Re: [Gimp-user] Path Tool Problems

If I hover my mouse above a certain segments holding Control, some
will allow to add a node, while other segments won't. This also effects
deleting line segments.



Now that I think about it I have the last instance on video from a
I made. It's kinda perfect since I have it showing my key-presses as well.
6:35 to around 8:30 is the problem. I also realized that this also was a
copied and pasted path.

Really weird. I cannot reproduce this here though. *shrug*

Where did you copy/paste the path from? Inkscape?

Earlier the video you can see that I copied it from another gimp drawing.

Ok, I think what you're seeing there is expected behaviour. The problem
is, that when you move two tangents closely together (i.e. you have a very
sharp corner) the end point of the stroke moves towards infinity, i.e.
you need to cap this at some point. The parameter controlling this is
the mitre limit. We use cairo for rendering and the behaviour is
described as follows in the cairo documentation:

    If the current line join style is set to CAIRO_LINE_JOIN_MITER (see
    cairo_set_line_join()), the miter limit is used to determine whether
    the lines should be joined with a bevel instead of a miter. Cairo
    divides the length of the miter by the line width. If the result is
    greater than the miter limit, the style is converted to a bevel.


    The default miter limit value is 10.0, which will convert joins with
    interior angles less than 11 degrees to bevels instead of miters.
    For reference, a miter limit of 2.0 makes the miter cutoff at 60
    degrees, and a miter limit of 1.414 makes the cutoff at 90 degrees.

    A miter limit for a desired angle can be computed as: miter limit =

There is no way to completely disable the miter limit, but maybe the
range of the limit in the UI is not sufficient.

I hope this helps,

I will play around with the mitre limit some more and see what I can come up
with. Thanks for the tips.

Simon Budig wrote
Akovia (


) wrote:
Simon Budig wrote
akovia (


) wrote:
2. Node selection precision.

No idea about that one. I don't think I've seen that.

Ok I just ran into this. This isn't a worst case as sometimes the move
is even further away than this.
It does appear to be affected by the zoom level which I never noticed
before. I usually zoom in further which normally fixes things, but this
I noticed that zooming out can also recalibrate the mouse pointer.

Maybe this will help.

I strongly suspect that in this case the behaviour is caused by the
guides. The "hot spot" of the mouse cursor is dragged towards the guide
(within the snapping distance) and hence the click does not happen at
the anchor.

Not sure if this is fixable, since placing new points along a guide is a
desireable behaviour as well.

Try to disable snapping.


That just might be possible. It never occurred to me since there is no
visible snapping of the mouse. I will check that for sure the next time it
happens and report back. I really hope that's it. 

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