Adding a waypoint to a route - what is going on?

[Antipole]

OpenCPN has excellent capabilities for constructing and editing a route. This is much enhanced in the imminent v5.5.

A route can comprise 'private' routepoints which by default get sequential names 001, 002, 003 et seq. A route can also include a free-standing waypoint, such as "Clear of Rocky Head".

This process may not always be what it seems.

Method A

The waypoint is simply included in the route. Suppose another hazard is discovered off Rocky Head and the waypoint is moved further off. This takes effect in all the routes around the head, even if the route is not visible at the time the waypoint is moved.

If a route is deleted, OpenCPN knows which included routepoints are waypoints and does not delete them along with the private routepoints.

Method B

I have a script for the JavaScript plugin that lists duplicate route and waypoint names. As expected, this shows up duplicates of, say, 001, 002 in multiple routes.

In my case it also shows some duplicates of my free-standing waypoints that have been included in routes - up to seven duplicates of some waypoints and dozens overall.

It seems that sometimes when a waypoint is included in a route, OpenCPN creates a duplicate to include in the route. This is not normally apparent to the user, as the duplicate exactly overlays the original. But if you open the attributes of one of these waypoints and edit its position very slightly, it moves aside to reveal the underlying one. You can then see the original waypoint and the corresponding routepoint.

When a route is deleted, all the routepoints are simply deleted - there is no need to check whether a routepoint is also a waypoint and should be left.

A consequence of this strategy is that if I move my 'Clear of Rocky Head' waypoint to a safer position, a duplicate in a route will not be moved - beware


I have not determined why there are two strategies nor when one is used over the other. None of my waypoints or routes are in layers, which might make them immutable and led to use of Method B.

I have not delved into the innards of OpenCPN here but would be very interested to have some light shone on this. What is going on?

Postscript: I have just realised that these routes may be ones I imported from my previous system and the duplication arises because of the non-uniqueness of routepoint names.

I have just realised that these routes may be ones I imported from my previous system and the duplication arises because of the non-uniqueness of routepoint names.
How to fix? Unfortunately, there is no API to replace a routepoint with one with a different GUID so this cannot be scripted and automated. But if you drag one of these routepoints aside, you can then see the free-standing waypoint. Since OpenCPN v5.5 you can then drag the routepoint over the waypoint and OpenCPN will offer to replace it with the nearby waypoint.

[Douwe Fokkema]

Originally Posted by Antipole

OpenCPN has excellent capabilities for constructing and editing a route. This is much enhanced in the imminent v5.5.

A route can comprise 'private' routepoints which by default get sequential names 001, 002, 003 et seq. A route can also include a free-standing waypoint, such as "Clear of Rocky Head".

This process may not always be what it seems.

You are right. If you have two routes with (some) shared waypoints, export both, delete your routes, import the two routes again, you have a different situation than the one you started with. First you had two routes with shared waypoints, you end up with two routes with separate waypoints. To get is right again, you have to move all waypoints to be shared a little and answer yes to the question posed each time.

One could think of a command in O doing this for you.

Douwe Fokkema

[fgd3]

Originally Posted by Douwe Fokkema

You are right. If you have two routes with (some) shared waypoints, export both, delete your routes, import the two routes again, you have a different situation than the one you started with. First you had two routes with shared waypoints, you end up with two routes with separate waypoints.

That's not true for 4.8.8 and I don't believe the logic has been updated since then. If you have two routes with shared waypoints, export both, delete both, and import both you will have two routes with the same shared waypoints.

[Douwe Fokkema]

Originally Posted by fgd3

That's not true for 4.8.8 and I don't believe the logic has been updated since then. If you have two routes with shared waypoints, export both, delete both, and import both you will have two routes with the same shared waypoints.

You are right. I imported the same route twice, then all waypoints are doubled.

[Antipole]

You could resolve the duplicate waypoint issue using the JavaScript plugin. In outline:

1. Read in all waypoints
2. Identify duplicates (Same name and position)
3. Decide which is to become the master and which will be replaced, noting the GUIDs
4. Read through all routes looking for waypoints to be replaced and replace with the master one.
5. Delete the waypoints no longer being used.

[fgd3]

Originally Posted by Douwe Fokkema

You are right. I imported the same route twice, then all waypoints are doubled.

That's not the way it works for me. I imported a route, then imported it again. The route showed up twice in the route manager but when I went to the Waypoints tab the waypoints in the route (all shared) showed up just once for each waypoint in the route. When I deleted one copy of the route the list of waypoints did not change. When I deleted the other copy the waypoints disappeared from the Waypoints tab as well.

[Antipole]

I have added a script to the JavaScript script library called DuplicateCounter.js

When you run this it produces a report for all duplicate route and waypoint names including the count of how many times the name is used.
Names like 001, 002 are used many times, of course. But I was surprised to discover some of my 'permanent' waypoints existed as many as eleven times!

[rgleason]

Originally Posted by Antipole

I have added a script to the JavaScript script library called DuplicateCounter.js

When you run this it produces a report for all duplicate route and waypoint names including the count of how many times the name is used.
Names like 001, 002 are used many times, of course. But I was surprised to discover some of my 'permanent' waypoints existed as many as eleven times!

It sounds like OpenCPN could use a waypoint cleanup script eventually.

[Antipole]

It sounds like OpenCPN could use a waypoint cleanup script eventually.

Yes - the more I think about it, the more I see can be checked out and resolved.
But FS#2803 is essential before it can be done.

[rgleason]

Antipole wrote:

How to fix? Unfortunately, there is no API to replace a routepoint with one with a different GUID so this cannot be scripted and automated. But if you drag one of these routepoints aside, you can then see the free-standing waypoint. Since OpenCPN v5.5 you can then drag the routepoint over the waypoint and OpenCPN will offer to replace it with the nearby waypoint.

With bdbcats recent changes of routes in api is this abilty covered? I think so.