Feature Request: Draw Curved Lines

[mCHSNUg5Pz8cPap]

I know this has been requested in the past, but with the release of v10 and the ability to edit paths, which is a round-about way to achieve the same thing, I thought it was a good time to request it again.

As it stands, the polyline tool has 90% of what is needed to draw a curved line. A curved line tool can be the same as the polyline tool but have curves in place of the sharp corners. V10 of PDF-XChange has the ability to create curved lines (with the little bar handles that allow the curves to be manipulated) so it seems it shouldn't be too much trouble to just make a curved line tool that can be accessed directly from the Comments tab.

The polyline tool was used to draw the image below on the left. The image on the right was created by flattenening a copy of the image on the left and editing the path to have a curved shape.

image.png

All I want is the ability to do this directly and avoid the hassle of editing the path.

[Tracker Supp-Stefan]

Hello mCHSNUg5Pz8cPap,

I believe that annotations are limited by the PDF specification. So I am not sure if it's technically possible to create such curved ones with arrow pointings.

You can also use the pencil tool - and that would have a smoothing applied to it once you finish drawing such annotations, so it can be drawn to look as your required shape relatively quickly.

Kind regards,
Stefan

[mCHSNUg5Pz8cPap]

I believe that annotations are limited by the PDF specification. So I am not sure if it's technically possible to create such curved ones with arrow pointings.

I downloaded the PDF spec (it's now free!). It defines certain standard annotation types but also allows for additional annotation types. Here is what it says in the last paragraph of Section 12.5.1 (titled Annotations–General):

Conceptually, the behaviour of each annotation type may be implemented by a software module called an annotation handler. A PDF processor shall provide annotation handlers for all of the conforming annotation types. The set of annotation types is extensible. An interactive PDF processor shall provide certain expected behaviour for all annotation types that it does not recognise, as documented in 12.5.5, "Appearance streams" and "Table 167 - Annotation flags" (bit positions 1 and 2)

(emphasis added)

Note that it explicitly says: (1) a PDF processor shall support all conforming annotation types (i.e., the standard ones listed in the PDF spec), (2) the set of annotation types can be extended, and (3) the PDF processor shall provide certain behavior for annotation types it may not recognize with the behavior being defined in Section 12.5.5 and Table 167 bit positions 1 and 2.

This means the PDF specification does allow for the creation of a curved line annotation and other PDF processors must provide certain expected behavior for such an annotation. It seems that because the curved line annotation is so similar to the polyline annotation that other PDF processors that comply with the spec should be able to handle it without a problem.

As for the pencil tool, it has two problems: (1) the line is not uniformly curved (I could probably live with this) and (2) it does not have the ability to add an arrow to the end of the line and drawing it with a mouse makes it look like it was made by a kindergartener (I cannot live with this).

[Paul - Tracker Supp]

Hi, mCHSNUg5Pz8cPap

well now you are into details that need the dev team's feedback.

Let me see what they have to say about it and get back to you.

[mCHSNUg5Pz8cPap]

I'm bumping this because I think it may have been overlooked in view of the Easter holiday.

[Paul - Tracker Supp]

Hi, mCHSNUg5Pz8cPap

Did you know that curves are already supported, just not as "comments"? I should have thought of this before. If you flatten the "Arrow" annotation you can then convert it to a "Bezier":

PDFXEdit_GcrXbPtBn0.png

Tweak it's shape:

PDFXEdit_omWvbbrCge.png

and get a result like this:

PDFXEdit_AqyBb8mjDN.png

Will that work for you?

[mCHSNUg5Pz8cPap]

Yes, I know I can flatten the line and modify it using the "Path Editing Tools." That's how I created the curved line in the original post. As I noted in the original post, the flattening/edit path process is quite tedious. I often create twenty to thirty lines per page so flattening and editing each one is not efficient at all.

The other problems with the flatten/edit path process include:
1. The flattened line no longer scales like a comment. If the line is lengthened or shortened, its diameter increases/decreases accordingly. The different diameter sizes give a weird appearance to the document.
2. If the flattened line has an arrow at the end and is then adjusted to be curved, then the line pivots relative to the arrow so that the line and arrow are no longer aligned, which means the arrow must also be rotated separately to now align with the curved line (like what you did between the last two images; although you didn't note this extra step). This adds further complexity to the process.

I think there is demand for this feature (do a search for past requests for this). I requested it again in view of the release of v10 because it added the edit path functionality, which means the logic for creating/handling curved lines exists in the software in the context of the edit path tool. This means it should be possible/not difficult to implement it in the context of annotations to allow creation of a curved line annotation.

The ability to quickly create curved lines (just like adding a polyline) would be a killer feature ... and the pdf spec allows it.

[Paul - Tracker Supp]

Hi, mCHSNUg5Pz8cPap

we thought this was actually already in the system, but after some extensive searching it appears it was not. It is now.

The ticket for your reference is: RT#6861: Feature Request :: Editor :: support for curves in polygon and poly line tools

It is not currently set as a high priority, but it is definitely formally in the works.

Again, I do not have any ETA for this item, there is a lot ahead of it in the queue!

[mCHSNUg5Pz8cPap]

The ticket for your reference is: RT#6861: Feature Request :: Editor :: support for curves in polygon and poly line tools

This is fantastic!

It will be such a great feature to have.

[TrackerSupp-Daniel]