Maps looks bad on retina screen

[johnd0e]

Many included basemaps are looking not good enough, like low-res.
I suppose that it's possible to play with argument in order to improve maps.

Here will be the list with maps that have to be enhanced

• Bing
• Yandex
• ...

[modos189]

Increasing quality will require increasing traffic. It is not uncommon for IITC to get confused when there is poor Internet connection away from city during any operation.

[johnd0e]

Increasing quality will require increasing traffic.

Well, IITC was created many years ago, and since then mobile internet get much better, so I suppose we can afford it.
In many cases connection is fast enough, and traffic even may not be charged.

Besides, this could be optional.

[modos189]

As optional, it would be useful.

But even now, we sometimes play in places where internet is almost absent)

[modos189]

Option should only be placed in the mobile version, I think

[johnd0e]

Option should only be placed in the mobile version, I think

Could be useful in desktop as well.

But I wonder how we should implement this option.
Simplest way is to control it with plugin, but applying it can require full iitc reloading.

[johnd0e]

Some general thoughts:

• Standard tile size is 256*256.
  • Some tile providers are able to deliver other sizes, such as 128x128 and 512x512.
• Leaflet can detect hi-res mode (see L.Browser.retina), and use hi-res icons (if defined) and map tiles (see below):
  • Leaflet has template {r} to request high-res tiles, this can be used to add scale modifier @2x to url (e.g. thunderforest).
    NB: some services (e.g. HERE) use other url parameters to specify tile size.
  • Also leaflet has special layer option detectRetina, which is more universal.
    NB: this option is broken in our current leaflet version (1.3.0), so we need to update it (see leaflet update #78).
• While using hi-res tiles all labels/captions get smaller.
  Workarounds:
  • Some services allow to specify ppi parameter
  • Labels could be added as separate layer (in some services)

[johnd0e]

• detectRetina option is individual per tilelayer, but better if we could control it in single place (still leaving the possibility to disable it per some maps).
• Sometimes we may need to force-disable the option (e.g.: poor connection conditions).
• Sometimes we may need to force-enable the option even on non-retina screen.
• We have not rely solely on detectRetina, as:
  • The option has no effect on some maps with own API (Bing, Google, Yandex).
  • There could be other possibilities to increase tile resolution (like request 512*512 tiles, which is available in some providers).

[johnd0e]

I've made some corrections in Bing and Yandex plugins (and their upstreams).
Now maps seems looking better.

But anyway, we need global retina option.