How to copy pixmap and keep scale ratio?

[Teerayoot]

I need to copy portion of pixmap and fill into onscreen painter.

my code that not work

painter.drawPixmap(pixMap->rect(),*pixMap,recvMap);

painter.drawPixmap(pixMap->rect(),*pixMap,recvMap);

To copy to clipboard, switch view to plain text mode 

the problem is image on screen is not correctly scale like original one
seem it ratio is enlarge to fit target rect.

I just need raw portion of pixmap and scale that keep image ratio.

Thank.