Rotate shape adds node
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Inkscape |
Fix Released
|
Medium
|
Krzysztof Kosinski |
Bug Description
hi,
Rotating a relatively simple shape by 120 degrees adds a node to the path. The shape is a kind of like the letter V. The original has six nodes but when rotated 120 degrees another node gets added resulting in seven nodes. Rotating by 90 or 135 does not add a new node. This problem occurred by selecting the shape, clicking on it again which shows the rotation arrows. Mouse down on a corner rotation arrow and move the mouse to rotate the object, release the mouse button when 120 degree and a node will be added. This happens both when the constrained rotate, that is when the ctrl key is held down, and in the normal non-constrained rotate. In the non-constrained rotate the rotation does not have to be exactly 120 degrees.
The extra node was causing me confusion because the new node is in the same position as another node so it is not easily visible.
Attached is a file showing the original shape and rotated duplicates.
tags: | added: transformations |
Changed in inkscape: | |
importance: | Undecided → Medium |
status: | In Progress → Triaged |
It looks as if the problem is caused by round-off error.
In the XML editor all four objects are identical, they all have a start point followed by 6 nodes, as expected. The difference is that three of them have relative coordinates that add up perfectly to zero, while the fourth one does not.
Attached is a file with the calculation of the net movement of the final point relative to the initial point, which should be zero. In the third object there is an error of .00023 in the x-coordinate net movement which is enough to apparently make the parser think that the object is not closed, so it adds on an additional point.