Implement drawStaticTextItem() in OpenGL paint engines

The OpenGL and OpenGL2 engines now have support for static text, as
well as the QEmulationPaintEngine.

Also contains an optimization: Instead of passing both the position and
glyph positions to drawStaticTextItem() we add the position into the
glyph position and update it only when it changes. Otherwise we would
have to do this work in all engines for every call. This means we have
to cache the position in QStaticTextPrivate as well, but it seems like
a small price to pay, since it's a per-text overhead and only 16 bytes.

1 files changed, 18 insertions, 2 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index c75547f..524f243 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -5787,11 +5787,27 @@ void QPainter::drawStaticText(const QPointF &position, const QStaticText &static
 
     // Recreate the layout of the static text because the matrix or font has changed
     if (staticTextNeedsReinit)
-        staticText_d->init();
+        staticText_d->init();    
+
+    if (transformedPosition != staticText_d->position) { // Translate to actual position
+        QFixed fx = QFixed::fromReal(transformedPosition.x());
+        QFixed fy = QFixed::fromReal(transformedPosition.y());
+        QFixed oldX = QFixed::fromReal(staticText_d->position.x());
+        QFixed oldY = QFixed::fromReal(staticText_d->position.y());
+        for (int item=0; item<staticText_d->itemCount;++item) {
+            QStaticTextItem *textItem = staticText_d->items + item;
+            for (int i=0; i<textItem->numGlyphs; ++i) {
+                textItem->glyphPositions[i].x += fx - oldX;
+                textItem->glyphPositions[i].y += fy - oldY;
+            }
+        }
+
+        staticText_d->position = transformedPosition;
+    }
 
     for (int i=0; i<staticText_d->itemCount; ++i) {
         QStaticTextItem *item = staticText_d->items + i;
-        d->extended->drawStaticTextItem(transformedPosition, item);
+        d->extended->drawStaticTextItem(item);
     }
 
     if (restoreWhenFinished)