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CLOSED  Bug report #495  -  Half split tangents doesn't scale with Scale Tool
Posted Oct 10, 2013 - updated Oct 10, 2013
icon_info.png This issue has been closed with status "Closed" and resolution "RESOLVED".
Issue details
  • Type of issue
    Bug report
  • Status
  • Assigned to
     Carlos López
  • Progress
  • Type of bug
    Not triaged
  • Likelihood
    Not triaged
  • Effect
    Not triaged
  • Posted by
     Carlos López
  • Owned by
    Not owned by anyone
  • Time spent
    1 hour
  • Category
    User interface
  • Resolution
  • Priority
    Not determined
  • Targetted for
    icon_milestones.png Not determined
  • Tags
    icon_customdatatype.png tangent scale tool
  • Difficulty
    icon_customdatatype.png Not determined
Issue description
Using the Scale tool over a Spline with the tangents not full split or merged doesn't achieve wanted result. Tangents aren't scaled.

The root cause of this is due that the tangent handle from a splinepoint is updated when the other tangent is modified by a tool. If both tangents are modified at the same time (as it happens in the Scale tool) then they are fighting one each other to be modified (because there is a soft dependence between both tangents - i.e. radius is merged or angle is merged).

That doesn't happen when it is full split (because tangents are independent) or when they are full merged (because they are moved exactly the same)

Steps to reproduce this issue
Create a Spline layer and select all the handles. Then try to scale it using the Scale tool. Notice that the tangents remains unscaled, giving a bad shape after scale.

Comment posted by
 Carlos López
Oct 10, 12:50
I've fixed the issue by avoiding to update the dependent ducks when they are in the selection. It produces strange updates for tangent 2 when both tangents are been modified in those cases:

1) Been modified by the Smooth move tool. They move independent but when the mouse is released the tangent 2 is updated to what tangent 1 obligates to. 2) When both tangents are modified by any tool and the origin is not selected. Then the tangent 2 behaves weird but it is properly updated once release the mouse.

Scale tool works fine when both tangents and vertex are selected. I think that this is the best solution for this problem because at last, the final shape is the correct.

The issue was updated with the following change(s):
  • This issue has been closed
  • The status has been updated, from Being worked on to Closed.
  • This issue's progression has been updated to 100 percent completed.
  • The resolution has been updated, from Not determined to RESOLVED.
  • Information about the user working on this issue has been changed, from Carlos López to Not being worked on.
  • Time spent on this issue, from No time spent to 1 hour.