Support transformations in drawStaticText() and optimize for space

1. Support transformations on the painter in drawStaticText().
Transforming the painter will cause the text layout to be recalculated,
except for translations, which are handled by shifting the position of
the text items.

2. Make const length arrays of the internal data in QStaticTextItem in
order to minimize the memory consumption.

1 files changed, 62 insertions, 15 deletions

diff --git a/src/gui/text/qstatictext.cpp b/src/gui/text/qstatictext.cpp
index c43eeb0..e6f2cc6 100644
--- a/src/gui/text/qstatictext.cpp
+++ b/src/gui/text/qstatictext.cpp
@@ -262,7 +262,7 @@ bool QStaticText::isEmpty() const
 }
 
 QStaticTextPrivate::QStaticTextPrivate()
-        : items(0), itemCount(0)
+        : items(0), itemCount(0), glyphPool(0), positionPool(0)
 {
     ref = 1;    
 }
@@ -279,6 +279,8 @@ QStaticTextPrivate::QStaticTextPrivate(const QStaticTextPrivate &other)
 QStaticTextPrivate::~QStaticTextPrivate()
 {
     delete[] items;    
+    delete[] glyphPool;
+    delete[] positionPool;
 }
 
 QStaticTextPrivate *QStaticTextPrivate::get(const QStaticText *q)
@@ -295,37 +297,58 @@ namespace {
     class DrawTextItemRecorder: public QPaintEngine
     {
     public:
-        DrawTextItemRecorder(int expectedItemCount, QStaticTextItem *items)
+        DrawTextItemRecorder(int expectedItemCount, QStaticTextItem *items,
+                             int expectedGlyphCount, QFixedPoint *positionPool, glyph_t *glyphPool)
                 : m_items(items),
                   m_expectedItemCount(expectedItemCount),
-                  m_itemCount(0)
+                  m_expectedGlyphCount(expectedGlyphCount),
+                  m_itemCount(0), m_glyphCount(0),
+                  m_positionPool(positionPool),
+                  m_glyphPool(glyphPool)
         {
         }
 
         virtual void drawTextItem(const QPointF &p, const QTextItem &textItem)
         {
             const QTextItemInt &ti = static_cast<const QTextItemInt &>(textItem);          
-            
-            Q_ASSERT(m_expectedItemCount < 0 || m_itemCount < m_expectedItemCount);
-            m_itemCount++;
 
+            m_itemCount++;
+            m_glyphCount += ti.glyphs.numGlyphs;
             if (m_items == 0)
                 return;
 
+            Q_ASSERT(m_itemCount <= m_expectedItemCount);
+            Q_ASSERT(m_glyphCount <= m_expectedGlyphCount);
+
             QStaticTextItem *currentItem = (m_items + (m_itemCount - 1));
             currentItem->fontEngine = ti.fontEngine;
             currentItem->chars = ti.chars;
             currentItem->numChars = ti.num_chars;
-            ti.fontEngine->getGlyphPositions(ti.glyphs, QTransform(), ti.flags, currentItem->glyphs,
-                                             currentItem->glyphPositions);
+            currentItem->numGlyphs = ti.glyphs.numGlyphs;
+            currentItem->glyphs = m_glyphPool;
+            currentItem->glyphPositions = m_positionPool;
+
+            QVarLengthArray<glyph_t> glyphs;
+            QVarLengthArray<QFixedPoint> positions;
+            ti.fontEngine->getGlyphPositions(ti.glyphs, state->transform(), ti.flags,
+                                             glyphs, positions);
+
+            int size = glyphs.size();
+            Q_ASSERT(size == ti.glyphs.numGlyphs);
+            Q_ASSERT(size == positions.size());
+
+            memmove(currentItem->glyphs, glyphs.constData(), sizeof(glyph_t) * size);
+            memmove(currentItem->glyphPositions, positions.constData(), sizeof(QFixedPoint) * size);
 
             QFixed fx = QFixed::fromReal(p.x());
             QFixed fy = QFixed::fromReal(p.y());
-
-            for (int i=0; i<currentItem->glyphPositions.size(); ++i) {
+            for (int i=0; i<size; ++i) {
                 currentItem->glyphPositions[i].x += fx;
                 currentItem->glyphPositions[i].y += fy;
             }
+
+            m_glyphPool += size;
+            m_positionPool += size;
         }                
 
 
@@ -343,18 +366,31 @@ namespace {
             return m_itemCount;
         }
 
+        int glyphCount() const
+        {
+            return m_glyphCount;
+        }
+
     private:
         QStaticTextItem *m_items;
         int m_itemCount;
+        int m_glyphCount;
         int m_expectedItemCount;
+        int m_expectedGlyphCount;
+
+        glyph_t *m_glyphPool;
+        QFixedPoint *m_positionPool;
     };
 
     class DrawTextItemDevice: public QPaintDevice
     {
     public:
-        DrawTextItemDevice(int expectedItemCount = -1,  QStaticTextItem *items = 0)
+        DrawTextItemDevice(int expectedItemCount = -1,  QStaticTextItem *items = 0,
+                           int expectedGlyphCount = -1, QFixedPoint *positionPool = 0,
+                           glyph_t *glyphPool = 0)
         {
-            m_paintEngine = new DrawTextItemRecorder(expectedItemCount, items);
+            m_paintEngine = new DrawTextItemRecorder(expectedItemCount, items,
+                                                     expectedGlyphCount, positionPool, glyphPool);
         }
 
         ~DrawTextItemDevice()
@@ -403,7 +439,10 @@ namespace {
             return m_paintEngine->itemCount();
         }
 
-
+        int glyphCount() const
+        {
+            return m_paintEngine->glyphCount();
+        }
 
     private:
         DrawTextItemRecorder *m_paintEngine;
@@ -414,6 +453,8 @@ namespace {
 void QStaticTextPrivate::init()
 {
     delete[] items;
+    delete[] glyphPool;
+    delete[] positionPool;
 
     // Draw once to count number of items and glyphs, so that we can use as little memory
     // as possible to store the data
@@ -421,6 +462,7 @@ void QStaticTextPrivate::init()
     {
         QPainter painter(&counterDevice);
         painter.setFont(font);
+        painter.setTransform(matrix);
 
         if (size.isValid())
             painter.drawText(QRectF(QPointF(0, 0), size), text);
@@ -428,14 +470,19 @@ void QStaticTextPrivate::init()
             painter.drawText(0, 0, text);
     }
 
-    itemCount = counterDevice.itemCount();
+    itemCount = counterDevice.itemCount();    
     items = new QStaticTextItem[itemCount];
 
+    int glyphCount = counterDevice.glyphCount();
+    glyphPool = new glyph_t[glyphCount];
+    positionPool = new QFixedPoint[glyphCount];
+
     // Draw again to actually record the items and glyphs
-    DrawTextItemDevice recorderDevice(itemCount, items);
+    DrawTextItemDevice recorderDevice(itemCount, items, glyphCount, positionPool, glyphPool);
     {
         QPainter painter(&recorderDevice);
         painter.setFont(font);
+        painter.setTransform(matrix);
 
         if (size.isValid())
             painter.drawText(QRectF(QPointF(0, 0), size), text);