Endpoint of scaled line segment moves

[Alex Valavanis]

Forwarded from Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=345841
Reported by: Ambrose Li <email address hidden>
Date: Tue, 3 Jan 2006 21:48:08 UTC
Severity: normal
Found in version inkscape/0.43-2

1. Create some position marker, e.g. a rectangle, or a guide

2. Draw a very short line segment and align it to the marker

   [A longer line has the problem too, but the problem will be less apparent]

3. Scale the line segment by dragging the other endpoint

Result: The endpoint that was previously aligned with the marker is no longer
aligned.

* This happens irrespective of the "scale stroke width" preference.

* This also happens irrespective of line cap style.

IIRC, this problem did not exist in very old versions of inkscape (before
scaling line segments would cause a change in the line segment's thickness),
but I may not be remembering correctly.

[Alex Valavanis (valavanisalex)]

Comment from suv via email:

example SVG file would be helpful
a) Possibly related to <https://bugs.launchpad.net/inkscape/+bug/452102>
b) reproduced with visual bbox and square caps with horizontal line
c) OTOH, depending on the chosen bbox mode, the reference point when
scaling with the mouse is not the node itself but the opposite corner of
the bounding box. therefore the angle and node position has to change if
the visual bbox of a stroked line is scaled. To avoid, use the geometric
bbox mode or scale the line segment using the node tool.

[su_v (suv-lp)]

Attaching test file with different settings.

Occurs when a horizontal or vertical path is scaled, with visual bbox mode, when snapping is either disabled or set to snap bbox corners (instead of nodes), with all types of line caps.

Same change of the x-coordinate of the bbox of a horizontal line (or y-coordinate of a vertical line) occurs when changing the width by numeric input on the select tool controls bar - described in bug #452102.

[su_v (suv-lp)]

Affects scaling and stretching transforms which normally use the opposite corner|edge of the bbox as fixed point.