyphPositions.constData())
+        , glyphPositionDataSize(0)
     {
     }
 
@@ -82,6 +86,10 @@ public:
       , overline(other.overline)
       , underline(other.underline)
       , strikeOut(other.strikeOut)
+      , glyphIndexData(other.glyphIndexData)
+      , glyphIndexDataSize(other.glyphIndexDataSize)
+      , glyphPositionData(other.glyphPositionData)
+      , glyphPositionDataSize(other.glyphPositionDataSize)
     {
     }
 
@@ -89,6 +97,17 @@ public:
     QVector<QPointF> glyphPositions;
     QRawFont rawFont;
 
+    const quint32 *glyphIndexData;
+    int glyphIndexDataSize;
+
+    const QPointF *glyphPositionData;
+    int glyphPositionDataSize;
+
+    static QGlyphRunPrivate *get(const QGlyphRun &glyphRun)
+    {
+        return glyphRun.d.data();
+    }
+
     uint overline  : 1;
     uint underline : 1;
     uint strikeOut : 1;
diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index 7bc87ee..203886b 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -2233,10 +2233,20 @@ QList<QGlyphRun> QTextLine::glyphs(int from, int length) const
             glyphIndexes.setRawFont(font);
 
             QPair<QFontEngine *, int> key(fontEngine, int(flags));
-            if (!glyphsHash.contains(key))
+            if (!glyphsHash.contains(key)) {
                 glyphsHash.insert(key, glyphIndexes);
-            else
-                glyphsHash[key] += glyphIndexes;
+            } else {
+                QGlyphRun &glyphRun = glyphsHash[key];
+
+                QVector<quint32> indexes = glyphRun.glyphIndexes();
+                QVector<QPointF> positions = glyphRun.positions();
+
+                indexes += glyphIndexes.glyphIndexes();
+                positions += glyphIndexes.positions();
+
+                glyphRun.setGlyphIndexes(indexes);
+                glyphRun.setPositions(positions);
+            }
         }
     }