qcam: Support scaling of the viewfinder

The viewfinder is drawn using a QLabel. This could support scaling
through QLabel::setScaledContents(), but in a very inefficient way. To
maintain reasonable efficiency, turn the viewfinder into a QWidget and
draw the image directly using a QPainter.

No performance change was noticed running on a fast x86 machine, and
performance was 60% higher when scaling up to full screen compared to
QLabel.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

0 files changed, 0 insertions, 0 deletions