Guideline angle from two points

[Thebugfinder]

0.46 released angled guidelines--cool! However, the angle of these guidelines is determined from a user-specified angle and ONE point. I would like to be able to give Inkscape two points and for it to calculate the angle for me. This would be useful in vanishing point drawings: give it the vanishing point and a point on the subject and you're ready to go. I'd also like to see it take slope (as in m from y=mx+b) in addition to angles.

[prkos (prkos)]

Have you tried the Object > Objects to Guides (Shift + G)?

Draw a simple line from your vanishing point to the object and turn it into a guide.

When you double-click the guide you'll see the exact angle, so you can easily calculate the "m" if you need it.

If you deal with "m" in your workflow you can easily calculate the angle and set a guide to it. Is the automatic input-"m"-to-get-guide an important feature to you? Maybe that should be a separate feature request or you should edit this one as your first request seems to be met.

If you edit the description set the bug status back to New

[Alex Valavanis (valavanisalex)]

A request for more information about this bug report has been
outstanding for over a month, so the developers aren't able to take any
action at the moment. I'll close this report for now, but if anyone can
provide the requested information then please feel free to reopen the
report.

[su_v (suv-lp)]

Reopening and confirming: combined with snapping for rotate (bug #170919) being able to have more options to position a guide at a certain angle/slope (two points, slope) would be a useful feature that IMHO is too basic as technical drawing aid to settle with the workaround described in comment #1.

[LucaDC (lucadc)]

This is already possible tanks to snapping: you can place a guide attaching it to the first point (so the origin is placed there), pressing shift while grabbing a point outside its origin you start rotating it then after releasing shift you can snap it to the second point.

The option of specifying a slope would be solved if mathematical expressions input is added to numerical fields, so you could simply write atan(<slope>)... :)

Regards.

[LucaDC (lucadc)]

Ah, something already asked and partially related to the issue reported here: guide duplication!
If creating an arbitrary-angled guide is pretty straightforward (considering that you have to specify the angle so some sort of setup is always needed), creating a bunch of them (with the same angle, of course) is not as you have to repeat the setup over and over and over... again.

[su_v (suv-lp)]

@LucaDC - thanks for reminding me to test more thoroughly before reopening a wishlist report that is already implemented: rotational snap for guides indeed works and allows to place a guide through 2 points! Great!

Closing this as 'Fix released' because it already works in 0.47.

Duplicate guides could be seen as part of
Bug #170355 “Extended UI for managing guides”
and has been reported in
Bug #511788 “Cannot duplicate a guide”
Bug #535573 “copy guides”

Allowing mathematical expressions input to numerical fields has been reported elsewhere and could probably reused for the guides dialog once implemented:
Bug #170414 “mathematical operations in Value entry widgets”
Bug #223002 “Drawing to scale (for home use)”