Remove unnecessary copying from paintCroppedPageOnPainter

PagePainter::paintCroppedPageOnPainter had a few calls to
QPixmap::setDevicePixelRatio on pixmaps it does not own, which detaches
the pixmap, making a deep copy. It turns out these were all unnecessary.
It also copied scaled before drawing them onto the painter.

I've tested all the changes except for the annotation stamps, which I'm
just assuming works like the others.

Also ran clang-format.

gui/pagepainter.cpp

@@ -106,7 +106,6 @@ void PagePainter::paintCroppedPageOnPainter(QPainter *destPainter,
 
         if (p != nullptr) {
             pixmap = *p;
-            pixmap.setDevicePixelRatio(dpr);
         }
 
         /** 1B - IF NO PIXMAP, DRAW EMPTY PAGE **/
@@ -255,7 +254,6 @@ void PagePainter::paintCroppedPageOnPainter(QPainter *destPainter,
 
                 if (!limitsInTile.isEmpty()) {
                     QPixmap *tilePixmap = tile.pixmap();
-                    tilePixmap->setDevicePixelRatio(dpr);
 
                     if (tilePixmap->width() == dTileRect.width() && tilePixmap->height() == dTileRect.height()) {
                         destPainter->drawPixmap(limitsInTile.topLeft(), *tilePixmap, dLimitsInTile.translated(-dTileRect.topLeft()));
@@ -266,9 +264,7 @@ void PagePainter::paintCroppedPageOnPainter(QPainter *destPainter,
                 tIt++;
             }
         } else {
-            QPixmap scaledCroppedPixmap = pixmap.scaled(dScaledWidth, dScaledHeight).copy(dLimitsInPixmap);
-            scaledCroppedPixmap.setDevicePixelRatio(dpr);
-            destPainter->drawPixmap(limits.topLeft(), scaledCroppedPixmap, QRectF(0, 0, dLimits.width(), dLimits.height()));
+            destPainter->drawPixmap(limits, pixmap.scaled(dScaledWidth, dScaledHeight), dLimitsInPixmap);
         }
 
         // 4A.2. active painter is the one passed to this method
@@ -295,7 +291,6 @@ void PagePainter::paintCroppedPageOnPainter(QPainter *destPainter,
 
                 if (!limitsInTile.isEmpty()) {
                     QPixmap *tilePixmap = tile.pixmap();
-                    tilePixmap->setDevicePixelRatio(dpr);
 
                     if (tilePixmap->width() == dTileRect.width() && tilePixmap->height() == dTileRect.height()) {
                         p.drawPixmap(limitsInTile.translated(-limits.topLeft()).topLeft(), *tilePixmap, dLimitsInTile.translated(-dTileRect.topLeft()));
@@ -310,9 +305,8 @@ void PagePainter::paintCroppedPageOnPainter(QPainter *destPainter,
             }
         } else {
             // 4B.1. draw the page pixmap: normal or scaled
-            QPixmap scaledCroppedPixmap = pixmap.scaled(dScaledWidth, dScaledHeight).copy(dLimitsInPixmap);
-            scaledCroppedPixmap.setDevicePixelRatio(dpr);
-            p.drawPixmap(0, 0, scaledCroppedPixmap);
+
+            p.drawPixmap(QRectF(0, 0, limits.width(), limits.height()), pixmap.scaled(dScaledWidth, dScaledHeight), dLimitsInPixmap);
         }
 
         p.end();
@@ -599,13 +593,12 @@ void PagePainter::paintCroppedPageOnPainter(QPainter *destPainter,
                 QPixmap pixmap = Okular::AnnotationUtils::loadStamp(stamp->stampIconName(), qMax(annotBoundary.width(), annotBoundary.height()) * dpr);
                 if (!pixmap.isNull()) // should never happen but can happen on huge sizes
                 {
-                    QPixmap scaledCroppedPixmap = pixmap.scaled(annotBoundary.width() * dpr, annotBoundary.height() * dpr).copy(dInnerRect.toAlignedRect());
-                    scaledCroppedPixmap.setDevicePixelRatio(dpr);
-
                     // Draw pixmap with opacity:
                     mixedPainter->save();
                     mixedPainter->setOpacity(mixedPainter->opacity() * opacity / 255.0);
-                    mixedPainter->drawPixmap(annotRect.topLeft(), scaledCroppedPixmap);
+
+                    mixedPainter->drawPixmap(annotRect.topLeft(), pixmap.scaled(annotBoundary.width() * dpr, annotBoundary.height() * dpr), dInnerRect.toAlignedRect());
+
                     mixedPainter->restore();
                 }
             }