linked offset from masked object doesn't follow position

[Popolon2]

when on a masked path, a linked offset is created.
* linked offset is well deformed as the original masked
shape.

but

* At creation, the linked offset appears exactly at the
place where the path was, when the mask was applied.

* linked offset doesn't follow masked object position
and rotation.

[Popolon2 (popolon2)]

changed summary

[Frederik Elwert (frederik-elwert)]

Originator: NO

I think this does not only aplly to masked objects, but to all objects
whose position is changed by the transform/translate attribute. Steps to
reproduce:

* Draw an ellipse.
* Move it around a bit
(* Rotate it a bit)
* Create a linked offset
-> the offset is created at the ellipses original position (and with it's
original orientation).

[prkos (prkos)]

Tested on WinXP, build from 23rd Dec. If its set

Inkscape Preferences > Transforms > Optimized:
Moving object and then creating Linked Offset works ok
If the object is rotated or skewed the Linked Offset will turn up in an unexpected position and wont be rotated/skewed.

Inkscape Preferences > Transforms > Preserved:
Moving object and then creating Linked Offset moves the Offset to the position where the object was created.
If the object is rotated or skewed the Linked Offset will be centered (to the object) but it isnt rotated or skewed.

related to bug 167419?

[John Curwood (marketing-lovinglearning)]

I tested this on Ubuntu 8.10 -
I imported a png image and then used the rectangle tool to draw around the part of the picture that I wanted. I then tested this on both Clip and Mask and got the same results.
I applied the clip/mask tool to the image/rectangle. I then moved the clipped/masked image around and then selected the node tool and then the edit clipping path or edit mask tool. When I did this the rectangle's outline appeared in the original position of the object when I applied the mask/clipping path. Just in case this was linked to the basic shapes I released the effect converted the rectangle to a path and re-applied the effect, getting the same results.

One other thing I found while doing this test was that when I duplicated or copied and pasted the clipped/masked object, when I went to select the original object by clicking on it the Pasted object was selected. The only way to select the original object was to lasso it by dragging a rectangle around it with the select tool.

Regards,

John Curwood

[Jonathan Hofinger (jhofinger)]

Linked offset is never supposed to move along with the object. It just reacts to changes of the object, just as a clone.

In 1.1-dev (6b4d57f, 2020-04-01), Linked offset correctly changes when the masked object is changed (i.e. rotated or through node manipulation)

However, the offset doesn't respect the clip-path, it is calculated from the unclipped path. When converting an object to path (which is done when linked offset is applied), the clip-path remains and is not converted to a path - so that's a design choice.

Closed by: https://gitlab.com/jhofinger