Reverse engineering OpenCPN layers

[spithost]

I recently created and added a wiki-page to the OpenCPN-manual-pages about creating layers for OpenCPN:

https://opencpn.org/wiki/dokuwiki/do...reating_layers


For the larger part it is based on skattered information about layers in the rest of the current and earlier versions of the OpenCPN-manual and general gpx-information.
I recently exported some info and found some additional information with extensions and tried to add that ;-)
As I'm not a C++-developer it's difficult for me to "dig through" the code to determine if my information is correct and/or could be enhanced.

Maybe one of the developers (preferably but maybe not mandatory having worked on the layers-functionality) could assist me with some questions I still have and in this way help me to enhance the OpenCPN-manual?

[rgleason]

Klaus, thank you for your contributions. Layers are a very powerful feature, we use them extensively in CAD programs for managing information and controlling viewing of that information. I hope we can strengthen the support of gpx and layers in OpenCPN.


I know that Pavel [Nohal] has done a lot with layers. Some other developers who have an interest in and worked with layers and GPX are Mike R. [Rasbats] who just improved the use of gpx "speed" when imported into Opencpn while improving SAR_pi. Also TransmitterDan and Håkan S. [S/V Momo] come to mind as possible resources.

Some other OpenCPN resources
Layers
Guide - SV Matilda - Setting up Layers in OpenPlotter
Guide - SV Matilda - Setting up Waypoint Tracks & Route Layers

GPX Resources https://en.wikipedia.org/wiki/GPS_Exchange_Format
GPX Format https://www.topografix.com/gpx.asp
GPX 1.1 Documentation https://www.topografix.com/GPX/1/1/
GPX validation https://www.topografix.com/gpx_validation.asp

What improvements are you looking for?

[spithost]

Rick, Sofar I kept myself to documenting what allready is allthough it's not allways easy to figure out the logic ;-) For that, it would be nice to have a "way in" to someone that could help me further document what's allready there, so more people could use the functionality and build on projects with OpenCPN as a wonderfull base.

Ofcourse it could very well be that some feature-requests could come out of further documenting, but it's not my main goal at this moment ;-)

A question I have (for example) are the incertancies in the extensions to gpx in OpenCPN. I tried finding information about it but couldn't find it in the current documentation.

Maybe it never has been documented and has it only be used indirectly...
Maybe it's somewhere in the code or determinable from the code....
The use of units="x" in the extension: waypoint_range_rings and the use of ScaleMax="y" in scale_min_max is unclear to me.
I sort of reverse engineered the rest of the "settings" in those two :-)
But there are two more extensions of which I have no idea of what they do (arrival_radius and viz_name).

[rgleason]

I can help with some of this. In Extended Marks
Range Rings
https://opencpn.org/wiki/dokuwiki/do...tended_marks&s[]=waypoint&s[]=range&s[]=ring
Range Rings Show range rings, number of rings, ring spacing, units and color.

Arrival Radius
Arrival Radius Read more in Options Setting , where the default is set. The arrival radius can also be set individually for each waypoint.
The manual needs updating and mods but under Options > Ships > Routes/Waypoints see the pic below.
Also Arrival Radius is used here with the autopilot
Send Route to Autopilot


Others will help with the other two terms you are interested in.
ScaleMax="y" in scale_min_max
units="x"
viz_name

[spithost]

Ah thanks Rick. I'll read and will try to comprehend the references in your reaction and will try to document those as well (where applicable) in "my" page documenting the creation of custom layers.
Even if there's no "obvious use" for the extensions when creating your own layers to be used in OpenCPN, it's better to be as complete as possible ;-)

[rooiedirk]

If you send me a private message with your e-mail adress, I think I'm able to answer most question in dutch. Might be easier.
Dirk

[rgleason]

Closed Tracker item for GPS <---> GPSbabel Improvements

https://opencpn.org/flyspray/index.p...status%5B0%5D=

Dirk knows about this. Sent Dirk your email too.


Dirk is the author of the Waypoint Extensions, so you are in good hands Klaus.