Replace the implementation of MainWindow::exportDocument in the bode example with the code I have posted and check the result. Then try to find out what you are doing wrong in your application.
No, not with the double based render engine of Qwt 6.But this will (as far as I can see it) have the disadvantage that the number of curve points is determined by the size of QRectF( QPointF(0, 0), sz / scaleFactor ). These points are then stretched to the "full" resolution.
When painting to a paint device, that is aligning to integer coordinates (like a QWidget or QImage), Qwt manually rounds certain coordinates - instead of letting Qt floor them. Unfortunately this rounding is based on logical coordinates - not respecting the scale factor of the painter. But this is a bug - not a problem in general.My tests using setDotsPerMeterX/setDotsPerMeterY resulted in a curve that has visible "steps" and I assume this will also be the case for your proposed solution.
When you modify the implementation of QwtPainter::isAligning like below you might have some effects because of the flooring but it should be very close to what you expect.
Qt Code:
{ if ( painter && painter->transform().isScaling() ) return false; ... }To copy to clipboard, switch view to plain text mode
Uwe
PS: Forget about trying to find your code for Qwt5 - you won't succeed. Better try to support the development of Qwt 6
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