[Qt-interest] trying to rotate ellipse

[Arnold Krille]

On Friday 18 March 2011 21:34:14 Caius wrote:
> i tried painter.rotate before draw ellipse but then it didnt draw any
> ellipse.

That is because rotate() rotates the coordinate-system around the point (0,0) 
and then your ellipse was drawn outside the visible area.

The steps to draw a rotated ellipse are:
 - translate() the coordinate system to the center of the to-be-drawn ellipse
 - rotate() by the needed angle (check the docs whether it takes degree or 
radiant as argument)
 - draw your ellipse symmetrical to (0,0)

Enclose this within QPainter.save() and QPainter.restore() and the coordinate 
system is back to the original.

Have fun,

Arnold
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