Performance issues on longer routes

[narimiran]

I've been using https://open-map-maker.vercel.app in last few days and it has been great for creating the routes and saving them as .gpx files. Thanks for making it!!

But I've experienced very noticeable performance issues when trying to build longer routes.
For the first ~200 km everything is ok and responsive(-ish), but after ~ 200 km it starts to visibly lag (I can see my CPU running at 100%) and I have to wait several seconds before a point is added to the route and the site becomes responsive again.
And if you try to make routes longer than ~350 km, it becomes really painful to use. The pauses are even longer.

• Is there some "recalculate everything from the beginning" going on, which becomes more noticeable as a route grows longer?
• Is the amount of .gpx points along the route (and I don't mean the user-placed control points) getting huge? Can this be purged/optimized that only every-N points are taken? (If a route is multi-hundred kilometers long, the resolution doesn't have to be in single meters)
• Can it maybe be done that a single long route is internally split into multiple shorter routes, so instead of one long route from A do D, there would be routes A-B, B-C, C-D (where B and C can be user-placed control points)? This way the "current route" would only be C-D, which would hopefully help with the performance.
• The last point (multiple shorter routes) could also be made explicit and user-visible — to have an option to create multiple routes/layers. And then when saving, the user could choose if they want to save a single route (layer?) or all of them.

Let me know what you think....

[HatAndBread]

@narimiran

Thank you for the feedback. I had no idea anyone (aside from me) was actively using this, so am very pleased 🙂
I’ll look into the performance issues you brought up, but realistically it will probably be a few months until I can commit the time.
A few guesses if you want to look into it yourself:
Undo redo: The undo functionality keeps copies of the entire route in memory. As the route gets longer this can add up to a lot of data. I don’t know if there is a more efficient way to do this without storing the data in a database.
Elevation Profile: As I recall the elevation profile is recalculated every time a new point is added to the route. Presumably the longer the route the more expensive the calculation.

I’ll look into the other suggestions when I find the time to tackle this. I do like the idea of being able to split a route into multiple smaller routes. 💡

[narimiran]

Undo redo: The undo functionality keeps copies of the entire route in memory. As the route gets longer this can add up to a lot of data.

I've tried to make shorter routes with a lot of control points and I haven't experienced the same slowdown as when the route gets longer (with fewer control points).
But if undo-redo keeps all points along the route (not just the user-added ones), that might explain the slowdown on longer routes.

As I recall the elevation profile is recalculated every time a new point is added to the route.

If that's the case, can the elevation profile be disabled by default (or to have an option for that), and then to have a button to calculate/plot the profile when the user wants it?

A few guesses if you want to look into it yourself:

I don't have any JavaScript/TypeScript experience, but I'll try to take a look....

[narimiran]

it will probably be a few months until I can commit the time

In case you maybe have some extra time now, here's a friendly ping about this.... :)

I've tried to fix it myself, but I couldn't make the app work locally. I'm guessing it's because I don't have a mapbox account (and I couldn't create a free one).

[HatAndBread]

Hi, I will get around to it eventually, but not just yet. In the midst of a move and taking care of small children.
In the meantime, the mapbox key is not a secret, it is the public key. You can copy and paste it from network requests. That should be all you need. I'm not going to go as far as pasting it in text here, but...

[narimiran]

the mapbox key is not a secret, it is the public key. You can copy and paste it from network requests.

Thanks for the hint!
With the key, I was able to run it locally. And......

As I recall the elevation profile is recalculated every time a new point is added to the route. Presumably the longer the route the more expensive the calculation.

...your guess about the elevation being expensive was correct.
With the elevation disabled, I was able to create very long (over 700 km) routes without any slowdowns.

The next step for me: try to get familiar with JS/TS and the codebase, before I try to create something more useful than "disabled elevation".

[HatAndBread]

@narimiran

You may be interested in this project:
https://github.com/HatAndBread/map-maker-2
https://hatandbread.github.io/map-maker-2/

I am remaking this project in plain JS and fixing some of the issues.

[narimiran]

Thanks for the ping!
I've tried to make some random 1000 km long route and every new point was added instantly. Superb!!