Scaling round objects - MacOS

[Peter_P]

Hi,
I switched form Windows to MacOS, I'm using QCAD Community Edition ver. 3.29.6.0 (3.29.6)
When I try to scale objects in my projects (MacOS QCAD), round ones disappears rest of them is scaled correctly. When I repeat this operation on Windows PC it works fine.

Problem appears when only when x does not equal y (as on screenshot).

Maybe I'm doing sth wrong? I use QCAD occasionally.

Before scaling

Zrzut ekranu 2024-06-9 o 14.56.04.png (721.16 KiB) Viewed 66720 times

After scaling

Zrzut ekranu 2024-06-9 o 14.56.13.png (472.39 KiB) Viewed 66720 times

[CVH]

Hi, and welcome to the QCAD forum.

Is the Windows PC running the same QCAD CE version?
I then think there is an issue with ellipses for QCAD CE on MAC.
A circle scaled 200% in Y is an ellipse with ratio 0.5

For scaling Arcs, Circles and Ellipses it is especially related to an inscribed ellipse given 4 points.
About 6 months ago the support of that has changed.

Regards,
CVH

[Peter_P]

Thank CVH!

My Windows PC is running 2.28.2.0 (3.28.2) version.

Can downgrading QCAD to an older version solve the problem?

[CVH]

QCAD 2.28.2 was released on 2023/09/04
The change to the Ellipse core was issued on 2023/12/04
https://github.com/qcad/qcad/commit/909 ... c7f8f55e24
As of then it returns an invalid RShape without the ellipse proxy (Without QCAD Pro resources)

Investigating the Scale code in detail:
Scale.getOperation >> Transform.getOperation >> this.transform = Scale.transform for each selected entity
Uniform scaling is supported by all entities.
Non-uniform scaling of arc, circle or ellipse >> Scale.transformArc
A circle is replaced by a full circular arc >> RShape.scaleArc >> RShape.transformArc
And that relies on REllipse.createInscribed(v1, v2, v3, v4)
Casting an Arc or a Circle instead of an Ellipse(-arc) if the resulting ratio is about 1.0 within 1e-3.

Basically meaning that non-uniform scaling of an arc, a circle or an ellipse is no longer supported for QCAD CE.
This is by designer choice.

Can downgrading QCAD to an older version solve the problem?

If you have a copy of the installation file of QCAD 2.28.2 trial for MAC OS ... Yes, but that is not advisable.
The real solution is to upgrade to the latest QCAD Pro version.

Regards,
CVH